* [PATCH 5.10 55/63] io_uring: import 5.15-stable io_uring
2023-01-03 8:13 [PATCH 5.10 00/63] 5.10.162-rc1 review Greg Kroah-Hartman
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2023-01-03 8:14 ` [PATCH 5.10 54/63] task_work: add helper for more targeted task_work canceling Greg Kroah-Hartman
@ 2023-01-03 8:14 ` Greg Kroah-Hartman
2023-01-03 8:14 ` [PATCH 5.10 56/63] signal: kill JOBCTL_TASK_WORK Greg Kroah-Hartman
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68 siblings, 0 replies; 73+ messages in thread
From: Greg Kroah-Hartman @ 2023-01-03 8:14 UTC (permalink / raw)
To: stable; +Cc: Greg Kroah-Hartman, patches, Jens Axboe
From: Jens Axboe <axboe@kernel.dk>
No upstream commit exists.
This imports the io_uring codebase from 5.15.85, wholesale. Changes
from that code base:
- Drop IOCB_ALLOC_CACHE, we don't have that in 5.10.
- Drop MKDIRAT/SYMLINKAT/LINKAT. Would require further VFS backports,
and we don't support these in 5.10 to begin with.
- sock_from_file() old style calling convention.
- Use compat_get_bitmap() only for CONFIG_COMPAT=y
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Makefile | 2
fs/Makefile | 2
fs/io-wq.c | 1242 ----
fs/io-wq.h | 157
fs/io_uring.c | 9971 ------------------------------------
include/linux/io_uring.h | 46
include/linux/sched.h | 3
include/linux/syscalls.h | 2
include/trace/events/io_uring.h | 121
include/uapi/linux/io_uring.h | 115
io_uring/Makefile | 6
io_uring/io-wq.c | 1398 +++++
io_uring/io-wq.h | 160
io_uring/io_uring.c |10945 ++++++++++++++++++++++++++++++++++++++++
kernel/exit.c | 2
kernel/fork.c | 1
kernel/sched/core.c | 2
17 files changed, 12704 insertions(+), 11471 deletions(-)
delete mode 100644 fs/io-wq.c
create mode 100644 io_uring/Makefile
create mode 100644 io_uring/io-wq.c
rename {fs => io_uring}/io-wq.h (81%)
rename {fs => io_uring}/io_uring.c (51%)
--- a/Makefile
+++ b/Makefile
@@ -1128,7 +1128,7 @@ export MODORDER := $(extmod-prefix)modul
export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps
ifeq ($(KBUILD_EXTMOD),)
-core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
+core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/ io_uring/
vmlinux-dirs := $(patsubst %/,%,$(filter %/, \
$(core-y) $(core-m) $(drivers-y) $(drivers-m) \
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -32,8 +32,6 @@ obj-$(CONFIG_TIMERFD) += timerfd.o
obj-$(CONFIG_EVENTFD) += eventfd.o
obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
obj-$(CONFIG_AIO) += aio.o
-obj-$(CONFIG_IO_URING) += io_uring.o
-obj-$(CONFIG_IO_WQ) += io-wq.o
obj-$(CONFIG_FS_DAX) += dax.o
obj-$(CONFIG_FS_ENCRYPTION) += crypto/
obj-$(CONFIG_FS_VERITY) += verity/
--- a/fs/io-wq.c
+++ /dev/null
@@ -1,1242 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Basic worker thread pool for io_uring
- *
- * Copyright (C) 2019 Jens Axboe
- *
- */
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/sched/signal.h>
-#include <linux/mm.h>
-#include <linux/sched/mm.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <linux/kthread.h>
-#include <linux/rculist_nulls.h>
-#include <linux/fs_struct.h>
-#include <linux/task_work.h>
-#include <linux/blk-cgroup.h>
-#include <linux/audit.h>
-#include <linux/cpu.h>
-
-#include "../kernel/sched/sched.h"
-#include "io-wq.h"
-
-#define WORKER_IDLE_TIMEOUT (5 * HZ)
-
-enum {
- IO_WORKER_F_UP = 1, /* up and active */
- IO_WORKER_F_RUNNING = 2, /* account as running */
- IO_WORKER_F_FREE = 4, /* worker on free list */
- IO_WORKER_F_FIXED = 8, /* static idle worker */
- IO_WORKER_F_BOUND = 16, /* is doing bounded work */
-};
-
-enum {
- IO_WQ_BIT_EXIT = 0, /* wq exiting */
- IO_WQ_BIT_CANCEL = 1, /* cancel work on list */
- IO_WQ_BIT_ERROR = 2, /* error on setup */
-};
-
-enum {
- IO_WQE_FLAG_STALLED = 1, /* stalled on hash */
-};
-
-/*
- * One for each thread in a wqe pool
- */
-struct io_worker {
- refcount_t ref;
- unsigned flags;
- struct hlist_nulls_node nulls_node;
- struct list_head all_list;
- struct task_struct *task;
- struct io_wqe *wqe;
-
- struct io_wq_work *cur_work;
- spinlock_t lock;
-
- struct rcu_head rcu;
- struct mm_struct *mm;
-#ifdef CONFIG_BLK_CGROUP
- struct cgroup_subsys_state *blkcg_css;
-#endif
- const struct cred *cur_creds;
- const struct cred *saved_creds;
- struct files_struct *restore_files;
- struct nsproxy *restore_nsproxy;
- struct fs_struct *restore_fs;
-};
-
-#if BITS_PER_LONG == 64
-#define IO_WQ_HASH_ORDER 6
-#else
-#define IO_WQ_HASH_ORDER 5
-#endif
-
-#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER)
-
-struct io_wqe_acct {
- unsigned nr_workers;
- unsigned max_workers;
- atomic_t nr_running;
-};
-
-enum {
- IO_WQ_ACCT_BOUND,
- IO_WQ_ACCT_UNBOUND,
-};
-
-/*
- * Per-node worker thread pool
- */
-struct io_wqe {
- struct {
- raw_spinlock_t lock;
- struct io_wq_work_list work_list;
- unsigned long hash_map;
- unsigned flags;
- } ____cacheline_aligned_in_smp;
-
- int node;
- struct io_wqe_acct acct[2];
-
- struct hlist_nulls_head free_list;
- struct list_head all_list;
-
- struct io_wq *wq;
- struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS];
-};
-
-/*
- * Per io_wq state
- */
-struct io_wq {
- struct io_wqe **wqes;
- unsigned long state;
-
- free_work_fn *free_work;
- io_wq_work_fn *do_work;
-
- struct task_struct *manager;
- struct user_struct *user;
- refcount_t refs;
- struct completion done;
-
- struct hlist_node cpuhp_node;
-
- refcount_t use_refs;
-};
-
-static enum cpuhp_state io_wq_online;
-
-static bool io_worker_get(struct io_worker *worker)
-{
- return refcount_inc_not_zero(&worker->ref);
-}
-
-static void io_worker_release(struct io_worker *worker)
-{
- if (refcount_dec_and_test(&worker->ref))
- wake_up_process(worker->task);
-}
-
-/*
- * Note: drops the wqe->lock if returning true! The caller must re-acquire
- * the lock in that case. Some callers need to restart handling if this
- * happens, so we can't just re-acquire the lock on behalf of the caller.
- */
-static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker)
-{
- bool dropped_lock = false;
-
- if (worker->saved_creds) {
- revert_creds(worker->saved_creds);
- worker->cur_creds = worker->saved_creds = NULL;
- }
-
- if (current->files != worker->restore_files) {
- __acquire(&wqe->lock);
- raw_spin_unlock_irq(&wqe->lock);
- dropped_lock = true;
-
- task_lock(current);
- current->files = worker->restore_files;
- current->nsproxy = worker->restore_nsproxy;
- task_unlock(current);
- }
-
- if (current->fs != worker->restore_fs)
- current->fs = worker->restore_fs;
-
- /*
- * If we have an active mm, we need to drop the wq lock before unusing
- * it. If we do, return true and let the caller retry the idle loop.
- */
- if (worker->mm) {
- if (!dropped_lock) {
- __acquire(&wqe->lock);
- raw_spin_unlock_irq(&wqe->lock);
- dropped_lock = true;
- }
- __set_current_state(TASK_RUNNING);
- kthread_unuse_mm(worker->mm);
- mmput(worker->mm);
- worker->mm = NULL;
- }
-
-#ifdef CONFIG_BLK_CGROUP
- if (worker->blkcg_css) {
- kthread_associate_blkcg(NULL);
- worker->blkcg_css = NULL;
- }
-#endif
- if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY)
- current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
- return dropped_lock;
-}
-
-static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe,
- struct io_wq_work *work)
-{
- if (work->flags & IO_WQ_WORK_UNBOUND)
- return &wqe->acct[IO_WQ_ACCT_UNBOUND];
-
- return &wqe->acct[IO_WQ_ACCT_BOUND];
-}
-
-static inline struct io_wqe_acct *io_wqe_get_acct(struct io_wqe *wqe,
- struct io_worker *worker)
-{
- if (worker->flags & IO_WORKER_F_BOUND)
- return &wqe->acct[IO_WQ_ACCT_BOUND];
-
- return &wqe->acct[IO_WQ_ACCT_UNBOUND];
-}
-
-static void io_worker_exit(struct io_worker *worker)
-{
- struct io_wqe *wqe = worker->wqe;
- struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
-
- /*
- * If we're not at zero, someone else is holding a brief reference
- * to the worker. Wait for that to go away.
- */
- set_current_state(TASK_INTERRUPTIBLE);
- if (!refcount_dec_and_test(&worker->ref))
- schedule();
- __set_current_state(TASK_RUNNING);
-
- preempt_disable();
- current->flags &= ~PF_IO_WORKER;
- if (worker->flags & IO_WORKER_F_RUNNING)
- atomic_dec(&acct->nr_running);
- if (!(worker->flags & IO_WORKER_F_BOUND))
- atomic_dec(&wqe->wq->user->processes);
- worker->flags = 0;
- preempt_enable();
-
- raw_spin_lock_irq(&wqe->lock);
- hlist_nulls_del_rcu(&worker->nulls_node);
- list_del_rcu(&worker->all_list);
- if (__io_worker_unuse(wqe, worker)) {
- __release(&wqe->lock);
- raw_spin_lock_irq(&wqe->lock);
- }
- acct->nr_workers--;
- raw_spin_unlock_irq(&wqe->lock);
-
- kfree_rcu(worker, rcu);
- if (refcount_dec_and_test(&wqe->wq->refs))
- complete(&wqe->wq->done);
-}
-
-static inline bool io_wqe_run_queue(struct io_wqe *wqe)
- __must_hold(wqe->lock)
-{
- if (!wq_list_empty(&wqe->work_list) &&
- !(wqe->flags & IO_WQE_FLAG_STALLED))
- return true;
- return false;
-}
-
-/*
- * Check head of free list for an available worker. If one isn't available,
- * caller must wake up the wq manager to create one.
- */
-static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
- __must_hold(RCU)
-{
- struct hlist_nulls_node *n;
- struct io_worker *worker;
-
- n = rcu_dereference(hlist_nulls_first_rcu(&wqe->free_list));
- if (is_a_nulls(n))
- return false;
-
- worker = hlist_nulls_entry(n, struct io_worker, nulls_node);
- if (io_worker_get(worker)) {
- wake_up_process(worker->task);
- io_worker_release(worker);
- return true;
- }
-
- return false;
-}
-
-/*
- * We need a worker. If we find a free one, we're good. If not, and we're
- * below the max number of workers, wake up the manager to create one.
- */
-static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
-{
- bool ret;
-
- /*
- * Most likely an attempt to queue unbounded work on an io_wq that
- * wasn't setup with any unbounded workers.
- */
- if (unlikely(!acct->max_workers))
- pr_warn_once("io-wq is not configured for unbound workers");
-
- rcu_read_lock();
- ret = io_wqe_activate_free_worker(wqe);
- rcu_read_unlock();
-
- if (!ret && acct->nr_workers < acct->max_workers)
- wake_up_process(wqe->wq->manager);
-}
-
-static void io_wqe_inc_running(struct io_wqe *wqe, struct io_worker *worker)
-{
- struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
-
- atomic_inc(&acct->nr_running);
-}
-
-static void io_wqe_dec_running(struct io_wqe *wqe, struct io_worker *worker)
- __must_hold(wqe->lock)
-{
- struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
-
- if (atomic_dec_and_test(&acct->nr_running) && io_wqe_run_queue(wqe))
- io_wqe_wake_worker(wqe, acct);
-}
-
-static void io_worker_start(struct io_wqe *wqe, struct io_worker *worker)
-{
- allow_kernel_signal(SIGINT);
-
- current->flags |= PF_IO_WORKER;
-
- worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
- worker->restore_files = current->files;
- worker->restore_nsproxy = current->nsproxy;
- worker->restore_fs = current->fs;
- io_wqe_inc_running(wqe, worker);
-}
-
-/*
- * Worker will start processing some work. Move it to the busy list, if
- * it's currently on the freelist
- */
-static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
- struct io_wq_work *work)
- __must_hold(wqe->lock)
-{
- bool worker_bound, work_bound;
-
- if (worker->flags & IO_WORKER_F_FREE) {
- worker->flags &= ~IO_WORKER_F_FREE;
- hlist_nulls_del_init_rcu(&worker->nulls_node);
- }
-
- /*
- * If worker is moving from bound to unbound (or vice versa), then
- * ensure we update the running accounting.
- */
- worker_bound = (worker->flags & IO_WORKER_F_BOUND) != 0;
- work_bound = (work->flags & IO_WQ_WORK_UNBOUND) == 0;
- if (worker_bound != work_bound) {
- io_wqe_dec_running(wqe, worker);
- if (work_bound) {
- worker->flags |= IO_WORKER_F_BOUND;
- wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers--;
- wqe->acct[IO_WQ_ACCT_BOUND].nr_workers++;
- atomic_dec(&wqe->wq->user->processes);
- } else {
- worker->flags &= ~IO_WORKER_F_BOUND;
- wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers++;
- wqe->acct[IO_WQ_ACCT_BOUND].nr_workers--;
- atomic_inc(&wqe->wq->user->processes);
- }
- io_wqe_inc_running(wqe, worker);
- }
-}
-
-/*
- * No work, worker going to sleep. Move to freelist, and unuse mm if we
- * have one attached. Dropping the mm may potentially sleep, so we drop
- * the lock in that case and return success. Since the caller has to
- * retry the loop in that case (we changed task state), we don't regrab
- * the lock if we return success.
- */
-static bool __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
- __must_hold(wqe->lock)
-{
- if (!(worker->flags & IO_WORKER_F_FREE)) {
- worker->flags |= IO_WORKER_F_FREE;
- hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
- }
-
- return __io_worker_unuse(wqe, worker);
-}
-
-static inline unsigned int io_get_work_hash(struct io_wq_work *work)
-{
- return work->flags >> IO_WQ_HASH_SHIFT;
-}
-
-static struct io_wq_work *io_get_next_work(struct io_wqe *wqe)
- __must_hold(wqe->lock)
-{
- struct io_wq_work_node *node, *prev;
- struct io_wq_work *work, *tail;
- unsigned int hash;
-
- wq_list_for_each(node, prev, &wqe->work_list) {
- work = container_of(node, struct io_wq_work, list);
-
- /* not hashed, can run anytime */
- if (!io_wq_is_hashed(work)) {
- wq_list_del(&wqe->work_list, node, prev);
- return work;
- }
-
- /* hashed, can run if not already running */
- hash = io_get_work_hash(work);
- if (!(wqe->hash_map & BIT(hash))) {
- wqe->hash_map |= BIT(hash);
- /* all items with this hash lie in [work, tail] */
- tail = wqe->hash_tail[hash];
- wqe->hash_tail[hash] = NULL;
- wq_list_cut(&wqe->work_list, &tail->list, prev);
- return work;
- }
- }
-
- return NULL;
-}
-
-static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work)
-{
- if (worker->mm) {
- kthread_unuse_mm(worker->mm);
- mmput(worker->mm);
- worker->mm = NULL;
- }
-
- if (mmget_not_zero(work->identity->mm)) {
- kthread_use_mm(work->identity->mm);
- worker->mm = work->identity->mm;
- return;
- }
-
- /* failed grabbing mm, ensure work gets cancelled */
- work->flags |= IO_WQ_WORK_CANCEL;
-}
-
-static inline void io_wq_switch_blkcg(struct io_worker *worker,
- struct io_wq_work *work)
-{
-#ifdef CONFIG_BLK_CGROUP
- if (!(work->flags & IO_WQ_WORK_BLKCG))
- return;
- if (work->identity->blkcg_css != worker->blkcg_css) {
- kthread_associate_blkcg(work->identity->blkcg_css);
- worker->blkcg_css = work->identity->blkcg_css;
- }
-#endif
-}
-
-static void io_wq_switch_creds(struct io_worker *worker,
- struct io_wq_work *work)
-{
- const struct cred *old_creds = override_creds(work->identity->creds);
-
- worker->cur_creds = work->identity->creds;
- if (worker->saved_creds)
- put_cred(old_creds); /* creds set by previous switch */
- else
- worker->saved_creds = old_creds;
-}
-
-static void io_impersonate_work(struct io_worker *worker,
- struct io_wq_work *work)
-{
- if ((work->flags & IO_WQ_WORK_FILES) &&
- current->files != work->identity->files) {
- task_lock(current);
- current->files = work->identity->files;
- current->nsproxy = work->identity->nsproxy;
- task_unlock(current);
- if (!work->identity->files) {
- /* failed grabbing files, ensure work gets cancelled */
- work->flags |= IO_WQ_WORK_CANCEL;
- }
- }
- if ((work->flags & IO_WQ_WORK_FS) && current->fs != work->identity->fs)
- current->fs = work->identity->fs;
- if ((work->flags & IO_WQ_WORK_MM) && work->identity->mm != worker->mm)
- io_wq_switch_mm(worker, work);
- if ((work->flags & IO_WQ_WORK_CREDS) &&
- worker->cur_creds != work->identity->creds)
- io_wq_switch_creds(worker, work);
- if (work->flags & IO_WQ_WORK_FSIZE)
- current->signal->rlim[RLIMIT_FSIZE].rlim_cur = work->identity->fsize;
- else if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY)
- current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
- io_wq_switch_blkcg(worker, work);
-#ifdef CONFIG_AUDIT
- current->loginuid = work->identity->loginuid;
- current->sessionid = work->identity->sessionid;
-#endif
-}
-
-static void io_assign_current_work(struct io_worker *worker,
- struct io_wq_work *work)
-{
- if (work) {
- /* flush pending signals before assigning new work */
- if (signal_pending(current))
- flush_signals(current);
- cond_resched();
- }
-
-#ifdef CONFIG_AUDIT
- current->loginuid = KUIDT_INIT(AUDIT_UID_UNSET);
- current->sessionid = AUDIT_SID_UNSET;
-#endif
-
- spin_lock_irq(&worker->lock);
- worker->cur_work = work;
- spin_unlock_irq(&worker->lock);
-}
-
-static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
-
-static void io_worker_handle_work(struct io_worker *worker)
- __releases(wqe->lock)
-{
- struct io_wqe *wqe = worker->wqe;
- struct io_wq *wq = wqe->wq;
-
- do {
- struct io_wq_work *work;
-get_next:
- /*
- * If we got some work, mark us as busy. If we didn't, but
- * the list isn't empty, it means we stalled on hashed work.
- * Mark us stalled so we don't keep looking for work when we
- * can't make progress, any work completion or insertion will
- * clear the stalled flag.
- */
- work = io_get_next_work(wqe);
- if (work)
- __io_worker_busy(wqe, worker, work);
- else if (!wq_list_empty(&wqe->work_list))
- wqe->flags |= IO_WQE_FLAG_STALLED;
-
- raw_spin_unlock_irq(&wqe->lock);
- if (!work)
- break;
- io_assign_current_work(worker, work);
-
- /* handle a whole dependent link */
- do {
- struct io_wq_work *old_work, *next_hashed, *linked;
- unsigned int hash = io_get_work_hash(work);
-
- next_hashed = wq_next_work(work);
- io_impersonate_work(worker, work);
- /*
- * OK to set IO_WQ_WORK_CANCEL even for uncancellable
- * work, the worker function will do the right thing.
- */
- if (test_bit(IO_WQ_BIT_CANCEL, &wq->state))
- work->flags |= IO_WQ_WORK_CANCEL;
-
- old_work = work;
- linked = wq->do_work(work);
-
- work = next_hashed;
- if (!work && linked && !io_wq_is_hashed(linked)) {
- work = linked;
- linked = NULL;
- }
- io_assign_current_work(worker, work);
- wq->free_work(old_work);
-
- if (linked)
- io_wqe_enqueue(wqe, linked);
-
- if (hash != -1U && !next_hashed) {
- raw_spin_lock_irq(&wqe->lock);
- wqe->hash_map &= ~BIT_ULL(hash);
- wqe->flags &= ~IO_WQE_FLAG_STALLED;
- /* skip unnecessary unlock-lock wqe->lock */
- if (!work)
- goto get_next;
- raw_spin_unlock_irq(&wqe->lock);
- }
- } while (work);
-
- raw_spin_lock_irq(&wqe->lock);
- } while (1);
-}
-
-static int io_wqe_worker(void *data)
-{
- struct io_worker *worker = data;
- struct io_wqe *wqe = worker->wqe;
- struct io_wq *wq = wqe->wq;
-
- io_worker_start(wqe, worker);
-
- while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
- set_current_state(TASK_INTERRUPTIBLE);
-loop:
- raw_spin_lock_irq(&wqe->lock);
- if (io_wqe_run_queue(wqe)) {
- __set_current_state(TASK_RUNNING);
- io_worker_handle_work(worker);
- goto loop;
- }
- /* drops the lock on success, retry */
- if (__io_worker_idle(wqe, worker)) {
- __release(&wqe->lock);
- goto loop;
- }
- raw_spin_unlock_irq(&wqe->lock);
- if (signal_pending(current))
- flush_signals(current);
- if (schedule_timeout(WORKER_IDLE_TIMEOUT))
- continue;
- /* timed out, exit unless we're the fixed worker */
- if (test_bit(IO_WQ_BIT_EXIT, &wq->state) ||
- !(worker->flags & IO_WORKER_F_FIXED))
- break;
- }
-
- if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
- raw_spin_lock_irq(&wqe->lock);
- if (!wq_list_empty(&wqe->work_list))
- io_worker_handle_work(worker);
- else
- raw_spin_unlock_irq(&wqe->lock);
- }
-
- io_worker_exit(worker);
- return 0;
-}
-
-/*
- * Called when a worker is scheduled in. Mark us as currently running.
- */
-void io_wq_worker_running(struct task_struct *tsk)
-{
- struct io_worker *worker = kthread_data(tsk);
- struct io_wqe *wqe = worker->wqe;
-
- if (!(worker->flags & IO_WORKER_F_UP))
- return;
- if (worker->flags & IO_WORKER_F_RUNNING)
- return;
- worker->flags |= IO_WORKER_F_RUNNING;
- io_wqe_inc_running(wqe, worker);
-}
-
-/*
- * Called when worker is going to sleep. If there are no workers currently
- * running and we have work pending, wake up a free one or have the manager
- * set one up.
- */
-void io_wq_worker_sleeping(struct task_struct *tsk)
-{
- struct io_worker *worker = kthread_data(tsk);
- struct io_wqe *wqe = worker->wqe;
-
- if (!(worker->flags & IO_WORKER_F_UP))
- return;
- if (!(worker->flags & IO_WORKER_F_RUNNING))
- return;
-
- worker->flags &= ~IO_WORKER_F_RUNNING;
-
- raw_spin_lock_irq(&wqe->lock);
- io_wqe_dec_running(wqe, worker);
- raw_spin_unlock_irq(&wqe->lock);
-}
-
-static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
-{
- struct io_wqe_acct *acct = &wqe->acct[index];
- struct io_worker *worker;
-
- worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node);
- if (!worker)
- return false;
-
- refcount_set(&worker->ref, 1);
- worker->nulls_node.pprev = NULL;
- worker->wqe = wqe;
- spin_lock_init(&worker->lock);
-
- worker->task = kthread_create_on_node(io_wqe_worker, worker, wqe->node,
- "io_wqe_worker-%d/%d", index, wqe->node);
- if (IS_ERR(worker->task)) {
- kfree(worker);
- return false;
- }
- kthread_bind_mask(worker->task, cpumask_of_node(wqe->node));
-
- raw_spin_lock_irq(&wqe->lock);
- hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
- list_add_tail_rcu(&worker->all_list, &wqe->all_list);
- worker->flags |= IO_WORKER_F_FREE;
- if (index == IO_WQ_ACCT_BOUND)
- worker->flags |= IO_WORKER_F_BOUND;
- if (!acct->nr_workers && (worker->flags & IO_WORKER_F_BOUND))
- worker->flags |= IO_WORKER_F_FIXED;
- acct->nr_workers++;
- raw_spin_unlock_irq(&wqe->lock);
-
- if (index == IO_WQ_ACCT_UNBOUND)
- atomic_inc(&wq->user->processes);
-
- refcount_inc(&wq->refs);
- wake_up_process(worker->task);
- return true;
-}
-
-static inline bool io_wqe_need_worker(struct io_wqe *wqe, int index)
- __must_hold(wqe->lock)
-{
- struct io_wqe_acct *acct = &wqe->acct[index];
-
- /* if we have available workers or no work, no need */
- if (!hlist_nulls_empty(&wqe->free_list) || !io_wqe_run_queue(wqe))
- return false;
- return acct->nr_workers < acct->max_workers;
-}
-
-static bool io_wqe_worker_send_sig(struct io_worker *worker, void *data)
-{
- send_sig(SIGINT, worker->task, 1);
- return false;
-}
-
-/*
- * Iterate the passed in list and call the specific function for each
- * worker that isn't exiting
- */
-static bool io_wq_for_each_worker(struct io_wqe *wqe,
- bool (*func)(struct io_worker *, void *),
- void *data)
-{
- struct io_worker *worker;
- bool ret = false;
-
- list_for_each_entry_rcu(worker, &wqe->all_list, all_list) {
- if (io_worker_get(worker)) {
- /* no task if node is/was offline */
- if (worker->task)
- ret = func(worker, data);
- io_worker_release(worker);
- if (ret)
- break;
- }
- }
-
- return ret;
-}
-
-static bool io_wq_worker_wake(struct io_worker *worker, void *data)
-{
- wake_up_process(worker->task);
- return false;
-}
-
-/*
- * Manager thread. Tasked with creating new workers, if we need them.
- */
-static int io_wq_manager(void *data)
-{
- struct io_wq *wq = data;
- int node;
-
- /* create fixed workers */
- refcount_set(&wq->refs, 1);
- for_each_node(node) {
- if (!node_online(node))
- continue;
- if (create_io_worker(wq, wq->wqes[node], IO_WQ_ACCT_BOUND))
- continue;
- set_bit(IO_WQ_BIT_ERROR, &wq->state);
- set_bit(IO_WQ_BIT_EXIT, &wq->state);
- goto out;
- }
-
- complete(&wq->done);
-
- while (!kthread_should_stop()) {
- if (current->task_works)
- task_work_run();
-
- for_each_node(node) {
- struct io_wqe *wqe = wq->wqes[node];
- bool fork_worker[2] = { false, false };
-
- if (!node_online(node))
- continue;
-
- raw_spin_lock_irq(&wqe->lock);
- if (io_wqe_need_worker(wqe, IO_WQ_ACCT_BOUND))
- fork_worker[IO_WQ_ACCT_BOUND] = true;
- if (io_wqe_need_worker(wqe, IO_WQ_ACCT_UNBOUND))
- fork_worker[IO_WQ_ACCT_UNBOUND] = true;
- raw_spin_unlock_irq(&wqe->lock);
- if (fork_worker[IO_WQ_ACCT_BOUND])
- create_io_worker(wq, wqe, IO_WQ_ACCT_BOUND);
- if (fork_worker[IO_WQ_ACCT_UNBOUND])
- create_io_worker(wq, wqe, IO_WQ_ACCT_UNBOUND);
- }
- set_current_state(TASK_INTERRUPTIBLE);
- schedule_timeout(HZ);
- }
-
- if (current->task_works)
- task_work_run();
-
-out:
- if (refcount_dec_and_test(&wq->refs)) {
- complete(&wq->done);
- return 0;
- }
- /* if ERROR is set and we get here, we have workers to wake */
- if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) {
- rcu_read_lock();
- for_each_node(node)
- io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL);
- rcu_read_unlock();
- }
- return 0;
-}
-
-static bool io_wq_can_queue(struct io_wqe *wqe, struct io_wqe_acct *acct,
- struct io_wq_work *work)
-{
- bool free_worker;
-
- if (!(work->flags & IO_WQ_WORK_UNBOUND))
- return true;
- if (atomic_read(&acct->nr_running))
- return true;
-
- rcu_read_lock();
- free_worker = !hlist_nulls_empty(&wqe->free_list);
- rcu_read_unlock();
- if (free_worker)
- return true;
-
- if (atomic_read(&wqe->wq->user->processes) >= acct->max_workers &&
- !(capable(CAP_SYS_RESOURCE) || capable(CAP_SYS_ADMIN)))
- return false;
-
- return true;
-}
-
-static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
-{
- struct io_wq *wq = wqe->wq;
-
- do {
- struct io_wq_work *old_work = work;
-
- work->flags |= IO_WQ_WORK_CANCEL;
- work = wq->do_work(work);
- wq->free_work(old_work);
- } while (work);
-}
-
-static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work)
-{
- unsigned int hash;
- struct io_wq_work *tail;
-
- if (!io_wq_is_hashed(work)) {
-append:
- wq_list_add_tail(&work->list, &wqe->work_list);
- return;
- }
-
- hash = io_get_work_hash(work);
- tail = wqe->hash_tail[hash];
- wqe->hash_tail[hash] = work;
- if (!tail)
- goto append;
-
- wq_list_add_after(&work->list, &tail->list, &wqe->work_list);
-}
-
-static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
-{
- struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
- bool do_wake;
- unsigned long flags;
-
- /*
- * Do early check to see if we need a new unbound worker, and if we do,
- * if we're allowed to do so. This isn't 100% accurate as there's a
- * gap between this check and incrementing the value, but that's OK.
- * It's close enough to not be an issue, fork() has the same delay.
- */
- if (unlikely(!io_wq_can_queue(wqe, acct, work))) {
- io_run_cancel(work, wqe);
- return;
- }
-
- raw_spin_lock_irqsave(&wqe->lock, flags);
- io_wqe_insert_work(wqe, work);
- wqe->flags &= ~IO_WQE_FLAG_STALLED;
- do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) ||
- !atomic_read(&acct->nr_running);
- raw_spin_unlock_irqrestore(&wqe->lock, flags);
-
- if (do_wake)
- io_wqe_wake_worker(wqe, acct);
-}
-
-void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
-{
- struct io_wqe *wqe = wq->wqes[numa_node_id()];
-
- io_wqe_enqueue(wqe, work);
-}
-
-/*
- * Work items that hash to the same value will not be done in parallel.
- * Used to limit concurrent writes, generally hashed by inode.
- */
-void io_wq_hash_work(struct io_wq_work *work, void *val)
-{
- unsigned int bit;
-
- bit = hash_ptr(val, IO_WQ_HASH_ORDER);
- work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT));
-}
-
-void io_wq_cancel_all(struct io_wq *wq)
-{
- int node;
-
- set_bit(IO_WQ_BIT_CANCEL, &wq->state);
-
- rcu_read_lock();
- for_each_node(node) {
- struct io_wqe *wqe = wq->wqes[node];
-
- io_wq_for_each_worker(wqe, io_wqe_worker_send_sig, NULL);
- }
- rcu_read_unlock();
-}
-
-struct io_cb_cancel_data {
- work_cancel_fn *fn;
- void *data;
- int nr_running;
- int nr_pending;
- bool cancel_all;
-};
-
-static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
-{
- struct io_cb_cancel_data *match = data;
- unsigned long flags;
-
- /*
- * Hold the lock to avoid ->cur_work going out of scope, caller
- * may dereference the passed in work.
- */
- spin_lock_irqsave(&worker->lock, flags);
- if (worker->cur_work &&
- !(worker->cur_work->flags & IO_WQ_WORK_NO_CANCEL) &&
- match->fn(worker->cur_work, match->data)) {
- send_sig(SIGINT, worker->task, 1);
- match->nr_running++;
- }
- spin_unlock_irqrestore(&worker->lock, flags);
-
- return match->nr_running && !match->cancel_all;
-}
-
-static inline void io_wqe_remove_pending(struct io_wqe *wqe,
- struct io_wq_work *work,
- struct io_wq_work_node *prev)
-{
- unsigned int hash = io_get_work_hash(work);
- struct io_wq_work *prev_work = NULL;
-
- if (io_wq_is_hashed(work) && work == wqe->hash_tail[hash]) {
- if (prev)
- prev_work = container_of(prev, struct io_wq_work, list);
- if (prev_work && io_get_work_hash(prev_work) == hash)
- wqe->hash_tail[hash] = prev_work;
- else
- wqe->hash_tail[hash] = NULL;
- }
- wq_list_del(&wqe->work_list, &work->list, prev);
-}
-
-static void io_wqe_cancel_pending_work(struct io_wqe *wqe,
- struct io_cb_cancel_data *match)
-{
- struct io_wq_work_node *node, *prev;
- struct io_wq_work *work;
- unsigned long flags;
-
-retry:
- raw_spin_lock_irqsave(&wqe->lock, flags);
- wq_list_for_each(node, prev, &wqe->work_list) {
- work = container_of(node, struct io_wq_work, list);
- if (!match->fn(work, match->data))
- continue;
- io_wqe_remove_pending(wqe, work, prev);
- raw_spin_unlock_irqrestore(&wqe->lock, flags);
- io_run_cancel(work, wqe);
- match->nr_pending++;
- if (!match->cancel_all)
- return;
-
- /* not safe to continue after unlock */
- goto retry;
- }
- raw_spin_unlock_irqrestore(&wqe->lock, flags);
-}
-
-static void io_wqe_cancel_running_work(struct io_wqe *wqe,
- struct io_cb_cancel_data *match)
-{
- rcu_read_lock();
- io_wq_for_each_worker(wqe, io_wq_worker_cancel, match);
- rcu_read_unlock();
-}
-
-enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
- void *data, bool cancel_all)
-{
- struct io_cb_cancel_data match = {
- .fn = cancel,
- .data = data,
- .cancel_all = cancel_all,
- };
- int node;
-
- /*
- * First check pending list, if we're lucky we can just remove it
- * from there. CANCEL_OK means that the work is returned as-new,
- * no completion will be posted for it.
- */
- for_each_node(node) {
- struct io_wqe *wqe = wq->wqes[node];
-
- io_wqe_cancel_pending_work(wqe, &match);
- if (match.nr_pending && !match.cancel_all)
- return IO_WQ_CANCEL_OK;
- }
-
- /*
- * Now check if a free (going busy) or busy worker has the work
- * currently running. If we find it there, we'll return CANCEL_RUNNING
- * as an indication that we attempt to signal cancellation. The
- * completion will run normally in this case.
- */
- for_each_node(node) {
- struct io_wqe *wqe = wq->wqes[node];
-
- io_wqe_cancel_running_work(wqe, &match);
- if (match.nr_running && !match.cancel_all)
- return IO_WQ_CANCEL_RUNNING;
- }
-
- if (match.nr_running)
- return IO_WQ_CANCEL_RUNNING;
- if (match.nr_pending)
- return IO_WQ_CANCEL_OK;
- return IO_WQ_CANCEL_NOTFOUND;
-}
-
-struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
-{
- int ret = -ENOMEM, node;
- struct io_wq *wq;
-
- if (WARN_ON_ONCE(!data->free_work || !data->do_work))
- return ERR_PTR(-EINVAL);
- if (WARN_ON_ONCE(!bounded))
- return ERR_PTR(-EINVAL);
-
- wq = kzalloc(sizeof(*wq), GFP_KERNEL);
- if (!wq)
- return ERR_PTR(-ENOMEM);
-
- wq->wqes = kcalloc(nr_node_ids, sizeof(struct io_wqe *), GFP_KERNEL);
- if (!wq->wqes)
- goto err_wq;
-
- ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node);
- if (ret)
- goto err_wqes;
-
- wq->free_work = data->free_work;
- wq->do_work = data->do_work;
-
- /* caller must already hold a reference to this */
- wq->user = data->user;
-
- ret = -ENOMEM;
- for_each_node(node) {
- struct io_wqe *wqe;
- int alloc_node = node;
-
- if (!node_online(alloc_node))
- alloc_node = NUMA_NO_NODE;
- wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node);
- if (!wqe)
- goto err;
- wq->wqes[node] = wqe;
- wqe->node = alloc_node;
- wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
- atomic_set(&wqe->acct[IO_WQ_ACCT_BOUND].nr_running, 0);
- if (wq->user) {
- wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers =
- task_rlimit(current, RLIMIT_NPROC);
- }
- atomic_set(&wqe->acct[IO_WQ_ACCT_UNBOUND].nr_running, 0);
- wqe->wq = wq;
- raw_spin_lock_init(&wqe->lock);
- INIT_WQ_LIST(&wqe->work_list);
- INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0);
- INIT_LIST_HEAD(&wqe->all_list);
- }
-
- init_completion(&wq->done);
-
- wq->manager = kthread_create(io_wq_manager, wq, "io_wq_manager");
- if (!IS_ERR(wq->manager)) {
- wake_up_process(wq->manager);
- wait_for_completion(&wq->done);
- if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) {
- ret = -ENOMEM;
- goto err;
- }
- refcount_set(&wq->use_refs, 1);
- reinit_completion(&wq->done);
- return wq;
- }
-
- ret = PTR_ERR(wq->manager);
- complete(&wq->done);
-err:
- cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
- for_each_node(node)
- kfree(wq->wqes[node]);
-err_wqes:
- kfree(wq->wqes);
-err_wq:
- kfree(wq);
- return ERR_PTR(ret);
-}
-
-bool io_wq_get(struct io_wq *wq, struct io_wq_data *data)
-{
- if (data->free_work != wq->free_work || data->do_work != wq->do_work)
- return false;
-
- return refcount_inc_not_zero(&wq->use_refs);
-}
-
-static void __io_wq_destroy(struct io_wq *wq)
-{
- int node;
-
- cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
-
- set_bit(IO_WQ_BIT_EXIT, &wq->state);
- if (wq->manager)
- kthread_stop(wq->manager);
-
- rcu_read_lock();
- for_each_node(node)
- io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL);
- rcu_read_unlock();
-
- wait_for_completion(&wq->done);
-
- for_each_node(node)
- kfree(wq->wqes[node]);
- kfree(wq->wqes);
- kfree(wq);
-}
-
-void io_wq_destroy(struct io_wq *wq)
-{
- if (refcount_dec_and_test(&wq->use_refs))
- __io_wq_destroy(wq);
-}
-
-struct task_struct *io_wq_get_task(struct io_wq *wq)
-{
- return wq->manager;
-}
-
-static bool io_wq_worker_affinity(struct io_worker *worker, void *data)
-{
- struct task_struct *task = worker->task;
- struct rq_flags rf;
- struct rq *rq;
-
- rq = task_rq_lock(task, &rf);
- do_set_cpus_allowed(task, cpumask_of_node(worker->wqe->node));
- task->flags |= PF_NO_SETAFFINITY;
- task_rq_unlock(rq, task, &rf);
- return false;
-}
-
-static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node)
-{
- struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node);
- int i;
-
- rcu_read_lock();
- for_each_node(i)
- io_wq_for_each_worker(wq->wqes[i], io_wq_worker_affinity, NULL);
- rcu_read_unlock();
- return 0;
-}
-
-static __init int io_wq_init(void)
-{
- int ret;
-
- ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "io-wq/online",
- io_wq_cpu_online, NULL);
- if (ret < 0)
- return ret;
- io_wq_online = ret;
- return 0;
-}
-subsys_initcall(io_wq_init);
--- a/fs/io-wq.h
+++ /dev/null
@@ -1,157 +0,0 @@
-#ifndef INTERNAL_IO_WQ_H
-#define INTERNAL_IO_WQ_H
-
-#include <linux/io_uring.h>
-
-struct io_wq;
-
-enum {
- IO_WQ_WORK_CANCEL = 1,
- IO_WQ_WORK_HASHED = 2,
- IO_WQ_WORK_UNBOUND = 4,
- IO_WQ_WORK_NO_CANCEL = 8,
- IO_WQ_WORK_CONCURRENT = 16,
-
- IO_WQ_WORK_FILES = 32,
- IO_WQ_WORK_FS = 64,
- IO_WQ_WORK_MM = 128,
- IO_WQ_WORK_CREDS = 256,
- IO_WQ_WORK_BLKCG = 512,
- IO_WQ_WORK_FSIZE = 1024,
-
- IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */
-};
-
-enum io_wq_cancel {
- IO_WQ_CANCEL_OK, /* cancelled before started */
- IO_WQ_CANCEL_RUNNING, /* found, running, and attempted cancelled */
- IO_WQ_CANCEL_NOTFOUND, /* work not found */
-};
-
-struct io_wq_work_node {
- struct io_wq_work_node *next;
-};
-
-struct io_wq_work_list {
- struct io_wq_work_node *first;
- struct io_wq_work_node *last;
-};
-
-static inline void wq_list_add_after(struct io_wq_work_node *node,
- struct io_wq_work_node *pos,
- struct io_wq_work_list *list)
-{
- struct io_wq_work_node *next = pos->next;
-
- pos->next = node;
- node->next = next;
- if (!next)
- list->last = node;
-}
-
-static inline void wq_list_add_tail(struct io_wq_work_node *node,
- struct io_wq_work_list *list)
-{
- if (!list->first) {
- list->last = node;
- WRITE_ONCE(list->first, node);
- } else {
- list->last->next = node;
- list->last = node;
- }
- node->next = NULL;
-}
-
-static inline void wq_list_cut(struct io_wq_work_list *list,
- struct io_wq_work_node *last,
- struct io_wq_work_node *prev)
-{
- /* first in the list, if prev==NULL */
- if (!prev)
- WRITE_ONCE(list->first, last->next);
- else
- prev->next = last->next;
-
- if (last == list->last)
- list->last = prev;
- last->next = NULL;
-}
-
-static inline void wq_list_del(struct io_wq_work_list *list,
- struct io_wq_work_node *node,
- struct io_wq_work_node *prev)
-{
- wq_list_cut(list, node, prev);
-}
-
-#define wq_list_for_each(pos, prv, head) \
- for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
-
-#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL)
-#define INIT_WQ_LIST(list) do { \
- (list)->first = NULL; \
- (list)->last = NULL; \
-} while (0)
-
-struct io_wq_work {
- struct io_wq_work_node list;
- struct io_identity *identity;
- unsigned flags;
-};
-
-static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
-{
- if (!work->list.next)
- return NULL;
-
- return container_of(work->list.next, struct io_wq_work, list);
-}
-
-typedef void (free_work_fn)(struct io_wq_work *);
-typedef struct io_wq_work *(io_wq_work_fn)(struct io_wq_work *);
-
-struct io_wq_data {
- struct user_struct *user;
-
- io_wq_work_fn *do_work;
- free_work_fn *free_work;
-};
-
-struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
-bool io_wq_get(struct io_wq *wq, struct io_wq_data *data);
-void io_wq_destroy(struct io_wq *wq);
-
-void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
-void io_wq_hash_work(struct io_wq_work *work, void *val);
-
-static inline bool io_wq_is_hashed(struct io_wq_work *work)
-{
- return work->flags & IO_WQ_WORK_HASHED;
-}
-
-void io_wq_cancel_all(struct io_wq *wq);
-
-typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
-
-enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
- void *data, bool cancel_all);
-
-struct task_struct *io_wq_get_task(struct io_wq *wq);
-
-#if defined(CONFIG_IO_WQ)
-extern void io_wq_worker_sleeping(struct task_struct *);
-extern void io_wq_worker_running(struct task_struct *);
-#else
-static inline void io_wq_worker_sleeping(struct task_struct *tsk)
-{
-}
-static inline void io_wq_worker_running(struct task_struct *tsk)
-{
-}
-#endif
-
-static inline bool io_wq_current_is_worker(void)
-{
- return in_task() && (current->flags & PF_IO_WORKER);
-}
-#endif
--- a/fs/io_uring.c
+++ /dev/null
@@ -1,9971 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Shared application/kernel submission and completion ring pairs, for
- * supporting fast/efficient IO.
- *
- * A note on the read/write ordering memory barriers that are matched between
- * the application and kernel side.
- *
- * After the application reads the CQ ring tail, it must use an
- * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
- * before writing the tail (using smp_load_acquire to read the tail will
- * do). It also needs a smp_mb() before updating CQ head (ordering the
- * entry load(s) with the head store), pairing with an implicit barrier
- * through a control-dependency in io_get_cqring (smp_store_release to
- * store head will do). Failure to do so could lead to reading invalid
- * CQ entries.
- *
- * Likewise, the application must use an appropriate smp_wmb() before
- * writing the SQ tail (ordering SQ entry stores with the tail store),
- * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
- * to store the tail will do). And it needs a barrier ordering the SQ
- * head load before writing new SQ entries (smp_load_acquire to read
- * head will do).
- *
- * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
- * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
- * updating the SQ tail; a full memory barrier smp_mb() is needed
- * between.
- *
- * Also see the examples in the liburing library:
- *
- * git://git.kernel.dk/liburing
- *
- * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
- * from data shared between the kernel and application. This is done both
- * for ordering purposes, but also to ensure that once a value is loaded from
- * data that the application could potentially modify, it remains stable.
- *
- * Copyright (C) 2018-2019 Jens Axboe
- * Copyright (c) 2018-2019 Christoph Hellwig
- */
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/syscalls.h>
-#include <linux/compat.h>
-#include <net/compat.h>
-#include <linux/refcount.h>
-#include <linux/uio.h>
-#include <linux/bits.h>
-
-#include <linux/sched/signal.h>
-#include <linux/fs.h>
-#include <linux/file.h>
-#include <linux/fdtable.h>
-#include <linux/mm.h>
-#include <linux/mman.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <linux/kthread.h>
-#include <linux/blkdev.h>
-#include <linux/bvec.h>
-#include <linux/net.h>
-#include <net/sock.h>
-#include <net/af_unix.h>
-#include <net/scm.h>
-#include <linux/anon_inodes.h>
-#include <linux/sched/mm.h>
-#include <linux/uaccess.h>
-#include <linux/nospec.h>
-#include <linux/sizes.h>
-#include <linux/hugetlb.h>
-#include <linux/highmem.h>
-#include <linux/namei.h>
-#include <linux/fsnotify.h>
-#include <linux/fadvise.h>
-#include <linux/eventpoll.h>
-#include <linux/fs_struct.h>
-#include <linux/splice.h>
-#include <linux/task_work.h>
-#include <linux/pagemap.h>
-#include <linux/io_uring.h>
-#include <linux/blk-cgroup.h>
-#include <linux/audit.h>
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/io_uring.h>
-
-#include <uapi/linux/io_uring.h>
-
-#include "internal.h"
-#include "io-wq.h"
-
-#define IORING_MAX_ENTRIES 32768
-#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
-
-/*
- * Shift of 9 is 512 entries, or exactly one page on 64-bit archs
- */
-#define IORING_FILE_TABLE_SHIFT 9
-#define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT)
-#define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1)
-#define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE)
-#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
- IORING_REGISTER_LAST + IORING_OP_LAST)
-
-struct io_uring {
- u32 head ____cacheline_aligned_in_smp;
- u32 tail ____cacheline_aligned_in_smp;
-};
-
-/*
- * This data is shared with the application through the mmap at offsets
- * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
- *
- * The offsets to the member fields are published through struct
- * io_sqring_offsets when calling io_uring_setup.
- */
-struct io_rings {
- /*
- * Head and tail offsets into the ring; the offsets need to be
- * masked to get valid indices.
- *
- * The kernel controls head of the sq ring and the tail of the cq ring,
- * and the application controls tail of the sq ring and the head of the
- * cq ring.
- */
- struct io_uring sq, cq;
- /*
- * Bitmasks to apply to head and tail offsets (constant, equals
- * ring_entries - 1)
- */
- u32 sq_ring_mask, cq_ring_mask;
- /* Ring sizes (constant, power of 2) */
- u32 sq_ring_entries, cq_ring_entries;
- /*
- * Number of invalid entries dropped by the kernel due to
- * invalid index stored in array
- *
- * Written by the kernel, shouldn't be modified by the
- * application (i.e. get number of "new events" by comparing to
- * cached value).
- *
- * After a new SQ head value was read by the application this
- * counter includes all submissions that were dropped reaching
- * the new SQ head (and possibly more).
- */
- u32 sq_dropped;
- /*
- * Runtime SQ flags
- *
- * Written by the kernel, shouldn't be modified by the
- * application.
- *
- * The application needs a full memory barrier before checking
- * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
- */
- u32 sq_flags;
- /*
- * Runtime CQ flags
- *
- * Written by the application, shouldn't be modified by the
- * kernel.
- */
- u32 cq_flags;
- /*
- * Number of completion events lost because the queue was full;
- * this should be avoided by the application by making sure
- * there are not more requests pending than there is space in
- * the completion queue.
- *
- * Written by the kernel, shouldn't be modified by the
- * application (i.e. get number of "new events" by comparing to
- * cached value).
- *
- * As completion events come in out of order this counter is not
- * ordered with any other data.
- */
- u32 cq_overflow;
- /*
- * Ring buffer of completion events.
- *
- * The kernel writes completion events fresh every time they are
- * produced, so the application is allowed to modify pending
- * entries.
- */
- struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
-};
-
-struct io_mapped_ubuf {
- u64 ubuf;
- size_t len;
- struct bio_vec *bvec;
- unsigned int nr_bvecs;
- unsigned long acct_pages;
-};
-
-struct fixed_file_table {
- struct file **files;
-};
-
-struct fixed_file_ref_node {
- struct percpu_ref refs;
- struct list_head node;
- struct list_head file_list;
- struct fixed_file_data *file_data;
- struct llist_node llist;
- bool done;
-};
-
-struct fixed_file_data {
- struct fixed_file_table *table;
- struct io_ring_ctx *ctx;
-
- struct fixed_file_ref_node *node;
- struct percpu_ref refs;
- struct completion done;
- struct list_head ref_list;
- spinlock_t lock;
- bool quiesce;
-};
-
-struct io_buffer {
- struct list_head list;
- __u64 addr;
- __u32 len;
- __u16 bid;
-};
-
-struct io_restriction {
- DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
- DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
- u8 sqe_flags_allowed;
- u8 sqe_flags_required;
- bool registered;
-};
-
-struct io_sq_data {
- refcount_t refs;
- struct mutex lock;
-
- /* ctx's that are using this sqd */
- struct list_head ctx_list;
- struct list_head ctx_new_list;
- struct mutex ctx_lock;
-
- struct task_struct *thread;
- struct wait_queue_head wait;
-};
-
-struct io_ring_ctx {
- struct {
- struct percpu_ref refs;
- } ____cacheline_aligned_in_smp;
-
- struct {
- unsigned int flags;
- unsigned int compat: 1;
- unsigned int limit_mem: 1;
- unsigned int cq_overflow_flushed: 1;
- unsigned int drain_next: 1;
- unsigned int eventfd_async: 1;
- unsigned int restricted: 1;
- unsigned int sqo_dead: 1;
-
- /*
- * Ring buffer of indices into array of io_uring_sqe, which is
- * mmapped by the application using the IORING_OFF_SQES offset.
- *
- * This indirection could e.g. be used to assign fixed
- * io_uring_sqe entries to operations and only submit them to
- * the queue when needed.
- *
- * The kernel modifies neither the indices array nor the entries
- * array.
- */
- u32 *sq_array;
- unsigned cached_sq_head;
- unsigned sq_entries;
- unsigned sq_mask;
- unsigned sq_thread_idle;
- unsigned cached_sq_dropped;
- unsigned cached_cq_overflow;
- unsigned long sq_check_overflow;
-
- struct list_head defer_list;
- struct list_head timeout_list;
- struct list_head cq_overflow_list;
-
- struct io_uring_sqe *sq_sqes;
- } ____cacheline_aligned_in_smp;
-
- struct io_rings *rings;
-
- /* IO offload */
- struct io_wq *io_wq;
-
- /*
- * For SQPOLL usage - we hold a reference to the parent task, so we
- * have access to the ->files
- */
- struct task_struct *sqo_task;
-
- /* Only used for accounting purposes */
- struct mm_struct *mm_account;
-
-#ifdef CONFIG_BLK_CGROUP
- struct cgroup_subsys_state *sqo_blkcg_css;
-#endif
-
- struct io_sq_data *sq_data; /* if using sq thread polling */
-
- struct wait_queue_head sqo_sq_wait;
- struct wait_queue_entry sqo_wait_entry;
- struct list_head sqd_list;
-
- /*
- * If used, fixed file set. Writers must ensure that ->refs is dead,
- * readers must ensure that ->refs is alive as long as the file* is
- * used. Only updated through io_uring_register(2).
- */
- struct fixed_file_data *file_data;
- unsigned nr_user_files;
-
- /* if used, fixed mapped user buffers */
- unsigned nr_user_bufs;
- struct io_mapped_ubuf *user_bufs;
-
- struct user_struct *user;
-
- const struct cred *creds;
-
-#ifdef CONFIG_AUDIT
- kuid_t loginuid;
- unsigned int sessionid;
-#endif
-
- struct completion ref_comp;
- struct completion sq_thread_comp;
-
- /* if all else fails... */
- struct io_kiocb *fallback_req;
-
-#if defined(CONFIG_UNIX)
- struct socket *ring_sock;
-#endif
-
- struct xarray io_buffers;
-
- struct xarray personalities;
- u32 pers_next;
-
- struct {
- unsigned cached_cq_tail;
- unsigned cq_entries;
- unsigned cq_mask;
- atomic_t cq_timeouts;
- unsigned cq_last_tm_flush;
- unsigned long cq_check_overflow;
- struct wait_queue_head cq_wait;
- struct fasync_struct *cq_fasync;
- struct eventfd_ctx *cq_ev_fd;
- } ____cacheline_aligned_in_smp;
-
- struct {
- struct mutex uring_lock;
- wait_queue_head_t wait;
- } ____cacheline_aligned_in_smp;
-
- struct {
- spinlock_t completion_lock;
-
- /*
- * ->iopoll_list is protected by the ctx->uring_lock for
- * io_uring instances that don't use IORING_SETUP_SQPOLL.
- * For SQPOLL, only the single threaded io_sq_thread() will
- * manipulate the list, hence no extra locking is needed there.
- */
- struct list_head iopoll_list;
- struct hlist_head *cancel_hash;
- unsigned cancel_hash_bits;
- bool poll_multi_file;
-
- spinlock_t inflight_lock;
- struct list_head inflight_list;
- } ____cacheline_aligned_in_smp;
-
- struct delayed_work file_put_work;
- struct llist_head file_put_llist;
-
- struct work_struct exit_work;
- struct io_restriction restrictions;
-};
-
-/*
- * First field must be the file pointer in all the
- * iocb unions! See also 'struct kiocb' in <linux/fs.h>
- */
-struct io_poll_iocb {
- struct file *file;
- union {
- struct wait_queue_head *head;
- u64 addr;
- };
- __poll_t events;
- bool done;
- bool canceled;
- struct wait_queue_entry wait;
-};
-
-struct io_close {
- struct file *file;
- struct file *put_file;
- int fd;
-};
-
-struct io_timeout_data {
- struct io_kiocb *req;
- struct hrtimer timer;
- struct timespec64 ts;
- enum hrtimer_mode mode;
-};
-
-struct io_accept {
- struct file *file;
- struct sockaddr __user *addr;
- int __user *addr_len;
- int flags;
- unsigned long nofile;
-};
-
-struct io_sync {
- struct file *file;
- loff_t len;
- loff_t off;
- int flags;
- int mode;
-};
-
-struct io_cancel {
- struct file *file;
- u64 addr;
-};
-
-struct io_timeout {
- struct file *file;
- u32 off;
- u32 target_seq;
- struct list_head list;
-};
-
-struct io_timeout_rem {
- struct file *file;
- u64 addr;
-};
-
-struct io_rw {
- /* NOTE: kiocb has the file as the first member, so don't do it here */
- struct kiocb kiocb;
- u64 addr;
- u64 len;
-};
-
-struct io_connect {
- struct file *file;
- struct sockaddr __user *addr;
- int addr_len;
-};
-
-struct io_sr_msg {
- struct file *file;
- union {
- struct user_msghdr __user *umsg;
- void __user *buf;
- };
- int msg_flags;
- int bgid;
- size_t len;
- struct io_buffer *kbuf;
-};
-
-struct io_open {
- struct file *file;
- int dfd;
- bool ignore_nonblock;
- struct filename *filename;
- struct open_how how;
- unsigned long nofile;
-};
-
-struct io_files_update {
- struct file *file;
- u64 arg;
- u32 nr_args;
- u32 offset;
-};
-
-struct io_fadvise {
- struct file *file;
- u64 offset;
- u32 len;
- u32 advice;
-};
-
-struct io_madvise {
- struct file *file;
- u64 addr;
- u32 len;
- u32 advice;
-};
-
-struct io_epoll {
- struct file *file;
- int epfd;
- int op;
- int fd;
- struct epoll_event event;
-};
-
-struct io_splice {
- struct file *file_out;
- struct file *file_in;
- loff_t off_out;
- loff_t off_in;
- u64 len;
- unsigned int flags;
-};
-
-struct io_provide_buf {
- struct file *file;
- __u64 addr;
- __u32 len;
- __u32 bgid;
- __u16 nbufs;
- __u16 bid;
-};
-
-struct io_statx {
- struct file *file;
- int dfd;
- unsigned int mask;
- unsigned int flags;
- const char __user *filename;
- struct statx __user *buffer;
-};
-
-struct io_completion {
- struct file *file;
- struct list_head list;
- u32 cflags;
-};
-
-struct io_async_connect {
- struct sockaddr_storage address;
-};
-
-struct io_async_msghdr {
- struct iovec fast_iov[UIO_FASTIOV];
- struct iovec *iov;
- struct sockaddr __user *uaddr;
- struct msghdr msg;
- struct sockaddr_storage addr;
-};
-
-struct io_async_rw {
- struct iovec fast_iov[UIO_FASTIOV];
- const struct iovec *free_iovec;
- struct iov_iter iter;
- size_t bytes_done;
- struct wait_page_queue wpq;
-};
-
-enum {
- REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
- REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
- REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
- REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
- REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
- REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
-
- REQ_F_LINK_HEAD_BIT,
- REQ_F_FAIL_LINK_BIT,
- REQ_F_INFLIGHT_BIT,
- REQ_F_CUR_POS_BIT,
- REQ_F_NOWAIT_BIT,
- REQ_F_LINK_TIMEOUT_BIT,
- REQ_F_ISREG_BIT,
- REQ_F_NEED_CLEANUP_BIT,
- REQ_F_POLLED_BIT,
- REQ_F_BUFFER_SELECTED_BIT,
- REQ_F_NO_FILE_TABLE_BIT,
- REQ_F_WORK_INITIALIZED_BIT,
- REQ_F_LTIMEOUT_ACTIVE_BIT,
-
- /* not a real bit, just to check we're not overflowing the space */
- __REQ_F_LAST_BIT,
-};
-
-enum {
- /* ctx owns file */
- REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
- /* drain existing IO first */
- REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
- /* linked sqes */
- REQ_F_LINK = BIT(REQ_F_LINK_BIT),
- /* doesn't sever on completion < 0 */
- REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
- /* IOSQE_ASYNC */
- REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
- /* IOSQE_BUFFER_SELECT */
- REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
-
- /* head of a link */
- REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT),
- /* fail rest of links */
- REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT),
- /* on inflight list */
- REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
- /* read/write uses file position */
- REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
- /* must not punt to workers */
- REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
- /* has or had linked timeout */
- REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
- /* regular file */
- REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
- /* needs cleanup */
- REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
- /* already went through poll handler */
- REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
- /* buffer already selected */
- REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
- /* doesn't need file table for this request */
- REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
- /* io_wq_work is initialized */
- REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT),
- /* linked timeout is active, i.e. prepared by link's head */
- REQ_F_LTIMEOUT_ACTIVE = BIT(REQ_F_LTIMEOUT_ACTIVE_BIT),
-};
-
-struct async_poll {
- struct io_poll_iocb poll;
- struct io_poll_iocb *double_poll;
-};
-
-/*
- * NOTE! Each of the iocb union members has the file pointer
- * as the first entry in their struct definition. So you can
- * access the file pointer through any of the sub-structs,
- * or directly as just 'ki_filp' in this struct.
- */
-struct io_kiocb {
- union {
- struct file *file;
- struct io_rw rw;
- struct io_poll_iocb poll;
- struct io_accept accept;
- struct io_sync sync;
- struct io_cancel cancel;
- struct io_timeout timeout;
- struct io_timeout_rem timeout_rem;
- struct io_connect connect;
- struct io_sr_msg sr_msg;
- struct io_open open;
- struct io_close close;
- struct io_files_update files_update;
- struct io_fadvise fadvise;
- struct io_madvise madvise;
- struct io_epoll epoll;
- struct io_splice splice;
- struct io_provide_buf pbuf;
- struct io_statx statx;
- /* use only after cleaning per-op data, see io_clean_op() */
- struct io_completion compl;
- };
-
- /* opcode allocated if it needs to store data for async defer */
- void *async_data;
- u8 opcode;
- /* polled IO has completed */
- u8 iopoll_completed;
-
- u16 buf_index;
- u32 result;
-
- struct io_ring_ctx *ctx;
- unsigned int flags;
- refcount_t refs;
- struct task_struct *task;
- u64 user_data;
-
- struct list_head link_list;
-
- /*
- * 1. used with ctx->iopoll_list with reads/writes
- * 2. to track reqs with ->files (see io_op_def::file_table)
- */
- struct list_head inflight_entry;
-
- struct list_head iopoll_entry;
-
- struct percpu_ref *fixed_file_refs;
- struct callback_head task_work;
- /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
- struct hlist_node hash_node;
- struct async_poll *apoll;
- struct io_wq_work work;
-};
-
-struct io_defer_entry {
- struct list_head list;
- struct io_kiocb *req;
- u32 seq;
-};
-
-#define IO_IOPOLL_BATCH 8
-
-struct io_comp_state {
- unsigned int nr;
- struct list_head list;
- struct io_ring_ctx *ctx;
-};
-
-struct io_submit_state {
- struct blk_plug plug;
-
- /*
- * io_kiocb alloc cache
- */
- void *reqs[IO_IOPOLL_BATCH];
- unsigned int free_reqs;
-
- /*
- * Batch completion logic
- */
- struct io_comp_state comp;
-
- /*
- * File reference cache
- */
- struct file *file;
- unsigned int fd;
- unsigned int has_refs;
- unsigned int ios_left;
-};
-
-struct io_op_def {
- /* needs req->file assigned */
- unsigned needs_file : 1;
- /* don't fail if file grab fails */
- unsigned needs_file_no_error : 1;
- /* hash wq insertion if file is a regular file */
- unsigned hash_reg_file : 1;
- /* unbound wq insertion if file is a non-regular file */
- unsigned unbound_nonreg_file : 1;
- /* opcode is not supported by this kernel */
- unsigned not_supported : 1;
- /* set if opcode supports polled "wait" */
- unsigned pollin : 1;
- unsigned pollout : 1;
- /* op supports buffer selection */
- unsigned buffer_select : 1;
- /* must always have async data allocated */
- unsigned needs_async_data : 1;
- /* size of async data needed, if any */
- unsigned short async_size;
- unsigned work_flags;
-};
-
-static const struct io_op_def io_op_defs[] = {
- [IORING_OP_NOP] = {},
- [IORING_OP_READV] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollin = 1,
- .buffer_select = 1,
- .needs_async_data = 1,
- .async_size = sizeof(struct io_async_rw),
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FILES,
- },
- [IORING_OP_WRITEV] = {
- .needs_file = 1,
- .hash_reg_file = 1,
- .unbound_nonreg_file = 1,
- .pollout = 1,
- .needs_async_data = 1,
- .async_size = sizeof(struct io_async_rw),
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FSIZE | IO_WQ_WORK_FILES,
- },
- [IORING_OP_FSYNC] = {
- .needs_file = 1,
- .work_flags = IO_WQ_WORK_BLKCG,
- },
- [IORING_OP_READ_FIXED] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollin = 1,
- .async_size = sizeof(struct io_async_rw),
- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM |
- IO_WQ_WORK_FILES,
- },
- [IORING_OP_WRITE_FIXED] = {
- .needs_file = 1,
- .hash_reg_file = 1,
- .unbound_nonreg_file = 1,
- .pollout = 1,
- .async_size = sizeof(struct io_async_rw),
- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE |
- IO_WQ_WORK_MM | IO_WQ_WORK_FILES,
- },
- [IORING_OP_POLL_ADD] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- },
- [IORING_OP_POLL_REMOVE] = {},
- [IORING_OP_SYNC_FILE_RANGE] = {
- .needs_file = 1,
- .work_flags = IO_WQ_WORK_BLKCG,
- },
- [IORING_OP_SENDMSG] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollout = 1,
- .needs_async_data = 1,
- .async_size = sizeof(struct io_async_msghdr),
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FS,
- },
- [IORING_OP_RECVMSG] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollin = 1,
- .buffer_select = 1,
- .needs_async_data = 1,
- .async_size = sizeof(struct io_async_msghdr),
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FS,
- },
- [IORING_OP_TIMEOUT] = {
- .needs_async_data = 1,
- .async_size = sizeof(struct io_timeout_data),
- .work_flags = IO_WQ_WORK_MM,
- },
- [IORING_OP_TIMEOUT_REMOVE] = {},
- [IORING_OP_ACCEPT] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollin = 1,
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES,
- },
- [IORING_OP_ASYNC_CANCEL] = {},
- [IORING_OP_LINK_TIMEOUT] = {
- .needs_async_data = 1,
- .async_size = sizeof(struct io_timeout_data),
- .work_flags = IO_WQ_WORK_MM,
- },
- [IORING_OP_CONNECT] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollout = 1,
- .needs_async_data = 1,
- .async_size = sizeof(struct io_async_connect),
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FS,
- },
- [IORING_OP_FALLOCATE] = {
- .needs_file = 1,
- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE,
- },
- [IORING_OP_OPENAT] = {
- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FS,
- },
- [IORING_OP_CLOSE] = {
- .needs_file = 1,
- .needs_file_no_error = 1,
- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG,
- },
- [IORING_OP_FILES_UPDATE] = {
- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM,
- },
- [IORING_OP_STATX] = {
- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM |
- IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
- },
- [IORING_OP_READ] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollin = 1,
- .buffer_select = 1,
- .async_size = sizeof(struct io_async_rw),
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FILES,
- },
- [IORING_OP_WRITE] = {
- .needs_file = 1,
- .hash_reg_file = 1,
- .unbound_nonreg_file = 1,
- .pollout = 1,
- .async_size = sizeof(struct io_async_rw),
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FSIZE | IO_WQ_WORK_FILES,
- },
- [IORING_OP_FADVISE] = {
- .needs_file = 1,
- .work_flags = IO_WQ_WORK_BLKCG,
- },
- [IORING_OP_MADVISE] = {
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
- },
- [IORING_OP_SEND] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollout = 1,
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FS,
- },
- [IORING_OP_RECV] = {
- .needs_file = 1,
- .unbound_nonreg_file = 1,
- .pollin = 1,
- .buffer_select = 1,
- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
- IO_WQ_WORK_FS,
- },
- [IORING_OP_OPENAT2] = {
- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_FS |
- IO_WQ_WORK_BLKCG,
- },
- [IORING_OP_EPOLL_CTL] = {
- .unbound_nonreg_file = 1,
- .work_flags = IO_WQ_WORK_FILES,
- },
- [IORING_OP_SPLICE] = {
- .needs_file = 1,
- .hash_reg_file = 1,
- .unbound_nonreg_file = 1,
- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FILES,
- },
- [IORING_OP_PROVIDE_BUFFERS] = {},
- [IORING_OP_REMOVE_BUFFERS] = {},
- [IORING_OP_TEE] = {
- .needs_file = 1,
- .hash_reg_file = 1,
- .unbound_nonreg_file = 1,
- },
-};
-
-enum io_mem_account {
- ACCT_LOCKED,
- ACCT_PINNED,
-};
-
-static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node);
-static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
- struct io_ring_ctx *ctx);
-
-static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
- struct io_comp_state *cs);
-static void io_cqring_fill_event(struct io_kiocb *req, long res);
-static void io_put_req(struct io_kiocb *req);
-static void io_put_req_deferred(struct io_kiocb *req, int nr);
-static void io_double_put_req(struct io_kiocb *req);
-static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
-static void __io_queue_linked_timeout(struct io_kiocb *req);
-static void io_queue_linked_timeout(struct io_kiocb *req);
-static int __io_sqe_files_update(struct io_ring_ctx *ctx,
- struct io_uring_files_update *ip,
- unsigned nr_args);
-static void __io_clean_op(struct io_kiocb *req);
-static struct file *io_file_get(struct io_submit_state *state,
- struct io_kiocb *req, int fd, bool fixed);
-static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs);
-static void io_file_put_work(struct work_struct *work);
-
-static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
- struct iovec **iovec, struct iov_iter *iter,
- bool needs_lock);
-static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
- const struct iovec *fast_iov,
- struct iov_iter *iter, bool force);
-static void io_req_drop_files(struct io_kiocb *req);
-static void io_req_task_queue(struct io_kiocb *req);
-
-static struct kmem_cache *req_cachep;
-
-static const struct file_operations io_uring_fops;
-
-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
- if (file->f_op == &io_uring_fops) {
- struct io_ring_ctx *ctx = file->private_data;
-
- return ctx->ring_sock->sk;
- }
-#endif
- return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
-static inline void io_clean_op(struct io_kiocb *req)
-{
- if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED))
- __io_clean_op(req);
-}
-
-static inline bool __io_match_files(struct io_kiocb *req,
- struct files_struct *files)
-{
- if (req->file && req->file->f_op == &io_uring_fops)
- return true;
-
- return ((req->flags & REQ_F_WORK_INITIALIZED) &&
- (req->work.flags & IO_WQ_WORK_FILES)) &&
- req->work.identity->files == files;
-}
-
-static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl)
-{
- bool got = percpu_ref_tryget(ref);
-
- /* already at zero, wait for ->release() */
- if (!got)
- wait_for_completion(compl);
- percpu_ref_resurrect(ref);
- if (got)
- percpu_ref_put(ref);
-}
-
-static bool io_match_task(struct io_kiocb *head,
- struct task_struct *task,
- struct files_struct *files)
-{
- struct io_kiocb *link;
-
- if (task && head->task != task) {
- /* in terms of cancelation, always match if req task is dead */
- if (head->task->flags & PF_EXITING)
- return true;
- return false;
- }
- if (!files)
- return true;
- if (__io_match_files(head, files))
- return true;
- if (head->flags & REQ_F_LINK_HEAD) {
- list_for_each_entry(link, &head->link_list, link_list) {
- if (__io_match_files(link, files))
- return true;
- }
- }
- return false;
-}
-
-
-static void io_sq_thread_drop_mm(void)
-{
- struct mm_struct *mm = current->mm;
-
- if (mm) {
- kthread_unuse_mm(mm);
- mmput(mm);
- current->mm = NULL;
- }
-}
-
-static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
-{
- struct mm_struct *mm;
-
- if (current->flags & PF_EXITING)
- return -EFAULT;
- if (current->mm)
- return 0;
-
- /* Should never happen */
- if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL)))
- return -EFAULT;
-
- task_lock(ctx->sqo_task);
- mm = ctx->sqo_task->mm;
- if (unlikely(!mm || !mmget_not_zero(mm)))
- mm = NULL;
- task_unlock(ctx->sqo_task);
-
- if (mm) {
- kthread_use_mm(mm);
- return 0;
- }
-
- return -EFAULT;
-}
-
-static int io_sq_thread_acquire_mm(struct io_ring_ctx *ctx,
- struct io_kiocb *req)
-{
- if (!(io_op_defs[req->opcode].work_flags & IO_WQ_WORK_MM))
- return 0;
- return __io_sq_thread_acquire_mm(ctx);
-}
-
-static void io_sq_thread_associate_blkcg(struct io_ring_ctx *ctx,
- struct cgroup_subsys_state **cur_css)
-
-{
-#ifdef CONFIG_BLK_CGROUP
- /* puts the old one when swapping */
- if (*cur_css != ctx->sqo_blkcg_css) {
- kthread_associate_blkcg(ctx->sqo_blkcg_css);
- *cur_css = ctx->sqo_blkcg_css;
- }
-#endif
-}
-
-static void io_sq_thread_unassociate_blkcg(void)
-{
-#ifdef CONFIG_BLK_CGROUP
- kthread_associate_blkcg(NULL);
-#endif
-}
-
-static inline void req_set_fail_links(struct io_kiocb *req)
-{
- if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK)
- req->flags |= REQ_F_FAIL_LINK;
-}
-
-/*
- * None of these are dereferenced, they are simply used to check if any of
- * them have changed. If we're under current and check they are still the
- * same, we're fine to grab references to them for actual out-of-line use.
- */
-static void io_init_identity(struct io_identity *id)
-{
- id->files = current->files;
- id->mm = current->mm;
-#ifdef CONFIG_BLK_CGROUP
- rcu_read_lock();
- id->blkcg_css = blkcg_css();
- rcu_read_unlock();
-#endif
- id->creds = current_cred();
- id->nsproxy = current->nsproxy;
- id->fs = current->fs;
- id->fsize = rlimit(RLIMIT_FSIZE);
-#ifdef CONFIG_AUDIT
- id->loginuid = current->loginuid;
- id->sessionid = current->sessionid;
-#endif
- refcount_set(&id->count, 1);
-}
-
-static inline void __io_req_init_async(struct io_kiocb *req)
-{
- memset(&req->work, 0, sizeof(req->work));
- req->flags |= REQ_F_WORK_INITIALIZED;
-}
-
-/*
- * Note: must call io_req_init_async() for the first time you
- * touch any members of io_wq_work.
- */
-static inline void io_req_init_async(struct io_kiocb *req)
-{
- struct io_uring_task *tctx = req->task->io_uring;
-
- if (req->flags & REQ_F_WORK_INITIALIZED)
- return;
-
- __io_req_init_async(req);
-
- /* Grab a ref if this isn't our static identity */
- req->work.identity = tctx->identity;
- if (tctx->identity != &tctx->__identity)
- refcount_inc(&req->work.identity->count);
-}
-
-static inline bool io_async_submit(struct io_ring_ctx *ctx)
-{
- return ctx->flags & IORING_SETUP_SQPOLL;
-}
-
-static void io_ring_ctx_ref_free(struct percpu_ref *ref)
-{
- struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
-
- complete(&ctx->ref_comp);
-}
-
-static inline bool io_is_timeout_noseq(struct io_kiocb *req)
-{
- return !req->timeout.off;
-}
-
-static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
-{
- struct io_ring_ctx *ctx;
- int hash_bits;
-
- ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
- if (!ctx)
- return NULL;
-
- ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL);
- if (!ctx->fallback_req)
- goto err;
-
- /*
- * Use 5 bits less than the max cq entries, that should give us around
- * 32 entries per hash list if totally full and uniformly spread.
- */
- hash_bits = ilog2(p->cq_entries);
- hash_bits -= 5;
- if (hash_bits <= 0)
- hash_bits = 1;
- ctx->cancel_hash_bits = hash_bits;
- ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
- GFP_KERNEL);
- if (!ctx->cancel_hash)
- goto err;
- __hash_init(ctx->cancel_hash, 1U << hash_bits);
-
- if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
- PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
- goto err;
-
- ctx->flags = p->flags;
- init_waitqueue_head(&ctx->sqo_sq_wait);
- INIT_LIST_HEAD(&ctx->sqd_list);
- init_waitqueue_head(&ctx->cq_wait);
- INIT_LIST_HEAD(&ctx->cq_overflow_list);
- init_completion(&ctx->ref_comp);
- init_completion(&ctx->sq_thread_comp);
- xa_init_flags(&ctx->io_buffers, XA_FLAGS_ALLOC1);
- xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
- mutex_init(&ctx->uring_lock);
- init_waitqueue_head(&ctx->wait);
- spin_lock_init(&ctx->completion_lock);
- INIT_LIST_HEAD(&ctx->iopoll_list);
- INIT_LIST_HEAD(&ctx->defer_list);
- INIT_LIST_HEAD(&ctx->timeout_list);
- spin_lock_init(&ctx->inflight_lock);
- INIT_LIST_HEAD(&ctx->inflight_list);
- INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work);
- init_llist_head(&ctx->file_put_llist);
- return ctx;
-err:
- if (ctx->fallback_req)
- kmem_cache_free(req_cachep, ctx->fallback_req);
- kfree(ctx->cancel_hash);
- kfree(ctx);
- return NULL;
-}
-
-static bool req_need_defer(struct io_kiocb *req, u32 seq)
-{
- if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
- struct io_ring_ctx *ctx = req->ctx;
-
- return seq != ctx->cached_cq_tail
- + READ_ONCE(ctx->cached_cq_overflow);
- }
-
- return false;
-}
-
-static void __io_commit_cqring(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
-
- /* order cqe stores with ring update */
- smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
-}
-
-static void io_put_identity(struct io_uring_task *tctx, struct io_kiocb *req)
-{
- if (req->work.identity == &tctx->__identity)
- return;
- if (refcount_dec_and_test(&req->work.identity->count))
- kfree(req->work.identity);
-}
-
-static void io_req_clean_work(struct io_kiocb *req)
-{
- if (!(req->flags & REQ_F_WORK_INITIALIZED))
- return;
-
- req->flags &= ~REQ_F_WORK_INITIALIZED;
-
- if (req->work.flags & IO_WQ_WORK_MM) {
- mmdrop(req->work.identity->mm);
- req->work.flags &= ~IO_WQ_WORK_MM;
- }
-#ifdef CONFIG_BLK_CGROUP
- if (req->work.flags & IO_WQ_WORK_BLKCG) {
- css_put(req->work.identity->blkcg_css);
- req->work.flags &= ~IO_WQ_WORK_BLKCG;
- }
-#endif
- if (req->work.flags & IO_WQ_WORK_CREDS) {
- put_cred(req->work.identity->creds);
- req->work.flags &= ~IO_WQ_WORK_CREDS;
- }
- if (req->work.flags & IO_WQ_WORK_FS) {
- struct fs_struct *fs = req->work.identity->fs;
-
- spin_lock(&req->work.identity->fs->lock);
- if (--fs->users)
- fs = NULL;
- spin_unlock(&req->work.identity->fs->lock);
- if (fs)
- free_fs_struct(fs);
- req->work.flags &= ~IO_WQ_WORK_FS;
- }
- if (req->flags & REQ_F_INFLIGHT)
- io_req_drop_files(req);
-
- io_put_identity(req->task->io_uring, req);
-}
-
-/*
- * Create a private copy of io_identity, since some fields don't match
- * the current context.
- */
-static bool io_identity_cow(struct io_kiocb *req)
-{
- struct io_uring_task *tctx = req->task->io_uring;
- const struct cred *creds = NULL;
- struct io_identity *id;
-
- if (req->work.flags & IO_WQ_WORK_CREDS)
- creds = req->work.identity->creds;
-
- id = kmemdup(req->work.identity, sizeof(*id), GFP_KERNEL);
- if (unlikely(!id)) {
- req->work.flags |= IO_WQ_WORK_CANCEL;
- return false;
- }
-
- /*
- * We can safely just re-init the creds we copied Either the field
- * matches the current one, or we haven't grabbed it yet. The only
- * exception is ->creds, through registered personalities, so handle
- * that one separately.
- */
- io_init_identity(id);
- if (creds)
- id->creds = creds;
-
- /* add one for this request */
- refcount_inc(&id->count);
-
- /* drop tctx and req identity references, if needed */
- if (tctx->identity != &tctx->__identity &&
- refcount_dec_and_test(&tctx->identity->count))
- kfree(tctx->identity);
- if (req->work.identity != &tctx->__identity &&
- refcount_dec_and_test(&req->work.identity->count))
- kfree(req->work.identity);
-
- req->work.identity = id;
- tctx->identity = id;
- return true;
-}
-
-static bool io_grab_identity(struct io_kiocb *req)
-{
- const struct io_op_def *def = &io_op_defs[req->opcode];
- struct io_identity *id = req->work.identity;
- struct io_ring_ctx *ctx = req->ctx;
-
- if (def->work_flags & IO_WQ_WORK_FSIZE) {
- if (id->fsize != rlimit(RLIMIT_FSIZE))
- return false;
- req->work.flags |= IO_WQ_WORK_FSIZE;
- }
-#ifdef CONFIG_BLK_CGROUP
- if (!(req->work.flags & IO_WQ_WORK_BLKCG) &&
- (def->work_flags & IO_WQ_WORK_BLKCG)) {
- rcu_read_lock();
- if (id->blkcg_css != blkcg_css()) {
- rcu_read_unlock();
- return false;
- }
- /*
- * This should be rare, either the cgroup is dying or the task
- * is moving cgroups. Just punt to root for the handful of ios.
- */
- if (css_tryget_online(id->blkcg_css))
- req->work.flags |= IO_WQ_WORK_BLKCG;
- rcu_read_unlock();
- }
-#endif
- if (!(req->work.flags & IO_WQ_WORK_CREDS)) {
- if (id->creds != current_cred())
- return false;
- get_cred(id->creds);
- req->work.flags |= IO_WQ_WORK_CREDS;
- }
-#ifdef CONFIG_AUDIT
- if (!uid_eq(current->loginuid, id->loginuid) ||
- current->sessionid != id->sessionid)
- return false;
-#endif
- if (!(req->work.flags & IO_WQ_WORK_FS) &&
- (def->work_flags & IO_WQ_WORK_FS)) {
- if (current->fs != id->fs)
- return false;
- spin_lock(&id->fs->lock);
- if (!id->fs->in_exec) {
- id->fs->users++;
- req->work.flags |= IO_WQ_WORK_FS;
- } else {
- req->work.flags |= IO_WQ_WORK_CANCEL;
- }
- spin_unlock(¤t->fs->lock);
- }
- if (!(req->work.flags & IO_WQ_WORK_FILES) &&
- (def->work_flags & IO_WQ_WORK_FILES) &&
- !(req->flags & REQ_F_NO_FILE_TABLE)) {
- if (id->files != current->files ||
- id->nsproxy != current->nsproxy)
- return false;
- atomic_inc(&id->files->count);
- get_nsproxy(id->nsproxy);
-
- if (!(req->flags & REQ_F_INFLIGHT)) {
- req->flags |= REQ_F_INFLIGHT;
-
- spin_lock_irq(&ctx->inflight_lock);
- list_add(&req->inflight_entry, &ctx->inflight_list);
- spin_unlock_irq(&ctx->inflight_lock);
- }
- req->work.flags |= IO_WQ_WORK_FILES;
- }
- if (!(req->work.flags & IO_WQ_WORK_MM) &&
- (def->work_flags & IO_WQ_WORK_MM)) {
- if (id->mm != current->mm)
- return false;
- mmgrab(id->mm);
- req->work.flags |= IO_WQ_WORK_MM;
- }
-
- return true;
-}
-
-static void io_prep_async_work(struct io_kiocb *req)
-{
- const struct io_op_def *def = &io_op_defs[req->opcode];
- struct io_ring_ctx *ctx = req->ctx;
- struct io_identity *id;
-
- io_req_init_async(req);
- id = req->work.identity;
-
- if (req->flags & REQ_F_FORCE_ASYNC)
- req->work.flags |= IO_WQ_WORK_CONCURRENT;
-
- if (req->flags & REQ_F_ISREG) {
- if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
- io_wq_hash_work(&req->work, file_inode(req->file));
- } else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
- if (def->unbound_nonreg_file)
- req->work.flags |= IO_WQ_WORK_UNBOUND;
- }
-
- /* if we fail grabbing identity, we must COW, regrab, and retry */
- if (io_grab_identity(req))
- return;
-
- if (!io_identity_cow(req))
- return;
-
- /* can't fail at this point */
- if (!io_grab_identity(req))
- WARN_ON(1);
-}
-
-static void io_prep_async_link(struct io_kiocb *req)
-{
- struct io_kiocb *cur;
-
- io_prep_async_work(req);
- if (req->flags & REQ_F_LINK_HEAD)
- list_for_each_entry(cur, &req->link_list, link_list)
- io_prep_async_work(cur);
-}
-
-static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct io_kiocb *link = io_prep_linked_timeout(req);
-
- trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
- &req->work, req->flags);
- io_wq_enqueue(ctx->io_wq, &req->work);
- return link;
-}
-
-static void io_queue_async_work(struct io_kiocb *req)
-{
- struct io_kiocb *link;
-
- /* init ->work of the whole link before punting */
- io_prep_async_link(req);
- link = __io_queue_async_work(req);
-
- if (link)
- io_queue_linked_timeout(link);
-}
-
-static void io_kill_timeout(struct io_kiocb *req, int status)
-{
- struct io_timeout_data *io = req->async_data;
- int ret;
-
- ret = hrtimer_try_to_cancel(&io->timer);
- if (ret != -1) {
- if (status)
- req_set_fail_links(req);
- atomic_set(&req->ctx->cq_timeouts,
- atomic_read(&req->ctx->cq_timeouts) + 1);
- list_del_init(&req->timeout.list);
- io_cqring_fill_event(req, status);
- io_put_req_deferred(req, 1);
- }
-}
-
-/*
- * Returns true if we found and killed one or more timeouts
- */
-static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
- struct files_struct *files)
-{
- struct io_kiocb *req, *tmp;
- int canceled = 0;
-
- spin_lock_irq(&ctx->completion_lock);
- list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
- if (io_match_task(req, tsk, files)) {
- io_kill_timeout(req, -ECANCELED);
- canceled++;
- }
- }
- spin_unlock_irq(&ctx->completion_lock);
- return canceled != 0;
-}
-
-static void __io_queue_deferred(struct io_ring_ctx *ctx)
-{
- do {
- struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
- struct io_defer_entry, list);
-
- if (req_need_defer(de->req, de->seq))
- break;
- list_del_init(&de->list);
- io_req_task_queue(de->req);
- kfree(de);
- } while (!list_empty(&ctx->defer_list));
-}
-
-static void io_flush_timeouts(struct io_ring_ctx *ctx)
-{
- struct io_kiocb *req, *tmp;
- u32 seq;
-
- if (list_empty(&ctx->timeout_list))
- return;
-
- seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
-
- list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
- u32 events_needed, events_got;
-
- if (io_is_timeout_noseq(req))
- break;
-
- /*
- * Since seq can easily wrap around over time, subtract
- * the last seq at which timeouts were flushed before comparing.
- * Assuming not more than 2^31-1 events have happened since,
- * these subtractions won't have wrapped, so we can check if
- * target is in [last_seq, current_seq] by comparing the two.
- */
- events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush;
- events_got = seq - ctx->cq_last_tm_flush;
- if (events_got < events_needed)
- break;
-
- io_kill_timeout(req, 0);
- }
-
- ctx->cq_last_tm_flush = seq;
-}
-
-static void io_commit_cqring(struct io_ring_ctx *ctx)
-{
- io_flush_timeouts(ctx);
- __io_commit_cqring(ctx);
-
- if (unlikely(!list_empty(&ctx->defer_list)))
- __io_queue_deferred(ctx);
-}
-
-static inline bool io_sqring_full(struct io_ring_ctx *ctx)
-{
- struct io_rings *r = ctx->rings;
-
- return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries;
-}
-
-static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
- unsigned tail;
-
- tail = ctx->cached_cq_tail;
- /*
- * writes to the cq entry need to come after reading head; the
- * control dependency is enough as we're using WRITE_ONCE to
- * fill the cq entry
- */
- if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
- return NULL;
-
- ctx->cached_cq_tail++;
- return &rings->cqes[tail & ctx->cq_mask];
-}
-
-static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
-{
- if (!ctx->cq_ev_fd)
- return false;
- if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
- return false;
- if (!ctx->eventfd_async)
- return true;
- return io_wq_current_is_worker();
-}
-
-static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
-{
- if (wq_has_sleeper(&ctx->cq_wait)) {
- wake_up_interruptible(&ctx->cq_wait);
- kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
- }
- if (waitqueue_active(&ctx->wait))
- wake_up(&ctx->wait);
- if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait))
- wake_up(&ctx->sq_data->wait);
- if (io_should_trigger_evfd(ctx))
- eventfd_signal(ctx->cq_ev_fd, 1);
-}
-
-static void io_cqring_mark_overflow(struct io_ring_ctx *ctx)
-{
- if (list_empty(&ctx->cq_overflow_list)) {
- clear_bit(0, &ctx->sq_check_overflow);
- clear_bit(0, &ctx->cq_check_overflow);
- ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
- }
-}
-
-/* Returns true if there are no backlogged entries after the flush */
-static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
- struct task_struct *tsk,
- struct files_struct *files)
-{
- struct io_rings *rings = ctx->rings;
- struct io_kiocb *req, *tmp;
- struct io_uring_cqe *cqe;
- unsigned long flags;
- LIST_HEAD(list);
-
- if (!force) {
- if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) ==
- rings->cq_ring_entries))
- return false;
- }
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
-
- cqe = NULL;
- list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) {
- if (!io_match_task(req, tsk, files))
- continue;
-
- cqe = io_get_cqring(ctx);
- if (!cqe && !force)
- break;
-
- list_move(&req->compl.list, &list);
- if (cqe) {
- WRITE_ONCE(cqe->user_data, req->user_data);
- WRITE_ONCE(cqe->res, req->result);
- WRITE_ONCE(cqe->flags, req->compl.cflags);
- } else {
- ctx->cached_cq_overflow++;
- WRITE_ONCE(ctx->rings->cq_overflow,
- ctx->cached_cq_overflow);
- }
- }
-
- io_commit_cqring(ctx);
- io_cqring_mark_overflow(ctx);
-
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
- io_cqring_ev_posted(ctx);
-
- while (!list_empty(&list)) {
- req = list_first_entry(&list, struct io_kiocb, compl.list);
- list_del(&req->compl.list);
- io_put_req(req);
- }
-
- return cqe != NULL;
-}
-
-static void io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
- struct task_struct *tsk,
- struct files_struct *files)
-{
- if (test_bit(0, &ctx->cq_check_overflow)) {
- /* iopoll syncs against uring_lock, not completion_lock */
- if (ctx->flags & IORING_SETUP_IOPOLL)
- mutex_lock(&ctx->uring_lock);
- __io_cqring_overflow_flush(ctx, force, tsk, files);
- if (ctx->flags & IORING_SETUP_IOPOLL)
- mutex_unlock(&ctx->uring_lock);
- }
-}
-
-static void __io_cqring_fill_event(struct io_kiocb *req, long res,
- unsigned int cflags)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct io_uring_cqe *cqe;
-
- trace_io_uring_complete(ctx, req->user_data, res);
-
- /*
- * If we can't get a cq entry, userspace overflowed the
- * submission (by quite a lot). Increment the overflow count in
- * the ring.
- */
- cqe = io_get_cqring(ctx);
- if (likely(cqe)) {
- WRITE_ONCE(cqe->user_data, req->user_data);
- WRITE_ONCE(cqe->res, res);
- WRITE_ONCE(cqe->flags, cflags);
- } else if (ctx->cq_overflow_flushed ||
- atomic_read(&req->task->io_uring->in_idle)) {
- /*
- * If we're in ring overflow flush mode, or in task cancel mode,
- * then we cannot store the request for later flushing, we need
- * to drop it on the floor.
- */
- ctx->cached_cq_overflow++;
- WRITE_ONCE(ctx->rings->cq_overflow, ctx->cached_cq_overflow);
- } else {
- if (list_empty(&ctx->cq_overflow_list)) {
- set_bit(0, &ctx->sq_check_overflow);
- set_bit(0, &ctx->cq_check_overflow);
- ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW;
- }
- io_clean_op(req);
- req->result = res;
- req->compl.cflags = cflags;
- refcount_inc(&req->refs);
- list_add_tail(&req->compl.list, &ctx->cq_overflow_list);
- }
-}
-
-static void io_cqring_fill_event(struct io_kiocb *req, long res)
-{
- __io_cqring_fill_event(req, res, 0);
-}
-
-static void io_cqring_add_event(struct io_kiocb *req, long res, long cflags)
-{
- struct io_ring_ctx *ctx = req->ctx;
- unsigned long flags;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
- __io_cqring_fill_event(req, res, cflags);
- io_commit_cqring(ctx);
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-
- io_cqring_ev_posted(ctx);
-}
-
-static void io_submit_flush_completions(struct io_comp_state *cs)
-{
- struct io_ring_ctx *ctx = cs->ctx;
-
- spin_lock_irq(&ctx->completion_lock);
- while (!list_empty(&cs->list)) {
- struct io_kiocb *req;
-
- req = list_first_entry(&cs->list, struct io_kiocb, compl.list);
- list_del(&req->compl.list);
- __io_cqring_fill_event(req, req->result, req->compl.cflags);
-
- /*
- * io_free_req() doesn't care about completion_lock unless one
- * of these flags is set. REQ_F_WORK_INITIALIZED is in the list
- * because of a potential deadlock with req->work.fs->lock
- */
- if (req->flags & (REQ_F_FAIL_LINK|REQ_F_LINK_TIMEOUT
- |REQ_F_WORK_INITIALIZED)) {
- spin_unlock_irq(&ctx->completion_lock);
- io_put_req(req);
- spin_lock_irq(&ctx->completion_lock);
- } else {
- io_put_req(req);
- }
- }
- io_commit_cqring(ctx);
- spin_unlock_irq(&ctx->completion_lock);
-
- io_cqring_ev_posted(ctx);
- cs->nr = 0;
-}
-
-static void __io_req_complete(struct io_kiocb *req, long res, unsigned cflags,
- struct io_comp_state *cs)
-{
- if (!cs) {
- io_cqring_add_event(req, res, cflags);
- io_put_req(req);
- } else {
- io_clean_op(req);
- req->result = res;
- req->compl.cflags = cflags;
- list_add_tail(&req->compl.list, &cs->list);
- if (++cs->nr >= 32)
- io_submit_flush_completions(cs);
- }
-}
-
-static void io_req_complete(struct io_kiocb *req, long res)
-{
- __io_req_complete(req, res, 0, NULL);
-}
-
-static inline bool io_is_fallback_req(struct io_kiocb *req)
-{
- return req == (struct io_kiocb *)
- ((unsigned long) req->ctx->fallback_req & ~1UL);
-}
-
-static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
-{
- struct io_kiocb *req;
-
- req = ctx->fallback_req;
- if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
- return req;
-
- return NULL;
-}
-
-static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx,
- struct io_submit_state *state)
-{
- if (!state->free_reqs) {
- gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
- size_t sz;
- int ret;
-
- sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
- ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs);
-
- /*
- * Bulk alloc is all-or-nothing. If we fail to get a batch,
- * retry single alloc to be on the safe side.
- */
- if (unlikely(ret <= 0)) {
- state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
- if (!state->reqs[0])
- goto fallback;
- ret = 1;
- }
- state->free_reqs = ret;
- }
-
- state->free_reqs--;
- return state->reqs[state->free_reqs];
-fallback:
- return io_get_fallback_req(ctx);
-}
-
-static inline void io_put_file(struct io_kiocb *req, struct file *file,
- bool fixed)
-{
- if (fixed)
- percpu_ref_put(req->fixed_file_refs);
- else
- fput(file);
-}
-
-static void io_dismantle_req(struct io_kiocb *req)
-{
- io_clean_op(req);
-
- if (req->async_data)
- kfree(req->async_data);
- if (req->file)
- io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
-
- io_req_clean_work(req);
-}
-
-static void __io_free_req(struct io_kiocb *req)
-{
- struct io_uring_task *tctx = req->task->io_uring;
- struct io_ring_ctx *ctx = req->ctx;
-
- io_dismantle_req(req);
-
- percpu_counter_dec(&tctx->inflight);
- if (atomic_read(&tctx->in_idle))
- wake_up(&tctx->wait);
- put_task_struct(req->task);
-
- if (likely(!io_is_fallback_req(req)))
- kmem_cache_free(req_cachep, req);
- else
- clear_bit_unlock(0, (unsigned long *) &ctx->fallback_req);
- percpu_ref_put(&ctx->refs);
-}
-
-static void io_kill_linked_timeout(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct io_kiocb *link;
- bool cancelled = false;
- unsigned long flags;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
- link = list_first_entry_or_null(&req->link_list, struct io_kiocb,
- link_list);
- /*
- * Can happen if a linked timeout fired and link had been like
- * req -> link t-out -> link t-out [-> ...]
- */
- if (link && (link->flags & REQ_F_LTIMEOUT_ACTIVE)) {
- struct io_timeout_data *io = link->async_data;
- int ret;
-
- list_del_init(&link->link_list);
- ret = hrtimer_try_to_cancel(&io->timer);
- if (ret != -1) {
- io_cqring_fill_event(link, -ECANCELED);
- io_commit_cqring(ctx);
- cancelled = true;
- }
- }
- req->flags &= ~REQ_F_LINK_TIMEOUT;
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-
- if (cancelled) {
- io_cqring_ev_posted(ctx);
- io_put_req(link);
- }
-}
-
-static struct io_kiocb *io_req_link_next(struct io_kiocb *req)
-{
- struct io_kiocb *nxt;
-
- /*
- * The list should never be empty when we are called here. But could
- * potentially happen if the chain is messed up, check to be on the
- * safe side.
- */
- if (unlikely(list_empty(&req->link_list)))
- return NULL;
-
- nxt = list_first_entry(&req->link_list, struct io_kiocb, link_list);
- list_del_init(&req->link_list);
- if (!list_empty(&nxt->link_list))
- nxt->flags |= REQ_F_LINK_HEAD;
- return nxt;
-}
-
-/*
- * Called if REQ_F_LINK_HEAD is set, and we fail the head request
- */
-static void io_fail_links(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- unsigned long flags;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
- while (!list_empty(&req->link_list)) {
- struct io_kiocb *link = list_first_entry(&req->link_list,
- struct io_kiocb, link_list);
-
- list_del_init(&link->link_list);
- trace_io_uring_fail_link(req, link);
-
- io_cqring_fill_event(link, -ECANCELED);
-
- /*
- * It's ok to free under spinlock as they're not linked anymore,
- * but avoid REQ_F_WORK_INITIALIZED because it may deadlock on
- * work.fs->lock.
- */
- if (link->flags & REQ_F_WORK_INITIALIZED)
- io_put_req_deferred(link, 2);
- else
- io_double_put_req(link);
- }
-
- io_commit_cqring(ctx);
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-
- io_cqring_ev_posted(ctx);
-}
-
-static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
-{
- req->flags &= ~REQ_F_LINK_HEAD;
- if (req->flags & REQ_F_LINK_TIMEOUT)
- io_kill_linked_timeout(req);
-
- /*
- * If LINK is set, we have dependent requests in this chain. If we
- * didn't fail this request, queue the first one up, moving any other
- * dependencies to the next request. In case of failure, fail the rest
- * of the chain.
- */
- if (likely(!(req->flags & REQ_F_FAIL_LINK)))
- return io_req_link_next(req);
- io_fail_links(req);
- return NULL;
-}
-
-static struct io_kiocb *io_req_find_next(struct io_kiocb *req)
-{
- if (likely(!(req->flags & REQ_F_LINK_HEAD)))
- return NULL;
- return __io_req_find_next(req);
-}
-
-static int io_req_task_work_add(struct io_kiocb *req, bool twa_signal_ok)
-{
- struct task_struct *tsk = req->task;
- struct io_ring_ctx *ctx = req->ctx;
- enum task_work_notify_mode notify;
- int ret;
-
- if (tsk->flags & PF_EXITING)
- return -ESRCH;
-
- /*
- * SQPOLL kernel thread doesn't need notification, just a wakeup. For
- * all other cases, use TWA_SIGNAL unconditionally to ensure we're
- * processing task_work. There's no reliable way to tell if TWA_RESUME
- * will do the job.
- */
- notify = TWA_NONE;
- if (!(ctx->flags & IORING_SETUP_SQPOLL) && twa_signal_ok)
- notify = TWA_SIGNAL;
-
- ret = task_work_add(tsk, &req->task_work, notify);
- if (!ret)
- wake_up_process(tsk);
-
- return ret;
-}
-
-static void __io_req_task_cancel(struct io_kiocb *req, int error)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- spin_lock_irq(&ctx->completion_lock);
- io_cqring_fill_event(req, error);
- io_commit_cqring(ctx);
- spin_unlock_irq(&ctx->completion_lock);
-
- io_cqring_ev_posted(ctx);
- req_set_fail_links(req);
- io_double_put_req(req);
-}
-
-static void io_req_task_cancel(struct callback_head *cb)
-{
- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
- struct io_ring_ctx *ctx = req->ctx;
-
- mutex_lock(&ctx->uring_lock);
- __io_req_task_cancel(req, -ECANCELED);
- mutex_unlock(&ctx->uring_lock);
- percpu_ref_put(&ctx->refs);
-}
-
-static void __io_req_task_submit(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- mutex_lock(&ctx->uring_lock);
- if (!ctx->sqo_dead && !__io_sq_thread_acquire_mm(ctx))
- __io_queue_sqe(req, NULL);
- else
- __io_req_task_cancel(req, -EFAULT);
- mutex_unlock(&ctx->uring_lock);
-
- if (ctx->flags & IORING_SETUP_SQPOLL)
- io_sq_thread_drop_mm();
-}
-
-static void io_req_task_submit(struct callback_head *cb)
-{
- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
- struct io_ring_ctx *ctx = req->ctx;
-
- __io_req_task_submit(req);
- percpu_ref_put(&ctx->refs);
-}
-
-static void io_req_task_queue(struct io_kiocb *req)
-{
- int ret;
-
- init_task_work(&req->task_work, io_req_task_submit);
- percpu_ref_get(&req->ctx->refs);
-
- ret = io_req_task_work_add(req, true);
- if (unlikely(ret)) {
- struct task_struct *tsk;
-
- init_task_work(&req->task_work, io_req_task_cancel);
- tsk = io_wq_get_task(req->ctx->io_wq);
- task_work_add(tsk, &req->task_work, TWA_NONE);
- wake_up_process(tsk);
- }
-}
-
-static void io_queue_next(struct io_kiocb *req)
-{
- struct io_kiocb *nxt = io_req_find_next(req);
-
- if (nxt)
- io_req_task_queue(nxt);
-}
-
-static void io_free_req(struct io_kiocb *req)
-{
- io_queue_next(req);
- __io_free_req(req);
-}
-
-struct req_batch {
- void *reqs[IO_IOPOLL_BATCH];
- int to_free;
-
- struct task_struct *task;
- int task_refs;
-};
-
-static inline void io_init_req_batch(struct req_batch *rb)
-{
- rb->to_free = 0;
- rb->task_refs = 0;
- rb->task = NULL;
-}
-
-static void __io_req_free_batch_flush(struct io_ring_ctx *ctx,
- struct req_batch *rb)
-{
- kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs);
- percpu_ref_put_many(&ctx->refs, rb->to_free);
- rb->to_free = 0;
-}
-
-static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
- struct req_batch *rb)
-{
- if (rb->to_free)
- __io_req_free_batch_flush(ctx, rb);
- if (rb->task) {
- struct io_uring_task *tctx = rb->task->io_uring;
-
- percpu_counter_sub(&tctx->inflight, rb->task_refs);
- if (atomic_read(&tctx->in_idle))
- wake_up(&tctx->wait);
- put_task_struct_many(rb->task, rb->task_refs);
- rb->task = NULL;
- }
-}
-
-static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req)
-{
- if (unlikely(io_is_fallback_req(req))) {
- io_free_req(req);
- return;
- }
- if (req->flags & REQ_F_LINK_HEAD)
- io_queue_next(req);
-
- if (req->task != rb->task) {
- if (rb->task) {
- struct io_uring_task *tctx = rb->task->io_uring;
-
- percpu_counter_sub(&tctx->inflight, rb->task_refs);
- if (atomic_read(&tctx->in_idle))
- wake_up(&tctx->wait);
- put_task_struct_many(rb->task, rb->task_refs);
- }
- rb->task = req->task;
- rb->task_refs = 0;
- }
- rb->task_refs++;
-
- io_dismantle_req(req);
- rb->reqs[rb->to_free++] = req;
- if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs)))
- __io_req_free_batch_flush(req->ctx, rb);
-}
-
-/*
- * Drop reference to request, return next in chain (if there is one) if this
- * was the last reference to this request.
- */
-static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
-{
- struct io_kiocb *nxt = NULL;
-
- if (refcount_dec_and_test(&req->refs)) {
- nxt = io_req_find_next(req);
- __io_free_req(req);
- }
- return nxt;
-}
-
-static void io_put_req(struct io_kiocb *req)
-{
- if (refcount_dec_and_test(&req->refs))
- io_free_req(req);
-}
-
-static void io_put_req_deferred_cb(struct callback_head *cb)
-{
- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
-
- io_free_req(req);
-}
-
-static void io_free_req_deferred(struct io_kiocb *req)
-{
- int ret;
-
- init_task_work(&req->task_work, io_put_req_deferred_cb);
- ret = io_req_task_work_add(req, true);
- if (unlikely(ret)) {
- struct task_struct *tsk;
-
- tsk = io_wq_get_task(req->ctx->io_wq);
- task_work_add(tsk, &req->task_work, TWA_NONE);
- wake_up_process(tsk);
- }
-}
-
-static inline void io_put_req_deferred(struct io_kiocb *req, int refs)
-{
- if (refcount_sub_and_test(refs, &req->refs))
- io_free_req_deferred(req);
-}
-
-static struct io_wq_work *io_steal_work(struct io_kiocb *req)
-{
- struct io_kiocb *nxt;
-
- /*
- * A ref is owned by io-wq in which context we're. So, if that's the
- * last one, it's safe to steal next work. False negatives are Ok,
- * it just will be re-punted async in io_put_work()
- */
- if (refcount_read(&req->refs) != 1)
- return NULL;
-
- nxt = io_req_find_next(req);
- return nxt ? &nxt->work : NULL;
-}
-
-static void io_double_put_req(struct io_kiocb *req)
-{
- /* drop both submit and complete references */
- if (refcount_sub_and_test(2, &req->refs))
- io_free_req(req);
-}
-
-static unsigned io_cqring_events(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
-
- /* See comment at the top of this file */
- smp_rmb();
- return ctx->cached_cq_tail - READ_ONCE(rings->cq.head);
-}
-
-static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
-
- /* make sure SQ entry isn't read before tail */
- return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
-}
-
-static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
-{
- unsigned int cflags;
-
- cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
- cflags |= IORING_CQE_F_BUFFER;
- req->flags &= ~REQ_F_BUFFER_SELECTED;
- kfree(kbuf);
- return cflags;
-}
-
-static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
-{
- struct io_buffer *kbuf;
-
- kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
- return io_put_kbuf(req, kbuf);
-}
-
-static inline bool io_run_task_work(void)
-{
- /*
- * Not safe to run on exiting task, and the task_work handling will
- * not add work to such a task.
- */
- if (unlikely(current->flags & PF_EXITING))
- return false;
- if (current->task_works) {
- __set_current_state(TASK_RUNNING);
- task_work_run();
- return true;
- }
-
- return false;
-}
-
-static void io_iopoll_queue(struct list_head *again)
-{
- struct io_kiocb *req;
-
- do {
- req = list_first_entry(again, struct io_kiocb, iopoll_entry);
- list_del(&req->iopoll_entry);
- __io_complete_rw(req, -EAGAIN, 0, NULL);
- } while (!list_empty(again));
-}
-
-/*
- * Find and free completed poll iocbs
- */
-static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
- struct list_head *done)
-{
- struct req_batch rb;
- struct io_kiocb *req;
- LIST_HEAD(again);
-
- /* order with ->result store in io_complete_rw_iopoll() */
- smp_rmb();
-
- io_init_req_batch(&rb);
- while (!list_empty(done)) {
- int cflags = 0;
-
- req = list_first_entry(done, struct io_kiocb, iopoll_entry);
- if (READ_ONCE(req->result) == -EAGAIN) {
- req->result = 0;
- req->iopoll_completed = 0;
- list_move_tail(&req->iopoll_entry, &again);
- continue;
- }
- list_del(&req->iopoll_entry);
-
- if (req->flags & REQ_F_BUFFER_SELECTED)
- cflags = io_put_rw_kbuf(req);
-
- __io_cqring_fill_event(req, req->result, cflags);
- (*nr_events)++;
-
- if (refcount_dec_and_test(&req->refs))
- io_req_free_batch(&rb, req);
- }
-
- io_commit_cqring(ctx);
- if (ctx->flags & IORING_SETUP_SQPOLL)
- io_cqring_ev_posted(ctx);
- io_req_free_batch_finish(ctx, &rb);
-
- if (!list_empty(&again))
- io_iopoll_queue(&again);
-}
-
-static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
- long min)
-{
- struct io_kiocb *req, *tmp;
- LIST_HEAD(done);
- bool spin;
- int ret;
-
- /*
- * Only spin for completions if we don't have multiple devices hanging
- * off our complete list, and we're under the requested amount.
- */
- spin = !ctx->poll_multi_file && *nr_events < min;
-
- ret = 0;
- list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, iopoll_entry) {
- struct kiocb *kiocb = &req->rw.kiocb;
-
- /*
- * Move completed and retryable entries to our local lists.
- * If we find a request that requires polling, break out
- * and complete those lists first, if we have entries there.
- */
- if (READ_ONCE(req->iopoll_completed)) {
- list_move_tail(&req->iopoll_entry, &done);
- continue;
- }
- if (!list_empty(&done))
- break;
-
- ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
- if (ret < 0)
- break;
-
- /* iopoll may have completed current req */
- if (READ_ONCE(req->iopoll_completed))
- list_move_tail(&req->iopoll_entry, &done);
-
- if (ret && spin)
- spin = false;
- ret = 0;
- }
-
- if (!list_empty(&done))
- io_iopoll_complete(ctx, nr_events, &done);
-
- return ret;
-}
-
-/*
- * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a
- * non-spinning poll check - we'll still enter the driver poll loop, but only
- * as a non-spinning completion check.
- */
-static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events,
- long min)
-{
- while (!list_empty(&ctx->iopoll_list) && !need_resched()) {
- int ret;
-
- ret = io_do_iopoll(ctx, nr_events, min);
- if (ret < 0)
- return ret;
- if (*nr_events >= min)
- return 0;
- }
-
- return 1;
-}
-
-/*
- * We can't just wait for polled events to come to us, we have to actively
- * find and complete them.
- */
-static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
-{
- if (!(ctx->flags & IORING_SETUP_IOPOLL))
- return;
-
- mutex_lock(&ctx->uring_lock);
- while (!list_empty(&ctx->iopoll_list)) {
- unsigned int nr_events = 0;
-
- io_do_iopoll(ctx, &nr_events, 0);
-
- /* let it sleep and repeat later if can't complete a request */
- if (nr_events == 0)
- break;
- /*
- * Ensure we allow local-to-the-cpu processing to take place,
- * in this case we need to ensure that we reap all events.
- * Also let task_work, etc. to progress by releasing the mutex
- */
- if (need_resched()) {
- mutex_unlock(&ctx->uring_lock);
- cond_resched();
- mutex_lock(&ctx->uring_lock);
- }
- }
- mutex_unlock(&ctx->uring_lock);
-}
-
-static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
-{
- unsigned int nr_events = 0;
- int iters = 0, ret = 0;
-
- /*
- * We disallow the app entering submit/complete with polling, but we
- * still need to lock the ring to prevent racing with polled issue
- * that got punted to a workqueue.
- */
- mutex_lock(&ctx->uring_lock);
- do {
- /*
- * Don't enter poll loop if we already have events pending.
- * If we do, we can potentially be spinning for commands that
- * already triggered a CQE (eg in error).
- */
- if (test_bit(0, &ctx->cq_check_overflow))
- __io_cqring_overflow_flush(ctx, false, NULL, NULL);
- if (io_cqring_events(ctx))
- break;
-
- /*
- * If a submit got punted to a workqueue, we can have the
- * application entering polling for a command before it gets
- * issued. That app will hold the uring_lock for the duration
- * of the poll right here, so we need to take a breather every
- * now and then to ensure that the issue has a chance to add
- * the poll to the issued list. Otherwise we can spin here
- * forever, while the workqueue is stuck trying to acquire the
- * very same mutex.
- */
- if (!(++iters & 7)) {
- mutex_unlock(&ctx->uring_lock);
- io_run_task_work();
- mutex_lock(&ctx->uring_lock);
- }
-
- ret = io_iopoll_getevents(ctx, &nr_events, min);
- if (ret <= 0)
- break;
- ret = 0;
- } while (min && !nr_events && !need_resched());
-
- mutex_unlock(&ctx->uring_lock);
- return ret;
-}
-
-static void kiocb_end_write(struct io_kiocb *req)
-{
- /*
- * Tell lockdep we inherited freeze protection from submission
- * thread.
- */
- if (req->flags & REQ_F_ISREG) {
- struct inode *inode = file_inode(req->file);
-
- __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
- }
- file_end_write(req->file);
-}
-
-static void io_complete_rw_common(struct kiocb *kiocb, long res,
- struct io_comp_state *cs)
-{
- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
- int cflags = 0;
-
- if (kiocb->ki_flags & IOCB_WRITE)
- kiocb_end_write(req);
-
- if (res != req->result)
- req_set_fail_links(req);
- if (req->flags & REQ_F_BUFFER_SELECTED)
- cflags = io_put_rw_kbuf(req);
- __io_req_complete(req, res, cflags, cs);
-}
-
-#ifdef CONFIG_BLOCK
-static bool io_resubmit_prep(struct io_kiocb *req, int error)
-{
- req_set_fail_links(req);
- return false;
-}
-#endif
-
-static bool io_rw_reissue(struct io_kiocb *req, long res)
-{
-#ifdef CONFIG_BLOCK
- umode_t mode = file_inode(req->file)->i_mode;
- int ret;
-
- if (!S_ISBLK(mode) && !S_ISREG(mode))
- return false;
- if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker())
- return false;
- /*
- * If ref is dying, we might be running poll reap from the exit work.
- * Don't attempt to reissue from that path, just let it fail with
- * -EAGAIN.
- */
- if (percpu_ref_is_dying(&req->ctx->refs))
- return false;
-
- ret = io_sq_thread_acquire_mm(req->ctx, req);
-
- if (io_resubmit_prep(req, ret)) {
- refcount_inc(&req->refs);
- io_queue_async_work(req);
- return true;
- }
-
-#endif
- return false;
-}
-
-static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
- struct io_comp_state *cs)
-{
- if (!io_rw_reissue(req, res))
- io_complete_rw_common(&req->rw.kiocb, res, cs);
-}
-
-static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
-{
- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
-
- __io_complete_rw(req, res, res2, NULL);
-}
-
-static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
-{
- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
-
- if (kiocb->ki_flags & IOCB_WRITE)
- kiocb_end_write(req);
-
- if (res != -EAGAIN && res != req->result)
- req_set_fail_links(req);
-
- WRITE_ONCE(req->result, res);
- /* order with io_poll_complete() checking ->result */
- smp_wmb();
- WRITE_ONCE(req->iopoll_completed, 1);
-}
-
-/*
- * After the iocb has been issued, it's safe to be found on the poll list.
- * Adding the kiocb to the list AFTER submission ensures that we don't
- * find it from a io_iopoll_getevents() thread before the issuer is done
- * accessing the kiocb cookie.
- */
-static void io_iopoll_req_issued(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- /*
- * Track whether we have multiple files in our lists. This will impact
- * how we do polling eventually, not spinning if we're on potentially
- * different devices.
- */
- if (list_empty(&ctx->iopoll_list)) {
- ctx->poll_multi_file = false;
- } else if (!ctx->poll_multi_file) {
- struct io_kiocb *list_req;
-
- list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
- iopoll_entry);
- if (list_req->file != req->file)
- ctx->poll_multi_file = true;
- }
-
- /*
- * For fast devices, IO may have already completed. If it has, add
- * it to the front so we find it first.
- */
- if (READ_ONCE(req->iopoll_completed))
- list_add(&req->iopoll_entry, &ctx->iopoll_list);
- else
- list_add_tail(&req->iopoll_entry, &ctx->iopoll_list);
-
- if ((ctx->flags & IORING_SETUP_SQPOLL) &&
- wq_has_sleeper(&ctx->sq_data->wait))
- wake_up(&ctx->sq_data->wait);
-}
-
-static void __io_state_file_put(struct io_submit_state *state)
-{
- if (state->has_refs)
- fput_many(state->file, state->has_refs);
- state->file = NULL;
-}
-
-static inline void io_state_file_put(struct io_submit_state *state)
-{
- if (state->file)
- __io_state_file_put(state);
-}
-
-/*
- * Get as many references to a file as we have IOs left in this submission,
- * assuming most submissions are for one file, or at least that each file
- * has more than one submission.
- */
-static struct file *__io_file_get(struct io_submit_state *state, int fd)
-{
- if (!state)
- return fget(fd);
-
- if (state->file) {
- if (state->fd == fd) {
- state->has_refs--;
- return state->file;
- }
- __io_state_file_put(state);
- }
- state->file = fget_many(fd, state->ios_left);
- if (!state->file)
- return NULL;
-
- state->fd = fd;
- state->has_refs = state->ios_left - 1;
- return state->file;
-}
-
-static bool io_bdev_nowait(struct block_device *bdev)
-{
-#ifdef CONFIG_BLOCK
- return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
-#else
- return true;
-#endif
-}
-
-/*
- * If we tracked the file through the SCM inflight mechanism, we could support
- * any file. For now, just ensure that anything potentially problematic is done
- * inline.
- */
-static bool io_file_supports_async(struct file *file, int rw)
-{
- umode_t mode = file_inode(file)->i_mode;
-
- if (S_ISBLK(mode)) {
- if (io_bdev_nowait(file->f_inode->i_bdev))
- return true;
- return false;
- }
- if (S_ISSOCK(mode))
- return true;
- if (S_ISREG(mode)) {
- if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
- file->f_op != &io_uring_fops)
- return true;
- return false;
- }
-
- /* any ->read/write should understand O_NONBLOCK */
- if (file->f_flags & O_NONBLOCK)
- return true;
-
- if (!(file->f_mode & FMODE_NOWAIT))
- return false;
-
- if (rw == READ)
- return file->f_op->read_iter != NULL;
-
- return file->f_op->write_iter != NULL;
-}
-
-static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct kiocb *kiocb = &req->rw.kiocb;
- unsigned ioprio;
- int ret;
-
- if (S_ISREG(file_inode(req->file)->i_mode))
- req->flags |= REQ_F_ISREG;
-
- kiocb->ki_pos = READ_ONCE(sqe->off);
- if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
- req->flags |= REQ_F_CUR_POS;
- kiocb->ki_pos = req->file->f_pos;
- }
- kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
- kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
- ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
- if (unlikely(ret))
- return ret;
-
- ioprio = READ_ONCE(sqe->ioprio);
- if (ioprio) {
- ret = ioprio_check_cap(ioprio);
- if (ret)
- return ret;
-
- kiocb->ki_ioprio = ioprio;
- } else
- kiocb->ki_ioprio = get_current_ioprio();
-
- /* don't allow async punt if RWF_NOWAIT was requested */
- if (kiocb->ki_flags & IOCB_NOWAIT)
- req->flags |= REQ_F_NOWAIT;
-
- if (ctx->flags & IORING_SETUP_IOPOLL) {
- if (!(kiocb->ki_flags & IOCB_DIRECT) ||
- !kiocb->ki_filp->f_op->iopoll)
- return -EOPNOTSUPP;
-
- kiocb->ki_flags |= IOCB_HIPRI;
- kiocb->ki_complete = io_complete_rw_iopoll;
- req->iopoll_completed = 0;
- } else {
- if (kiocb->ki_flags & IOCB_HIPRI)
- return -EINVAL;
- kiocb->ki_complete = io_complete_rw;
- }
-
- req->rw.addr = READ_ONCE(sqe->addr);
- req->rw.len = READ_ONCE(sqe->len);
- req->buf_index = READ_ONCE(sqe->buf_index);
- return 0;
-}
-
-static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
-{
- switch (ret) {
- case -EIOCBQUEUED:
- break;
- case -ERESTARTSYS:
- case -ERESTARTNOINTR:
- case -ERESTARTNOHAND:
- case -ERESTART_RESTARTBLOCK:
- /*
- * We can't just restart the syscall, since previously
- * submitted sqes may already be in progress. Just fail this
- * IO with EINTR.
- */
- ret = -EINTR;
- fallthrough;
- default:
- kiocb->ki_complete(kiocb, ret, 0);
- }
-}
-
-static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
- struct io_comp_state *cs)
-{
- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
- struct io_async_rw *io = req->async_data;
-
- /* add previously done IO, if any */
- if (io && io->bytes_done > 0) {
- if (ret < 0)
- ret = io->bytes_done;
- else
- ret += io->bytes_done;
- }
-
- if (req->flags & REQ_F_CUR_POS)
- req->file->f_pos = kiocb->ki_pos;
- if (ret >= 0 && kiocb->ki_complete == io_complete_rw)
- __io_complete_rw(req, ret, 0, cs);
- else
- io_rw_done(kiocb, ret);
-}
-
-static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
- struct iov_iter *iter)
-{
- struct io_ring_ctx *ctx = req->ctx;
- size_t len = req->rw.len;
- struct io_mapped_ubuf *imu;
- u16 index, buf_index = req->buf_index;
- size_t offset;
- u64 buf_addr;
-
- if (unlikely(buf_index >= ctx->nr_user_bufs))
- return -EFAULT;
- index = array_index_nospec(buf_index, ctx->nr_user_bufs);
- imu = &ctx->user_bufs[index];
- buf_addr = req->rw.addr;
-
- /* overflow */
- if (buf_addr + len < buf_addr)
- return -EFAULT;
- /* not inside the mapped region */
- if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len)
- return -EFAULT;
-
- /*
- * May not be a start of buffer, set size appropriately
- * and advance us to the beginning.
- */
- offset = buf_addr - imu->ubuf;
- iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
-
- if (offset) {
- /*
- * Don't use iov_iter_advance() here, as it's really slow for
- * using the latter parts of a big fixed buffer - it iterates
- * over each segment manually. We can cheat a bit here, because
- * we know that:
- *
- * 1) it's a BVEC iter, we set it up
- * 2) all bvecs are PAGE_SIZE in size, except potentially the
- * first and last bvec
- *
- * So just find our index, and adjust the iterator afterwards.
- * If the offset is within the first bvec (or the whole first
- * bvec, just use iov_iter_advance(). This makes it easier
- * since we can just skip the first segment, which may not
- * be PAGE_SIZE aligned.
- */
- const struct bio_vec *bvec = imu->bvec;
-
- if (offset <= bvec->bv_len) {
- iov_iter_advance(iter, offset);
- } else {
- unsigned long seg_skip;
-
- /* skip first vec */
- offset -= bvec->bv_len;
- seg_skip = 1 + (offset >> PAGE_SHIFT);
-
- iter->bvec = bvec + seg_skip;
- iter->nr_segs -= seg_skip;
- iter->count -= bvec->bv_len + offset;
- iter->iov_offset = offset & ~PAGE_MASK;
- }
- }
-
- return len;
-}
-
-static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
-{
- if (needs_lock)
- mutex_unlock(&ctx->uring_lock);
-}
-
-static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
-{
- /*
- * "Normal" inline submissions always hold the uring_lock, since we
- * grab it from the system call. Same is true for the SQPOLL offload.
- * The only exception is when we've detached the request and issue it
- * from an async worker thread, grab the lock for that case.
- */
- if (needs_lock)
- mutex_lock(&ctx->uring_lock);
-}
-
-static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
- int bgid, struct io_buffer *kbuf,
- bool needs_lock)
-{
- struct io_buffer *head;
-
- if (req->flags & REQ_F_BUFFER_SELECTED)
- return kbuf;
-
- io_ring_submit_lock(req->ctx, needs_lock);
-
- lockdep_assert_held(&req->ctx->uring_lock);
-
- head = xa_load(&req->ctx->io_buffers, bgid);
- if (head) {
- if (!list_empty(&head->list)) {
- kbuf = list_last_entry(&head->list, struct io_buffer,
- list);
- list_del(&kbuf->list);
- } else {
- kbuf = head;
- xa_erase(&req->ctx->io_buffers, bgid);
- }
- if (*len > kbuf->len)
- *len = kbuf->len;
- } else {
- kbuf = ERR_PTR(-ENOBUFS);
- }
-
- io_ring_submit_unlock(req->ctx, needs_lock);
-
- return kbuf;
-}
-
-static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
- bool needs_lock)
-{
- struct io_buffer *kbuf;
- u16 bgid;
-
- kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
- bgid = req->buf_index;
- kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
- if (IS_ERR(kbuf))
- return kbuf;
- req->rw.addr = (u64) (unsigned long) kbuf;
- req->flags |= REQ_F_BUFFER_SELECTED;
- return u64_to_user_ptr(kbuf->addr);
-}
-
-#ifdef CONFIG_COMPAT
-static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
- bool needs_lock)
-{
- struct compat_iovec __user *uiov;
- compat_ssize_t clen;
- void __user *buf;
- ssize_t len;
-
- uiov = u64_to_user_ptr(req->rw.addr);
- if (!access_ok(uiov, sizeof(*uiov)))
- return -EFAULT;
- if (__get_user(clen, &uiov->iov_len))
- return -EFAULT;
- if (clen < 0)
- return -EINVAL;
-
- len = clen;
- buf = io_rw_buffer_select(req, &len, needs_lock);
- if (IS_ERR(buf))
- return PTR_ERR(buf);
- iov[0].iov_base = buf;
- iov[0].iov_len = (compat_size_t) len;
- return 0;
-}
-#endif
-
-static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
- bool needs_lock)
-{
- struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
- void __user *buf;
- ssize_t len;
-
- if (copy_from_user(iov, uiov, sizeof(*uiov)))
- return -EFAULT;
-
- len = iov[0].iov_len;
- if (len < 0)
- return -EINVAL;
- buf = io_rw_buffer_select(req, &len, needs_lock);
- if (IS_ERR(buf))
- return PTR_ERR(buf);
- iov[0].iov_base = buf;
- iov[0].iov_len = len;
- return 0;
-}
-
-static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
- bool needs_lock)
-{
- if (req->flags & REQ_F_BUFFER_SELECTED) {
- struct io_buffer *kbuf;
-
- kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
- iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
- iov[0].iov_len = kbuf->len;
- return 0;
- }
- if (req->rw.len != 1)
- return -EINVAL;
-
-#ifdef CONFIG_COMPAT
- if (req->ctx->compat)
- return io_compat_import(req, iov, needs_lock);
-#endif
-
- return __io_iov_buffer_select(req, iov, needs_lock);
-}
-
-static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,
- struct iovec **iovec, struct iov_iter *iter,
- bool needs_lock)
-{
- void __user *buf = u64_to_user_ptr(req->rw.addr);
- size_t sqe_len = req->rw.len;
- ssize_t ret;
- u8 opcode;
-
- opcode = req->opcode;
- if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
- *iovec = NULL;
- return io_import_fixed(req, rw, iter);
- }
-
- /* buffer index only valid with fixed read/write, or buffer select */
- if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
- return -EINVAL;
-
- if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
- if (req->flags & REQ_F_BUFFER_SELECT) {
- buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
- if (IS_ERR(buf))
- return PTR_ERR(buf);
- req->rw.len = sqe_len;
- }
-
- ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
- *iovec = NULL;
- return ret;
- }
-
- if (req->flags & REQ_F_BUFFER_SELECT) {
- ret = io_iov_buffer_select(req, *iovec, needs_lock);
- if (!ret) {
- ret = (*iovec)->iov_len;
- iov_iter_init(iter, rw, *iovec, 1, ret);
- }
- *iovec = NULL;
- return ret;
- }
-
- return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
- req->ctx->compat);
-}
-
-static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
- struct iovec **iovec, struct iov_iter *iter,
- bool needs_lock)
-{
- struct io_async_rw *iorw = req->async_data;
-
- if (!iorw)
- return __io_import_iovec(rw, req, iovec, iter, needs_lock);
- *iovec = NULL;
- return 0;
-}
-
-static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
-{
- return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
-}
-
-/*
- * For files that don't have ->read_iter() and ->write_iter(), handle them
- * by looping over ->read() or ->write() manually.
- */
-static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
-{
- struct kiocb *kiocb = &req->rw.kiocb;
- struct file *file = req->file;
- ssize_t ret = 0;
-
- /*
- * Don't support polled IO through this interface, and we can't
- * support non-blocking either. For the latter, this just causes
- * the kiocb to be handled from an async context.
- */
- if (kiocb->ki_flags & IOCB_HIPRI)
- return -EOPNOTSUPP;
- if (kiocb->ki_flags & IOCB_NOWAIT)
- return -EAGAIN;
-
- while (iov_iter_count(iter)) {
- struct iovec iovec;
- ssize_t nr;
-
- if (!iov_iter_is_bvec(iter)) {
- iovec = iov_iter_iovec(iter);
- } else {
- iovec.iov_base = u64_to_user_ptr(req->rw.addr);
- iovec.iov_len = req->rw.len;
- }
-
- if (rw == READ) {
- nr = file->f_op->read(file, iovec.iov_base,
- iovec.iov_len, io_kiocb_ppos(kiocb));
- } else {
- nr = file->f_op->write(file, iovec.iov_base,
- iovec.iov_len, io_kiocb_ppos(kiocb));
- }
-
- if (nr < 0) {
- if (!ret)
- ret = nr;
- break;
- }
- ret += nr;
- if (!iov_iter_is_bvec(iter)) {
- iov_iter_advance(iter, nr);
- } else {
- req->rw.addr += nr;
- req->rw.len -= nr;
- if (!req->rw.len)
- break;
- }
- if (nr != iovec.iov_len)
- break;
- }
-
- return ret;
-}
-
-static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
- const struct iovec *fast_iov, struct iov_iter *iter)
-{
- struct io_async_rw *rw = req->async_data;
-
- memcpy(&rw->iter, iter, sizeof(*iter));
- rw->free_iovec = iovec;
- rw->bytes_done = 0;
- /* can only be fixed buffers, no need to do anything */
- if (iov_iter_is_bvec(iter))
- return;
- if (!iovec) {
- unsigned iov_off = 0;
-
- rw->iter.iov = rw->fast_iov;
- if (iter->iov != fast_iov) {
- iov_off = iter->iov - fast_iov;
- rw->iter.iov += iov_off;
- }
- if (rw->fast_iov != fast_iov)
- memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
- sizeof(struct iovec) * iter->nr_segs);
- } else {
- req->flags |= REQ_F_NEED_CLEANUP;
- }
-}
-
-static inline int __io_alloc_async_data(struct io_kiocb *req)
-{
- WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
- req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL);
- return req->async_data == NULL;
-}
-
-static int io_alloc_async_data(struct io_kiocb *req)
-{
- if (!io_op_defs[req->opcode].needs_async_data)
- return 0;
-
- return __io_alloc_async_data(req);
-}
-
-static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
- const struct iovec *fast_iov,
- struct iov_iter *iter, bool force)
-{
- if (!force && !io_op_defs[req->opcode].needs_async_data)
- return 0;
- if (!req->async_data) {
- if (__io_alloc_async_data(req))
- return -ENOMEM;
-
- io_req_map_rw(req, iovec, fast_iov, iter);
- }
- return 0;
-}
-
-static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
-{
- struct io_async_rw *iorw = req->async_data;
- struct iovec *iov = iorw->fast_iov;
- ssize_t ret;
-
- ret = __io_import_iovec(rw, req, &iov, &iorw->iter, false);
- if (unlikely(ret < 0))
- return ret;
-
- iorw->bytes_done = 0;
- iorw->free_iovec = iov;
- if (iov)
- req->flags |= REQ_F_NEED_CLEANUP;
- return 0;
-}
-
-static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- ssize_t ret;
-
- ret = io_prep_rw(req, sqe);
- if (ret)
- return ret;
-
- if (unlikely(!(req->file->f_mode & FMODE_READ)))
- return -EBADF;
-
- /* either don't need iovec imported or already have it */
- if (!req->async_data)
- return 0;
- return io_rw_prep_async(req, READ);
-}
-
-/*
- * This is our waitqueue callback handler, registered through lock_page_async()
- * when we initially tried to do the IO with the iocb armed our waitqueue.
- * This gets called when the page is unlocked, and we generally expect that to
- * happen when the page IO is completed and the page is now uptodate. This will
- * queue a task_work based retry of the operation, attempting to copy the data
- * again. If the latter fails because the page was NOT uptodate, then we will
- * do a thread based blocking retry of the operation. That's the unexpected
- * slow path.
- */
-static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
- int sync, void *arg)
-{
- struct wait_page_queue *wpq;
- struct io_kiocb *req = wait->private;
- struct wait_page_key *key = arg;
- int ret;
-
- wpq = container_of(wait, struct wait_page_queue, wait);
-
- if (!wake_page_match(wpq, key))
- return 0;
-
- req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
- list_del_init(&wait->entry);
-
- init_task_work(&req->task_work, io_req_task_submit);
- percpu_ref_get(&req->ctx->refs);
-
- /* submit ref gets dropped, acquire a new one */
- refcount_inc(&req->refs);
- ret = io_req_task_work_add(req, true);
- if (unlikely(ret)) {
- struct task_struct *tsk;
-
- /* queue just for cancelation */
- init_task_work(&req->task_work, io_req_task_cancel);
- tsk = io_wq_get_task(req->ctx->io_wq);
- task_work_add(tsk, &req->task_work, TWA_NONE);
- wake_up_process(tsk);
- }
- return 1;
-}
-
-/*
- * This controls whether a given IO request should be armed for async page
- * based retry. If we return false here, the request is handed to the async
- * worker threads for retry. If we're doing buffered reads on a regular file,
- * we prepare a private wait_page_queue entry and retry the operation. This
- * will either succeed because the page is now uptodate and unlocked, or it
- * will register a callback when the page is unlocked at IO completion. Through
- * that callback, io_uring uses task_work to setup a retry of the operation.
- * That retry will attempt the buffered read again. The retry will generally
- * succeed, or in rare cases where it fails, we then fall back to using the
- * async worker threads for a blocking retry.
- */
-static bool io_rw_should_retry(struct io_kiocb *req)
-{
- struct io_async_rw *rw = req->async_data;
- struct wait_page_queue *wait = &rw->wpq;
- struct kiocb *kiocb = &req->rw.kiocb;
-
- /* never retry for NOWAIT, we just complete with -EAGAIN */
- if (req->flags & REQ_F_NOWAIT)
- return false;
-
- /* Only for buffered IO */
- if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
- return false;
-
- /*
- * just use poll if we can, and don't attempt if the fs doesn't
- * support callback based unlocks
- */
- if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
- return false;
-
- wait->wait.func = io_async_buf_func;
- wait->wait.private = req;
- wait->wait.flags = 0;
- INIT_LIST_HEAD(&wait->wait.entry);
- kiocb->ki_flags |= IOCB_WAITQ;
- kiocb->ki_flags &= ~IOCB_NOWAIT;
- kiocb->ki_waitq = wait;
- return true;
-}
-
-static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
-{
- if (req->file->f_op->read_iter)
- return call_read_iter(req->file, &req->rw.kiocb, iter);
- else if (req->file->f_op->read)
- return loop_rw_iter(READ, req, iter);
- else
- return -EINVAL;
-}
-
-static int io_read(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
- struct kiocb *kiocb = &req->rw.kiocb;
- struct iov_iter __iter, *iter = &__iter;
- struct iov_iter iter_cp;
- struct io_async_rw *rw = req->async_data;
- ssize_t io_size, ret, ret2;
- bool no_async;
-
- if (rw)
- iter = &rw->iter;
-
- ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
- if (ret < 0)
- return ret;
- iter_cp = *iter;
- io_size = iov_iter_count(iter);
- req->result = io_size;
- ret = 0;
-
- /* Ensure we clear previously set non-block flag */
- if (!force_nonblock)
- kiocb->ki_flags &= ~IOCB_NOWAIT;
- else
- kiocb->ki_flags |= IOCB_NOWAIT;
-
-
- /* If the file doesn't support async, just async punt */
- no_async = force_nonblock && !io_file_supports_async(req->file, READ);
- if (no_async)
- goto copy_iov;
-
- ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), io_size);
- if (unlikely(ret))
- goto out_free;
-
- ret = io_iter_do_read(req, iter);
-
- if (!ret) {
- goto done;
- } else if (ret == -EIOCBQUEUED) {
- ret = 0;
- goto out_free;
- } else if (ret == -EAGAIN) {
- /* IOPOLL retry should happen for io-wq threads */
- if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
- goto done;
- /* no retry on NONBLOCK marked file */
- if (req->file->f_flags & O_NONBLOCK)
- goto done;
- /* some cases will consume bytes even on error returns */
- *iter = iter_cp;
- ret = 0;
- goto copy_iov;
- } else if (ret < 0) {
- /* make sure -ERESTARTSYS -> -EINTR is done */
- goto done;
- }
-
- /* read it all, or we did blocking attempt. no retry. */
- if (!iov_iter_count(iter) || !force_nonblock ||
- (req->file->f_flags & O_NONBLOCK) || !(req->flags & REQ_F_ISREG))
- goto done;
-
- io_size -= ret;
-copy_iov:
- ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
- if (ret2) {
- ret = ret2;
- goto out_free;
- }
- if (no_async)
- return -EAGAIN;
- rw = req->async_data;
- /* it's copied and will be cleaned with ->io */
- iovec = NULL;
- /* now use our persistent iterator, if we aren't already */
- iter = &rw->iter;
-retry:
- rw->bytes_done += ret;
- /* if we can retry, do so with the callbacks armed */
- if (!io_rw_should_retry(req)) {
- kiocb->ki_flags &= ~IOCB_WAITQ;
- return -EAGAIN;
- }
-
- /*
- * Now retry read with the IOCB_WAITQ parts set in the iocb. If we
- * get -EIOCBQUEUED, then we'll get a notification when the desired
- * page gets unlocked. We can also get a partial read here, and if we
- * do, then just retry at the new offset.
- */
- ret = io_iter_do_read(req, iter);
- if (ret == -EIOCBQUEUED) {
- ret = 0;
- goto out_free;
- } else if (ret > 0 && ret < io_size) {
- /* we got some bytes, but not all. retry. */
- kiocb->ki_flags &= ~IOCB_WAITQ;
- goto retry;
- }
-done:
- kiocb_done(kiocb, ret, cs);
- ret = 0;
-out_free:
- /* it's reportedly faster than delegating the null check to kfree() */
- if (iovec)
- kfree(iovec);
- return ret;
-}
-
-static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- ssize_t ret;
-
- ret = io_prep_rw(req, sqe);
- if (ret)
- return ret;
-
- if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
- return -EBADF;
-
- /* either don't need iovec imported or already have it */
- if (!req->async_data)
- return 0;
- return io_rw_prep_async(req, WRITE);
-}
-
-static int io_write(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
- struct kiocb *kiocb = &req->rw.kiocb;
- struct iov_iter __iter, *iter = &__iter;
- struct iov_iter iter_cp;
- struct io_async_rw *rw = req->async_data;
- ssize_t ret, ret2, io_size;
-
- if (rw)
- iter = &rw->iter;
-
- ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
- if (ret < 0)
- return ret;
- iter_cp = *iter;
- io_size = iov_iter_count(iter);
- req->result = io_size;
-
- /* Ensure we clear previously set non-block flag */
- if (!force_nonblock)
- kiocb->ki_flags &= ~IOCB_NOWAIT;
- else
- kiocb->ki_flags |= IOCB_NOWAIT;
-
- /* If the file doesn't support async, just async punt */
- if (force_nonblock && !io_file_supports_async(req->file, WRITE))
- goto copy_iov;
-
- /* file path doesn't support NOWAIT for non-direct_IO */
- if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
- (req->flags & REQ_F_ISREG))
- goto copy_iov;
-
- ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), io_size);
- if (unlikely(ret))
- goto out_free;
-
- /*
- * Open-code file_start_write here to grab freeze protection,
- * which will be released by another thread in
- * io_complete_rw(). Fool lockdep by telling it the lock got
- * released so that it doesn't complain about the held lock when
- * we return to userspace.
- */
- if (req->flags & REQ_F_ISREG) {
- sb_start_write(file_inode(req->file)->i_sb);
- __sb_writers_release(file_inode(req->file)->i_sb,
- SB_FREEZE_WRITE);
- }
- kiocb->ki_flags |= IOCB_WRITE;
-
- if (req->file->f_op->write_iter)
- ret2 = call_write_iter(req->file, kiocb, iter);
- else if (req->file->f_op->write)
- ret2 = loop_rw_iter(WRITE, req, iter);
- else
- ret2 = -EINVAL;
-
- /*
- * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
- * retry them without IOCB_NOWAIT.
- */
- if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
- ret2 = -EAGAIN;
- /* no retry on NONBLOCK marked file */
- if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK))
- goto done;
- if (!force_nonblock || ret2 != -EAGAIN) {
- /* IOPOLL retry should happen for io-wq threads */
- if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
- goto copy_iov;
-done:
- kiocb_done(kiocb, ret2, cs);
- } else {
-copy_iov:
- /* some cases will consume bytes even on error returns */
- *iter = iter_cp;
- ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
- if (!ret)
- return -EAGAIN;
- }
-out_free:
- /* it's reportedly faster than delegating the null check to kfree() */
- if (iovec)
- kfree(iovec);
- return ret;
-}
-
-static int __io_splice_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- struct io_splice* sp = &req->splice;
- unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
-
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
-
- sp->file_in = NULL;
- sp->len = READ_ONCE(sqe->len);
- sp->flags = READ_ONCE(sqe->splice_flags);
-
- if (unlikely(sp->flags & ~valid_flags))
- return -EINVAL;
-
- sp->file_in = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in),
- (sp->flags & SPLICE_F_FD_IN_FIXED));
- if (!sp->file_in)
- return -EBADF;
- req->flags |= REQ_F_NEED_CLEANUP;
-
- if (!S_ISREG(file_inode(sp->file_in)->i_mode)) {
- /*
- * Splice operation will be punted aync, and here need to
- * modify io_wq_work.flags, so initialize io_wq_work firstly.
- */
- io_req_init_async(req);
- req->work.flags |= IO_WQ_WORK_UNBOUND;
- }
-
- return 0;
-}
-
-static int io_tee_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
- return -EINVAL;
- return __io_splice_prep(req, sqe);
-}
-
-static int io_tee(struct io_kiocb *req, bool force_nonblock)
-{
- struct io_splice *sp = &req->splice;
- struct file *in = sp->file_in;
- struct file *out = sp->file_out;
- unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
- long ret = 0;
-
- if (force_nonblock)
- return -EAGAIN;
- if (sp->len)
- ret = do_tee(in, out, sp->len, flags);
-
- io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
- req->flags &= ~REQ_F_NEED_CLEANUP;
-
- if (ret != sp->len)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_splice* sp = &req->splice;
-
- sp->off_in = READ_ONCE(sqe->splice_off_in);
- sp->off_out = READ_ONCE(sqe->off);
- return __io_splice_prep(req, sqe);
-}
-
-static int io_splice(struct io_kiocb *req, bool force_nonblock)
-{
- struct io_splice *sp = &req->splice;
- struct file *in = sp->file_in;
- struct file *out = sp->file_out;
- unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
- loff_t *poff_in, *poff_out;
- long ret = 0;
-
- if (force_nonblock)
- return -EAGAIN;
-
- poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
- poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
-
- if (sp->len)
- ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
-
- io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
- req->flags &= ~REQ_F_NEED_CLEANUP;
-
- if (ret != sp->len)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-/*
- * IORING_OP_NOP just posts a completion event, nothing else.
- */
-static int io_nop(struct io_kiocb *req, struct io_comp_state *cs)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
-
- __io_req_complete(req, 0, 0, cs);
- return 0;
-}
-
-static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- if (!req->file)
- return -EBADF;
-
- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
- sqe->splice_fd_in))
- return -EINVAL;
-
- req->sync.flags = READ_ONCE(sqe->fsync_flags);
- if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
- return -EINVAL;
-
- req->sync.off = READ_ONCE(sqe->off);
- req->sync.len = READ_ONCE(sqe->len);
- return 0;
-}
-
-static int io_fsync(struct io_kiocb *req, bool force_nonblock)
-{
- loff_t end = req->sync.off + req->sync.len;
- int ret;
-
- /* fsync always requires a blocking context */
- if (force_nonblock)
- return -EAGAIN;
-
- ret = vfs_fsync_range(req->file, req->sync.off,
- end > 0 ? end : LLONG_MAX,
- req->sync.flags & IORING_FSYNC_DATASYNC);
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-static int io_fallocate_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- if (sqe->ioprio || sqe->buf_index || sqe->rw_flags ||
- sqe->splice_fd_in)
- return -EINVAL;
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
-
- req->sync.off = READ_ONCE(sqe->off);
- req->sync.len = READ_ONCE(sqe->addr);
- req->sync.mode = READ_ONCE(sqe->len);
- return 0;
-}
-
-static int io_fallocate(struct io_kiocb *req, bool force_nonblock)
-{
- int ret;
-
- /* fallocate always requiring blocking context */
- if (force_nonblock)
- return -EAGAIN;
- ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
- req->sync.len);
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- const char __user *fname;
- int ret;
-
- if (unlikely(sqe->ioprio || sqe->buf_index || sqe->splice_fd_in))
- return -EINVAL;
- if (unlikely(req->flags & REQ_F_FIXED_FILE))
- return -EBADF;
-
- /* open.how should be already initialised */
- if (!(req->open.how.flags & O_PATH) && force_o_largefile())
- req->open.how.flags |= O_LARGEFILE;
-
- req->open.dfd = READ_ONCE(sqe->fd);
- fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
- req->open.filename = getname(fname);
- if (IS_ERR(req->open.filename)) {
- ret = PTR_ERR(req->open.filename);
- req->open.filename = NULL;
- return ret;
- }
- req->open.nofile = rlimit(RLIMIT_NOFILE);
- req->open.ignore_nonblock = false;
- req->flags |= REQ_F_NEED_CLEANUP;
- return 0;
-}
-
-static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- u64 flags, mode;
-
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
- return -EINVAL;
- mode = READ_ONCE(sqe->len);
- flags = READ_ONCE(sqe->open_flags);
- req->open.how = build_open_how(flags, mode);
- return __io_openat_prep(req, sqe);
-}
-
-static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct open_how __user *how;
- size_t len;
- int ret;
-
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
- return -EINVAL;
- how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
- len = READ_ONCE(sqe->len);
- if (len < OPEN_HOW_SIZE_VER0)
- return -EINVAL;
-
- ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
- len);
- if (ret)
- return ret;
-
- return __io_openat_prep(req, sqe);
-}
-
-static int io_openat2(struct io_kiocb *req, bool force_nonblock)
-{
- struct open_flags op;
- struct file *file;
- int ret;
-
- if (force_nonblock && !req->open.ignore_nonblock)
- return -EAGAIN;
-
- ret = build_open_flags(&req->open.how, &op);
- if (ret)
- goto err;
-
- ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
- if (ret < 0)
- goto err;
-
- file = do_filp_open(req->open.dfd, req->open.filename, &op);
- if (IS_ERR(file)) {
- put_unused_fd(ret);
- ret = PTR_ERR(file);
- /*
- * A work-around to ensure that /proc/self works that way
- * that it should - if we get -EOPNOTSUPP back, then assume
- * that proc_self_get_link() failed us because we're in async
- * context. We should be safe to retry this from the task
- * itself with force_nonblock == false set, as it should not
- * block on lookup. Would be nice to know this upfront and
- * avoid the async dance, but doesn't seem feasible.
- */
- if (ret == -EOPNOTSUPP && io_wq_current_is_worker()) {
- req->open.ignore_nonblock = true;
- refcount_inc(&req->refs);
- io_req_task_queue(req);
- return 0;
- }
- } else {
- fsnotify_open(file);
- fd_install(ret, file);
- }
-err:
- putname(req->open.filename);
- req->flags &= ~REQ_F_NEED_CLEANUP;
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-static int io_openat(struct io_kiocb *req, bool force_nonblock)
-{
- return io_openat2(req, force_nonblock);
-}
-
-static int io_remove_buffers_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- struct io_provide_buf *p = &req->pbuf;
- u64 tmp;
-
- if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off ||
- sqe->splice_fd_in)
- return -EINVAL;
-
- tmp = READ_ONCE(sqe->fd);
- if (!tmp || tmp > USHRT_MAX)
- return -EINVAL;
-
- memset(p, 0, sizeof(*p));
- p->nbufs = tmp;
- p->bgid = READ_ONCE(sqe->buf_group);
- return 0;
-}
-
-static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
- int bgid, unsigned nbufs)
-{
- unsigned i = 0;
-
- /* shouldn't happen */
- if (!nbufs)
- return 0;
-
- /* the head kbuf is the list itself */
- while (!list_empty(&buf->list)) {
- struct io_buffer *nxt;
-
- nxt = list_first_entry(&buf->list, struct io_buffer, list);
- list_del(&nxt->list);
- kfree(nxt);
- if (++i == nbufs)
- return i;
- }
- i++;
- kfree(buf);
- xa_erase(&ctx->io_buffers, bgid);
-
- return i;
-}
-
-static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_provide_buf *p = &req->pbuf;
- struct io_ring_ctx *ctx = req->ctx;
- struct io_buffer *head;
- int ret = 0;
-
- io_ring_submit_lock(ctx, !force_nonblock);
-
- lockdep_assert_held(&ctx->uring_lock);
-
- ret = -ENOENT;
- head = xa_load(&ctx->io_buffers, p->bgid);
- if (head)
- ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
- if (ret < 0)
- req_set_fail_links(req);
-
- /* need to hold the lock to complete IOPOLL requests */
- if (ctx->flags & IORING_SETUP_IOPOLL) {
- __io_req_complete(req, ret, 0, cs);
- io_ring_submit_unlock(ctx, !force_nonblock);
- } else {
- io_ring_submit_unlock(ctx, !force_nonblock);
- __io_req_complete(req, ret, 0, cs);
- }
- return 0;
-}
-
-static int io_provide_buffers_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- unsigned long size, tmp_check;
- struct io_provide_buf *p = &req->pbuf;
- u64 tmp;
-
- if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
- return -EINVAL;
-
- tmp = READ_ONCE(sqe->fd);
- if (!tmp || tmp > USHRT_MAX)
- return -E2BIG;
- p->nbufs = tmp;
- p->addr = READ_ONCE(sqe->addr);
- p->len = READ_ONCE(sqe->len);
-
- if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs,
- &size))
- return -EOVERFLOW;
- if (check_add_overflow((unsigned long)p->addr, size, &tmp_check))
- return -EOVERFLOW;
-
- size = (unsigned long)p->len * p->nbufs;
- if (!access_ok(u64_to_user_ptr(p->addr), size))
- return -EFAULT;
-
- p->bgid = READ_ONCE(sqe->buf_group);
- tmp = READ_ONCE(sqe->off);
- if (tmp > USHRT_MAX)
- return -E2BIG;
- p->bid = tmp;
- return 0;
-}
-
-static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
-{
- struct io_buffer *buf;
- u64 addr = pbuf->addr;
- int i, bid = pbuf->bid;
-
- for (i = 0; i < pbuf->nbufs; i++) {
- buf = kmalloc(sizeof(*buf), GFP_KERNEL_ACCOUNT);
- if (!buf)
- break;
-
- buf->addr = addr;
- buf->len = min_t(__u32, pbuf->len, MAX_RW_COUNT);
- buf->bid = bid;
- addr += pbuf->len;
- bid++;
- if (!*head) {
- INIT_LIST_HEAD(&buf->list);
- *head = buf;
- } else {
- list_add_tail(&buf->list, &(*head)->list);
- }
- cond_resched();
- }
-
- return i ? i : -ENOMEM;
-}
-
-static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_provide_buf *p = &req->pbuf;
- struct io_ring_ctx *ctx = req->ctx;
- struct io_buffer *head, *list;
- int ret = 0;
-
- io_ring_submit_lock(ctx, !force_nonblock);
-
- lockdep_assert_held(&ctx->uring_lock);
-
- list = head = xa_load(&ctx->io_buffers, p->bgid);
-
- ret = io_add_buffers(p, &head);
- if (ret >= 0 && !list) {
- ret = xa_insert(&ctx->io_buffers, p->bgid, head, GFP_KERNEL);
- if (ret < 0)
- __io_remove_buffers(ctx, head, p->bgid, -1U);
- }
- if (ret < 0)
- req_set_fail_links(req);
-
- /* need to hold the lock to complete IOPOLL requests */
- if (ctx->flags & IORING_SETUP_IOPOLL) {
- __io_req_complete(req, ret, 0, cs);
- io_ring_submit_unlock(ctx, !force_nonblock);
- } else {
- io_ring_submit_unlock(ctx, !force_nonblock);
- __io_req_complete(req, ret, 0, cs);
- }
- return 0;
-}
-
-static int io_epoll_ctl_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
-#if defined(CONFIG_EPOLL)
- if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
- return -EINVAL;
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
- return -EINVAL;
-
- req->epoll.epfd = READ_ONCE(sqe->fd);
- req->epoll.op = READ_ONCE(sqe->len);
- req->epoll.fd = READ_ONCE(sqe->off);
-
- if (ep_op_has_event(req->epoll.op)) {
- struct epoll_event __user *ev;
-
- ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
- if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
- return -EFAULT;
- }
-
- return 0;
-#else
- return -EOPNOTSUPP;
-#endif
-}
-
-static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
-#if defined(CONFIG_EPOLL)
- struct io_epoll *ie = &req->epoll;
- int ret;
-
- ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
- if (force_nonblock && ret == -EAGAIN)
- return -EAGAIN;
-
- if (ret < 0)
- req_set_fail_links(req);
- __io_req_complete(req, ret, 0, cs);
- return 0;
-#else
- return -EOPNOTSUPP;
-#endif
-}
-
-static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
-#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
- if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->splice_fd_in)
- return -EINVAL;
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
-
- req->madvise.addr = READ_ONCE(sqe->addr);
- req->madvise.len = READ_ONCE(sqe->len);
- req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
- return 0;
-#else
- return -EOPNOTSUPP;
-#endif
-}
-
-static int io_madvise(struct io_kiocb *req, bool force_nonblock)
-{
-#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
- struct io_madvise *ma = &req->madvise;
- int ret;
-
- if (force_nonblock)
- return -EAGAIN;
-
- ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-#else
- return -EOPNOTSUPP;
-#endif
-}
-
-static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- if (sqe->ioprio || sqe->buf_index || sqe->addr || sqe->splice_fd_in)
- return -EINVAL;
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
-
- req->fadvise.offset = READ_ONCE(sqe->off);
- req->fadvise.len = READ_ONCE(sqe->len);
- req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
- return 0;
-}
-
-static int io_fadvise(struct io_kiocb *req, bool force_nonblock)
-{
- struct io_fadvise *fa = &req->fadvise;
- int ret;
-
- if (force_nonblock) {
- switch (fa->advice) {
- case POSIX_FADV_NORMAL:
- case POSIX_FADV_RANDOM:
- case POSIX_FADV_SEQUENTIAL:
- break;
- default:
- return -EAGAIN;
- }
- }
-
- ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
- return -EINVAL;
- if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
- return -EINVAL;
- if (req->flags & REQ_F_FIXED_FILE)
- return -EBADF;
-
- req->statx.dfd = READ_ONCE(sqe->fd);
- req->statx.mask = READ_ONCE(sqe->len);
- req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
- req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
- req->statx.flags = READ_ONCE(sqe->statx_flags);
-
- return 0;
-}
-
-static int io_statx(struct io_kiocb *req, bool force_nonblock)
-{
- struct io_statx *ctx = &req->statx;
- int ret;
-
- if (force_nonblock)
- return -EAGAIN;
-
- ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
- ctx->buffer);
-
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- /*
- * If we queue this for async, it must not be cancellable. That would
- * leave the 'file' in an undeterminate state, and here need to modify
- * io_wq_work.flags, so initialize io_wq_work firstly.
- */
- io_req_init_async(req);
-
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
- return -EINVAL;
- if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
- sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
- return -EINVAL;
- if (req->flags & REQ_F_FIXED_FILE)
- return -EBADF;
-
- req->close.fd = READ_ONCE(sqe->fd);
- if ((req->file && req->file->f_op == &io_uring_fops))
- return -EBADF;
-
- req->close.put_file = NULL;
- return 0;
-}
-
-static int io_close(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_close *close = &req->close;
- int ret;
-
- /* might be already done during nonblock submission */
- if (!close->put_file) {
- ret = close_fd_get_file(close->fd, &close->put_file);
- if (ret < 0)
- return (ret == -ENOENT) ? -EBADF : ret;
- }
-
- /* if the file has a flush method, be safe and punt to async */
- if (close->put_file->f_op->flush && force_nonblock) {
- /* not safe to cancel at this point */
- req->work.flags |= IO_WQ_WORK_NO_CANCEL;
- /* was never set, but play safe */
- req->flags &= ~REQ_F_NOWAIT;
- /* avoid grabbing files - we don't need the files */
- req->flags |= REQ_F_NO_FILE_TABLE;
- return -EAGAIN;
- }
-
- /* No ->flush() or already async, safely close from here */
- ret = filp_close(close->put_file, req->work.identity->files);
- if (ret < 0)
- req_set_fail_links(req);
- fput(close->put_file);
- close->put_file = NULL;
- __io_req_complete(req, ret, 0, cs);
- return 0;
-}
-
-static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- if (!req->file)
- return -EBADF;
-
- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
- sqe->splice_fd_in))
- return -EINVAL;
-
- req->sync.off = READ_ONCE(sqe->off);
- req->sync.len = READ_ONCE(sqe->len);
- req->sync.flags = READ_ONCE(sqe->sync_range_flags);
- return 0;
-}
-
-static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
-{
- int ret;
-
- /* sync_file_range always requires a blocking context */
- if (force_nonblock)
- return -EAGAIN;
-
- ret = sync_file_range(req->file, req->sync.off, req->sync.len,
- req->sync.flags);
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-#if defined(CONFIG_NET)
-static int io_setup_async_msg(struct io_kiocb *req,
- struct io_async_msghdr *kmsg)
-{
- struct io_async_msghdr *async_msg = req->async_data;
-
- if (async_msg)
- return -EAGAIN;
- if (io_alloc_async_data(req)) {
- if (kmsg->iov != kmsg->fast_iov)
- kfree(kmsg->iov);
- return -ENOMEM;
- }
- async_msg = req->async_data;
- req->flags |= REQ_F_NEED_CLEANUP;
- memcpy(async_msg, kmsg, sizeof(*kmsg));
- return -EAGAIN;
-}
-
-static int io_sendmsg_copy_hdr(struct io_kiocb *req,
- struct io_async_msghdr *iomsg)
-{
- iomsg->iov = iomsg->fast_iov;
- iomsg->msg.msg_name = &iomsg->addr;
- return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
- req->sr_msg.msg_flags, &iomsg->iov);
-}
-
-static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_async_msghdr *async_msg = req->async_data;
- struct io_sr_msg *sr = &req->sr_msg;
- int ret;
-
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (unlikely(sqe->addr2 || sqe->splice_fd_in || sqe->ioprio))
- return -EINVAL;
-
- sr->msg_flags = READ_ONCE(sqe->msg_flags);
- sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
- sr->len = READ_ONCE(sqe->len);
-
-#ifdef CONFIG_COMPAT
- if (req->ctx->compat)
- sr->msg_flags |= MSG_CMSG_COMPAT;
-#endif
-
- if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
- return 0;
- ret = io_sendmsg_copy_hdr(req, async_msg);
- if (!ret)
- req->flags |= REQ_F_NEED_CLEANUP;
- return ret;
-}
-
-static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_async_msghdr iomsg, *kmsg;
- struct socket *sock;
- unsigned flags;
- int min_ret = 0;
- int ret;
-
- sock = sock_from_file(req->file, &ret);
- if (unlikely(!sock))
- return ret;
-
- if (req->async_data) {
- kmsg = req->async_data;
- kmsg->msg.msg_name = &kmsg->addr;
- /* if iov is set, it's allocated already */
- if (!kmsg->iov)
- kmsg->iov = kmsg->fast_iov;
- kmsg->msg.msg_iter.iov = kmsg->iov;
- } else {
- ret = io_sendmsg_copy_hdr(req, &iomsg);
- if (ret)
- return ret;
- kmsg = &iomsg;
- }
-
- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
- if (flags & MSG_DONTWAIT)
- req->flags |= REQ_F_NOWAIT;
- else if (force_nonblock)
- flags |= MSG_DONTWAIT;
-
- if (flags & MSG_WAITALL)
- min_ret = iov_iter_count(&kmsg->msg.msg_iter);
-
- ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
- if (force_nonblock && ret == -EAGAIN)
- return io_setup_async_msg(req, kmsg);
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
-
- if (kmsg->iov != kmsg->fast_iov)
- kfree(kmsg->iov);
- req->flags &= ~REQ_F_NEED_CLEANUP;
- if (ret < min_ret)
- req_set_fail_links(req);
- __io_req_complete(req, ret, 0, cs);
- return 0;
-}
-
-static int io_send(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_sr_msg *sr = &req->sr_msg;
- struct msghdr msg;
- struct iovec iov;
- struct socket *sock;
- unsigned flags;
- int min_ret = 0;
- int ret;
-
- sock = sock_from_file(req->file, &ret);
- if (unlikely(!sock))
- return ret;
-
- ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
- if (unlikely(ret))
- return ret;
-
- msg.msg_name = NULL;
- msg.msg_control = NULL;
- msg.msg_controllen = 0;
- msg.msg_namelen = 0;
-
- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
- if (flags & MSG_DONTWAIT)
- req->flags |= REQ_F_NOWAIT;
- else if (force_nonblock)
- flags |= MSG_DONTWAIT;
-
- if (flags & MSG_WAITALL)
- min_ret = iov_iter_count(&msg.msg_iter);
-
- msg.msg_flags = flags;
- ret = sock_sendmsg(sock, &msg);
- if (force_nonblock && ret == -EAGAIN)
- return -EAGAIN;
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
-
- if (ret < min_ret)
- req_set_fail_links(req);
- __io_req_complete(req, ret, 0, cs);
- return 0;
-}
-
-static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
- struct io_async_msghdr *iomsg)
-{
- struct io_sr_msg *sr = &req->sr_msg;
- struct iovec __user *uiov;
- size_t iov_len;
- int ret;
-
- ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
- &iomsg->uaddr, &uiov, &iov_len);
- if (ret)
- return ret;
-
- if (req->flags & REQ_F_BUFFER_SELECT) {
- if (iov_len > 1)
- return -EINVAL;
- if (copy_from_user(iomsg->iov, uiov, sizeof(*uiov)))
- return -EFAULT;
- sr->len = iomsg->iov[0].iov_len;
- iov_iter_init(&iomsg->msg.msg_iter, READ, iomsg->iov, 1,
- sr->len);
- iomsg->iov = NULL;
- } else {
- ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
- &iomsg->iov, &iomsg->msg.msg_iter,
- false);
- if (ret > 0)
- ret = 0;
- }
-
- return ret;
-}
-
-#ifdef CONFIG_COMPAT
-static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
- struct io_async_msghdr *iomsg)
-{
- struct compat_msghdr __user *msg_compat;
- struct io_sr_msg *sr = &req->sr_msg;
- struct compat_iovec __user *uiov;
- compat_uptr_t ptr;
- compat_size_t len;
- int ret;
-
- msg_compat = (struct compat_msghdr __user *) sr->umsg;
- ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr,
- &ptr, &len);
- if (ret)
- return ret;
-
- uiov = compat_ptr(ptr);
- if (req->flags & REQ_F_BUFFER_SELECT) {
- compat_ssize_t clen;
-
- if (len > 1)
- return -EINVAL;
- if (!access_ok(uiov, sizeof(*uiov)))
- return -EFAULT;
- if (__get_user(clen, &uiov->iov_len))
- return -EFAULT;
- if (clen < 0)
- return -EINVAL;
- sr->len = clen;
- iomsg->iov[0].iov_len = clen;
- iomsg->iov = NULL;
- } else {
- ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
- UIO_FASTIOV, &iomsg->iov,
- &iomsg->msg.msg_iter, true);
- if (ret < 0)
- return ret;
- }
-
- return 0;
-}
-#endif
-
-static int io_recvmsg_copy_hdr(struct io_kiocb *req,
- struct io_async_msghdr *iomsg)
-{
- iomsg->msg.msg_name = &iomsg->addr;
- iomsg->iov = iomsg->fast_iov;
-
-#ifdef CONFIG_COMPAT
- if (req->ctx->compat)
- return __io_compat_recvmsg_copy_hdr(req, iomsg);
-#endif
-
- return __io_recvmsg_copy_hdr(req, iomsg);
-}
-
-static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
- bool needs_lock)
-{
- struct io_sr_msg *sr = &req->sr_msg;
- struct io_buffer *kbuf;
-
- kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
- if (IS_ERR(kbuf))
- return kbuf;
-
- sr->kbuf = kbuf;
- req->flags |= REQ_F_BUFFER_SELECTED;
- return kbuf;
-}
-
-static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
-{
- return io_put_kbuf(req, req->sr_msg.kbuf);
-}
-
-static int io_recvmsg_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- struct io_async_msghdr *async_msg = req->async_data;
- struct io_sr_msg *sr = &req->sr_msg;
- int ret;
-
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (unlikely(sqe->addr2 || sqe->splice_fd_in || sqe->ioprio))
- return -EINVAL;
-
- sr->msg_flags = READ_ONCE(sqe->msg_flags);
- sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
- sr->len = READ_ONCE(sqe->len);
- sr->bgid = READ_ONCE(sqe->buf_group);
-
-#ifdef CONFIG_COMPAT
- if (req->ctx->compat)
- sr->msg_flags |= MSG_CMSG_COMPAT;
-#endif
-
- if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
- return 0;
- ret = io_recvmsg_copy_hdr(req, async_msg);
- if (!ret)
- req->flags |= REQ_F_NEED_CLEANUP;
- return ret;
-}
-
-static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_async_msghdr iomsg, *kmsg;
- struct socket *sock;
- struct io_buffer *kbuf;
- unsigned flags;
- int min_ret = 0;
- int ret, cflags = 0;
-
- sock = sock_from_file(req->file, &ret);
- if (unlikely(!sock))
- return ret;
-
- if (req->async_data) {
- kmsg = req->async_data;
- kmsg->msg.msg_name = &kmsg->addr;
- /* if iov is set, it's allocated already */
- if (!kmsg->iov)
- kmsg->iov = kmsg->fast_iov;
- kmsg->msg.msg_iter.iov = kmsg->iov;
- } else {
- ret = io_recvmsg_copy_hdr(req, &iomsg);
- if (ret)
- return ret;
- kmsg = &iomsg;
- }
-
- if (req->flags & REQ_F_BUFFER_SELECT) {
- kbuf = io_recv_buffer_select(req, !force_nonblock);
- if (IS_ERR(kbuf))
- return PTR_ERR(kbuf);
- kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
- iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov,
- 1, req->sr_msg.len);
- }
-
- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
- if (flags & MSG_DONTWAIT)
- req->flags |= REQ_F_NOWAIT;
- else if (force_nonblock)
- flags |= MSG_DONTWAIT;
-
- if (flags & MSG_WAITALL)
- min_ret = iov_iter_count(&kmsg->msg.msg_iter);
-
- ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
- kmsg->uaddr, flags);
- if (force_nonblock && ret == -EAGAIN)
- return io_setup_async_msg(req, kmsg);
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
-
- if (req->flags & REQ_F_BUFFER_SELECTED)
- cflags = io_put_recv_kbuf(req);
- if (kmsg->iov != kmsg->fast_iov)
- kfree(kmsg->iov);
- req->flags &= ~REQ_F_NEED_CLEANUP;
- if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
- req_set_fail_links(req);
- __io_req_complete(req, ret, cflags, cs);
- return 0;
-}
-
-static int io_recv(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_buffer *kbuf;
- struct io_sr_msg *sr = &req->sr_msg;
- struct msghdr msg;
- void __user *buf = sr->buf;
- struct socket *sock;
- struct iovec iov;
- unsigned flags;
- int min_ret = 0;
- int ret, cflags = 0;
-
- sock = sock_from_file(req->file, &ret);
- if (unlikely(!sock))
- return ret;
-
- if (req->flags & REQ_F_BUFFER_SELECT) {
- kbuf = io_recv_buffer_select(req, !force_nonblock);
- if (IS_ERR(kbuf))
- return PTR_ERR(kbuf);
- buf = u64_to_user_ptr(kbuf->addr);
- }
-
- ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
- if (unlikely(ret))
- goto out_free;
-
- msg.msg_name = NULL;
- msg.msg_control = NULL;
- msg.msg_controllen = 0;
- msg.msg_namelen = 0;
- msg.msg_iocb = NULL;
- msg.msg_flags = 0;
-
- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
- if (flags & MSG_DONTWAIT)
- req->flags |= REQ_F_NOWAIT;
- else if (force_nonblock)
- flags |= MSG_DONTWAIT;
-
- if (flags & MSG_WAITALL)
- min_ret = iov_iter_count(&msg.msg_iter);
-
- ret = sock_recvmsg(sock, &msg, flags);
- if (force_nonblock && ret == -EAGAIN)
- return -EAGAIN;
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
-out_free:
- if (req->flags & REQ_F_BUFFER_SELECTED)
- cflags = io_put_recv_kbuf(req);
- if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
- req_set_fail_links(req);
- __io_req_complete(req, ret, cflags, cs);
- return 0;
-}
-
-static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_accept *accept = &req->accept;
-
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
- return -EINVAL;
- if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->splice_fd_in)
- return -EINVAL;
-
- accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
- accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
- accept->flags = READ_ONCE(sqe->accept_flags);
- accept->nofile = rlimit(RLIMIT_NOFILE);
- return 0;
-}
-
-static int io_accept(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_accept *accept = &req->accept;
- unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
- int ret;
-
- if (req->file->f_flags & O_NONBLOCK)
- req->flags |= REQ_F_NOWAIT;
-
- ret = __sys_accept4_file(req->file, file_flags, accept->addr,
- accept->addr_len, accept->flags,
- accept->nofile);
- if (ret == -EAGAIN && force_nonblock)
- return -EAGAIN;
- if (ret < 0) {
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
- req_set_fail_links(req);
- }
- __io_req_complete(req, ret, 0, cs);
- return 0;
-}
-
-static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_connect *conn = &req->connect;
- struct io_async_connect *io = req->async_data;
-
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
- return -EINVAL;
- if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags ||
- sqe->splice_fd_in)
- return -EINVAL;
-
- conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
- conn->addr_len = READ_ONCE(sqe->addr2);
-
- if (!io)
- return 0;
-
- return move_addr_to_kernel(conn->addr, conn->addr_len,
- &io->address);
-}
-
-static int io_connect(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_async_connect __io, *io;
- unsigned file_flags;
- int ret;
-
- if (req->async_data) {
- io = req->async_data;
- } else {
- ret = move_addr_to_kernel(req->connect.addr,
- req->connect.addr_len,
- &__io.address);
- if (ret)
- goto out;
- io = &__io;
- }
-
- file_flags = force_nonblock ? O_NONBLOCK : 0;
-
- ret = __sys_connect_file(req->file, &io->address,
- req->connect.addr_len, file_flags);
- if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
- if (req->async_data)
- return -EAGAIN;
- if (io_alloc_async_data(req)) {
- ret = -ENOMEM;
- goto out;
- }
- io = req->async_data;
- memcpy(req->async_data, &__io, sizeof(__io));
- return -EAGAIN;
- }
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
-out:
- if (ret < 0)
- req_set_fail_links(req);
- __io_req_complete(req, ret, 0, cs);
- return 0;
-}
-#else /* !CONFIG_NET */
-static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_send(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_recvmsg_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_recv(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_accept(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- return -EOPNOTSUPP;
-}
-
-static int io_connect(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- return -EOPNOTSUPP;
-}
-#endif /* CONFIG_NET */
-
-struct io_poll_table {
- struct poll_table_struct pt;
- struct io_kiocb *req;
- int nr_entries;
- int error;
-};
-
-static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
- __poll_t mask, task_work_func_t func)
-{
- bool twa_signal_ok;
- int ret;
-
- /* for instances that support it check for an event match first: */
- if (mask && !(mask & poll->events))
- return 0;
-
- trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
-
- list_del_init(&poll->wait.entry);
-
- req->result = mask;
- init_task_work(&req->task_work, func);
- percpu_ref_get(&req->ctx->refs);
-
- /*
- * If we using the signalfd wait_queue_head for this wakeup, then
- * it's not safe to use TWA_SIGNAL as we could be recursing on the
- * tsk->sighand->siglock on doing the wakeup. Should not be needed
- * either, as the normal wakeup will suffice.
- */
- twa_signal_ok = (poll->head != &req->task->sighand->signalfd_wqh);
-
- /*
- * If this fails, then the task is exiting. When a task exits, the
- * work gets canceled, so just cancel this request as well instead
- * of executing it. We can't safely execute it anyway, as we may not
- * have the needed state needed for it anyway.
- */
- ret = io_req_task_work_add(req, twa_signal_ok);
- if (unlikely(ret)) {
- struct task_struct *tsk;
-
- WRITE_ONCE(poll->canceled, true);
- tsk = io_wq_get_task(req->ctx->io_wq);
- task_work_add(tsk, &req->task_work, TWA_NONE);
- wake_up_process(tsk);
- }
- return 1;
-}
-
-static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
- __acquires(&req->ctx->completion_lock)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- if (!req->result && !READ_ONCE(poll->canceled)) {
- struct poll_table_struct pt = { ._key = poll->events };
-
- req->result = vfs_poll(req->file, &pt) & poll->events;
- }
-
- spin_lock_irq(&ctx->completion_lock);
- if (!req->result && !READ_ONCE(poll->canceled)) {
- add_wait_queue(poll->head, &poll->wait);
- return true;
- }
-
- return false;
-}
-
-static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
-{
- /* pure poll stashes this in ->async_data, poll driven retry elsewhere */
- if (req->opcode == IORING_OP_POLL_ADD)
- return req->async_data;
- return req->apoll->double_poll;
-}
-
-static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
-{
- if (req->opcode == IORING_OP_POLL_ADD)
- return &req->poll;
- return &req->apoll->poll;
-}
-
-static void io_poll_remove_double(struct io_kiocb *req)
-{
- struct io_poll_iocb *poll = io_poll_get_double(req);
-
- lockdep_assert_held(&req->ctx->completion_lock);
-
- if (poll && poll->head) {
- struct wait_queue_head *head = poll->head;
-
- spin_lock(&head->lock);
- list_del_init(&poll->wait.entry);
- if (poll->wait.private)
- refcount_dec(&req->refs);
- poll->head = NULL;
- spin_unlock(&head->lock);
- }
-}
-
-static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- io_poll_remove_double(req);
- req->poll.done = true;
- io_cqring_fill_event(req, error ? error : mangle_poll(mask));
- io_commit_cqring(ctx);
-}
-
-static void io_poll_task_func(struct callback_head *cb)
-{
- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
- struct io_ring_ctx *ctx = req->ctx;
- struct io_kiocb *nxt;
-
- if (io_poll_rewait(req, &req->poll)) {
- spin_unlock_irq(&ctx->completion_lock);
- } else {
- hash_del(&req->hash_node);
- io_poll_complete(req, req->result, 0);
- spin_unlock_irq(&ctx->completion_lock);
-
- nxt = io_put_req_find_next(req);
- io_cqring_ev_posted(ctx);
- if (nxt)
- __io_req_task_submit(nxt);
- }
-
- percpu_ref_put(&ctx->refs);
-}
-
-static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
- int sync, void *key)
-{
- struct io_kiocb *req = wait->private;
- struct io_poll_iocb *poll = io_poll_get_single(req);
- __poll_t mask = key_to_poll(key);
-
- /* for instances that support it check for an event match first: */
- if (mask && !(mask & poll->events))
- return 0;
-
- list_del_init(&wait->entry);
-
- if (poll && poll->head) {
- bool done;
-
- spin_lock(&poll->head->lock);
- done = list_empty(&poll->wait.entry);
- if (!done)
- list_del_init(&poll->wait.entry);
- /* make sure double remove sees this as being gone */
- wait->private = NULL;
- spin_unlock(&poll->head->lock);
- if (!done) {
- /* use wait func handler, so it matches the rq type */
- poll->wait.func(&poll->wait, mode, sync, key);
- }
- }
- refcount_dec(&req->refs);
- return 1;
-}
-
-static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
- wait_queue_func_t wake_func)
-{
- poll->head = NULL;
- poll->done = false;
- poll->canceled = false;
- poll->events = events;
- INIT_LIST_HEAD(&poll->wait.entry);
- init_waitqueue_func_entry(&poll->wait, wake_func);
-}
-
-static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
- struct wait_queue_head *head,
- struct io_poll_iocb **poll_ptr)
-{
- struct io_kiocb *req = pt->req;
-
- /*
- * The file being polled uses multiple waitqueues for poll handling
- * (e.g. one for read, one for write). Setup a separate io_poll_iocb
- * if this happens.
- */
- if (unlikely(pt->nr_entries)) {
- struct io_poll_iocb *poll_one = poll;
-
- /* already have a 2nd entry, fail a third attempt */
- if (*poll_ptr) {
- pt->error = -EINVAL;
- return;
- }
- /* double add on the same waitqueue head, ignore */
- if (poll->head == head)
- return;
- poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
- if (!poll) {
- pt->error = -ENOMEM;
- return;
- }
- io_init_poll_iocb(poll, poll_one->events, io_poll_double_wake);
- refcount_inc(&req->refs);
- poll->wait.private = req;
- *poll_ptr = poll;
- }
-
- pt->nr_entries++;
- poll->head = head;
-
- if (poll->events & EPOLLEXCLUSIVE)
- add_wait_queue_exclusive(head, &poll->wait);
- else
- add_wait_queue(head, &poll->wait);
-}
-
-static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
- struct poll_table_struct *p)
-{
- struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
- struct async_poll *apoll = pt->req->apoll;
-
- __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
-}
-
-static void io_async_task_func(struct callback_head *cb)
-{
- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
- struct async_poll *apoll = req->apoll;
- struct io_ring_ctx *ctx = req->ctx;
-
- trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
-
- if (io_poll_rewait(req, &apoll->poll)) {
- spin_unlock_irq(&ctx->completion_lock);
- percpu_ref_put(&ctx->refs);
- return;
- }
-
- /* If req is still hashed, it cannot have been canceled. Don't check. */
- if (hash_hashed(&req->hash_node))
- hash_del(&req->hash_node);
-
- io_poll_remove_double(req);
- spin_unlock_irq(&ctx->completion_lock);
-
- if (!READ_ONCE(apoll->poll.canceled))
- __io_req_task_submit(req);
- else
- __io_req_task_cancel(req, -ECANCELED);
-
- percpu_ref_put(&ctx->refs);
- kfree(apoll->double_poll);
- kfree(apoll);
-}
-
-static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
- void *key)
-{
- struct io_kiocb *req = wait->private;
- struct io_poll_iocb *poll = &req->apoll->poll;
-
- trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data,
- key_to_poll(key));
-
- return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func);
-}
-
-static void io_poll_req_insert(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct hlist_head *list;
-
- list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
- hlist_add_head(&req->hash_node, list);
-}
-
-static __poll_t __io_arm_poll_handler(struct io_kiocb *req,
- struct io_poll_iocb *poll,
- struct io_poll_table *ipt, __poll_t mask,
- wait_queue_func_t wake_func)
- __acquires(&ctx->completion_lock)
-{
- struct io_ring_ctx *ctx = req->ctx;
- bool cancel = false;
-
- if (req->file->f_op->may_pollfree) {
- spin_lock_irq(&ctx->completion_lock);
- return -EOPNOTSUPP;
- }
-
- INIT_HLIST_NODE(&req->hash_node);
- io_init_poll_iocb(poll, mask, wake_func);
- poll->file = req->file;
- poll->wait.private = req;
-
- ipt->pt._key = mask;
- ipt->req = req;
- ipt->error = 0;
- ipt->nr_entries = 0;
-
- mask = vfs_poll(req->file, &ipt->pt) & poll->events;
- if (unlikely(!ipt->nr_entries) && !ipt->error)
- ipt->error = -EINVAL;
-
- spin_lock_irq(&ctx->completion_lock);
- if (ipt->error)
- io_poll_remove_double(req);
- if (likely(poll->head)) {
- spin_lock(&poll->head->lock);
- if (unlikely(list_empty(&poll->wait.entry))) {
- if (ipt->error)
- cancel = true;
- ipt->error = 0;
- mask = 0;
- }
- if (mask || ipt->error)
- list_del_init(&poll->wait.entry);
- else if (cancel)
- WRITE_ONCE(poll->canceled, true);
- else if (!poll->done) /* actually waiting for an event */
- io_poll_req_insert(req);
- spin_unlock(&poll->head->lock);
- }
-
- return mask;
-}
-
-static bool io_arm_poll_handler(struct io_kiocb *req)
-{
- const struct io_op_def *def = &io_op_defs[req->opcode];
- struct io_ring_ctx *ctx = req->ctx;
- struct async_poll *apoll;
- struct io_poll_table ipt;
- __poll_t mask, ret;
- int rw;
-
- if (!req->file || !file_can_poll(req->file))
- return false;
- if (req->flags & REQ_F_POLLED)
- return false;
- if (def->pollin)
- rw = READ;
- else if (def->pollout)
- rw = WRITE;
- else
- return false;
- /* if we can't nonblock try, then no point in arming a poll handler */
- if (!io_file_supports_async(req->file, rw))
- return false;
-
- apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
- if (unlikely(!apoll))
- return false;
- apoll->double_poll = NULL;
-
- req->flags |= REQ_F_POLLED;
- req->apoll = apoll;
-
- mask = 0;
- if (def->pollin)
- mask |= POLLIN | POLLRDNORM;
- if (def->pollout)
- mask |= POLLOUT | POLLWRNORM;
-
- /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
- if ((req->opcode == IORING_OP_RECVMSG) &&
- (req->sr_msg.msg_flags & MSG_ERRQUEUE))
- mask &= ~POLLIN;
-
- mask |= POLLERR | POLLPRI;
-
- ipt.pt._qproc = io_async_queue_proc;
-
- ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask,
- io_async_wake);
- if (ret || ipt.error) {
- io_poll_remove_double(req);
- spin_unlock_irq(&ctx->completion_lock);
- kfree(apoll->double_poll);
- kfree(apoll);
- return false;
- }
- spin_unlock_irq(&ctx->completion_lock);
- trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask,
- apoll->poll.events);
- return true;
-}
-
-static bool __io_poll_remove_one(struct io_kiocb *req,
- struct io_poll_iocb *poll)
-{
- bool do_complete = false;
-
- spin_lock(&poll->head->lock);
- WRITE_ONCE(poll->canceled, true);
- if (!list_empty(&poll->wait.entry)) {
- list_del_init(&poll->wait.entry);
- do_complete = true;
- }
- spin_unlock(&poll->head->lock);
- hash_del(&req->hash_node);
- return do_complete;
-}
-
-static bool io_poll_remove_one(struct io_kiocb *req)
-{
- bool do_complete;
-
- io_poll_remove_double(req);
-
- if (req->opcode == IORING_OP_POLL_ADD) {
- do_complete = __io_poll_remove_one(req, &req->poll);
- } else {
- struct async_poll *apoll = req->apoll;
-
- /* non-poll requests have submit ref still */
- do_complete = __io_poll_remove_one(req, &apoll->poll);
- if (do_complete) {
- io_put_req(req);
- kfree(apoll->double_poll);
- kfree(apoll);
- }
- }
-
- if (do_complete) {
- io_cqring_fill_event(req, -ECANCELED);
- io_commit_cqring(req->ctx);
- req_set_fail_links(req);
- io_put_req_deferred(req, 1);
- }
-
- return do_complete;
-}
-
-/*
- * Returns true if we found and killed one or more poll requests
- */
-static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
- struct files_struct *files)
-{
- struct hlist_node *tmp;
- struct io_kiocb *req;
- int posted = 0, i;
-
- spin_lock_irq(&ctx->completion_lock);
- for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
- struct hlist_head *list;
-
- list = &ctx->cancel_hash[i];
- hlist_for_each_entry_safe(req, tmp, list, hash_node) {
- if (io_match_task(req, tsk, files))
- posted += io_poll_remove_one(req);
- }
- }
- spin_unlock_irq(&ctx->completion_lock);
-
- if (posted)
- io_cqring_ev_posted(ctx);
-
- return posted != 0;
-}
-
-static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
-{
- struct hlist_head *list;
- struct io_kiocb *req;
-
- list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
- hlist_for_each_entry(req, list, hash_node) {
- if (sqe_addr != req->user_data)
- continue;
- if (io_poll_remove_one(req))
- return 0;
- return -EALREADY;
- }
-
- return -ENOENT;
-}
-
-static int io_poll_remove_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
- sqe->poll_events)
- return -EINVAL;
-
- req->poll.addr = READ_ONCE(sqe->addr);
- return 0;
-}
-
-/*
- * Find a running poll command that matches one specified in sqe->addr,
- * and remove it if found.
- */
-static int io_poll_remove(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- u64 addr;
- int ret;
-
- addr = req->poll.addr;
- spin_lock_irq(&ctx->completion_lock);
- ret = io_poll_cancel(ctx, addr);
- spin_unlock_irq(&ctx->completion_lock);
-
- if (ret < 0)
- req_set_fail_links(req);
- io_req_complete(req, ret);
- return 0;
-}
-
-static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
- void *key)
-{
- struct io_kiocb *req = wait->private;
- struct io_poll_iocb *poll = &req->poll;
-
- return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func);
-}
-
-static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
- struct poll_table_struct *p)
-{
- struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
-
- __io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->async_data);
-}
-
-static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_poll_iocb *poll = &req->poll;
- u32 events;
-
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
- return -EINVAL;
-
- events = READ_ONCE(sqe->poll32_events);
-#ifdef __BIG_ENDIAN
- events = swahw32(events);
-#endif
- poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP |
- (events & EPOLLEXCLUSIVE);
- return 0;
-}
-
-static int io_poll_add(struct io_kiocb *req)
-{
- struct io_poll_iocb *poll = &req->poll;
- struct io_ring_ctx *ctx = req->ctx;
- struct io_poll_table ipt;
- __poll_t mask;
-
- ipt.pt._qproc = io_poll_queue_proc;
-
- mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events,
- io_poll_wake);
-
- if (mask) { /* no async, we'd stolen it */
- ipt.error = 0;
- io_poll_complete(req, mask, 0);
- }
- spin_unlock_irq(&ctx->completion_lock);
-
- if (mask) {
- io_cqring_ev_posted(ctx);
- io_put_req(req);
- }
- return ipt.error;
-}
-
-static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
-{
- struct io_timeout_data *data = container_of(timer,
- struct io_timeout_data, timer);
- struct io_kiocb *req = data->req;
- struct io_ring_ctx *ctx = req->ctx;
- unsigned long flags;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
- list_del_init(&req->timeout.list);
- atomic_set(&req->ctx->cq_timeouts,
- atomic_read(&req->ctx->cq_timeouts) + 1);
-
- io_cqring_fill_event(req, -ETIME);
- io_commit_cqring(ctx);
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-
- io_cqring_ev_posted(ctx);
- req_set_fail_links(req);
- io_put_req(req);
- return HRTIMER_NORESTART;
-}
-
-static int __io_timeout_cancel(struct io_kiocb *req)
-{
- struct io_timeout_data *io = req->async_data;
- int ret;
-
- ret = hrtimer_try_to_cancel(&io->timer);
- if (ret == -1)
- return -EALREADY;
- list_del_init(&req->timeout.list);
-
- req_set_fail_links(req);
- io_cqring_fill_event(req, -ECANCELED);
- io_put_req_deferred(req, 1);
- return 0;
-}
-
-static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
-{
- struct io_kiocb *req;
- int ret = -ENOENT;
-
- list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
- if (user_data == req->user_data) {
- ret = 0;
- break;
- }
- }
-
- if (ret == -ENOENT)
- return ret;
-
- return __io_timeout_cancel(req);
-}
-
-static int io_timeout_remove_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
- return -EINVAL;
- if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->timeout_flags ||
- sqe->splice_fd_in)
- return -EINVAL;
-
- req->timeout_rem.addr = READ_ONCE(sqe->addr);
- return 0;
-}
-
-/*
- * Remove or update an existing timeout command
- */
-static int io_timeout_remove(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- int ret;
-
- spin_lock_irq(&ctx->completion_lock);
- ret = io_timeout_cancel(ctx, req->timeout_rem.addr);
-
- io_cqring_fill_event(req, ret);
- io_commit_cqring(ctx);
- spin_unlock_irq(&ctx->completion_lock);
- io_cqring_ev_posted(ctx);
- if (ret < 0)
- req_set_fail_links(req);
- io_put_req(req);
- return 0;
-}
-
-static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
- bool is_timeout_link)
-{
- struct io_timeout_data *data;
- unsigned flags;
- u32 off = READ_ONCE(sqe->off);
-
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (sqe->ioprio || sqe->buf_index || sqe->len != 1 ||
- sqe->splice_fd_in)
- return -EINVAL;
- if (off && is_timeout_link)
- return -EINVAL;
- flags = READ_ONCE(sqe->timeout_flags);
- if (flags & ~IORING_TIMEOUT_ABS)
- return -EINVAL;
-
- req->timeout.off = off;
-
- if (!req->async_data && io_alloc_async_data(req))
- return -ENOMEM;
-
- data = req->async_data;
- data->req = req;
-
- if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
- return -EFAULT;
-
- if (flags & IORING_TIMEOUT_ABS)
- data->mode = HRTIMER_MODE_ABS;
- else
- data->mode = HRTIMER_MODE_REL;
-
- INIT_LIST_HEAD(&req->timeout.list);
- hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode);
- return 0;
-}
-
-static int io_timeout(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct io_timeout_data *data = req->async_data;
- struct list_head *entry;
- u32 tail, off = req->timeout.off;
-
- spin_lock_irq(&ctx->completion_lock);
-
- /*
- * sqe->off holds how many events that need to occur for this
- * timeout event to be satisfied. If it isn't set, then this is
- * a pure timeout request, sequence isn't used.
- */
- if (io_is_timeout_noseq(req)) {
- entry = ctx->timeout_list.prev;
- goto add;
- }
-
- tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
- req->timeout.target_seq = tail + off;
-
- /* Update the last seq here in case io_flush_timeouts() hasn't.
- * This is safe because ->completion_lock is held, and submissions
- * and completions are never mixed in the same ->completion_lock section.
- */
- ctx->cq_last_tm_flush = tail;
-
- /*
- * Insertion sort, ensuring the first entry in the list is always
- * the one we need first.
- */
- list_for_each_prev(entry, &ctx->timeout_list) {
- struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
- timeout.list);
-
- if (io_is_timeout_noseq(nxt))
- continue;
- /* nxt.seq is behind @tail, otherwise would've been completed */
- if (off >= nxt->timeout.target_seq - tail)
- break;
- }
-add:
- list_add(&req->timeout.list, entry);
- data->timer.function = io_timeout_fn;
- hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
- spin_unlock_irq(&ctx->completion_lock);
- return 0;
-}
-
-static bool io_cancel_cb(struct io_wq_work *work, void *data)
-{
- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-
- return req->user_data == (unsigned long) data;
-}
-
-static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
-{
- enum io_wq_cancel cancel_ret;
- int ret = 0;
-
- cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false);
- switch (cancel_ret) {
- case IO_WQ_CANCEL_OK:
- ret = 0;
- break;
- case IO_WQ_CANCEL_RUNNING:
- ret = -EALREADY;
- break;
- case IO_WQ_CANCEL_NOTFOUND:
- ret = -ENOENT;
- break;
- }
-
- return ret;
-}
-
-static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
- struct io_kiocb *req, __u64 sqe_addr,
- int success_ret)
-{
- unsigned long flags;
- int ret;
-
- ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr);
- if (ret != -ENOENT) {
- spin_lock_irqsave(&ctx->completion_lock, flags);
- goto done;
- }
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
- ret = io_timeout_cancel(ctx, sqe_addr);
- if (ret != -ENOENT)
- goto done;
- ret = io_poll_cancel(ctx, sqe_addr);
-done:
- if (!ret)
- ret = success_ret;
- io_cqring_fill_event(req, ret);
- io_commit_cqring(ctx);
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
- io_cqring_ev_posted(ctx);
-
- if (ret < 0)
- req_set_fail_links(req);
- io_put_req(req);
-}
-
-static int io_async_cancel_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
- return -EINVAL;
- if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags ||
- sqe->splice_fd_in)
- return -EINVAL;
-
- req->cancel.addr = READ_ONCE(sqe->addr);
- return 0;
-}
-
-static int io_async_cancel(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- io_async_find_and_cancel(ctx, req, req->cancel.addr, 0);
- return 0;
-}
-
-static int io_files_update_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL))
- return -EINVAL;
- if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
- return -EINVAL;
- if (sqe->ioprio || sqe->rw_flags)
- return -EINVAL;
-
- req->files_update.offset = READ_ONCE(sqe->off);
- req->files_update.nr_args = READ_ONCE(sqe->len);
- if (!req->files_update.nr_args)
- return -EINVAL;
- req->files_update.arg = READ_ONCE(sqe->addr);
- return 0;
-}
-
-static int io_files_update(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct io_uring_files_update up;
- int ret;
-
- if (force_nonblock)
- return -EAGAIN;
-
- up.offset = req->files_update.offset;
- up.fds = req->files_update.arg;
-
- mutex_lock(&ctx->uring_lock);
- ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
- mutex_unlock(&ctx->uring_lock);
-
- if (ret < 0)
- req_set_fail_links(req);
- __io_req_complete(req, ret, 0, cs);
- return 0;
-}
-
-static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- switch (req->opcode) {
- case IORING_OP_NOP:
- return 0;
- case IORING_OP_READV:
- case IORING_OP_READ_FIXED:
- case IORING_OP_READ:
- return io_read_prep(req, sqe);
- case IORING_OP_WRITEV:
- case IORING_OP_WRITE_FIXED:
- case IORING_OP_WRITE:
- return io_write_prep(req, sqe);
- case IORING_OP_POLL_ADD:
- return io_poll_add_prep(req, sqe);
- case IORING_OP_POLL_REMOVE:
- return io_poll_remove_prep(req, sqe);
- case IORING_OP_FSYNC:
- return io_prep_fsync(req, sqe);
- case IORING_OP_SYNC_FILE_RANGE:
- return io_prep_sfr(req, sqe);
- case IORING_OP_SENDMSG:
- case IORING_OP_SEND:
- return io_sendmsg_prep(req, sqe);
- case IORING_OP_RECVMSG:
- case IORING_OP_RECV:
- return io_recvmsg_prep(req, sqe);
- case IORING_OP_CONNECT:
- return io_connect_prep(req, sqe);
- case IORING_OP_TIMEOUT:
- return io_timeout_prep(req, sqe, false);
- case IORING_OP_TIMEOUT_REMOVE:
- return io_timeout_remove_prep(req, sqe);
- case IORING_OP_ASYNC_CANCEL:
- return io_async_cancel_prep(req, sqe);
- case IORING_OP_LINK_TIMEOUT:
- return io_timeout_prep(req, sqe, true);
- case IORING_OP_ACCEPT:
- return io_accept_prep(req, sqe);
- case IORING_OP_FALLOCATE:
- return io_fallocate_prep(req, sqe);
- case IORING_OP_OPENAT:
- return io_openat_prep(req, sqe);
- case IORING_OP_CLOSE:
- return io_close_prep(req, sqe);
- case IORING_OP_FILES_UPDATE:
- return io_files_update_prep(req, sqe);
- case IORING_OP_STATX:
- return io_statx_prep(req, sqe);
- case IORING_OP_FADVISE:
- return io_fadvise_prep(req, sqe);
- case IORING_OP_MADVISE:
- return io_madvise_prep(req, sqe);
- case IORING_OP_OPENAT2:
- return io_openat2_prep(req, sqe);
- case IORING_OP_EPOLL_CTL:
- return io_epoll_ctl_prep(req, sqe);
- case IORING_OP_SPLICE:
- return io_splice_prep(req, sqe);
- case IORING_OP_PROVIDE_BUFFERS:
- return io_provide_buffers_prep(req, sqe);
- case IORING_OP_REMOVE_BUFFERS:
- return io_remove_buffers_prep(req, sqe);
- case IORING_OP_TEE:
- return io_tee_prep(req, sqe);
- }
-
- printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
- req->opcode);
- return-EINVAL;
-}
-
-static int io_req_defer_prep(struct io_kiocb *req,
- const struct io_uring_sqe *sqe)
-{
- if (!sqe)
- return 0;
- if (io_alloc_async_data(req))
- return -EAGAIN;
- return io_req_prep(req, sqe);
-}
-
-static u32 io_get_sequence(struct io_kiocb *req)
-{
- struct io_kiocb *pos;
- struct io_ring_ctx *ctx = req->ctx;
- u32 total_submitted, nr_reqs = 1;
-
- if (req->flags & REQ_F_LINK_HEAD)
- list_for_each_entry(pos, &req->link_list, link_list)
- nr_reqs++;
-
- total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped;
- return total_submitted - nr_reqs;
-}
-
-static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct io_defer_entry *de;
- int ret;
- u32 seq;
-
- /* Still need defer if there is pending req in defer list. */
- if (likely(list_empty_careful(&ctx->defer_list) &&
- !(req->flags & REQ_F_IO_DRAIN)))
- return 0;
-
- seq = io_get_sequence(req);
- /* Still a chance to pass the sequence check */
- if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
- return 0;
-
- if (!req->async_data) {
- ret = io_req_defer_prep(req, sqe);
- if (ret)
- return ret;
- }
- io_prep_async_link(req);
- de = kmalloc(sizeof(*de), GFP_KERNEL);
- if (!de)
- return -ENOMEM;
-
- spin_lock_irq(&ctx->completion_lock);
- if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
- spin_unlock_irq(&ctx->completion_lock);
- kfree(de);
- io_queue_async_work(req);
- return -EIOCBQUEUED;
- }
-
- trace_io_uring_defer(ctx, req, req->user_data);
- de->req = req;
- de->seq = seq;
- list_add_tail(&de->list, &ctx->defer_list);
- spin_unlock_irq(&ctx->completion_lock);
- return -EIOCBQUEUED;
-}
-
-static void io_req_drop_files(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct io_uring_task *tctx = req->task->io_uring;
- unsigned long flags;
-
- if (req->work.flags & IO_WQ_WORK_FILES) {
- put_files_struct(req->work.identity->files);
- put_nsproxy(req->work.identity->nsproxy);
- }
- spin_lock_irqsave(&ctx->inflight_lock, flags);
- list_del(&req->inflight_entry);
- spin_unlock_irqrestore(&ctx->inflight_lock, flags);
- req->flags &= ~REQ_F_INFLIGHT;
- req->work.flags &= ~IO_WQ_WORK_FILES;
- if (atomic_read(&tctx->in_idle))
- wake_up(&tctx->wait);
-}
-
-static void __io_clean_op(struct io_kiocb *req)
-{
- if (req->flags & REQ_F_BUFFER_SELECTED) {
- switch (req->opcode) {
- case IORING_OP_READV:
- case IORING_OP_READ_FIXED:
- case IORING_OP_READ:
- kfree((void *)(unsigned long)req->rw.addr);
- break;
- case IORING_OP_RECVMSG:
- case IORING_OP_RECV:
- kfree(req->sr_msg.kbuf);
- break;
- }
- req->flags &= ~REQ_F_BUFFER_SELECTED;
- }
-
- if (req->flags & REQ_F_NEED_CLEANUP) {
- switch (req->opcode) {
- case IORING_OP_READV:
- case IORING_OP_READ_FIXED:
- case IORING_OP_READ:
- case IORING_OP_WRITEV:
- case IORING_OP_WRITE_FIXED:
- case IORING_OP_WRITE: {
- struct io_async_rw *io = req->async_data;
- if (io->free_iovec)
- kfree(io->free_iovec);
- break;
- }
- case IORING_OP_RECVMSG:
- case IORING_OP_SENDMSG: {
- struct io_async_msghdr *io = req->async_data;
- if (io->iov != io->fast_iov)
- kfree(io->iov);
- break;
- }
- case IORING_OP_SPLICE:
- case IORING_OP_TEE:
- io_put_file(req, req->splice.file_in,
- (req->splice.flags & SPLICE_F_FD_IN_FIXED));
- break;
- case IORING_OP_OPENAT:
- case IORING_OP_OPENAT2:
- if (req->open.filename)
- putname(req->open.filename);
- break;
- }
- req->flags &= ~REQ_F_NEED_CLEANUP;
- }
-}
-
-static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
- struct io_comp_state *cs)
-{
- struct io_ring_ctx *ctx = req->ctx;
- int ret;
-
- switch (req->opcode) {
- case IORING_OP_NOP:
- ret = io_nop(req, cs);
- break;
- case IORING_OP_READV:
- case IORING_OP_READ_FIXED:
- case IORING_OP_READ:
- ret = io_read(req, force_nonblock, cs);
- break;
- case IORING_OP_WRITEV:
- case IORING_OP_WRITE_FIXED:
- case IORING_OP_WRITE:
- ret = io_write(req, force_nonblock, cs);
- break;
- case IORING_OP_FSYNC:
- ret = io_fsync(req, force_nonblock);
- break;
- case IORING_OP_POLL_ADD:
- ret = io_poll_add(req);
- break;
- case IORING_OP_POLL_REMOVE:
- ret = io_poll_remove(req);
- break;
- case IORING_OP_SYNC_FILE_RANGE:
- ret = io_sync_file_range(req, force_nonblock);
- break;
- case IORING_OP_SENDMSG:
- ret = io_sendmsg(req, force_nonblock, cs);
- break;
- case IORING_OP_SEND:
- ret = io_send(req, force_nonblock, cs);
- break;
- case IORING_OP_RECVMSG:
- ret = io_recvmsg(req, force_nonblock, cs);
- break;
- case IORING_OP_RECV:
- ret = io_recv(req, force_nonblock, cs);
- break;
- case IORING_OP_TIMEOUT:
- ret = io_timeout(req);
- break;
- case IORING_OP_TIMEOUT_REMOVE:
- ret = io_timeout_remove(req);
- break;
- case IORING_OP_ACCEPT:
- ret = io_accept(req, force_nonblock, cs);
- break;
- case IORING_OP_CONNECT:
- ret = io_connect(req, force_nonblock, cs);
- break;
- case IORING_OP_ASYNC_CANCEL:
- ret = io_async_cancel(req);
- break;
- case IORING_OP_FALLOCATE:
- ret = io_fallocate(req, force_nonblock);
- break;
- case IORING_OP_OPENAT:
- ret = io_openat(req, force_nonblock);
- break;
- case IORING_OP_CLOSE:
- ret = io_close(req, force_nonblock, cs);
- break;
- case IORING_OP_FILES_UPDATE:
- ret = io_files_update(req, force_nonblock, cs);
- break;
- case IORING_OP_STATX:
- ret = io_statx(req, force_nonblock);
- break;
- case IORING_OP_FADVISE:
- ret = io_fadvise(req, force_nonblock);
- break;
- case IORING_OP_MADVISE:
- ret = io_madvise(req, force_nonblock);
- break;
- case IORING_OP_OPENAT2:
- ret = io_openat2(req, force_nonblock);
- break;
- case IORING_OP_EPOLL_CTL:
- ret = io_epoll_ctl(req, force_nonblock, cs);
- break;
- case IORING_OP_SPLICE:
- ret = io_splice(req, force_nonblock);
- break;
- case IORING_OP_PROVIDE_BUFFERS:
- ret = io_provide_buffers(req, force_nonblock, cs);
- break;
- case IORING_OP_REMOVE_BUFFERS:
- ret = io_remove_buffers(req, force_nonblock, cs);
- break;
- case IORING_OP_TEE:
- ret = io_tee(req, force_nonblock);
- break;
- default:
- ret = -EINVAL;
- break;
- }
-
- if (ret)
- return ret;
-
- /* If the op doesn't have a file, we're not polling for it */
- if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) {
- const bool in_async = io_wq_current_is_worker();
-
- /* workqueue context doesn't hold uring_lock, grab it now */
- if (in_async)
- mutex_lock(&ctx->uring_lock);
-
- io_iopoll_req_issued(req);
-
- if (in_async)
- mutex_unlock(&ctx->uring_lock);
- }
-
- return 0;
-}
-
-static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work)
-{
- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
- struct io_kiocb *timeout;
- int ret = 0;
-
- timeout = io_prep_linked_timeout(req);
- if (timeout)
- io_queue_linked_timeout(timeout);
-
- /* if NO_CANCEL is set, we must still run the work */
- if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
- IO_WQ_WORK_CANCEL) {
- ret = -ECANCELED;
- }
-
- if (!ret) {
- do {
- ret = io_issue_sqe(req, false, NULL);
- /*
- * We can get EAGAIN for polled IO even though we're
- * forcing a sync submission from here, since we can't
- * wait for request slots on the block side.
- */
- if (ret != -EAGAIN)
- break;
- cond_resched();
- } while (1);
- }
-
- if (ret) {
- struct io_ring_ctx *lock_ctx = NULL;
-
- if (req->ctx->flags & IORING_SETUP_IOPOLL)
- lock_ctx = req->ctx;
-
- /*
- * io_iopoll_complete() does not hold completion_lock to
- * complete polled io, so here for polled io, we can not call
- * io_req_complete() directly, otherwise there maybe concurrent
- * access to cqring, defer_list, etc, which is not safe. Given
- * that io_iopoll_complete() is always called under uring_lock,
- * so here for polled io, we also get uring_lock to complete
- * it.
- */
- if (lock_ctx)
- mutex_lock(&lock_ctx->uring_lock);
-
- req_set_fail_links(req);
- io_req_complete(req, ret);
-
- if (lock_ctx)
- mutex_unlock(&lock_ctx->uring_lock);
- }
-
- return io_steal_work(req);
-}
-
-static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
- int index)
-{
- struct fixed_file_table *table;
-
- table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
- return table->files[index & IORING_FILE_TABLE_MASK];
-}
-
-static struct file *io_file_get(struct io_submit_state *state,
- struct io_kiocb *req, int fd, bool fixed)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct file *file;
-
- if (fixed) {
- if (unlikely((unsigned int)fd >= ctx->nr_user_files))
- return NULL;
- fd = array_index_nospec(fd, ctx->nr_user_files);
- file = io_file_from_index(ctx, fd);
- if (file) {
- req->fixed_file_refs = &ctx->file_data->node->refs;
- percpu_ref_get(req->fixed_file_refs);
- }
- } else {
- trace_io_uring_file_get(ctx, fd);
- file = __io_file_get(state, fd);
- }
-
- if (file && file->f_op == &io_uring_fops &&
- !(req->flags & REQ_F_INFLIGHT)) {
- io_req_init_async(req);
- req->flags |= REQ_F_INFLIGHT;
-
- spin_lock_irq(&ctx->inflight_lock);
- list_add(&req->inflight_entry, &ctx->inflight_list);
- spin_unlock_irq(&ctx->inflight_lock);
- }
-
- return file;
-}
-
-static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
- int fd)
-{
- bool fixed;
-
- fixed = (req->flags & REQ_F_FIXED_FILE) != 0;
- if (unlikely(!fixed && io_async_submit(req->ctx)))
- return -EBADF;
-
- req->file = io_file_get(state, req, fd, fixed);
- if (req->file || io_op_defs[req->opcode].needs_file_no_error)
- return 0;
- return -EBADF;
-}
-
-static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
-{
- struct io_timeout_data *data = container_of(timer,
- struct io_timeout_data, timer);
- struct io_kiocb *req = data->req;
- struct io_ring_ctx *ctx = req->ctx;
- struct io_kiocb *prev = NULL;
- unsigned long flags;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
-
- /*
- * We don't expect the list to be empty, that will only happen if we
- * race with the completion of the linked work.
- */
- if (!list_empty(&req->link_list)) {
- prev = list_entry(req->link_list.prev, struct io_kiocb,
- link_list);
- list_del_init(&req->link_list);
- if (!refcount_inc_not_zero(&prev->refs))
- prev = NULL;
- }
-
- list_del(&req->timeout.list);
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-
- if (prev) {
- io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME);
- io_put_req_deferred(prev, 1);
- } else {
- io_cqring_add_event(req, -ETIME, 0);
- io_put_req_deferred(req, 1);
- }
- return HRTIMER_NORESTART;
-}
-
-static void __io_queue_linked_timeout(struct io_kiocb *req)
-{
- /*
- * If the list is now empty, then our linked request finished before
- * we got a chance to setup the timer
- */
- if (!list_empty(&req->link_list)) {
- struct io_timeout_data *data = req->async_data;
-
- data->timer.function = io_link_timeout_fn;
- hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
- data->mode);
- }
-}
-
-static void io_queue_linked_timeout(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- spin_lock_irq(&ctx->completion_lock);
- __io_queue_linked_timeout(req);
- spin_unlock_irq(&ctx->completion_lock);
-
- /* drop submission reference */
- io_put_req(req);
-}
-
-static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
-{
- struct io_kiocb *nxt;
-
- if (!(req->flags & REQ_F_LINK_HEAD))
- return NULL;
- if (req->flags & REQ_F_LINK_TIMEOUT)
- return NULL;
-
- nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
- link_list);
- if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT)
- return NULL;
-
- nxt->flags |= REQ_F_LTIMEOUT_ACTIVE;
- req->flags |= REQ_F_LINK_TIMEOUT;
- return nxt;
-}
-
-static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
-{
- struct io_kiocb *linked_timeout;
- const struct cred *old_creds = NULL;
- int ret;
-
-again:
- linked_timeout = io_prep_linked_timeout(req);
-
- if ((req->flags & REQ_F_WORK_INITIALIZED) &&
- (req->work.flags & IO_WQ_WORK_CREDS) &&
- req->work.identity->creds != current_cred()) {
- if (old_creds)
- revert_creds(old_creds);
- if (old_creds == req->work.identity->creds)
- old_creds = NULL; /* restored original creds */
- else
- old_creds = override_creds(req->work.identity->creds);
- }
-
- ret = io_issue_sqe(req, true, cs);
-
- /*
- * We async punt it if the file wasn't marked NOWAIT, or if the file
- * doesn't support non-blocking read/write attempts
- */
- if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
- if (!io_arm_poll_handler(req)) {
- /*
- * Queued up for async execution, worker will release
- * submit reference when the iocb is actually submitted.
- */
- io_queue_async_work(req);
- }
-
- if (linked_timeout)
- io_queue_linked_timeout(linked_timeout);
- } else if (likely(!ret)) {
- /* drop submission reference */
- req = io_put_req_find_next(req);
- if (linked_timeout)
- io_queue_linked_timeout(linked_timeout);
-
- if (req) {
- if (!(req->flags & REQ_F_FORCE_ASYNC))
- goto again;
- io_queue_async_work(req);
- }
- } else {
- /* un-prep timeout, so it'll be killed as any other linked */
- req->flags &= ~REQ_F_LINK_TIMEOUT;
- req_set_fail_links(req);
- io_put_req(req);
- io_req_complete(req, ret);
- }
-
- if (old_creds)
- revert_creds(old_creds);
-}
-
-static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
- struct io_comp_state *cs)
-{
- int ret;
-
- ret = io_req_defer(req, sqe);
- if (ret) {
- if (ret != -EIOCBQUEUED) {
-fail_req:
- req_set_fail_links(req);
- io_put_req(req);
- io_req_complete(req, ret);
- }
- } else if (req->flags & REQ_F_FORCE_ASYNC) {
- if (!req->async_data) {
- ret = io_req_defer_prep(req, sqe);
- if (unlikely(ret))
- goto fail_req;
- }
- io_queue_async_work(req);
- } else {
- if (sqe) {
- ret = io_req_prep(req, sqe);
- if (unlikely(ret))
- goto fail_req;
- }
- __io_queue_sqe(req, cs);
- }
-}
-
-static inline void io_queue_link_head(struct io_kiocb *req,
- struct io_comp_state *cs)
-{
- if (unlikely(req->flags & REQ_F_FAIL_LINK)) {
- io_put_req(req);
- io_req_complete(req, -ECANCELED);
- } else
- io_queue_sqe(req, NULL, cs);
-}
-
-static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
- struct io_kiocb **link, struct io_comp_state *cs)
-{
- struct io_ring_ctx *ctx = req->ctx;
- int ret;
-
- /*
- * If we already have a head request, queue this one for async
- * submittal once the head completes. If we don't have a head but
- * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
- * submitted sync once the chain is complete. If none of those
- * conditions are true (normal request), then just queue it.
- */
- if (*link) {
- struct io_kiocb *head = *link;
-
- /*
- * Taking sequential execution of a link, draining both sides
- * of the link also fullfils IOSQE_IO_DRAIN semantics for all
- * requests in the link. So, it drains the head and the
- * next after the link request. The last one is done via
- * drain_next flag to persist the effect across calls.
- */
- if (req->flags & REQ_F_IO_DRAIN) {
- head->flags |= REQ_F_IO_DRAIN;
- ctx->drain_next = 1;
- }
- ret = io_req_defer_prep(req, sqe);
- if (unlikely(ret)) {
- /* fail even hard links since we don't submit */
- head->flags |= REQ_F_FAIL_LINK;
- return ret;
- }
- trace_io_uring_link(ctx, req, head);
- list_add_tail(&req->link_list, &head->link_list);
-
- /* last request of a link, enqueue the link */
- if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
- io_queue_link_head(head, cs);
- *link = NULL;
- }
- } else {
- if (unlikely(ctx->drain_next)) {
- req->flags |= REQ_F_IO_DRAIN;
- ctx->drain_next = 0;
- }
- if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
- req->flags |= REQ_F_LINK_HEAD;
- INIT_LIST_HEAD(&req->link_list);
-
- ret = io_req_defer_prep(req, sqe);
- if (unlikely(ret))
- req->flags |= REQ_F_FAIL_LINK;
- *link = req;
- } else {
- io_queue_sqe(req, sqe, cs);
- }
- }
-
- return 0;
-}
-
-/*
- * Batched submission is done, ensure local IO is flushed out.
- */
-static void io_submit_state_end(struct io_submit_state *state)
-{
- if (!list_empty(&state->comp.list))
- io_submit_flush_completions(&state->comp);
- blk_finish_plug(&state->plug);
- io_state_file_put(state);
- if (state->free_reqs)
- kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
-}
-
-/*
- * Start submission side cache.
- */
-static void io_submit_state_start(struct io_submit_state *state,
- struct io_ring_ctx *ctx, unsigned int max_ios)
-{
- blk_start_plug(&state->plug);
- state->comp.nr = 0;
- INIT_LIST_HEAD(&state->comp.list);
- state->comp.ctx = ctx;
- state->free_reqs = 0;
- state->file = NULL;
- state->ios_left = max_ios;
-}
-
-static void io_commit_sqring(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
-
- /*
- * Ensure any loads from the SQEs are done at this point,
- * since once we write the new head, the application could
- * write new data to them.
- */
- smp_store_release(&rings->sq.head, ctx->cached_sq_head);
-}
-
-/*
- * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory
- * that is mapped by userspace. This means that care needs to be taken to
- * ensure that reads are stable, as we cannot rely on userspace always
- * being a good citizen. If members of the sqe are validated and then later
- * used, it's important that those reads are done through READ_ONCE() to
- * prevent a re-load down the line.
- */
-static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
-{
- u32 *sq_array = ctx->sq_array;
- unsigned head;
-
- /*
- * The cached sq head (or cq tail) serves two purposes:
- *
- * 1) allows us to batch the cost of updating the user visible
- * head updates.
- * 2) allows the kernel side to track the head on its own, even
- * though the application is the one updating it.
- */
- head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]);
- if (likely(head < ctx->sq_entries))
- return &ctx->sq_sqes[head];
-
- /* drop invalid entries */
- ctx->cached_sq_dropped++;
- WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);
- return NULL;
-}
-
-static inline void io_consume_sqe(struct io_ring_ctx *ctx)
-{
- ctx->cached_sq_head++;
-}
-
-/*
- * Check SQE restrictions (opcode and flags).
- *
- * Returns 'true' if SQE is allowed, 'false' otherwise.
- */
-static inline bool io_check_restriction(struct io_ring_ctx *ctx,
- struct io_kiocb *req,
- unsigned int sqe_flags)
-{
- if (!ctx->restricted)
- return true;
-
- if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
- return false;
-
- if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
- ctx->restrictions.sqe_flags_required)
- return false;
-
- if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
- ctx->restrictions.sqe_flags_required))
- return false;
-
- return true;
-}
-
-#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
- IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
- IOSQE_BUFFER_SELECT)
-
-static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
- const struct io_uring_sqe *sqe,
- struct io_submit_state *state)
-{
- unsigned int sqe_flags;
- int id, ret;
-
- req->opcode = READ_ONCE(sqe->opcode);
- req->user_data = READ_ONCE(sqe->user_data);
- req->async_data = NULL;
- req->file = NULL;
- req->ctx = ctx;
- req->flags = 0;
- /* one is dropped after submission, the other at completion */
- refcount_set(&req->refs, 2);
- req->task = current;
- req->result = 0;
-
- if (unlikely(req->opcode >= IORING_OP_LAST))
- return -EINVAL;
-
- if (unlikely(io_sq_thread_acquire_mm(ctx, req)))
- return -EFAULT;
-
- sqe_flags = READ_ONCE(sqe->flags);
- /* enforce forwards compatibility on users */
- if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
- return -EINVAL;
-
- if (unlikely(!io_check_restriction(ctx, req, sqe_flags)))
- return -EACCES;
-
- if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
- !io_op_defs[req->opcode].buffer_select)
- return -EOPNOTSUPP;
-
- id = READ_ONCE(sqe->personality);
- if (id) {
- struct io_identity *iod;
-
- iod = xa_load(&ctx->personalities, id);
- if (unlikely(!iod))
- return -EINVAL;
- refcount_inc(&iod->count);
-
- __io_req_init_async(req);
- get_cred(iod->creds);
- req->work.identity = iod;
- req->work.flags |= IO_WQ_WORK_CREDS;
- }
-
- /* same numerical values with corresponding REQ_F_*, safe to copy */
- req->flags |= sqe_flags;
-
- if (!io_op_defs[req->opcode].needs_file)
- return 0;
-
- ret = io_req_set_file(state, req, READ_ONCE(sqe->fd));
- state->ios_left--;
- return ret;
-}
-
-static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
-{
- struct io_submit_state state;
- struct io_kiocb *link = NULL;
- int i, submitted = 0;
-
- /* if we have a backlog and couldn't flush it all, return BUSY */
- if (test_bit(0, &ctx->sq_check_overflow)) {
- if (!__io_cqring_overflow_flush(ctx, false, NULL, NULL))
- return -EBUSY;
- }
-
- /* make sure SQ entry isn't read before tail */
- nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
-
- if (!percpu_ref_tryget_many(&ctx->refs, nr))
- return -EAGAIN;
-
- percpu_counter_add(¤t->io_uring->inflight, nr);
- refcount_add(nr, ¤t->usage);
-
- io_submit_state_start(&state, ctx, nr);
-
- for (i = 0; i < nr; i++) {
- const struct io_uring_sqe *sqe;
- struct io_kiocb *req;
- int err;
-
- sqe = io_get_sqe(ctx);
- if (unlikely(!sqe)) {
- io_consume_sqe(ctx);
- break;
- }
- req = io_alloc_req(ctx, &state);
- if (unlikely(!req)) {
- if (!submitted)
- submitted = -EAGAIN;
- break;
- }
- io_consume_sqe(ctx);
- /* will complete beyond this point, count as submitted */
- submitted++;
-
- err = io_init_req(ctx, req, sqe, &state);
- if (unlikely(err)) {
-fail_req:
- io_put_req(req);
- io_req_complete(req, err);
- break;
- }
-
- trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data,
- true, io_async_submit(ctx));
- err = io_submit_sqe(req, sqe, &link, &state.comp);
- if (err)
- goto fail_req;
- }
-
- if (unlikely(submitted != nr)) {
- int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
- struct io_uring_task *tctx = current->io_uring;
- int unused = nr - ref_used;
-
- percpu_ref_put_many(&ctx->refs, unused);
- percpu_counter_sub(&tctx->inflight, unused);
- put_task_struct_many(current, unused);
- }
- if (link)
- io_queue_link_head(link, &state.comp);
- io_submit_state_end(&state);
-
- /* Commit SQ ring head once we've consumed and submitted all SQEs */
- io_commit_sqring(ctx);
-
- return submitted;
-}
-
-static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
-{
- /* Tell userspace we may need a wakeup call */
- spin_lock_irq(&ctx->completion_lock);
- ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
- spin_unlock_irq(&ctx->completion_lock);
-}
-
-static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
-{
- spin_lock_irq(&ctx->completion_lock);
- ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
- spin_unlock_irq(&ctx->completion_lock);
-}
-
-static int io_sq_wake_function(struct wait_queue_entry *wqe, unsigned mode,
- int sync, void *key)
-{
- struct io_ring_ctx *ctx = container_of(wqe, struct io_ring_ctx, sqo_wait_entry);
- int ret;
-
- ret = autoremove_wake_function(wqe, mode, sync, key);
- if (ret) {
- unsigned long flags;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
- ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
- }
- return ret;
-}
-
-enum sq_ret {
- SQT_IDLE = 1,
- SQT_SPIN = 2,
- SQT_DID_WORK = 4,
-};
-
-static enum sq_ret __io_sq_thread(struct io_ring_ctx *ctx,
- unsigned long start_jiffies, bool cap_entries)
-{
- unsigned long timeout = start_jiffies + ctx->sq_thread_idle;
- struct io_sq_data *sqd = ctx->sq_data;
- unsigned int to_submit;
- int ret = 0;
-
-again:
- if (!list_empty(&ctx->iopoll_list)) {
- unsigned nr_events = 0;
-
- mutex_lock(&ctx->uring_lock);
- if (!list_empty(&ctx->iopoll_list) && !need_resched())
- io_do_iopoll(ctx, &nr_events, 0);
- mutex_unlock(&ctx->uring_lock);
- }
-
- to_submit = io_sqring_entries(ctx);
-
- /*
- * If submit got -EBUSY, flag us as needing the application
- * to enter the kernel to reap and flush events.
- */
- if (!to_submit || ret == -EBUSY || need_resched()) {
- /*
- * Drop cur_mm before scheduling, we can't hold it for
- * long periods (or over schedule()). Do this before
- * adding ourselves to the waitqueue, as the unuse/drop
- * may sleep.
- */
- io_sq_thread_drop_mm();
-
- /*
- * We're polling. If we're within the defined idle
- * period, then let us spin without work before going
- * to sleep. The exception is if we got EBUSY doing
- * more IO, we should wait for the application to
- * reap events and wake us up.
- */
- if (!list_empty(&ctx->iopoll_list) || need_resched() ||
- (!time_after(jiffies, timeout) && ret != -EBUSY &&
- !percpu_ref_is_dying(&ctx->refs)))
- return SQT_SPIN;
-
- prepare_to_wait(&sqd->wait, &ctx->sqo_wait_entry,
- TASK_INTERRUPTIBLE);
-
- /*
- * While doing polled IO, before going to sleep, we need
- * to check if there are new reqs added to iopoll_list,
- * it is because reqs may have been punted to io worker
- * and will be added to iopoll_list later, hence check
- * the iopoll_list again.
- */
- if ((ctx->flags & IORING_SETUP_IOPOLL) &&
- !list_empty_careful(&ctx->iopoll_list)) {
- finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
- goto again;
- }
-
- to_submit = io_sqring_entries(ctx);
- if (!to_submit || ret == -EBUSY)
- return SQT_IDLE;
- }
-
- finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
- io_ring_clear_wakeup_flag(ctx);
-
- /* if we're handling multiple rings, cap submit size for fairness */
- if (cap_entries && to_submit > 8)
- to_submit = 8;
-
- mutex_lock(&ctx->uring_lock);
- if (likely(!percpu_ref_is_dying(&ctx->refs) && !ctx->sqo_dead))
- ret = io_submit_sqes(ctx, to_submit);
- mutex_unlock(&ctx->uring_lock);
-
- if (!io_sqring_full(ctx) && wq_has_sleeper(&ctx->sqo_sq_wait))
- wake_up(&ctx->sqo_sq_wait);
-
- return SQT_DID_WORK;
-}
-
-static void io_sqd_init_new(struct io_sq_data *sqd)
-{
- struct io_ring_ctx *ctx;
-
- while (!list_empty(&sqd->ctx_new_list)) {
- ctx = list_first_entry(&sqd->ctx_new_list, struct io_ring_ctx, sqd_list);
- init_wait(&ctx->sqo_wait_entry);
- ctx->sqo_wait_entry.func = io_sq_wake_function;
- list_move_tail(&ctx->sqd_list, &sqd->ctx_list);
- complete(&ctx->sq_thread_comp);
- }
-}
-
-static int io_sq_thread(void *data)
-{
- struct cgroup_subsys_state *cur_css = NULL;
- const struct cred *old_cred = NULL;
- struct io_sq_data *sqd = data;
- struct io_ring_ctx *ctx;
- unsigned long start_jiffies;
-
- start_jiffies = jiffies;
- while (!kthread_should_stop()) {
- enum sq_ret ret = 0;
- bool cap_entries;
-
- /*
- * Any changes to the sqd lists are synchronized through the
- * kthread parking. This synchronizes the thread vs users,
- * the users are synchronized on the sqd->ctx_lock.
- */
- if (kthread_should_park()) {
- kthread_parkme();
- /*
- * When sq thread is unparked, in case the previous park operation
- * comes from io_put_sq_data(), which means that sq thread is going
- * to be stopped, so here needs to have a check.
- */
- if (kthread_should_stop())
- break;
- }
-
- if (unlikely(!list_empty(&sqd->ctx_new_list)))
- io_sqd_init_new(sqd);
-
- cap_entries = !list_is_singular(&sqd->ctx_list);
-
- list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
- if (current->cred != ctx->creds) {
- if (old_cred)
- revert_creds(old_cred);
- old_cred = override_creds(ctx->creds);
- }
- io_sq_thread_associate_blkcg(ctx, &cur_css);
-#ifdef CONFIG_AUDIT
- current->loginuid = ctx->loginuid;
- current->sessionid = ctx->sessionid;
-#endif
-
- ret |= __io_sq_thread(ctx, start_jiffies, cap_entries);
-
- io_sq_thread_drop_mm();
- }
-
- if (ret & SQT_SPIN) {
- io_run_task_work();
- io_sq_thread_drop_mm();
- cond_resched();
- } else if (ret == SQT_IDLE) {
- if (kthread_should_park())
- continue;
- list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
- io_ring_set_wakeup_flag(ctx);
- schedule();
- start_jiffies = jiffies;
- list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
- io_ring_clear_wakeup_flag(ctx);
- }
- }
-
- io_run_task_work();
- io_sq_thread_drop_mm();
-
- if (cur_css)
- io_sq_thread_unassociate_blkcg();
- if (old_cred)
- revert_creds(old_cred);
-
- kthread_parkme();
-
- return 0;
-}
-
-struct io_wait_queue {
- struct wait_queue_entry wq;
- struct io_ring_ctx *ctx;
- unsigned to_wait;
- unsigned nr_timeouts;
-};
-
-static inline bool io_should_wake(struct io_wait_queue *iowq)
-{
- struct io_ring_ctx *ctx = iowq->ctx;
-
- /*
- * Wake up if we have enough events, or if a timeout occurred since we
- * started waiting. For timeouts, we always want to return to userspace,
- * regardless of event count.
- */
- return io_cqring_events(ctx) >= iowq->to_wait ||
- atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
-}
-
-static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
- int wake_flags, void *key)
-{
- struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
- wq);
-
- /*
- * Cannot safely flush overflowed CQEs from here, ensure we wake up
- * the task, and the next invocation will do it.
- */
- if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->cq_check_overflow))
- return autoremove_wake_function(curr, mode, wake_flags, key);
- return -1;
-}
-
-static int io_run_task_work_sig(void)
-{
- if (io_run_task_work())
- return 1;
- if (!signal_pending(current))
- return 0;
- if (current->jobctl & JOBCTL_TASK_WORK) {
- spin_lock_irq(¤t->sighand->siglock);
- current->jobctl &= ~JOBCTL_TASK_WORK;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
- return 1;
- }
- return -EINTR;
-}
-
-/*
- * Wait until events become available, if we don't already have some. The
- * application must reap them itself, as they reside on the shared cq ring.
- */
-static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
- const sigset_t __user *sig, size_t sigsz)
-{
- struct io_wait_queue iowq = {
- .wq = {
- .private = current,
- .func = io_wake_function,
- .entry = LIST_HEAD_INIT(iowq.wq.entry),
- },
- .ctx = ctx,
- .to_wait = min_events,
- };
- struct io_rings *rings = ctx->rings;
- int ret = 0;
-
- do {
- io_cqring_overflow_flush(ctx, false, NULL, NULL);
- if (io_cqring_events(ctx) >= min_events)
- return 0;
- if (!io_run_task_work())
- break;
- } while (1);
-
- if (sig) {
-#ifdef CONFIG_COMPAT
- if (in_compat_syscall())
- ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
- sigsz);
- else
-#endif
- ret = set_user_sigmask(sig, sigsz);
-
- if (ret)
- return ret;
- }
-
- iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
- trace_io_uring_cqring_wait(ctx, min_events);
- do {
- io_cqring_overflow_flush(ctx, false, NULL, NULL);
- prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
- TASK_INTERRUPTIBLE);
- /* make sure we run task_work before checking for signals */
- ret = io_run_task_work_sig();
- if (ret > 0) {
- finish_wait(&ctx->wait, &iowq.wq);
- continue;
- }
- else if (ret < 0)
- break;
- if (io_should_wake(&iowq))
- break;
- if (test_bit(0, &ctx->cq_check_overflow)) {
- finish_wait(&ctx->wait, &iowq.wq);
- continue;
- }
- schedule();
- } while (1);
- finish_wait(&ctx->wait, &iowq.wq);
-
- restore_saved_sigmask_unless(ret == -EINTR);
-
- return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
-}
-
-static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
-{
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#else
- int i;
-
- for (i = 0; i < ctx->nr_user_files; i++) {
- struct file *file;
-
- file = io_file_from_index(ctx, i);
- if (file)
- fput(file);
- }
-#endif
-}
-
-static void io_file_ref_kill(struct percpu_ref *ref)
-{
- struct fixed_file_data *data;
-
- data = container_of(ref, struct fixed_file_data, refs);
- complete(&data->done);
-}
-
-static void io_sqe_files_set_node(struct fixed_file_data *file_data,
- struct fixed_file_ref_node *ref_node)
-{
- spin_lock_bh(&file_data->lock);
- file_data->node = ref_node;
- list_add_tail(&ref_node->node, &file_data->ref_list);
- spin_unlock_bh(&file_data->lock);
- percpu_ref_get(&file_data->refs);
-}
-
-
-static void io_sqe_files_kill_node(struct fixed_file_data *data)
-{
- struct fixed_file_ref_node *ref_node = NULL;
-
- spin_lock_bh(&data->lock);
- ref_node = data->node;
- spin_unlock_bh(&data->lock);
- if (ref_node)
- percpu_ref_kill(&ref_node->refs);
-}
-
-static int io_file_ref_quiesce(struct fixed_file_data *data,
- struct io_ring_ctx *ctx)
-{
- int ret;
- struct fixed_file_ref_node *backup_node;
-
- if (data->quiesce)
- return -ENXIO;
-
- data->quiesce = true;
- do {
- backup_node = alloc_fixed_file_ref_node(ctx);
- if (!backup_node)
- break;
-
- io_sqe_files_kill_node(data);
- percpu_ref_kill(&data->refs);
- flush_delayed_work(&ctx->file_put_work);
-
- ret = wait_for_completion_interruptible(&data->done);
- if (!ret)
- break;
-
- percpu_ref_resurrect(&data->refs);
- io_sqe_files_set_node(data, backup_node);
- backup_node = NULL;
- reinit_completion(&data->done);
- mutex_unlock(&ctx->uring_lock);
- ret = io_run_task_work_sig();
- mutex_lock(&ctx->uring_lock);
-
- if (ret < 0)
- break;
- backup_node = alloc_fixed_file_ref_node(ctx);
- ret = -ENOMEM;
- if (!backup_node)
- break;
- } while (1);
- data->quiesce = false;
-
- if (backup_node)
- destroy_fixed_file_ref_node(backup_node);
- return ret;
-}
-
-static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
-{
- struct fixed_file_data *data = ctx->file_data;
- unsigned nr_tables, i;
- int ret;
-
- /*
- * percpu_ref_is_dying() is to stop parallel files unregister
- * Since we possibly drop uring lock later in this function to
- * run task work.
- */
- if (!data || percpu_ref_is_dying(&data->refs))
- return -ENXIO;
- ret = io_file_ref_quiesce(data, ctx);
- if (ret)
- return ret;
-
- __io_sqe_files_unregister(ctx);
- nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
- for (i = 0; i < nr_tables; i++)
- kfree(data->table[i].files);
- kfree(data->table);
- percpu_ref_exit(&data->refs);
- kfree(data);
- ctx->file_data = NULL;
- ctx->nr_user_files = 0;
- return 0;
-}
-
-static void io_put_sq_data(struct io_sq_data *sqd)
-{
- if (refcount_dec_and_test(&sqd->refs)) {
- /*
- * The park is a bit of a work-around, without it we get
- * warning spews on shutdown with SQPOLL set and affinity
- * set to a single CPU.
- */
- if (sqd->thread) {
- kthread_park(sqd->thread);
- kthread_stop(sqd->thread);
- }
-
- kfree(sqd);
- }
-}
-
-static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p)
-{
- struct io_ring_ctx *ctx_attach;
- struct io_sq_data *sqd;
- struct fd f;
-
- f = fdget(p->wq_fd);
- if (!f.file)
- return ERR_PTR(-ENXIO);
- if (f.file->f_op != &io_uring_fops) {
- fdput(f);
- return ERR_PTR(-EINVAL);
- }
-
- ctx_attach = f.file->private_data;
- sqd = ctx_attach->sq_data;
- if (!sqd) {
- fdput(f);
- return ERR_PTR(-EINVAL);
- }
-
- refcount_inc(&sqd->refs);
- fdput(f);
- return sqd;
-}
-
-static struct io_sq_data *io_get_sq_data(struct io_uring_params *p)
-{
- struct io_sq_data *sqd;
-
- if (p->flags & IORING_SETUP_ATTACH_WQ)
- return io_attach_sq_data(p);
-
- sqd = kzalloc(sizeof(*sqd), GFP_KERNEL);
- if (!sqd)
- return ERR_PTR(-ENOMEM);
-
- refcount_set(&sqd->refs, 1);
- INIT_LIST_HEAD(&sqd->ctx_list);
- INIT_LIST_HEAD(&sqd->ctx_new_list);
- mutex_init(&sqd->ctx_lock);
- mutex_init(&sqd->lock);
- init_waitqueue_head(&sqd->wait);
- return sqd;
-}
-
-static void io_sq_thread_unpark(struct io_sq_data *sqd)
- __releases(&sqd->lock)
-{
- if (!sqd->thread)
- return;
- kthread_unpark(sqd->thread);
- mutex_unlock(&sqd->lock);
-}
-
-static void io_sq_thread_park(struct io_sq_data *sqd)
- __acquires(&sqd->lock)
-{
- if (!sqd->thread)
- return;
- mutex_lock(&sqd->lock);
- kthread_park(sqd->thread);
-}
-
-static void io_sq_thread_stop(struct io_ring_ctx *ctx)
-{
- struct io_sq_data *sqd = ctx->sq_data;
-
- if (sqd) {
- if (sqd->thread) {
- /*
- * We may arrive here from the error branch in
- * io_sq_offload_create() where the kthread is created
- * without being waked up, thus wake it up now to make
- * sure the wait will complete.
- */
- wake_up_process(sqd->thread);
- wait_for_completion(&ctx->sq_thread_comp);
-
- io_sq_thread_park(sqd);
- }
-
- mutex_lock(&sqd->ctx_lock);
- list_del(&ctx->sqd_list);
- mutex_unlock(&sqd->ctx_lock);
-
- if (sqd->thread) {
- finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
- io_sq_thread_unpark(sqd);
- }
-
- io_put_sq_data(sqd);
- ctx->sq_data = NULL;
- }
-}
-
-static void io_finish_async(struct io_ring_ctx *ctx)
-{
- io_sq_thread_stop(ctx);
-
- if (ctx->io_wq) {
- io_wq_destroy(ctx->io_wq);
- ctx->io_wq = NULL;
- }
-}
-
-#if defined(CONFIG_UNIX)
-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing.
- */
-static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
-{
- struct sock *sk = ctx->ring_sock->sk;
- struct scm_fp_list *fpl;
- struct sk_buff *skb;
- int i, nr_files;
-
- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
- if (!fpl)
- return -ENOMEM;
-
- skb = alloc_skb(0, GFP_KERNEL);
- if (!skb) {
- kfree(fpl);
- return -ENOMEM;
- }
-
- skb->sk = sk;
- skb->scm_io_uring = 1;
-
- nr_files = 0;
- fpl->user = get_uid(ctx->user);
- for (i = 0; i < nr; i++) {
- struct file *file = io_file_from_index(ctx, i + offset);
-
- if (!file)
- continue;
- fpl->fp[nr_files] = get_file(file);
- unix_inflight(fpl->user, fpl->fp[nr_files]);
- nr_files++;
- }
-
- if (nr_files) {
- fpl->max = SCM_MAX_FD;
- fpl->count = nr_files;
- UNIXCB(skb).fp = fpl;
- skb->destructor = unix_destruct_scm;
- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
- skb_queue_head(&sk->sk_receive_queue, skb);
-
- for (i = 0; i < nr; i++) {
- struct file *file = io_file_from_index(ctx, i + offset);
-
- if (file)
- fput(file);
- }
- } else {
- kfree_skb(skb);
- free_uid(fpl->user);
- kfree(fpl);
- }
-
- return 0;
-}
-
-/*
- * If UNIX sockets are enabled, fd passing can cause a reference cycle which
- * causes regular reference counting to break down. We rely on the UNIX
- * garbage collection to take care of this problem for us.
- */
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
- unsigned left, total;
- int ret = 0;
-
- total = 0;
- left = ctx->nr_user_files;
- while (left) {
- unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
-
- ret = __io_sqe_files_scm(ctx, this_files, total);
- if (ret)
- break;
- left -= this_files;
- total += this_files;
- }
-
- if (!ret)
- return 0;
-
- while (total < ctx->nr_user_files) {
- struct file *file = io_file_from_index(ctx, total);
-
- if (file)
- fput(file);
- total++;
- }
-
- return ret;
-}
-#else
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
- return 0;
-}
-#endif
-
-static int io_sqe_alloc_file_tables(struct fixed_file_data *file_data,
- unsigned nr_tables, unsigned nr_files)
-{
- int i;
-
- for (i = 0; i < nr_tables; i++) {
- struct fixed_file_table *table = &file_data->table[i];
- unsigned this_files;
-
- this_files = min(nr_files, IORING_MAX_FILES_TABLE);
- table->files = kcalloc(this_files, sizeof(struct file *),
- GFP_KERNEL_ACCOUNT);
- if (!table->files)
- break;
- nr_files -= this_files;
- }
-
- if (i == nr_tables)
- return 0;
-
- for (i = 0; i < nr_tables; i++) {
- struct fixed_file_table *table = &file_data->table[i];
- kfree(table->files);
- }
- return 1;
-}
-
-static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff_head list, *head = &sock->sk_receive_queue;
- struct sk_buff *skb;
- int i;
-
- __skb_queue_head_init(&list);
-
- /*
- * Find the skb that holds this file in its SCM_RIGHTS. When found,
- * remove this entry and rearrange the file array.
- */
- skb = skb_dequeue(head);
- while (skb) {
- struct scm_fp_list *fp;
-
- fp = UNIXCB(skb).fp;
- for (i = 0; i < fp->count; i++) {
- int left;
-
- if (fp->fp[i] != file)
- continue;
-
- unix_notinflight(fp->user, fp->fp[i]);
- left = fp->count - 1 - i;
- if (left) {
- memmove(&fp->fp[i], &fp->fp[i + 1],
- left * sizeof(struct file *));
- }
- fp->count--;
- if (!fp->count) {
- kfree_skb(skb);
- skb = NULL;
- } else {
- __skb_queue_tail(&list, skb);
- }
- fput(file);
- file = NULL;
- break;
- }
-
- if (!file)
- break;
-
- __skb_queue_tail(&list, skb);
-
- skb = skb_dequeue(head);
- }
-
- if (skb_peek(&list)) {
- spin_lock_irq(&head->lock);
- while ((skb = __skb_dequeue(&list)) != NULL)
- __skb_queue_tail(head, skb);
- spin_unlock_irq(&head->lock);
- }
-#else
- fput(file);
-#endif
-}
-
-struct io_file_put {
- struct list_head list;
- struct file *file;
-};
-
-static void __io_file_put_work(struct fixed_file_ref_node *ref_node)
-{
- struct fixed_file_data *file_data = ref_node->file_data;
- struct io_ring_ctx *ctx = file_data->ctx;
- struct io_file_put *pfile, *tmp;
-
- list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) {
- list_del(&pfile->list);
- io_ring_file_put(ctx, pfile->file);
- kfree(pfile);
- }
-
- percpu_ref_exit(&ref_node->refs);
- kfree(ref_node);
- percpu_ref_put(&file_data->refs);
-}
-
-static void io_file_put_work(struct work_struct *work)
-{
- struct io_ring_ctx *ctx;
- struct llist_node *node;
-
- ctx = container_of(work, struct io_ring_ctx, file_put_work.work);
- node = llist_del_all(&ctx->file_put_llist);
-
- while (node) {
- struct fixed_file_ref_node *ref_node;
- struct llist_node *next = node->next;
-
- ref_node = llist_entry(node, struct fixed_file_ref_node, llist);
- __io_file_put_work(ref_node);
- node = next;
- }
-}
-
-static void io_file_data_ref_zero(struct percpu_ref *ref)
-{
- struct fixed_file_ref_node *ref_node;
- struct fixed_file_data *data;
- struct io_ring_ctx *ctx;
- bool first_add = false;
- int delay = HZ;
-
- ref_node = container_of(ref, struct fixed_file_ref_node, refs);
- data = ref_node->file_data;
- ctx = data->ctx;
-
- spin_lock_bh(&data->lock);
- ref_node->done = true;
-
- while (!list_empty(&data->ref_list)) {
- ref_node = list_first_entry(&data->ref_list,
- struct fixed_file_ref_node, node);
- /* recycle ref nodes in order */
- if (!ref_node->done)
- break;
- list_del(&ref_node->node);
- first_add |= llist_add(&ref_node->llist, &ctx->file_put_llist);
- }
- spin_unlock_bh(&data->lock);
-
- if (percpu_ref_is_dying(&data->refs))
- delay = 0;
-
- if (!delay)
- mod_delayed_work(system_wq, &ctx->file_put_work, 0);
- else if (first_add)
- queue_delayed_work(system_wq, &ctx->file_put_work, delay);
-}
-
-static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
- struct io_ring_ctx *ctx)
-{
- struct fixed_file_ref_node *ref_node;
-
- ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
- if (!ref_node)
- return NULL;
-
- if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero,
- 0, GFP_KERNEL)) {
- kfree(ref_node);
- return NULL;
- }
- INIT_LIST_HEAD(&ref_node->node);
- INIT_LIST_HEAD(&ref_node->file_list);
- ref_node->file_data = ctx->file_data;
- ref_node->done = false;
- return ref_node;
-}
-
-static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node)
-{
- percpu_ref_exit(&ref_node->refs);
- kfree(ref_node);
-}
-
-static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
- unsigned nr_args)
-{
- __s32 __user *fds = (__s32 __user *) arg;
- unsigned nr_tables, i;
- struct file *file;
- int fd, ret = -ENOMEM;
- struct fixed_file_ref_node *ref_node;
- struct fixed_file_data *file_data;
-
- if (ctx->file_data)
- return -EBUSY;
- if (!nr_args)
- return -EINVAL;
- if (nr_args > IORING_MAX_FIXED_FILES)
- return -EMFILE;
- if (nr_args > rlimit(RLIMIT_NOFILE))
- return -EMFILE;
-
- file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL_ACCOUNT);
- if (!file_data)
- return -ENOMEM;
- file_data->ctx = ctx;
- init_completion(&file_data->done);
- INIT_LIST_HEAD(&file_data->ref_list);
- spin_lock_init(&file_data->lock);
-
- nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
- file_data->table = kcalloc(nr_tables, sizeof(*file_data->table),
- GFP_KERNEL_ACCOUNT);
- if (!file_data->table)
- goto out_free;
-
- if (percpu_ref_init(&file_data->refs, io_file_ref_kill,
- PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
- goto out_free;
-
- if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args))
- goto out_ref;
- ctx->file_data = file_data;
-
- for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
- struct fixed_file_table *table;
- unsigned index;
-
- if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
- ret = -EFAULT;
- goto out_fput;
- }
- /* allow sparse sets */
- if (fd == -1)
- continue;
-
- file = fget(fd);
- ret = -EBADF;
- if (!file)
- goto out_fput;
-
- /*
- * Don't allow io_uring instances to be registered. If UNIX
- * isn't enabled, then this causes a reference cycle and this
- * instance can never get freed. If UNIX is enabled we'll
- * handle it just fine, but there's still no point in allowing
- * a ring fd as it doesn't support regular read/write anyway.
- */
- if (file->f_op == &io_uring_fops) {
- fput(file);
- goto out_fput;
- }
- table = &file_data->table[i >> IORING_FILE_TABLE_SHIFT];
- index = i & IORING_FILE_TABLE_MASK;
- table->files[index] = file;
- }
-
- ret = io_sqe_files_scm(ctx);
- if (ret) {
- io_sqe_files_unregister(ctx);
- return ret;
- }
-
- ref_node = alloc_fixed_file_ref_node(ctx);
- if (!ref_node) {
- io_sqe_files_unregister(ctx);
- return -ENOMEM;
- }
-
- io_sqe_files_set_node(file_data, ref_node);
- return ret;
-out_fput:
- for (i = 0; i < ctx->nr_user_files; i++) {
- file = io_file_from_index(ctx, i);
- if (file)
- fput(file);
- }
- for (i = 0; i < nr_tables; i++)
- kfree(file_data->table[i].files);
- ctx->nr_user_files = 0;
-out_ref:
- percpu_ref_exit(&file_data->refs);
-out_free:
- kfree(file_data->table);
- kfree(file_data);
- ctx->file_data = NULL;
- return ret;
-}
-
-static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
- int index)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff_head *head = &sock->sk_receive_queue;
- struct sk_buff *skb;
-
- /*
- * See if we can merge this file into an existing skb SCM_RIGHTS
- * file set. If there's no room, fall back to allocating a new skb
- * and filling it in.
- */
- spin_lock_irq(&head->lock);
- skb = skb_peek(head);
- if (skb) {
- struct scm_fp_list *fpl = UNIXCB(skb).fp;
-
- if (fpl->count < SCM_MAX_FD) {
- __skb_unlink(skb, head);
- spin_unlock_irq(&head->lock);
- fpl->fp[fpl->count] = get_file(file);
- unix_inflight(fpl->user, fpl->fp[fpl->count]);
- fpl->count++;
- spin_lock_irq(&head->lock);
- __skb_queue_head(head, skb);
- } else {
- skb = NULL;
- }
- }
- spin_unlock_irq(&head->lock);
-
- if (skb) {
- fput(file);
- return 0;
- }
-
- return __io_sqe_files_scm(ctx, 1, index);
-#else
- return 0;
-#endif
-}
-
-static int io_queue_file_removal(struct fixed_file_data *data,
- struct file *file)
-{
- struct io_file_put *pfile;
- struct fixed_file_ref_node *ref_node = data->node;
-
- pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
- if (!pfile)
- return -ENOMEM;
-
- pfile->file = file;
- list_add(&pfile->list, &ref_node->file_list);
-
- return 0;
-}
-
-static int __io_sqe_files_update(struct io_ring_ctx *ctx,
- struct io_uring_files_update *up,
- unsigned nr_args)
-{
- struct fixed_file_data *data = ctx->file_data;
- struct fixed_file_ref_node *ref_node;
- struct file *file;
- __s32 __user *fds;
- int fd, i, err;
- __u32 done;
- bool needs_switch = false;
-
- if (check_add_overflow(up->offset, nr_args, &done))
- return -EOVERFLOW;
- if (done > ctx->nr_user_files)
- return -EINVAL;
-
- ref_node = alloc_fixed_file_ref_node(ctx);
- if (!ref_node)
- return -ENOMEM;
-
- done = 0;
- fds = u64_to_user_ptr(up->fds);
- while (nr_args) {
- struct fixed_file_table *table;
- unsigned index;
-
- err = 0;
- if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
- err = -EFAULT;
- break;
- }
- i = array_index_nospec(up->offset, ctx->nr_user_files);
- table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
- index = i & IORING_FILE_TABLE_MASK;
- if (table->files[index]) {
- file = table->files[index];
- err = io_queue_file_removal(data, file);
- if (err)
- break;
- table->files[index] = NULL;
- needs_switch = true;
- }
- if (fd != -1) {
- file = fget(fd);
- if (!file) {
- err = -EBADF;
- break;
- }
- /*
- * Don't allow io_uring instances to be registered. If
- * UNIX isn't enabled, then this causes a reference
- * cycle and this instance can never get freed. If UNIX
- * is enabled we'll handle it just fine, but there's
- * still no point in allowing a ring fd as it doesn't
- * support regular read/write anyway.
- */
- if (file->f_op == &io_uring_fops) {
- fput(file);
- err = -EBADF;
- break;
- }
- table->files[index] = file;
- err = io_sqe_file_register(ctx, file, i);
- if (err) {
- table->files[index] = NULL;
- fput(file);
- break;
- }
- }
- nr_args--;
- done++;
- up->offset++;
- }
-
- if (needs_switch) {
- percpu_ref_kill(&data->node->refs);
- io_sqe_files_set_node(data, ref_node);
- } else
- destroy_fixed_file_ref_node(ref_node);
-
- return done ? done : err;
-}
-
-static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
- unsigned nr_args)
-{
- struct io_uring_files_update up;
-
- if (!ctx->file_data)
- return -ENXIO;
- if (!nr_args)
- return -EINVAL;
- if (copy_from_user(&up, arg, sizeof(up)))
- return -EFAULT;
- if (up.resv)
- return -EINVAL;
-
- return __io_sqe_files_update(ctx, &up, nr_args);
-}
-
-static void io_free_work(struct io_wq_work *work)
-{
- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-
- /* Consider that io_steal_work() relies on this ref */
- io_put_req(req);
-}
-
-static int io_init_wq_offload(struct io_ring_ctx *ctx,
- struct io_uring_params *p)
-{
- struct io_wq_data data;
- struct fd f;
- struct io_ring_ctx *ctx_attach;
- unsigned int concurrency;
- int ret = 0;
-
- data.user = ctx->user;
- data.free_work = io_free_work;
- data.do_work = io_wq_submit_work;
-
- if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
- /* Do QD, or 4 * CPUS, whatever is smallest */
- concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
-
- ctx->io_wq = io_wq_create(concurrency, &data);
- if (IS_ERR(ctx->io_wq)) {
- ret = PTR_ERR(ctx->io_wq);
- ctx->io_wq = NULL;
- }
- return ret;
- }
-
- f = fdget(p->wq_fd);
- if (!f.file)
- return -EBADF;
-
- if (f.file->f_op != &io_uring_fops) {
- ret = -EINVAL;
- goto out_fput;
- }
-
- ctx_attach = f.file->private_data;
- /* @io_wq is protected by holding the fd */
- if (!io_wq_get(ctx_attach->io_wq, &data)) {
- ret = -EINVAL;
- goto out_fput;
- }
-
- ctx->io_wq = ctx_attach->io_wq;
-out_fput:
- fdput(f);
- return ret;
-}
-
-static int io_uring_alloc_task_context(struct task_struct *task)
-{
- struct io_uring_task *tctx;
- int ret;
-
- tctx = kmalloc(sizeof(*tctx), GFP_KERNEL);
- if (unlikely(!tctx))
- return -ENOMEM;
-
- ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
- if (unlikely(ret)) {
- kfree(tctx);
- return ret;
- }
-
- xa_init(&tctx->xa);
- init_waitqueue_head(&tctx->wait);
- tctx->last = NULL;
- atomic_set(&tctx->in_idle, 0);
- tctx->sqpoll = false;
- io_init_identity(&tctx->__identity);
- tctx->identity = &tctx->__identity;
- task->io_uring = tctx;
- return 0;
-}
-
-void __io_uring_free(struct task_struct *tsk)
-{
- struct io_uring_task *tctx = tsk->io_uring;
-
- WARN_ON_ONCE(!xa_empty(&tctx->xa));
- WARN_ON_ONCE(refcount_read(&tctx->identity->count) != 1);
- if (tctx->identity != &tctx->__identity)
- kfree(tctx->identity);
- percpu_counter_destroy(&tctx->inflight);
- kfree(tctx);
- tsk->io_uring = NULL;
-}
-
-static int io_sq_offload_create(struct io_ring_ctx *ctx,
- struct io_uring_params *p)
-{
- int ret;
-
- if (ctx->flags & IORING_SETUP_SQPOLL) {
- struct io_sq_data *sqd;
-
- ret = -EPERM;
- if (!capable(CAP_SYS_ADMIN))
- goto err;
-
- sqd = io_get_sq_data(p);
- if (IS_ERR(sqd)) {
- ret = PTR_ERR(sqd);
- goto err;
- }
-
- ctx->sq_data = sqd;
- io_sq_thread_park(sqd);
- mutex_lock(&sqd->ctx_lock);
- list_add(&ctx->sqd_list, &sqd->ctx_new_list);
- mutex_unlock(&sqd->ctx_lock);
- io_sq_thread_unpark(sqd);
-
- ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
- if (!ctx->sq_thread_idle)
- ctx->sq_thread_idle = HZ;
-
- if (sqd->thread)
- goto done;
-
- if (p->flags & IORING_SETUP_SQ_AFF) {
- int cpu = p->sq_thread_cpu;
-
- ret = -EINVAL;
- if (cpu >= nr_cpu_ids)
- goto err;
- if (!cpu_online(cpu))
- goto err;
-
- sqd->thread = kthread_create_on_cpu(io_sq_thread, sqd,
- cpu, "io_uring-sq");
- } else {
- sqd->thread = kthread_create(io_sq_thread, sqd,
- "io_uring-sq");
- }
- if (IS_ERR(sqd->thread)) {
- ret = PTR_ERR(sqd->thread);
- sqd->thread = NULL;
- goto err;
- }
- ret = io_uring_alloc_task_context(sqd->thread);
- if (ret)
- goto err;
- } else if (p->flags & IORING_SETUP_SQ_AFF) {
- /* Can't have SQ_AFF without SQPOLL */
- ret = -EINVAL;
- goto err;
- }
-
-done:
- ret = io_init_wq_offload(ctx, p);
- if (ret)
- goto err;
-
- return 0;
-err:
- io_finish_async(ctx);
- return ret;
-}
-
-static void io_sq_offload_start(struct io_ring_ctx *ctx)
-{
- struct io_sq_data *sqd = ctx->sq_data;
-
- ctx->flags &= ~IORING_SETUP_R_DISABLED;
- if ((ctx->flags & IORING_SETUP_SQPOLL) && sqd && sqd->thread)
- wake_up_process(sqd->thread);
-}
-
-static inline void __io_unaccount_mem(struct user_struct *user,
- unsigned long nr_pages)
-{
- atomic_long_sub(nr_pages, &user->locked_vm);
-}
-
-static inline int __io_account_mem(struct user_struct *user,
- unsigned long nr_pages)
-{
- unsigned long page_limit, cur_pages, new_pages;
-
- /* Don't allow more pages than we can safely lock */
- page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-
- do {
- cur_pages = atomic_long_read(&user->locked_vm);
- new_pages = cur_pages + nr_pages;
- if (new_pages > page_limit)
- return -ENOMEM;
- } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
- new_pages) != cur_pages);
-
- return 0;
-}
-
-static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
- enum io_mem_account acct)
-{
- if (ctx->limit_mem)
- __io_unaccount_mem(ctx->user, nr_pages);
-
- if (ctx->mm_account) {
- if (acct == ACCT_LOCKED)
- ctx->mm_account->locked_vm -= nr_pages;
- else if (acct == ACCT_PINNED)
- atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
- }
-}
-
-static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
- enum io_mem_account acct)
-{
- int ret;
-
- if (ctx->limit_mem) {
- ret = __io_account_mem(ctx->user, nr_pages);
- if (ret)
- return ret;
- }
-
- if (ctx->mm_account) {
- if (acct == ACCT_LOCKED)
- ctx->mm_account->locked_vm += nr_pages;
- else if (acct == ACCT_PINNED)
- atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
- }
-
- return 0;
-}
-
-static void io_mem_free(void *ptr)
-{
- struct page *page;
-
- if (!ptr)
- return;
-
- page = virt_to_head_page(ptr);
- if (put_page_testzero(page))
- free_compound_page(page);
-}
-
-static void *io_mem_alloc(size_t size)
-{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
- __GFP_NORETRY;
-
- return (void *) __get_free_pages(gfp_flags, get_order(size));
-}
-
-static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
- size_t *sq_offset)
-{
- struct io_rings *rings;
- size_t off, sq_array_size;
-
- off = struct_size(rings, cqes, cq_entries);
- if (off == SIZE_MAX)
- return SIZE_MAX;
-
-#ifdef CONFIG_SMP
- off = ALIGN(off, SMP_CACHE_BYTES);
- if (off == 0)
- return SIZE_MAX;
-#endif
-
- if (sq_offset)
- *sq_offset = off;
-
- sq_array_size = array_size(sizeof(u32), sq_entries);
- if (sq_array_size == SIZE_MAX)
- return SIZE_MAX;
-
- if (check_add_overflow(off, sq_array_size, &off))
- return SIZE_MAX;
-
- return off;
-}
-
-static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
-{
- size_t pages;
-
- pages = (size_t)1 << get_order(
- rings_size(sq_entries, cq_entries, NULL));
- pages += (size_t)1 << get_order(
- array_size(sizeof(struct io_uring_sqe), sq_entries));
-
- return pages;
-}
-
-static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
-{
- int i, j;
-
- if (!ctx->user_bufs)
- return -ENXIO;
-
- for (i = 0; i < ctx->nr_user_bufs; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
-
- for (j = 0; j < imu->nr_bvecs; j++)
- unpin_user_page(imu->bvec[j].bv_page);
-
- if (imu->acct_pages)
- io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED);
- kvfree(imu->bvec);
- imu->nr_bvecs = 0;
- }
-
- kfree(ctx->user_bufs);
- ctx->user_bufs = NULL;
- ctx->nr_user_bufs = 0;
- return 0;
-}
-
-static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
- void __user *arg, unsigned index)
-{
- struct iovec __user *src;
-
-#ifdef CONFIG_COMPAT
- if (ctx->compat) {
- struct compat_iovec __user *ciovs;
- struct compat_iovec ciov;
-
- ciovs = (struct compat_iovec __user *) arg;
- if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
- return -EFAULT;
-
- dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
- dst->iov_len = ciov.iov_len;
- return 0;
- }
-#endif
- src = (struct iovec __user *) arg;
- if (copy_from_user(dst, &src[index], sizeof(*dst)))
- return -EFAULT;
- return 0;
-}
-
-/*
- * Not super efficient, but this is just a registration time. And we do cache
- * the last compound head, so generally we'll only do a full search if we don't
- * match that one.
- *
- * We check if the given compound head page has already been accounted, to
- * avoid double accounting it. This allows us to account the full size of the
- * page, not just the constituent pages of a huge page.
- */
-static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
- int nr_pages, struct page *hpage)
-{
- int i, j;
-
- /* check current page array */
- for (i = 0; i < nr_pages; i++) {
- if (!PageCompound(pages[i]))
- continue;
- if (compound_head(pages[i]) == hpage)
- return true;
- }
-
- /* check previously registered pages */
- for (i = 0; i < ctx->nr_user_bufs; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
-
- for (j = 0; j < imu->nr_bvecs; j++) {
- if (!PageCompound(imu->bvec[j].bv_page))
- continue;
- if (compound_head(imu->bvec[j].bv_page) == hpage)
- return true;
- }
- }
-
- return false;
-}
-
-static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
- int nr_pages, struct io_mapped_ubuf *imu,
- struct page **last_hpage)
-{
- int i, ret;
-
- for (i = 0; i < nr_pages; i++) {
- if (!PageCompound(pages[i])) {
- imu->acct_pages++;
- } else {
- struct page *hpage;
-
- hpage = compound_head(pages[i]);
- if (hpage == *last_hpage)
- continue;
- *last_hpage = hpage;
- if (headpage_already_acct(ctx, pages, i, hpage))
- continue;
- imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
- }
- }
-
- if (!imu->acct_pages)
- return 0;
-
- ret = io_account_mem(ctx, imu->acct_pages, ACCT_PINNED);
- if (ret)
- imu->acct_pages = 0;
- return ret;
-}
-
-static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
- unsigned nr_args)
-{
- struct vm_area_struct **vmas = NULL;
- struct page **pages = NULL;
- struct page *last_hpage = NULL;
- int i, j, got_pages = 0;
- int ret = -EINVAL;
-
- if (ctx->user_bufs)
- return -EBUSY;
- if (!nr_args || nr_args > UIO_MAXIOV)
- return -EINVAL;
-
- ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
- GFP_KERNEL);
- if (!ctx->user_bufs)
- return -ENOMEM;
-
- for (i = 0; i < nr_args; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
- unsigned long off, start, end, ubuf;
- int pret, nr_pages;
- struct iovec iov;
- size_t size;
-
- ret = io_copy_iov(ctx, &iov, arg, i);
- if (ret)
- goto err;
-
- /*
- * Don't impose further limits on the size and buffer
- * constraints here, we'll -EINVAL later when IO is
- * submitted if they are wrong.
- */
- ret = -EFAULT;
- if (!iov.iov_base || !iov.iov_len)
- goto err;
-
- /* arbitrary limit, but we need something */
- if (iov.iov_len > SZ_1G)
- goto err;
-
- ubuf = (unsigned long) iov.iov_base;
- end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- start = ubuf >> PAGE_SHIFT;
- nr_pages = end - start;
-
- ret = 0;
- if (!pages || nr_pages > got_pages) {
- kvfree(vmas);
- kvfree(pages);
- pages = kvmalloc_array(nr_pages, sizeof(struct page *),
- GFP_KERNEL);
- vmas = kvmalloc_array(nr_pages,
- sizeof(struct vm_area_struct *),
- GFP_KERNEL);
- if (!pages || !vmas) {
- ret = -ENOMEM;
- goto err;
- }
- got_pages = nr_pages;
- }
-
- imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
- GFP_KERNEL);
- ret = -ENOMEM;
- if (!imu->bvec)
- goto err;
-
- ret = 0;
- mmap_read_lock(current->mm);
- pret = pin_user_pages(ubuf, nr_pages,
- FOLL_WRITE | FOLL_LONGTERM,
- pages, vmas);
- if (pret == nr_pages) {
- /* don't support file backed memory */
- for (j = 0; j < nr_pages; j++) {
- struct vm_area_struct *vma = vmas[j];
-
- if (vma->vm_file &&
- !is_file_hugepages(vma->vm_file)) {
- ret = -EOPNOTSUPP;
- break;
- }
- }
- } else {
- ret = pret < 0 ? pret : -EFAULT;
- }
- mmap_read_unlock(current->mm);
- if (ret) {
- /*
- * if we did partial map, or found file backed vmas,
- * release any pages we did get
- */
- if (pret > 0)
- unpin_user_pages(pages, pret);
- kvfree(imu->bvec);
- goto err;
- }
-
- ret = io_buffer_account_pin(ctx, pages, pret, imu, &last_hpage);
- if (ret) {
- unpin_user_pages(pages, pret);
- kvfree(imu->bvec);
- goto err;
- }
-
- off = ubuf & ~PAGE_MASK;
- size = iov.iov_len;
- for (j = 0; j < nr_pages; j++) {
- size_t vec_len;
-
- vec_len = min_t(size_t, size, PAGE_SIZE - off);
- imu->bvec[j].bv_page = pages[j];
- imu->bvec[j].bv_len = vec_len;
- imu->bvec[j].bv_offset = off;
- off = 0;
- size -= vec_len;
- }
- /* store original address for later verification */
- imu->ubuf = ubuf;
- imu->len = iov.iov_len;
- imu->nr_bvecs = nr_pages;
-
- ctx->nr_user_bufs++;
- }
- kvfree(pages);
- kvfree(vmas);
- return 0;
-err:
- kvfree(pages);
- kvfree(vmas);
- io_sqe_buffer_unregister(ctx);
- return ret;
-}
-
-static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
-{
- __s32 __user *fds = arg;
- int fd;
-
- if (ctx->cq_ev_fd)
- return -EBUSY;
-
- if (copy_from_user(&fd, fds, sizeof(*fds)))
- return -EFAULT;
-
- ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
- if (IS_ERR(ctx->cq_ev_fd)) {
- int ret = PTR_ERR(ctx->cq_ev_fd);
- ctx->cq_ev_fd = NULL;
- return ret;
- }
-
- return 0;
-}
-
-static int io_eventfd_unregister(struct io_ring_ctx *ctx)
-{
- if (ctx->cq_ev_fd) {
- eventfd_ctx_put(ctx->cq_ev_fd);
- ctx->cq_ev_fd = NULL;
- return 0;
- }
-
- return -ENXIO;
-}
-
-static void io_destroy_buffers(struct io_ring_ctx *ctx)
-{
- struct io_buffer *buf;
- unsigned long index;
-
- xa_for_each(&ctx->io_buffers, index, buf)
- __io_remove_buffers(ctx, buf, index, -1U);
-}
-
-static void io_ring_ctx_free(struct io_ring_ctx *ctx)
-{
- io_finish_async(ctx);
- io_sqe_buffer_unregister(ctx);
-
- if (ctx->sqo_task) {
- put_task_struct(ctx->sqo_task);
- ctx->sqo_task = NULL;
- }
-
-#ifdef CONFIG_BLK_CGROUP
- if (ctx->sqo_blkcg_css)
- css_put(ctx->sqo_blkcg_css);
-#endif
-
- mutex_lock(&ctx->uring_lock);
- io_sqe_files_unregister(ctx);
- mutex_unlock(&ctx->uring_lock);
- io_eventfd_unregister(ctx);
- io_destroy_buffers(ctx);
-
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
-
- if (ctx->mm_account) {
- mmdrop(ctx->mm_account);
- ctx->mm_account = NULL;
- }
-
- io_mem_free(ctx->rings);
- io_mem_free(ctx->sq_sqes);
-
- percpu_ref_exit(&ctx->refs);
- free_uid(ctx->user);
- put_cred(ctx->creds);
- kfree(ctx->cancel_hash);
- kmem_cache_free(req_cachep, ctx->fallback_req);
- kfree(ctx);
-}
-
-static __poll_t io_uring_poll(struct file *file, poll_table *wait)
-{
- struct io_ring_ctx *ctx = file->private_data;
- __poll_t mask = 0;
-
- poll_wait(file, &ctx->cq_wait, wait);
- /*
- * synchronizes with barrier from wq_has_sleeper call in
- * io_commit_cqring
- */
- smp_rmb();
- if (!io_sqring_full(ctx))
- mask |= EPOLLOUT | EPOLLWRNORM;
-
- /*
- * Don't flush cqring overflow list here, just do a simple check.
- * Otherwise there could possible be ABBA deadlock:
- * CPU0 CPU1
- * ---- ----
- * lock(&ctx->uring_lock);
- * lock(&ep->mtx);
- * lock(&ctx->uring_lock);
- * lock(&ep->mtx);
- *
- * Users may get EPOLLIN meanwhile seeing nothing in cqring, this
- * pushs them to do the flush.
- */
- if (io_cqring_events(ctx) || test_bit(0, &ctx->cq_check_overflow))
- mask |= EPOLLIN | EPOLLRDNORM;
-
- return mask;
-}
-
-static int io_uring_fasync(int fd, struct file *file, int on)
-{
- struct io_ring_ctx *ctx = file->private_data;
-
- return fasync_helper(fd, file, on, &ctx->cq_fasync);
-}
-
-static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
-{
- struct io_identity *iod;
-
- iod = xa_erase(&ctx->personalities, id);
- if (iod) {
- put_cred(iod->creds);
- if (refcount_dec_and_test(&iod->count))
- kfree(iod);
- return 0;
- }
-
- return -EINVAL;
-}
-
-static void io_ring_exit_work(struct work_struct *work)
-{
- struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
- exit_work);
-
- /*
- * If we're doing polled IO and end up having requests being
- * submitted async (out-of-line), then completions can come in while
- * we're waiting for refs to drop. We need to reap these manually,
- * as nobody else will be looking for them.
- */
- do {
- io_iopoll_try_reap_events(ctx);
- } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
- io_ring_ctx_free(ctx);
-}
-
-static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)
-{
- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-
- return req->ctx == data;
-}
-
-static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
-{
- unsigned long index;
- struct io_identify *iod;
-
- mutex_lock(&ctx->uring_lock);
- percpu_ref_kill(&ctx->refs);
- /* if force is set, the ring is going away. always drop after that */
-
- if (WARN_ON_ONCE((ctx->flags & IORING_SETUP_SQPOLL) && !ctx->sqo_dead))
- ctx->sqo_dead = 1;
-
- ctx->cq_overflow_flushed = 1;
- if (ctx->rings)
- __io_cqring_overflow_flush(ctx, true, NULL, NULL);
- mutex_unlock(&ctx->uring_lock);
-
- io_kill_timeouts(ctx, NULL, NULL);
- io_poll_remove_all(ctx, NULL, NULL);
-
- if (ctx->io_wq)
- io_wq_cancel_cb(ctx->io_wq, io_cancel_ctx_cb, ctx, true);
-
- /* if we failed setting up the ctx, we might not have any rings */
- io_iopoll_try_reap_events(ctx);
- xa_for_each(&ctx->personalities, index, iod)
- io_unregister_personality(ctx, index);
-
- /*
- * Do this upfront, so we won't have a grace period where the ring
- * is closed but resources aren't reaped yet. This can cause
- * spurious failure in setting up a new ring.
- */
- io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries),
- ACCT_LOCKED);
-
- INIT_WORK(&ctx->exit_work, io_ring_exit_work);
- /*
- * Use system_unbound_wq to avoid spawning tons of event kworkers
- * if we're exiting a ton of rings at the same time. It just adds
- * noise and overhead, there's no discernable change in runtime
- * over using system_wq.
- */
- queue_work(system_unbound_wq, &ctx->exit_work);
-}
-
-static int io_uring_release(struct inode *inode, struct file *file)
-{
- struct io_ring_ctx *ctx = file->private_data;
-
- file->private_data = NULL;
- io_ring_ctx_wait_and_kill(ctx);
- return 0;
-}
-
-struct io_task_cancel {
- struct task_struct *task;
- struct files_struct *files;
-};
-
-static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
-{
- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
- struct io_task_cancel *cancel = data;
- bool ret;
-
- if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) {
- unsigned long flags;
- struct io_ring_ctx *ctx = req->ctx;
-
- /* protect against races with linked timeouts */
- spin_lock_irqsave(&ctx->completion_lock, flags);
- ret = io_match_task(req, cancel->task, cancel->files);
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
- } else {
- ret = io_match_task(req, cancel->task, cancel->files);
- }
- return ret;
-}
-
-static void io_cancel_defer_files(struct io_ring_ctx *ctx,
- struct task_struct *task,
- struct files_struct *files)
-{
- struct io_defer_entry *de = NULL;
- LIST_HEAD(list);
-
- spin_lock_irq(&ctx->completion_lock);
- list_for_each_entry_reverse(de, &ctx->defer_list, list) {
- if (io_match_task(de->req, task, files)) {
- list_cut_position(&list, &ctx->defer_list, &de->list);
- break;
- }
- }
- spin_unlock_irq(&ctx->completion_lock);
-
- while (!list_empty(&list)) {
- de = list_first_entry(&list, struct io_defer_entry, list);
- list_del_init(&de->list);
- req_set_fail_links(de->req);
- io_put_req(de->req);
- io_req_complete(de->req, -ECANCELED);
- kfree(de);
- }
-}
-
-static int io_uring_count_inflight(struct io_ring_ctx *ctx,
- struct task_struct *task,
- struct files_struct *files)
-{
- struct io_kiocb *req;
- int cnt = 0;
-
- spin_lock_irq(&ctx->inflight_lock);
- list_for_each_entry(req, &ctx->inflight_list, inflight_entry)
- cnt += io_match_task(req, task, files);
- spin_unlock_irq(&ctx->inflight_lock);
- return cnt;
-}
-
-static void io_uring_cancel_files(struct io_ring_ctx *ctx,
- struct task_struct *task,
- struct files_struct *files)
-{
- while (!list_empty_careful(&ctx->inflight_list)) {
- struct io_task_cancel cancel = { .task = task, .files = files };
- DEFINE_WAIT(wait);
- int inflight;
-
- inflight = io_uring_count_inflight(ctx, task, files);
- if (!inflight)
- break;
-
- io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true);
- io_poll_remove_all(ctx, task, files);
- io_kill_timeouts(ctx, task, files);
- /* cancellations _may_ trigger task work */
- io_run_task_work();
-
- prepare_to_wait(&task->io_uring->wait, &wait,
- TASK_UNINTERRUPTIBLE);
- if (inflight == io_uring_count_inflight(ctx, task, files))
- schedule();
- finish_wait(&task->io_uring->wait, &wait);
- }
-}
-
-static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
- struct task_struct *task)
-{
- while (1) {
- struct io_task_cancel cancel = { .task = task, .files = NULL, };
- enum io_wq_cancel cret;
- bool ret = false;
-
- cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true);
- if (cret != IO_WQ_CANCEL_NOTFOUND)
- ret = true;
-
- /* SQPOLL thread does its own polling */
- if (!(ctx->flags & IORING_SETUP_SQPOLL)) {
- while (!list_empty_careful(&ctx->iopoll_list)) {
- io_iopoll_try_reap_events(ctx);
- ret = true;
- }
- }
-
- ret |= io_poll_remove_all(ctx, task, NULL);
- ret |= io_kill_timeouts(ctx, task, NULL);
- if (!ret)
- break;
- io_run_task_work();
- cond_resched();
- }
-}
-
-static void io_disable_sqo_submit(struct io_ring_ctx *ctx)
-{
- mutex_lock(&ctx->uring_lock);
- ctx->sqo_dead = 1;
- if (ctx->flags & IORING_SETUP_R_DISABLED)
- io_sq_offload_start(ctx);
- mutex_unlock(&ctx->uring_lock);
-
- /* make sure callers enter the ring to get error */
- if (ctx->rings)
- io_ring_set_wakeup_flag(ctx);
-}
-
-/*
- * We need to iteratively cancel requests, in case a request has dependent
- * hard links. These persist even for failure of cancelations, hence keep
- * looping until none are found.
- */
-static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
- struct files_struct *files)
-{
- struct task_struct *task = current;
-
- if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
- io_disable_sqo_submit(ctx);
- task = ctx->sq_data->thread;
- atomic_inc(&task->io_uring->in_idle);
- io_sq_thread_park(ctx->sq_data);
- }
-
- io_cancel_defer_files(ctx, task, files);
- io_cqring_overflow_flush(ctx, true, task, files);
-
- if (!files)
- __io_uring_cancel_task_requests(ctx, task);
- else
- io_uring_cancel_files(ctx, task, files);
-
- if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
- atomic_dec(&task->io_uring->in_idle);
- io_sq_thread_unpark(ctx->sq_data);
- }
-}
-
-/*
- * Note that this task has used io_uring. We use it for cancelation purposes.
- */
-static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
-{
- struct io_uring_task *tctx = current->io_uring;
- int ret;
-
- if (unlikely(!tctx)) {
- ret = io_uring_alloc_task_context(current);
- if (unlikely(ret))
- return ret;
- tctx = current->io_uring;
- }
- if (tctx->last != file) {
- void *old = xa_load(&tctx->xa, (unsigned long)file);
-
- if (!old) {
- get_file(file);
- ret = xa_err(xa_store(&tctx->xa, (unsigned long)file,
- file, GFP_KERNEL));
- if (ret) {
- fput(file);
- return ret;
- }
- }
- tctx->last = file;
- }
-
- /*
- * This is race safe in that the task itself is doing this, hence it
- * cannot be going through the exit/cancel paths at the same time.
- * This cannot be modified while exit/cancel is running.
- */
- if (!tctx->sqpoll && (ctx->flags & IORING_SETUP_SQPOLL))
- tctx->sqpoll = true;
-
- return 0;
-}
-
-/*
- * Remove this io_uring_file -> task mapping.
- */
-static void io_uring_del_task_file(struct file *file)
-{
- struct io_uring_task *tctx = current->io_uring;
-
- if (tctx->last == file)
- tctx->last = NULL;
- file = xa_erase(&tctx->xa, (unsigned long)file);
- if (file)
- fput(file);
-}
-
-static void io_uring_remove_task_files(struct io_uring_task *tctx)
-{
- struct file *file;
- unsigned long index;
-
- xa_for_each(&tctx->xa, index, file)
- io_uring_del_task_file(file);
-}
-
-void __io_uring_files_cancel(struct files_struct *files)
-{
- struct io_uring_task *tctx = current->io_uring;
- struct file *file;
- unsigned long index;
-
- /* make sure overflow events are dropped */
- atomic_inc(&tctx->in_idle);
- xa_for_each(&tctx->xa, index, file)
- io_uring_cancel_task_requests(file->private_data, files);
- atomic_dec(&tctx->in_idle);
-
- if (files)
- io_uring_remove_task_files(tctx);
-}
-
-static s64 tctx_inflight(struct io_uring_task *tctx)
-{
- unsigned long index;
- struct file *file;
- s64 inflight;
-
- inflight = percpu_counter_sum(&tctx->inflight);
- if (!tctx->sqpoll)
- return inflight;
-
- /*
- * If we have SQPOLL rings, then we need to iterate and find them, and
- * add the pending count for those.
- */
- xa_for_each(&tctx->xa, index, file) {
- struct io_ring_ctx *ctx = file->private_data;
-
- if (ctx->flags & IORING_SETUP_SQPOLL) {
- struct io_uring_task *__tctx = ctx->sqo_task->io_uring;
-
- inflight += percpu_counter_sum(&__tctx->inflight);
- }
- }
-
- return inflight;
-}
-
-/*
- * Find any io_uring fd that this task has registered or done IO on, and cancel
- * requests.
- */
-void __io_uring_task_cancel(void)
-{
- struct io_uring_task *tctx = current->io_uring;
- DEFINE_WAIT(wait);
- s64 inflight;
-
- /* make sure overflow events are dropped */
- atomic_inc(&tctx->in_idle);
-
- /* trigger io_disable_sqo_submit() */
- if (tctx->sqpoll)
- __io_uring_files_cancel(NULL);
-
- do {
- /* read completions before cancelations */
- inflight = tctx_inflight(tctx);
- if (!inflight)
- break;
- __io_uring_files_cancel(NULL);
-
- prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
-
- /*
- * If we've seen completions, retry without waiting. This
- * avoids a race where a completion comes in before we did
- * prepare_to_wait().
- */
- if (inflight == tctx_inflight(tctx))
- schedule();
- finish_wait(&tctx->wait, &wait);
- } while (1);
-
- atomic_dec(&tctx->in_idle);
-
- io_uring_remove_task_files(tctx);
-}
-
-static int io_uring_flush(struct file *file, void *data)
-{
- struct io_uring_task *tctx = current->io_uring;
- struct io_ring_ctx *ctx = file->private_data;
-
- if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
- io_uring_cancel_task_requests(ctx, NULL);
-
- if (!tctx)
- return 0;
-
- /* we should have cancelled and erased it before PF_EXITING */
- WARN_ON_ONCE((current->flags & PF_EXITING) &&
- xa_load(&tctx->xa, (unsigned long)file));
-
- /*
- * fput() is pending, will be 2 if the only other ref is our potential
- * task file note. If the task is exiting, drop regardless of count.
- */
- if (atomic_long_read(&file->f_count) != 2)
- return 0;
-
- if (ctx->flags & IORING_SETUP_SQPOLL) {
- /* there is only one file note, which is owned by sqo_task */
- WARN_ON_ONCE(ctx->sqo_task != current &&
- xa_load(&tctx->xa, (unsigned long)file));
- /* sqo_dead check is for when this happens after cancellation */
- WARN_ON_ONCE(ctx->sqo_task == current && !ctx->sqo_dead &&
- !xa_load(&tctx->xa, (unsigned long)file));
-
- io_disable_sqo_submit(ctx);
- }
-
- if (!(ctx->flags & IORING_SETUP_SQPOLL) || ctx->sqo_task == current)
- io_uring_del_task_file(file);
- return 0;
-}
-
-static void *io_uring_validate_mmap_request(struct file *file,
- loff_t pgoff, size_t sz)
-{
- struct io_ring_ctx *ctx = file->private_data;
- loff_t offset = pgoff << PAGE_SHIFT;
- struct page *page;
- void *ptr;
-
- switch (offset) {
- case IORING_OFF_SQ_RING:
- case IORING_OFF_CQ_RING:
- ptr = ctx->rings;
- break;
- case IORING_OFF_SQES:
- ptr = ctx->sq_sqes;
- break;
- default:
- return ERR_PTR(-EINVAL);
- }
-
- page = virt_to_head_page(ptr);
- if (sz > page_size(page))
- return ERR_PTR(-EINVAL);
-
- return ptr;
-}
-
-#ifdef CONFIG_MMU
-
-static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
-{
- size_t sz = vma->vm_end - vma->vm_start;
- unsigned long pfn;
- void *ptr;
-
- ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
- if (IS_ERR(ptr))
- return PTR_ERR(ptr);
-
- pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
- return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
-}
-
-#else /* !CONFIG_MMU */
-
-static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
-{
- return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
-}
-
-static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
-{
- return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
-}
-
-static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
- unsigned long addr, unsigned long len,
- unsigned long pgoff, unsigned long flags)
-{
- void *ptr;
-
- ptr = io_uring_validate_mmap_request(file, pgoff, len);
- if (IS_ERR(ptr))
- return PTR_ERR(ptr);
-
- return (unsigned long) ptr;
-}
-
-#endif /* !CONFIG_MMU */
-
-static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
-{
- int ret = 0;
- DEFINE_WAIT(wait);
-
- do {
- if (!io_sqring_full(ctx))
- break;
-
- prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);
-
- if (unlikely(ctx->sqo_dead)) {
- ret = -EOWNERDEAD;
- break;
- }
-
- if (!io_sqring_full(ctx))
- break;
-
- schedule();
- } while (!signal_pending(current));
-
- finish_wait(&ctx->sqo_sq_wait, &wait);
- return ret;
-}
-
-SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
- u32, min_complete, u32, flags, const sigset_t __user *, sig,
- size_t, sigsz)
-{
- struct io_ring_ctx *ctx;
- long ret = -EBADF;
- int submitted = 0;
- struct fd f;
-
- io_run_task_work();
-
- if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
- IORING_ENTER_SQ_WAIT))
- return -EINVAL;
-
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
-
- ret = -EOPNOTSUPP;
- if (f.file->f_op != &io_uring_fops)
- goto out_fput;
-
- ret = -ENXIO;
- ctx = f.file->private_data;
- if (!percpu_ref_tryget(&ctx->refs))
- goto out_fput;
-
- ret = -EBADFD;
- if (ctx->flags & IORING_SETUP_R_DISABLED)
- goto out;
-
- /*
- * For SQ polling, the thread will do all submissions and completions.
- * Just return the requested submit count, and wake the thread if
- * we were asked to.
- */
- ret = 0;
- if (ctx->flags & IORING_SETUP_SQPOLL) {
- io_cqring_overflow_flush(ctx, false, NULL, NULL);
-
- if (unlikely(ctx->sqo_dead)) {
- ret = -EOWNERDEAD;
- goto out;
- }
- if (flags & IORING_ENTER_SQ_WAKEUP)
- wake_up(&ctx->sq_data->wait);
- if (flags & IORING_ENTER_SQ_WAIT) {
- ret = io_sqpoll_wait_sq(ctx);
- if (ret)
- goto out;
- }
- submitted = to_submit;
- } else if (to_submit) {
- ret = io_uring_add_task_file(ctx, f.file);
- if (unlikely(ret))
- goto out;
- mutex_lock(&ctx->uring_lock);
- submitted = io_submit_sqes(ctx, to_submit);
- mutex_unlock(&ctx->uring_lock);
-
- if (submitted != to_submit)
- goto out;
- }
- if (flags & IORING_ENTER_GETEVENTS) {
- min_complete = min(min_complete, ctx->cq_entries);
-
- /*
- * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
- * space applications don't need to do io completion events
- * polling again, they can rely on io_sq_thread to do polling
- * work, which can reduce cpu usage and uring_lock contention.
- */
- if (ctx->flags & IORING_SETUP_IOPOLL &&
- !(ctx->flags & IORING_SETUP_SQPOLL)) {
- ret = io_iopoll_check(ctx, min_complete);
- } else {
- ret = io_cqring_wait(ctx, min_complete, sig, sigsz);
- }
- }
-
-out:
- percpu_ref_put(&ctx->refs);
-out_fput:
- fdput(f);
- return submitted ? submitted : ret;
-}
-
-#ifdef CONFIG_PROC_FS
-static int io_uring_show_cred(struct seq_file *m, unsigned int id,
- const struct io_identity *iod)
-{
- const struct cred *cred = iod->creds;
- struct user_namespace *uns = seq_user_ns(m);
- struct group_info *gi;
- kernel_cap_t cap;
- unsigned __capi;
- int g;
-
- seq_printf(m, "%5d\n", id);
- seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
- seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
- seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
- seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
- seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
- seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
- seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
- seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
- seq_puts(m, "\n\tGroups:\t");
- gi = cred->group_info;
- for (g = 0; g < gi->ngroups; g++) {
- seq_put_decimal_ull(m, g ? " " : "",
- from_kgid_munged(uns, gi->gid[g]));
- }
- seq_puts(m, "\n\tCapEff:\t");
- cap = cred->cap_effective;
- CAP_FOR_EACH_U32(__capi)
- seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
- seq_putc(m, '\n');
- return 0;
-}
-
-static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
-{
- struct io_sq_data *sq = NULL;
- bool has_lock;
- int i;
-
- /*
- * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
- * since fdinfo case grabs it in the opposite direction of normal use
- * cases. If we fail to get the lock, we just don't iterate any
- * structures that could be going away outside the io_uring mutex.
- */
- has_lock = mutex_trylock(&ctx->uring_lock);
-
- if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL))
- sq = ctx->sq_data;
-
- seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
- seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
- seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
- for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
- struct fixed_file_table *table;
- struct file *f;
-
- table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
- f = table->files[i & IORING_FILE_TABLE_MASK];
- if (f)
- seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
- else
- seq_printf(m, "%5u: <none>\n", i);
- }
- seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
- for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
- struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
-
- seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
- (unsigned int) buf->len);
- }
- if (has_lock && !xa_empty(&ctx->personalities)) {
- unsigned long index;
- const struct io_identity *iod;
-
- seq_printf(m, "Personalities:\n");
- xa_for_each(&ctx->personalities, index, iod)
- io_uring_show_cred(m, index, iod);
- }
- seq_printf(m, "PollList:\n");
- spin_lock_irq(&ctx->completion_lock);
- for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
- struct hlist_head *list = &ctx->cancel_hash[i];
- struct io_kiocb *req;
-
- hlist_for_each_entry(req, list, hash_node)
- seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
- req->task->task_works != NULL);
- }
- spin_unlock_irq(&ctx->completion_lock);
- if (has_lock)
- mutex_unlock(&ctx->uring_lock);
-}
-
-static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
-{
- struct io_ring_ctx *ctx = f->private_data;
-
- if (percpu_ref_tryget(&ctx->refs)) {
- __io_uring_show_fdinfo(ctx, m);
- percpu_ref_put(&ctx->refs);
- }
-}
-#endif
-
-static const struct file_operations io_uring_fops = {
- .release = io_uring_release,
- .flush = io_uring_flush,
- .mmap = io_uring_mmap,
-#ifndef CONFIG_MMU
- .get_unmapped_area = io_uring_nommu_get_unmapped_area,
- .mmap_capabilities = io_uring_nommu_mmap_capabilities,
-#endif
- .poll = io_uring_poll,
- .fasync = io_uring_fasync,
-#ifdef CONFIG_PROC_FS
- .show_fdinfo = io_uring_show_fdinfo,
-#endif
-};
-
-static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
- struct io_uring_params *p)
-{
- struct io_rings *rings;
- size_t size, sq_array_offset;
-
- /* make sure these are sane, as we already accounted them */
- ctx->sq_entries = p->sq_entries;
- ctx->cq_entries = p->cq_entries;
-
- size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
- if (size == SIZE_MAX)
- return -EOVERFLOW;
-
- rings = io_mem_alloc(size);
- if (!rings)
- return -ENOMEM;
-
- ctx->rings = rings;
- ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
- rings->sq_ring_mask = p->sq_entries - 1;
- rings->cq_ring_mask = p->cq_entries - 1;
- rings->sq_ring_entries = p->sq_entries;
- rings->cq_ring_entries = p->cq_entries;
- ctx->sq_mask = rings->sq_ring_mask;
- ctx->cq_mask = rings->cq_ring_mask;
-
- size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
- if (size == SIZE_MAX) {
- io_mem_free(ctx->rings);
- ctx->rings = NULL;
- return -EOVERFLOW;
- }
-
- ctx->sq_sqes = io_mem_alloc(size);
- if (!ctx->sq_sqes) {
- io_mem_free(ctx->rings);
- ctx->rings = NULL;
- return -ENOMEM;
- }
-
- return 0;
-}
-
-static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
-{
- int ret, fd;
-
- fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
- if (fd < 0)
- return fd;
-
- ret = io_uring_add_task_file(ctx, file);
- if (ret) {
- put_unused_fd(fd);
- return ret;
- }
- fd_install(fd, file);
- return fd;
-}
-
-/*
- * Allocate an anonymous fd, this is what constitutes the application
- * visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
- */
-static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
-{
- struct file *file;
-#if defined(CONFIG_UNIX)
- int ret;
-
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ERR_PTR(ret);
-#endif
-
- file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
- O_RDWR | O_CLOEXEC);
-#if defined(CONFIG_UNIX)
- if (IS_ERR(file)) {
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
- } else {
- ctx->ring_sock->file = file;
- }
-#endif
- return file;
-}
-
-static int io_uring_create(unsigned entries, struct io_uring_params *p,
- struct io_uring_params __user *params)
-{
- struct user_struct *user = NULL;
- struct io_ring_ctx *ctx;
- struct file *file;
- bool limit_mem;
- int ret;
-
- if (!entries)
- return -EINVAL;
- if (entries > IORING_MAX_ENTRIES) {
- if (!(p->flags & IORING_SETUP_CLAMP))
- return -EINVAL;
- entries = IORING_MAX_ENTRIES;
- }
-
- /*
- * Use twice as many entries for the CQ ring. It's possible for the
- * application to drive a higher depth than the size of the SQ ring,
- * since the sqes are only used at submission time. This allows for
- * some flexibility in overcommitting a bit. If the application has
- * set IORING_SETUP_CQSIZE, it will have passed in the desired number
- * of CQ ring entries manually.
- */
- p->sq_entries = roundup_pow_of_two(entries);
- if (p->flags & IORING_SETUP_CQSIZE) {
- /*
- * If IORING_SETUP_CQSIZE is set, we do the same roundup
- * to a power-of-two, if it isn't already. We do NOT impose
- * any cq vs sq ring sizing.
- */
- if (!p->cq_entries)
- return -EINVAL;
- if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
- if (!(p->flags & IORING_SETUP_CLAMP))
- return -EINVAL;
- p->cq_entries = IORING_MAX_CQ_ENTRIES;
- }
- p->cq_entries = roundup_pow_of_two(p->cq_entries);
- if (p->cq_entries < p->sq_entries)
- return -EINVAL;
- } else {
- p->cq_entries = 2 * p->sq_entries;
- }
-
- user = get_uid(current_user());
- limit_mem = !capable(CAP_IPC_LOCK);
-
- if (limit_mem) {
- ret = __io_account_mem(user,
- ring_pages(p->sq_entries, p->cq_entries));
- if (ret) {
- free_uid(user);
- return ret;
- }
- }
-
- ctx = io_ring_ctx_alloc(p);
- if (!ctx) {
- if (limit_mem)
- __io_unaccount_mem(user, ring_pages(p->sq_entries,
- p->cq_entries));
- free_uid(user);
- return -ENOMEM;
- }
- ctx->compat = in_compat_syscall();
- ctx->user = user;
- ctx->creds = get_current_cred();
-#ifdef CONFIG_AUDIT
- ctx->loginuid = current->loginuid;
- ctx->sessionid = current->sessionid;
-#endif
- ctx->sqo_task = get_task_struct(current);
-
- /*
- * This is just grabbed for accounting purposes. When a process exits,
- * the mm is exited and dropped before the files, hence we need to hang
- * on to this mm purely for the purposes of being able to unaccount
- * memory (locked/pinned vm). It's not used for anything else.
- */
- mmgrab(current->mm);
- ctx->mm_account = current->mm;
-
-#ifdef CONFIG_BLK_CGROUP
- /*
- * The sq thread will belong to the original cgroup it was inited in.
- * If the cgroup goes offline (e.g. disabling the io controller), then
- * issued bios will be associated with the closest cgroup later in the
- * block layer.
- */
- rcu_read_lock();
- ctx->sqo_blkcg_css = blkcg_css();
- ret = css_tryget_online(ctx->sqo_blkcg_css);
- rcu_read_unlock();
- if (!ret) {
- /* don't init against a dying cgroup, have the user try again */
- ctx->sqo_blkcg_css = NULL;
- ret = -ENODEV;
- goto err;
- }
-#endif
-
- /*
- * Account memory _before_ installing the file descriptor. Once
- * the descriptor is installed, it can get closed at any time. Also
- * do this before hitting the general error path, as ring freeing
- * will un-account as well.
- */
- io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries),
- ACCT_LOCKED);
- ctx->limit_mem = limit_mem;
-
- ret = io_allocate_scq_urings(ctx, p);
- if (ret)
- goto err;
-
- ret = io_sq_offload_create(ctx, p);
- if (ret)
- goto err;
-
- if (!(p->flags & IORING_SETUP_R_DISABLED))
- io_sq_offload_start(ctx);
-
- memset(&p->sq_off, 0, sizeof(p->sq_off));
- p->sq_off.head = offsetof(struct io_rings, sq.head);
- p->sq_off.tail = offsetof(struct io_rings, sq.tail);
- p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
- p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
- p->sq_off.flags = offsetof(struct io_rings, sq_flags);
- p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
- p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
-
- memset(&p->cq_off, 0, sizeof(p->cq_off));
- p->cq_off.head = offsetof(struct io_rings, cq.head);
- p->cq_off.tail = offsetof(struct io_rings, cq.tail);
- p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
- p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
- p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
- p->cq_off.cqes = offsetof(struct io_rings, cqes);
- p->cq_off.flags = offsetof(struct io_rings, cq_flags);
-
- p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
- IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
- IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
- IORING_FEAT_POLL_32BITS;
-
- if (copy_to_user(params, p, sizeof(*p))) {
- ret = -EFAULT;
- goto err;
- }
-
- file = io_uring_get_file(ctx);
- if (IS_ERR(file)) {
- ret = PTR_ERR(file);
- goto err;
- }
-
- /*
- * Install ring fd as the very last thing, so we don't risk someone
- * having closed it before we finish setup
- */
- ret = io_uring_install_fd(ctx, file);
- if (ret < 0) {
- io_disable_sqo_submit(ctx);
- /* fput will clean it up */
- fput(file);
- return ret;
- }
-
- trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
- return ret;
-err:
- io_disable_sqo_submit(ctx);
- io_ring_ctx_wait_and_kill(ctx);
- return ret;
-}
-
-/*
- * Sets up an aio uring context, and returns the fd. Applications asks for a
- * ring size, we return the actual sq/cq ring sizes (among other things) in the
- * params structure passed in.
- */
-static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
-{
- struct io_uring_params p;
- int i;
-
- if (copy_from_user(&p, params, sizeof(p)))
- return -EFAULT;
- for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
- if (p.resv[i])
- return -EINVAL;
- }
-
- if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
- IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
- IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
- IORING_SETUP_R_DISABLED))
- return -EINVAL;
-
- return io_uring_create(entries, &p, params);
-}
-
-SYSCALL_DEFINE2(io_uring_setup, u32, entries,
- struct io_uring_params __user *, params)
-{
- return io_uring_setup(entries, params);
-}
-
-static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
-{
- struct io_uring_probe *p;
- size_t size;
- int i, ret;
-
- size = struct_size(p, ops, nr_args);
- if (size == SIZE_MAX)
- return -EOVERFLOW;
- p = kzalloc(size, GFP_KERNEL);
- if (!p)
- return -ENOMEM;
-
- ret = -EFAULT;
- if (copy_from_user(p, arg, size))
- goto out;
- ret = -EINVAL;
- if (memchr_inv(p, 0, size))
- goto out;
-
- p->last_op = IORING_OP_LAST - 1;
- if (nr_args > IORING_OP_LAST)
- nr_args = IORING_OP_LAST;
-
- for (i = 0; i < nr_args; i++) {
- p->ops[i].op = i;
- if (!io_op_defs[i].not_supported)
- p->ops[i].flags = IO_URING_OP_SUPPORTED;
- }
- p->ops_len = i;
-
- ret = 0;
- if (copy_to_user(arg, p, size))
- ret = -EFAULT;
-out:
- kfree(p);
- return ret;
-}
-
-static int io_register_personality(struct io_ring_ctx *ctx)
-{
- struct io_identity *iod;
- u32 id;
- int ret;
-
- iod = kmalloc(sizeof(*iod), GFP_KERNEL);
- if (unlikely(!iod))
- return -ENOMEM;
-
- io_init_identity(iod);
- iod->creds = get_current_cred();
-
- ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)iod,
- XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
- if (ret < 0) {
- put_cred(iod->creds);
- kfree(iod);
- return ret;
- }
- return id;
-}
-
-static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
- unsigned int nr_args)
-{
- struct io_uring_restriction *res;
- size_t size;
- int i, ret;
-
- /* Restrictions allowed only if rings started disabled */
- if (!(ctx->flags & IORING_SETUP_R_DISABLED))
- return -EBADFD;
-
- /* We allow only a single restrictions registration */
- if (ctx->restrictions.registered)
- return -EBUSY;
-
- if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
- return -EINVAL;
-
- size = array_size(nr_args, sizeof(*res));
- if (size == SIZE_MAX)
- return -EOVERFLOW;
-
- res = memdup_user(arg, size);
- if (IS_ERR(res))
- return PTR_ERR(res);
-
- ret = 0;
-
- for (i = 0; i < nr_args; i++) {
- switch (res[i].opcode) {
- case IORING_RESTRICTION_REGISTER_OP:
- if (res[i].register_op >= IORING_REGISTER_LAST) {
- ret = -EINVAL;
- goto out;
- }
-
- __set_bit(res[i].register_op,
- ctx->restrictions.register_op);
- break;
- case IORING_RESTRICTION_SQE_OP:
- if (res[i].sqe_op >= IORING_OP_LAST) {
- ret = -EINVAL;
- goto out;
- }
-
- __set_bit(res[i].sqe_op, ctx->restrictions.sqe_op);
- break;
- case IORING_RESTRICTION_SQE_FLAGS_ALLOWED:
- ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags;
- break;
- case IORING_RESTRICTION_SQE_FLAGS_REQUIRED:
- ctx->restrictions.sqe_flags_required = res[i].sqe_flags;
- break;
- default:
- ret = -EINVAL;
- goto out;
- }
- }
-
-out:
- /* Reset all restrictions if an error happened */
- if (ret != 0)
- memset(&ctx->restrictions, 0, sizeof(ctx->restrictions));
- else
- ctx->restrictions.registered = true;
-
- kfree(res);
- return ret;
-}
-
-static int io_register_enable_rings(struct io_ring_ctx *ctx)
-{
- if (!(ctx->flags & IORING_SETUP_R_DISABLED))
- return -EBADFD;
-
- if (ctx->restrictions.registered)
- ctx->restricted = 1;
-
- io_sq_offload_start(ctx);
- return 0;
-}
-
-static bool io_register_op_must_quiesce(int op)
-{
- switch (op) {
- case IORING_UNREGISTER_FILES:
- case IORING_REGISTER_FILES_UPDATE:
- case IORING_REGISTER_PROBE:
- case IORING_REGISTER_PERSONALITY:
- case IORING_UNREGISTER_PERSONALITY:
- return false;
- default:
- return true;
- }
-}
-
-static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
- void __user *arg, unsigned nr_args)
- __releases(ctx->uring_lock)
- __acquires(ctx->uring_lock)
-{
- int ret;
-
- /*
- * We're inside the ring mutex, if the ref is already dying, then
- * someone else killed the ctx or is already going through
- * io_uring_register().
- */
- if (percpu_ref_is_dying(&ctx->refs))
- return -ENXIO;
-
- if (io_register_op_must_quiesce(opcode)) {
- percpu_ref_kill(&ctx->refs);
-
- /*
- * Drop uring mutex before waiting for references to exit. If
- * another thread is currently inside io_uring_enter() it might
- * need to grab the uring_lock to make progress. If we hold it
- * here across the drain wait, then we can deadlock. It's safe
- * to drop the mutex here, since no new references will come in
- * after we've killed the percpu ref.
- */
- mutex_unlock(&ctx->uring_lock);
- do {
- ret = wait_for_completion_interruptible(&ctx->ref_comp);
- if (!ret)
- break;
- ret = io_run_task_work_sig();
- if (ret < 0)
- break;
- } while (1);
- mutex_lock(&ctx->uring_lock);
-
- if (ret) {
- io_refs_resurrect(&ctx->refs, &ctx->ref_comp);
- return ret;
- }
- }
-
- if (ctx->restricted) {
- if (opcode >= IORING_REGISTER_LAST) {
- ret = -EINVAL;
- goto out;
- }
-
- if (!test_bit(opcode, ctx->restrictions.register_op)) {
- ret = -EACCES;
- goto out;
- }
- }
-
- switch (opcode) {
- case IORING_REGISTER_BUFFERS:
- ret = io_sqe_buffer_register(ctx, arg, nr_args);
- break;
- case IORING_UNREGISTER_BUFFERS:
- ret = -EINVAL;
- if (arg || nr_args)
- break;
- ret = io_sqe_buffer_unregister(ctx);
- break;
- case IORING_REGISTER_FILES:
- ret = io_sqe_files_register(ctx, arg, nr_args);
- break;
- case IORING_UNREGISTER_FILES:
- ret = -EINVAL;
- if (arg || nr_args)
- break;
- ret = io_sqe_files_unregister(ctx);
- break;
- case IORING_REGISTER_FILES_UPDATE:
- ret = io_sqe_files_update(ctx, arg, nr_args);
- break;
- case IORING_REGISTER_EVENTFD:
- case IORING_REGISTER_EVENTFD_ASYNC:
- ret = -EINVAL;
- if (nr_args != 1)
- break;
- ret = io_eventfd_register(ctx, arg);
- if (ret)
- break;
- if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
- ctx->eventfd_async = 1;
- else
- ctx->eventfd_async = 0;
- break;
- case IORING_UNREGISTER_EVENTFD:
- ret = -EINVAL;
- if (arg || nr_args)
- break;
- ret = io_eventfd_unregister(ctx);
- break;
- case IORING_REGISTER_PROBE:
- ret = -EINVAL;
- if (!arg || nr_args > 256)
- break;
- ret = io_probe(ctx, arg, nr_args);
- break;
- case IORING_REGISTER_PERSONALITY:
- ret = -EINVAL;
- if (arg || nr_args)
- break;
- ret = io_register_personality(ctx);
- break;
- case IORING_UNREGISTER_PERSONALITY:
- ret = -EINVAL;
- if (arg)
- break;
- ret = io_unregister_personality(ctx, nr_args);
- break;
- case IORING_REGISTER_ENABLE_RINGS:
- ret = -EINVAL;
- if (arg || nr_args)
- break;
- ret = io_register_enable_rings(ctx);
- break;
- case IORING_REGISTER_RESTRICTIONS:
- ret = io_register_restrictions(ctx, arg, nr_args);
- break;
- default:
- ret = -EINVAL;
- break;
- }
-
-out:
- if (io_register_op_must_quiesce(opcode)) {
- /* bring the ctx back to life */
- percpu_ref_reinit(&ctx->refs);
- reinit_completion(&ctx->ref_comp);
- }
- return ret;
-}
-
-SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
- void __user *, arg, unsigned int, nr_args)
-{
- struct io_ring_ctx *ctx;
- long ret = -EBADF;
- struct fd f;
-
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
-
- ret = -EOPNOTSUPP;
- if (f.file->f_op != &io_uring_fops)
- goto out_fput;
-
- ctx = f.file->private_data;
-
- mutex_lock(&ctx->uring_lock);
- ret = __io_uring_register(ctx, opcode, arg, nr_args);
- mutex_unlock(&ctx->uring_lock);
- trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
- ctx->cq_ev_fd != NULL, ret);
-out_fput:
- fdput(f);
- return ret;
-}
-
-static int __init io_uring_init(void)
-{
-#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
- BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
- BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
-} while (0)
-
-#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
- __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
- BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
- BUILD_BUG_SQE_ELEM(0, __u8, opcode);
- BUILD_BUG_SQE_ELEM(1, __u8, flags);
- BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
- BUILD_BUG_SQE_ELEM(4, __s32, fd);
- BUILD_BUG_SQE_ELEM(8, __u64, off);
- BUILD_BUG_SQE_ELEM(8, __u64, addr2);
- BUILD_BUG_SQE_ELEM(16, __u64, addr);
- BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
- BUILD_BUG_SQE_ELEM(24, __u32, len);
- BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
- BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
- BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
- BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
- BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
- BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
- BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
- BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
- BUILD_BUG_SQE_ELEM(32, __u64, user_data);
- BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
- BUILD_BUG_SQE_ELEM(42, __u16, personality);
- BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
-
- BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
- BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
- req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
- return 0;
-};
-__initcall(io_uring_init);
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -5,50 +5,20 @@
#include <linux/sched.h>
#include <linux/xarray.h>
-struct io_identity {
- struct files_struct *files;
- struct mm_struct *mm;
-#ifdef CONFIG_BLK_CGROUP
- struct cgroup_subsys_state *blkcg_css;
-#endif
- const struct cred *creds;
- struct nsproxy *nsproxy;
- struct fs_struct *fs;
- unsigned long fsize;
-#ifdef CONFIG_AUDIT
- kuid_t loginuid;
- unsigned int sessionid;
-#endif
- refcount_t count;
-};
-
-struct io_uring_task {
- /* submission side */
- struct xarray xa;
- struct wait_queue_head wait;
- struct file *last;
- struct percpu_counter inflight;
- struct io_identity __identity;
- struct io_identity *identity;
- atomic_t in_idle;
- bool sqpoll;
-};
-
#if defined(CONFIG_IO_URING)
struct sock *io_uring_get_socket(struct file *file);
-void __io_uring_task_cancel(void);
-void __io_uring_files_cancel(struct files_struct *files);
+void __io_uring_cancel(bool cancel_all);
void __io_uring_free(struct task_struct *tsk);
-static inline void io_uring_task_cancel(void)
+static inline void io_uring_files_cancel(void)
{
- if (current->io_uring && !xa_empty(¤t->io_uring->xa))
- __io_uring_task_cancel();
+ if (current->io_uring)
+ __io_uring_cancel(false);
}
-static inline void io_uring_files_cancel(struct files_struct *files)
+static inline void io_uring_task_cancel(void)
{
- if (current->io_uring && !xa_empty(¤t->io_uring->xa))
- __io_uring_files_cancel(files);
+ if (current->io_uring)
+ __io_uring_cancel(true);
}
static inline void io_uring_free(struct task_struct *tsk)
{
@@ -63,7 +33,7 @@ static inline struct sock *io_uring_get_
static inline void io_uring_task_cancel(void)
{
}
-static inline void io_uring_files_cancel(struct files_struct *files)
+static inline void io_uring_files_cancel(void)
{
}
static inline void io_uring_free(struct task_struct *tsk)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -885,6 +885,9 @@ struct task_struct {
/* CLONE_CHILD_CLEARTID: */
int __user *clear_child_tid;
+ /* PF_IO_WORKER */
+ void *pf_io_worker;
+
u64 utime;
u64 stime;
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -341,7 +341,7 @@ asmlinkage long sys_io_uring_setup(u32 e
struct io_uring_params __user *p);
asmlinkage long sys_io_uring_enter(unsigned int fd, u32 to_submit,
u32 min_complete, u32 flags,
- const sigset_t __user *sig, size_t sigsz);
+ const void __user *argp, size_t argsz);
asmlinkage long sys_io_uring_register(unsigned int fd, unsigned int op,
void __user *arg, unsigned int nr_args);
--- a/include/trace/events/io_uring.h
+++ b/include/trace/events/io_uring.h
@@ -12,11 +12,11 @@ struct io_wq_work;
/**
* io_uring_create - called after a new io_uring context was prepared
*
- * @fd: corresponding file descriptor
- * @ctx: pointer to a ring context structure
+ * @fd: corresponding file descriptor
+ * @ctx: pointer to a ring context structure
* @sq_entries: actual SQ size
* @cq_entries: actual CQ size
- * @flags: SQ ring flags, provided to io_uring_setup(2)
+ * @flags: SQ ring flags, provided to io_uring_setup(2)
*
* Allows to trace io_uring creation and provide pointer to a context, that can
* be used later to find correlated events.
@@ -49,15 +49,15 @@ TRACE_EVENT(io_uring_create,
);
/**
- * io_uring_register - called after a buffer/file/eventfd was succesfully
+ * io_uring_register - called after a buffer/file/eventfd was successfully
* registered for a ring
*
- * @ctx: pointer to a ring context structure
- * @opcode: describes which operation to perform
+ * @ctx: pointer to a ring context structure
+ * @opcode: describes which operation to perform
* @nr_user_files: number of registered files
* @nr_user_bufs: number of registered buffers
* @cq_ev_fd: whether eventfs registered or not
- * @ret: return code
+ * @ret: return code
*
* Allows to trace fixed files/buffers/eventfds, that could be registered to
* avoid an overhead of getting references to them for every operation. This
@@ -142,16 +142,16 @@ TRACE_EVENT(io_uring_queue_async_work,
TP_ARGS(ctx, rw, req, work, flags),
TP_STRUCT__entry (
- __field( void *, ctx )
- __field( int, rw )
- __field( void *, req )
+ __field( void *, ctx )
+ __field( int, rw )
+ __field( void *, req )
__field( struct io_wq_work *, work )
__field( unsigned int, flags )
),
TP_fast_assign(
__entry->ctx = ctx;
- __entry->rw = rw;
+ __entry->rw = rw;
__entry->req = req;
__entry->work = work;
__entry->flags = flags;
@@ -196,10 +196,10 @@ TRACE_EVENT(io_uring_defer,
/**
* io_uring_link - called before the io_uring request added into link_list of
- * another request
+ * another request
*
- * @ctx: pointer to a ring context structure
- * @req: pointer to a linked request
+ * @ctx: pointer to a ring context structure
+ * @req: pointer to a linked request
* @target_req: pointer to a previous request, that would contain @req
*
* Allows to track linked requests, to understand dependencies between requests
@@ -212,8 +212,8 @@ TRACE_EVENT(io_uring_link,
TP_ARGS(ctx, req, target_req),
TP_STRUCT__entry (
- __field( void *, ctx )
- __field( void *, req )
+ __field( void *, ctx )
+ __field( void *, req )
__field( void *, target_req )
),
@@ -244,7 +244,7 @@ TRACE_EVENT(io_uring_cqring_wait,
TP_ARGS(ctx, min_events),
TP_STRUCT__entry (
- __field( void *, ctx )
+ __field( void *, ctx )
__field( int, min_events )
),
@@ -272,7 +272,7 @@ TRACE_EVENT(io_uring_fail_link,
TP_ARGS(req, link),
TP_STRUCT__entry (
- __field( void *, req )
+ __field( void *, req )
__field( void *, link )
),
@@ -290,38 +290,42 @@ TRACE_EVENT(io_uring_fail_link,
* @ctx: pointer to a ring context structure
* @user_data: user data associated with the request
* @res: result of the request
+ * @cflags: completion flags
*
*/
TRACE_EVENT(io_uring_complete,
- TP_PROTO(void *ctx, u64 user_data, long res),
+ TP_PROTO(void *ctx, u64 user_data, int res, unsigned cflags),
- TP_ARGS(ctx, user_data, res),
+ TP_ARGS(ctx, user_data, res, cflags),
TP_STRUCT__entry (
__field( void *, ctx )
__field( u64, user_data )
- __field( long, res )
+ __field( int, res )
+ __field( unsigned, cflags )
),
TP_fast_assign(
__entry->ctx = ctx;
__entry->user_data = user_data;
__entry->res = res;
+ __entry->cflags = cflags;
),
- TP_printk("ring %p, user_data 0x%llx, result %ld",
+ TP_printk("ring %p, user_data 0x%llx, result %d, cflags %x",
__entry->ctx, (unsigned long long)__entry->user_data,
- __entry->res)
+ __entry->res, __entry->cflags)
);
-
/**
* io_uring_submit_sqe - called before submitting one SQE
*
* @ctx: pointer to a ring context structure
+ * @req: pointer to a submitted request
* @opcode: opcode of request
* @user_data: user data associated with the request
+ * @flags request flags
* @force_nonblock: whether a context blocking or not
* @sq_thread: true if sq_thread has submitted this SQE
*
@@ -330,41 +334,60 @@ TRACE_EVENT(io_uring_complete,
*/
TRACE_EVENT(io_uring_submit_sqe,
- TP_PROTO(void *ctx, u8 opcode, u64 user_data, bool force_nonblock,
- bool sq_thread),
+ TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data, u32 flags,
+ bool force_nonblock, bool sq_thread),
- TP_ARGS(ctx, opcode, user_data, force_nonblock, sq_thread),
+ TP_ARGS(ctx, req, opcode, user_data, flags, force_nonblock, sq_thread),
TP_STRUCT__entry (
__field( void *, ctx )
+ __field( void *, req )
__field( u8, opcode )
__field( u64, user_data )
+ __field( u32, flags )
__field( bool, force_nonblock )
__field( bool, sq_thread )
),
TP_fast_assign(
__entry->ctx = ctx;
+ __entry->req = req;
__entry->opcode = opcode;
__entry->user_data = user_data;
+ __entry->flags = flags;
__entry->force_nonblock = force_nonblock;
__entry->sq_thread = sq_thread;
),
- TP_printk("ring %p, op %d, data 0x%llx, non block %d, sq_thread %d",
- __entry->ctx, __entry->opcode,
- (unsigned long long) __entry->user_data,
- __entry->force_nonblock, __entry->sq_thread)
+ TP_printk("ring %p, req %p, op %d, data 0x%llx, flags %u, "
+ "non block %d, sq_thread %d", __entry->ctx, __entry->req,
+ __entry->opcode, (unsigned long long)__entry->user_data,
+ __entry->flags, __entry->force_nonblock, __entry->sq_thread)
);
+/*
+ * io_uring_poll_arm - called after arming a poll wait if successful
+ *
+ * @ctx: pointer to a ring context structure
+ * @req: pointer to the armed request
+ * @opcode: opcode of request
+ * @user_data: user data associated with the request
+ * @mask: request poll events mask
+ * @events: registered events of interest
+ *
+ * Allows to track which fds are waiting for and what are the events of
+ * interest.
+ */
TRACE_EVENT(io_uring_poll_arm,
- TP_PROTO(void *ctx, u8 opcode, u64 user_data, int mask, int events),
+ TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data,
+ int mask, int events),
- TP_ARGS(ctx, opcode, user_data, mask, events),
+ TP_ARGS(ctx, req, opcode, user_data, mask, events),
TP_STRUCT__entry (
__field( void *, ctx )
+ __field( void *, req )
__field( u8, opcode )
__field( u64, user_data )
__field( int, mask )
@@ -373,16 +396,17 @@ TRACE_EVENT(io_uring_poll_arm,
TP_fast_assign(
__entry->ctx = ctx;
+ __entry->req = req;
__entry->opcode = opcode;
__entry->user_data = user_data;
__entry->mask = mask;
__entry->events = events;
),
- TP_printk("ring %p, op %d, data 0x%llx, mask 0x%x, events 0x%x",
- __entry->ctx, __entry->opcode,
- (unsigned long long) __entry->user_data,
- __entry->mask, __entry->events)
+ TP_printk("ring %p, req %p, op %d, data 0x%llx, mask 0x%x, events 0x%x",
+ __entry->ctx, __entry->req, __entry->opcode,
+ (unsigned long long) __entry->user_data,
+ __entry->mask, __entry->events)
);
TRACE_EVENT(io_uring_poll_wake,
@@ -437,27 +461,40 @@ TRACE_EVENT(io_uring_task_add,
__entry->mask)
);
+/*
+ * io_uring_task_run - called when task_work_run() executes the poll events
+ * notification callbacks
+ *
+ * @ctx: pointer to a ring context structure
+ * @req: pointer to the armed request
+ * @opcode: opcode of request
+ * @user_data: user data associated with the request
+ *
+ * Allows to track when notified poll events are processed
+ */
TRACE_EVENT(io_uring_task_run,
- TP_PROTO(void *ctx, u8 opcode, u64 user_data),
+ TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data),
- TP_ARGS(ctx, opcode, user_data),
+ TP_ARGS(ctx, req, opcode, user_data),
TP_STRUCT__entry (
__field( void *, ctx )
+ __field( void *, req )
__field( u8, opcode )
__field( u64, user_data )
),
TP_fast_assign(
__entry->ctx = ctx;
+ __entry->req = req;
__entry->opcode = opcode;
__entry->user_data = user_data;
),
- TP_printk("ring %p, op %d, data 0x%llx",
- __entry->ctx, __entry->opcode,
- (unsigned long long) __entry->user_data)
+ TP_printk("ring %p, req %p, op %d, data 0x%llx",
+ __entry->ctx, __entry->req, __entry->opcode,
+ (unsigned long long) __entry->user_data)
);
#endif /* _TRACE_IO_URING_H */
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -42,23 +42,25 @@ struct io_uring_sqe {
__u32 statx_flags;
__u32 fadvise_advice;
__u32 splice_flags;
+ __u32 rename_flags;
+ __u32 unlink_flags;
+ __u32 hardlink_flags;
};
__u64 user_data; /* data to be passed back at completion time */
+ /* pack this to avoid bogus arm OABI complaints */
union {
- struct {
- /* pack this to avoid bogus arm OABI complaints */
- union {
- /* index into fixed buffers, if used */
- __u16 buf_index;
- /* for grouped buffer selection */
- __u16 buf_group;
- } __attribute__((packed));
- /* personality to use, if used */
- __u16 personality;
- __s32 splice_fd_in;
- };
- __u64 __pad2[3];
+ /* index into fixed buffers, if used */
+ __u16 buf_index;
+ /* for grouped buffer selection */
+ __u16 buf_group;
+ } __attribute__((packed));
+ /* personality to use, if used */
+ __u16 personality;
+ union {
+ __s32 splice_fd_in;
+ __u32 file_index;
};
+ __u64 __pad2[2];
};
enum {
@@ -132,6 +134,9 @@ enum {
IORING_OP_PROVIDE_BUFFERS,
IORING_OP_REMOVE_BUFFERS,
IORING_OP_TEE,
+ IORING_OP_SHUTDOWN,
+ IORING_OP_RENAMEAT,
+ IORING_OP_UNLINKAT,
/* this goes last, obviously */
IORING_OP_LAST,
@@ -145,8 +150,13 @@ enum {
/*
* sqe->timeout_flags
*/
-#define IORING_TIMEOUT_ABS (1U << 0)
-
+#define IORING_TIMEOUT_ABS (1U << 0)
+#define IORING_TIMEOUT_UPDATE (1U << 1)
+#define IORING_TIMEOUT_BOOTTIME (1U << 2)
+#define IORING_TIMEOUT_REALTIME (1U << 3)
+#define IORING_LINK_TIMEOUT_UPDATE (1U << 4)
+#define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
+#define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
/*
* sqe->splice_flags
* extends splice(2) flags
@@ -154,6 +164,21 @@ enum {
#define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
/*
+ * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
+ * command flags for POLL_ADD are stored in sqe->len.
+ *
+ * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if
+ * the poll handler will continue to report
+ * CQEs on behalf of the same SQE.
+ *
+ * IORING_POLL_UPDATE Update existing poll request, matching
+ * sqe->addr as the old user_data field.
+ */
+#define IORING_POLL_ADD_MULTI (1U << 0)
+#define IORING_POLL_UPDATE_EVENTS (1U << 1)
+#define IORING_POLL_UPDATE_USER_DATA (1U << 2)
+
+/*
* IO completion data structure (Completion Queue Entry)
*/
struct io_uring_cqe {
@@ -166,8 +191,10 @@ struct io_uring_cqe {
* cqe->flags
*
* IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
+ * IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries
*/
#define IORING_CQE_F_BUFFER (1U << 0)
+#define IORING_CQE_F_MORE (1U << 1)
enum {
IORING_CQE_BUFFER_SHIFT = 16,
@@ -226,6 +253,7 @@ struct io_cqring_offsets {
#define IORING_ENTER_GETEVENTS (1U << 0)
#define IORING_ENTER_SQ_WAKEUP (1U << 1)
#define IORING_ENTER_SQ_WAIT (1U << 2)
+#define IORING_ENTER_EXT_ARG (1U << 3)
/*
* Passed in for io_uring_setup(2). Copied back with updated info on success
@@ -253,6 +281,10 @@ struct io_uring_params {
#define IORING_FEAT_CUR_PERSONALITY (1U << 4)
#define IORING_FEAT_FAST_POLL (1U << 5)
#define IORING_FEAT_POLL_32BITS (1U << 6)
+#define IORING_FEAT_SQPOLL_NONFIXED (1U << 7)
+#define IORING_FEAT_EXT_ARG (1U << 8)
+#define IORING_FEAT_NATIVE_WORKERS (1U << 9)
+#define IORING_FEAT_RSRC_TAGS (1U << 10)
/*
* io_uring_register(2) opcodes and arguments
@@ -272,16 +304,62 @@ enum {
IORING_REGISTER_RESTRICTIONS = 11,
IORING_REGISTER_ENABLE_RINGS = 12,
+ /* extended with tagging */
+ IORING_REGISTER_FILES2 = 13,
+ IORING_REGISTER_FILES_UPDATE2 = 14,
+ IORING_REGISTER_BUFFERS2 = 15,
+ IORING_REGISTER_BUFFERS_UPDATE = 16,
+
+ /* set/clear io-wq thread affinities */
+ IORING_REGISTER_IOWQ_AFF = 17,
+ IORING_UNREGISTER_IOWQ_AFF = 18,
+
+ /* set/get max number of io-wq workers */
+ IORING_REGISTER_IOWQ_MAX_WORKERS = 19,
+
/* this goes last */
IORING_REGISTER_LAST
};
+/* io-wq worker categories */
+enum {
+ IO_WQ_BOUND,
+ IO_WQ_UNBOUND,
+};
+
+/* deprecated, see struct io_uring_rsrc_update */
struct io_uring_files_update {
__u32 offset;
__u32 resv;
__aligned_u64 /* __s32 * */ fds;
};
+struct io_uring_rsrc_register {
+ __u32 nr;
+ __u32 resv;
+ __u64 resv2;
+ __aligned_u64 data;
+ __aligned_u64 tags;
+};
+
+struct io_uring_rsrc_update {
+ __u32 offset;
+ __u32 resv;
+ __aligned_u64 data;
+};
+
+struct io_uring_rsrc_update2 {
+ __u32 offset;
+ __u32 resv;
+ __aligned_u64 data;
+ __aligned_u64 tags;
+ __u32 nr;
+ __u32 resv2;
+};
+
+/* Skip updating fd indexes set to this value in the fd table */
+#define IORING_REGISTER_FILES_SKIP (-2)
+
#define IO_URING_OP_SUPPORTED (1U << 0)
struct io_uring_probe_op {
@@ -329,4 +407,11 @@ enum {
IORING_RESTRICTION_LAST
};
+struct io_uring_getevents_arg {
+ __u64 sigmask;
+ __u32 sigmask_sz;
+ __u32 pad;
+ __u64 ts;
+};
+
#endif
--- /dev/null
+++ b/io_uring/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for io_uring
+
+obj-$(CONFIG_IO_URING) += io_uring.o
+obj-$(CONFIG_IO_WQ) += io-wq.o
--- /dev/null
+++ b/io_uring/io-wq.c
@@ -0,0 +1,1398 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Basic worker thread pool for io_uring
+ *
+ * Copyright (C) 2019 Jens Axboe
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sched/signal.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+#include <linux/rculist_nulls.h>
+#include <linux/cpu.h>
+#include <linux/tracehook.h>
+#include <uapi/linux/io_uring.h>
+
+#include "io-wq.h"
+
+#define WORKER_IDLE_TIMEOUT (5 * HZ)
+
+enum {
+ IO_WORKER_F_UP = 1, /* up and active */
+ IO_WORKER_F_RUNNING = 2, /* account as running */
+ IO_WORKER_F_FREE = 4, /* worker on free list */
+ IO_WORKER_F_BOUND = 8, /* is doing bounded work */
+};
+
+enum {
+ IO_WQ_BIT_EXIT = 0, /* wq exiting */
+};
+
+enum {
+ IO_ACCT_STALLED_BIT = 0, /* stalled on hash */
+};
+
+/*
+ * One for each thread in a wqe pool
+ */
+struct io_worker {
+ refcount_t ref;
+ unsigned flags;
+ struct hlist_nulls_node nulls_node;
+ struct list_head all_list;
+ struct task_struct *task;
+ struct io_wqe *wqe;
+
+ struct io_wq_work *cur_work;
+ spinlock_t lock;
+
+ struct completion ref_done;
+
+ unsigned long create_state;
+ struct callback_head create_work;
+ int create_index;
+
+ union {
+ struct rcu_head rcu;
+ struct work_struct work;
+ };
+};
+
+#if BITS_PER_LONG == 64
+#define IO_WQ_HASH_ORDER 6
+#else
+#define IO_WQ_HASH_ORDER 5
+#endif
+
+#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER)
+
+struct io_wqe_acct {
+ unsigned nr_workers;
+ unsigned max_workers;
+ int index;
+ atomic_t nr_running;
+ struct io_wq_work_list work_list;
+ unsigned long flags;
+};
+
+enum {
+ IO_WQ_ACCT_BOUND,
+ IO_WQ_ACCT_UNBOUND,
+ IO_WQ_ACCT_NR,
+};
+
+/*
+ * Per-node worker thread pool
+ */
+struct io_wqe {
+ raw_spinlock_t lock;
+ struct io_wqe_acct acct[2];
+
+ int node;
+
+ struct hlist_nulls_head free_list;
+ struct list_head all_list;
+
+ struct wait_queue_entry wait;
+
+ struct io_wq *wq;
+ struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS];
+
+ cpumask_var_t cpu_mask;
+};
+
+/*
+ * Per io_wq state
+ */
+struct io_wq {
+ unsigned long state;
+
+ free_work_fn *free_work;
+ io_wq_work_fn *do_work;
+
+ struct io_wq_hash *hash;
+
+ atomic_t worker_refs;
+ struct completion worker_done;
+
+ struct hlist_node cpuhp_node;
+
+ struct task_struct *task;
+
+ struct io_wqe *wqes[];
+};
+
+static enum cpuhp_state io_wq_online;
+
+struct io_cb_cancel_data {
+ work_cancel_fn *fn;
+ void *data;
+ int nr_running;
+ int nr_pending;
+ bool cancel_all;
+};
+
+static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index);
+static void io_wqe_dec_running(struct io_worker *worker);
+static bool io_acct_cancel_pending_work(struct io_wqe *wqe,
+ struct io_wqe_acct *acct,
+ struct io_cb_cancel_data *match);
+static void create_worker_cb(struct callback_head *cb);
+static void io_wq_cancel_tw_create(struct io_wq *wq);
+
+static bool io_worker_get(struct io_worker *worker)
+{
+ return refcount_inc_not_zero(&worker->ref);
+}
+
+static void io_worker_release(struct io_worker *worker)
+{
+ if (refcount_dec_and_test(&worker->ref))
+ complete(&worker->ref_done);
+}
+
+static inline struct io_wqe_acct *io_get_acct(struct io_wqe *wqe, bool bound)
+{
+ return &wqe->acct[bound ? IO_WQ_ACCT_BOUND : IO_WQ_ACCT_UNBOUND];
+}
+
+static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe,
+ struct io_wq_work *work)
+{
+ return io_get_acct(wqe, !(work->flags & IO_WQ_WORK_UNBOUND));
+}
+
+static inline struct io_wqe_acct *io_wqe_get_acct(struct io_worker *worker)
+{
+ return io_get_acct(worker->wqe, worker->flags & IO_WORKER_F_BOUND);
+}
+
+static void io_worker_ref_put(struct io_wq *wq)
+{
+ if (atomic_dec_and_test(&wq->worker_refs))
+ complete(&wq->worker_done);
+}
+
+static void io_worker_cancel_cb(struct io_worker *worker)
+{
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+ struct io_wqe *wqe = worker->wqe;
+ struct io_wq *wq = wqe->wq;
+
+ atomic_dec(&acct->nr_running);
+ raw_spin_lock(&worker->wqe->lock);
+ acct->nr_workers--;
+ raw_spin_unlock(&worker->wqe->lock);
+ io_worker_ref_put(wq);
+ clear_bit_unlock(0, &worker->create_state);
+ io_worker_release(worker);
+}
+
+static bool io_task_worker_match(struct callback_head *cb, void *data)
+{
+ struct io_worker *worker;
+
+ if (cb->func != create_worker_cb)
+ return false;
+ worker = container_of(cb, struct io_worker, create_work);
+ return worker == data;
+}
+
+static void io_worker_exit(struct io_worker *worker)
+{
+ struct io_wqe *wqe = worker->wqe;
+ struct io_wq *wq = wqe->wq;
+
+ while (1) {
+ struct callback_head *cb = task_work_cancel_match(wq->task,
+ io_task_worker_match, worker);
+
+ if (!cb)
+ break;
+ io_worker_cancel_cb(worker);
+ }
+
+ if (refcount_dec_and_test(&worker->ref))
+ complete(&worker->ref_done);
+ wait_for_completion(&worker->ref_done);
+
+ raw_spin_lock(&wqe->lock);
+ if (worker->flags & IO_WORKER_F_FREE)
+ hlist_nulls_del_rcu(&worker->nulls_node);
+ list_del_rcu(&worker->all_list);
+ preempt_disable();
+ io_wqe_dec_running(worker);
+ worker->flags = 0;
+ current->flags &= ~PF_IO_WORKER;
+ preempt_enable();
+ raw_spin_unlock(&wqe->lock);
+
+ kfree_rcu(worker, rcu);
+ io_worker_ref_put(wqe->wq);
+ do_exit(0);
+}
+
+static inline bool io_acct_run_queue(struct io_wqe_acct *acct)
+{
+ if (!wq_list_empty(&acct->work_list) &&
+ !test_bit(IO_ACCT_STALLED_BIT, &acct->flags))
+ return true;
+ return false;
+}
+
+/*
+ * Check head of free list for an available worker. If one isn't available,
+ * caller must create one.
+ */
+static bool io_wqe_activate_free_worker(struct io_wqe *wqe,
+ struct io_wqe_acct *acct)
+ __must_hold(RCU)
+{
+ struct hlist_nulls_node *n;
+ struct io_worker *worker;
+
+ /*
+ * Iterate free_list and see if we can find an idle worker to
+ * activate. If a given worker is on the free_list but in the process
+ * of exiting, keep trying.
+ */
+ hlist_nulls_for_each_entry_rcu(worker, n, &wqe->free_list, nulls_node) {
+ if (!io_worker_get(worker))
+ continue;
+ if (io_wqe_get_acct(worker) != acct) {
+ io_worker_release(worker);
+ continue;
+ }
+ if (wake_up_process(worker->task)) {
+ io_worker_release(worker);
+ return true;
+ }
+ io_worker_release(worker);
+ }
+
+ return false;
+}
+
+/*
+ * We need a worker. If we find a free one, we're good. If not, and we're
+ * below the max number of workers, create one.
+ */
+static bool io_wqe_create_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
+{
+ /*
+ * Most likely an attempt to queue unbounded work on an io_wq that
+ * wasn't setup with any unbounded workers.
+ */
+ if (unlikely(!acct->max_workers))
+ pr_warn_once("io-wq is not configured for unbound workers");
+
+ raw_spin_lock(&wqe->lock);
+ if (acct->nr_workers >= acct->max_workers) {
+ raw_spin_unlock(&wqe->lock);
+ return true;
+ }
+ acct->nr_workers++;
+ raw_spin_unlock(&wqe->lock);
+ atomic_inc(&acct->nr_running);
+ atomic_inc(&wqe->wq->worker_refs);
+ return create_io_worker(wqe->wq, wqe, acct->index);
+}
+
+static void io_wqe_inc_running(struct io_worker *worker)
+{
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+
+ atomic_inc(&acct->nr_running);
+}
+
+static void create_worker_cb(struct callback_head *cb)
+{
+ struct io_worker *worker;
+ struct io_wq *wq;
+ struct io_wqe *wqe;
+ struct io_wqe_acct *acct;
+ bool do_create = false;
+
+ worker = container_of(cb, struct io_worker, create_work);
+ wqe = worker->wqe;
+ wq = wqe->wq;
+ acct = &wqe->acct[worker->create_index];
+ raw_spin_lock(&wqe->lock);
+ if (acct->nr_workers < acct->max_workers) {
+ acct->nr_workers++;
+ do_create = true;
+ }
+ raw_spin_unlock(&wqe->lock);
+ if (do_create) {
+ create_io_worker(wq, wqe, worker->create_index);
+ } else {
+ atomic_dec(&acct->nr_running);
+ io_worker_ref_put(wq);
+ }
+ clear_bit_unlock(0, &worker->create_state);
+ io_worker_release(worker);
+}
+
+static bool io_queue_worker_create(struct io_worker *worker,
+ struct io_wqe_acct *acct,
+ task_work_func_t func)
+{
+ struct io_wqe *wqe = worker->wqe;
+ struct io_wq *wq = wqe->wq;
+
+ /* raced with exit, just ignore create call */
+ if (test_bit(IO_WQ_BIT_EXIT, &wq->state))
+ goto fail;
+ if (!io_worker_get(worker))
+ goto fail;
+ /*
+ * create_state manages ownership of create_work/index. We should
+ * only need one entry per worker, as the worker going to sleep
+ * will trigger the condition, and waking will clear it once it
+ * runs the task_work.
+ */
+ if (test_bit(0, &worker->create_state) ||
+ test_and_set_bit_lock(0, &worker->create_state))
+ goto fail_release;
+
+ atomic_inc(&wq->worker_refs);
+ init_task_work(&worker->create_work, func);
+ worker->create_index = acct->index;
+ if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL)) {
+ /*
+ * EXIT may have been set after checking it above, check after
+ * adding the task_work and remove any creation item if it is
+ * now set. wq exit does that too, but we can have added this
+ * work item after we canceled in io_wq_exit_workers().
+ */
+ if (test_bit(IO_WQ_BIT_EXIT, &wq->state))
+ io_wq_cancel_tw_create(wq);
+ io_worker_ref_put(wq);
+ return true;
+ }
+ io_worker_ref_put(wq);
+ clear_bit_unlock(0, &worker->create_state);
+fail_release:
+ io_worker_release(worker);
+fail:
+ atomic_dec(&acct->nr_running);
+ io_worker_ref_put(wq);
+ return false;
+}
+
+static void io_wqe_dec_running(struct io_worker *worker)
+ __must_hold(wqe->lock)
+{
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+ struct io_wqe *wqe = worker->wqe;
+
+ if (!(worker->flags & IO_WORKER_F_UP))
+ return;
+
+ if (atomic_dec_and_test(&acct->nr_running) && io_acct_run_queue(acct)) {
+ atomic_inc(&acct->nr_running);
+ atomic_inc(&wqe->wq->worker_refs);
+ raw_spin_unlock(&wqe->lock);
+ io_queue_worker_create(worker, acct, create_worker_cb);
+ raw_spin_lock(&wqe->lock);
+ }
+}
+
+/*
+ * Worker will start processing some work. Move it to the busy list, if
+ * it's currently on the freelist
+ */
+static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
+ struct io_wq_work *work)
+ __must_hold(wqe->lock)
+{
+ if (worker->flags & IO_WORKER_F_FREE) {
+ worker->flags &= ~IO_WORKER_F_FREE;
+ hlist_nulls_del_init_rcu(&worker->nulls_node);
+ }
+}
+
+/*
+ * No work, worker going to sleep. Move to freelist, and unuse mm if we
+ * have one attached. Dropping the mm may potentially sleep, so we drop
+ * the lock in that case and return success. Since the caller has to
+ * retry the loop in that case (we changed task state), we don't regrab
+ * the lock if we return success.
+ */
+static void __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
+ __must_hold(wqe->lock)
+{
+ if (!(worker->flags & IO_WORKER_F_FREE)) {
+ worker->flags |= IO_WORKER_F_FREE;
+ hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
+ }
+}
+
+static inline unsigned int io_get_work_hash(struct io_wq_work *work)
+{
+ return work->flags >> IO_WQ_HASH_SHIFT;
+}
+
+static bool io_wait_on_hash(struct io_wqe *wqe, unsigned int hash)
+{
+ struct io_wq *wq = wqe->wq;
+ bool ret = false;
+
+ spin_lock_irq(&wq->hash->wait.lock);
+ if (list_empty(&wqe->wait.entry)) {
+ __add_wait_queue(&wq->hash->wait, &wqe->wait);
+ if (!test_bit(hash, &wq->hash->map)) {
+ __set_current_state(TASK_RUNNING);
+ list_del_init(&wqe->wait.entry);
+ ret = true;
+ }
+ }
+ spin_unlock_irq(&wq->hash->wait.lock);
+ return ret;
+}
+
+static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct,
+ struct io_worker *worker)
+ __must_hold(wqe->lock)
+{
+ struct io_wq_work_node *node, *prev;
+ struct io_wq_work *work, *tail;
+ unsigned int stall_hash = -1U;
+ struct io_wqe *wqe = worker->wqe;
+
+ wq_list_for_each(node, prev, &acct->work_list) {
+ unsigned int hash;
+
+ work = container_of(node, struct io_wq_work, list);
+
+ /* not hashed, can run anytime */
+ if (!io_wq_is_hashed(work)) {
+ wq_list_del(&acct->work_list, node, prev);
+ return work;
+ }
+
+ hash = io_get_work_hash(work);
+ /* all items with this hash lie in [work, tail] */
+ tail = wqe->hash_tail[hash];
+
+ /* hashed, can run if not already running */
+ if (!test_and_set_bit(hash, &wqe->wq->hash->map)) {
+ wqe->hash_tail[hash] = NULL;
+ wq_list_cut(&acct->work_list, &tail->list, prev);
+ return work;
+ }
+ if (stall_hash == -1U)
+ stall_hash = hash;
+ /* fast forward to a next hash, for-each will fix up @prev */
+ node = &tail->list;
+ }
+
+ if (stall_hash != -1U) {
+ bool unstalled;
+
+ /*
+ * Set this before dropping the lock to avoid racing with new
+ * work being added and clearing the stalled bit.
+ */
+ set_bit(IO_ACCT_STALLED_BIT, &acct->flags);
+ raw_spin_unlock(&wqe->lock);
+ unstalled = io_wait_on_hash(wqe, stall_hash);
+ raw_spin_lock(&wqe->lock);
+ if (unstalled) {
+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
+ if (wq_has_sleeper(&wqe->wq->hash->wait))
+ wake_up(&wqe->wq->hash->wait);
+ }
+ }
+
+ return NULL;
+}
+
+static bool io_flush_signals(void)
+{
+ if (unlikely(test_thread_flag(TIF_NOTIFY_SIGNAL))) {
+ __set_current_state(TASK_RUNNING);
+ tracehook_notify_signal();
+ return true;
+ }
+ return false;
+}
+
+static void io_assign_current_work(struct io_worker *worker,
+ struct io_wq_work *work)
+{
+ if (work) {
+ io_flush_signals();
+ cond_resched();
+ }
+
+ spin_lock(&worker->lock);
+ worker->cur_work = work;
+ spin_unlock(&worker->lock);
+}
+
+static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
+
+static void io_worker_handle_work(struct io_worker *worker)
+ __releases(wqe->lock)
+{
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+ struct io_wqe *wqe = worker->wqe;
+ struct io_wq *wq = wqe->wq;
+ bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
+
+ do {
+ struct io_wq_work *work;
+get_next:
+ /*
+ * If we got some work, mark us as busy. If we didn't, but
+ * the list isn't empty, it means we stalled on hashed work.
+ * Mark us stalled so we don't keep looking for work when we
+ * can't make progress, any work completion or insertion will
+ * clear the stalled flag.
+ */
+ work = io_get_next_work(acct, worker);
+ if (work)
+ __io_worker_busy(wqe, worker, work);
+
+ raw_spin_unlock(&wqe->lock);
+ if (!work)
+ break;
+ io_assign_current_work(worker, work);
+ __set_current_state(TASK_RUNNING);
+
+ /* handle a whole dependent link */
+ do {
+ struct io_wq_work *next_hashed, *linked;
+ unsigned int hash = io_get_work_hash(work);
+
+ next_hashed = wq_next_work(work);
+
+ if (unlikely(do_kill) && (work->flags & IO_WQ_WORK_UNBOUND))
+ work->flags |= IO_WQ_WORK_CANCEL;
+ wq->do_work(work);
+ io_assign_current_work(worker, NULL);
+
+ linked = wq->free_work(work);
+ work = next_hashed;
+ if (!work && linked && !io_wq_is_hashed(linked)) {
+ work = linked;
+ linked = NULL;
+ }
+ io_assign_current_work(worker, work);
+ if (linked)
+ io_wqe_enqueue(wqe, linked);
+
+ if (hash != -1U && !next_hashed) {
+ /* serialize hash clear with wake_up() */
+ spin_lock_irq(&wq->hash->wait.lock);
+ clear_bit(hash, &wq->hash->map);
+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
+ spin_unlock_irq(&wq->hash->wait.lock);
+ if (wq_has_sleeper(&wq->hash->wait))
+ wake_up(&wq->hash->wait);
+ raw_spin_lock(&wqe->lock);
+ /* skip unnecessary unlock-lock wqe->lock */
+ if (!work)
+ goto get_next;
+ raw_spin_unlock(&wqe->lock);
+ }
+ } while (work);
+
+ raw_spin_lock(&wqe->lock);
+ } while (1);
+}
+
+static int io_wqe_worker(void *data)
+{
+ struct io_worker *worker = data;
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+ struct io_wqe *wqe = worker->wqe;
+ struct io_wq *wq = wqe->wq;
+ bool last_timeout = false;
+ char buf[TASK_COMM_LEN];
+
+ worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
+
+ snprintf(buf, sizeof(buf), "iou-wrk-%d", wq->task->pid);
+ set_task_comm(current, buf);
+
+ while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
+ long ret;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+loop:
+ raw_spin_lock(&wqe->lock);
+ if (io_acct_run_queue(acct)) {
+ io_worker_handle_work(worker);
+ goto loop;
+ }
+ /* timed out, exit unless we're the last worker */
+ if (last_timeout && acct->nr_workers > 1) {
+ acct->nr_workers--;
+ raw_spin_unlock(&wqe->lock);
+ __set_current_state(TASK_RUNNING);
+ break;
+ }
+ last_timeout = false;
+ __io_worker_idle(wqe, worker);
+ raw_spin_unlock(&wqe->lock);
+ if (io_flush_signals())
+ continue;
+ ret = schedule_timeout(WORKER_IDLE_TIMEOUT);
+ if (signal_pending(current)) {
+ struct ksignal ksig;
+
+ if (!get_signal(&ksig))
+ continue;
+ break;
+ }
+ last_timeout = !ret;
+ }
+
+ if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
+ raw_spin_lock(&wqe->lock);
+ io_worker_handle_work(worker);
+ }
+
+ io_worker_exit(worker);
+ return 0;
+}
+
+/*
+ * Called when a worker is scheduled in. Mark us as currently running.
+ */
+void io_wq_worker_running(struct task_struct *tsk)
+{
+ struct io_worker *worker = tsk->pf_io_worker;
+
+ if (!worker)
+ return;
+ if (!(worker->flags & IO_WORKER_F_UP))
+ return;
+ if (worker->flags & IO_WORKER_F_RUNNING)
+ return;
+ worker->flags |= IO_WORKER_F_RUNNING;
+ io_wqe_inc_running(worker);
+}
+
+/*
+ * Called when worker is going to sleep. If there are no workers currently
+ * running and we have work pending, wake up a free one or create a new one.
+ */
+void io_wq_worker_sleeping(struct task_struct *tsk)
+{
+ struct io_worker *worker = tsk->pf_io_worker;
+
+ if (!worker)
+ return;
+ if (!(worker->flags & IO_WORKER_F_UP))
+ return;
+ if (!(worker->flags & IO_WORKER_F_RUNNING))
+ return;
+
+ worker->flags &= ~IO_WORKER_F_RUNNING;
+
+ raw_spin_lock(&worker->wqe->lock);
+ io_wqe_dec_running(worker);
+ raw_spin_unlock(&worker->wqe->lock);
+}
+
+static void io_init_new_worker(struct io_wqe *wqe, struct io_worker *worker,
+ struct task_struct *tsk)
+{
+ tsk->pf_io_worker = worker;
+ worker->task = tsk;
+ set_cpus_allowed_ptr(tsk, wqe->cpu_mask);
+ tsk->flags |= PF_NO_SETAFFINITY;
+
+ raw_spin_lock(&wqe->lock);
+ hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
+ list_add_tail_rcu(&worker->all_list, &wqe->all_list);
+ worker->flags |= IO_WORKER_F_FREE;
+ raw_spin_unlock(&wqe->lock);
+ wake_up_new_task(tsk);
+}
+
+static bool io_wq_work_match_all(struct io_wq_work *work, void *data)
+{
+ return true;
+}
+
+static inline bool io_should_retry_thread(long err)
+{
+ /*
+ * Prevent perpetual task_work retry, if the task (or its group) is
+ * exiting.
+ */
+ if (fatal_signal_pending(current))
+ return false;
+
+ switch (err) {
+ case -EAGAIN:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ case -ERESTARTNOHAND:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static void create_worker_cont(struct callback_head *cb)
+{
+ struct io_worker *worker;
+ struct task_struct *tsk;
+ struct io_wqe *wqe;
+
+ worker = container_of(cb, struct io_worker, create_work);
+ clear_bit_unlock(0, &worker->create_state);
+ wqe = worker->wqe;
+ tsk = create_io_thread(io_wqe_worker, worker, wqe->node);
+ if (!IS_ERR(tsk)) {
+ io_init_new_worker(wqe, worker, tsk);
+ io_worker_release(worker);
+ return;
+ } else if (!io_should_retry_thread(PTR_ERR(tsk))) {
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+
+ atomic_dec(&acct->nr_running);
+ raw_spin_lock(&wqe->lock);
+ acct->nr_workers--;
+ if (!acct->nr_workers) {
+ struct io_cb_cancel_data match = {
+ .fn = io_wq_work_match_all,
+ .cancel_all = true,
+ };
+
+ while (io_acct_cancel_pending_work(wqe, acct, &match))
+ raw_spin_lock(&wqe->lock);
+ }
+ raw_spin_unlock(&wqe->lock);
+ io_worker_ref_put(wqe->wq);
+ kfree(worker);
+ return;
+ }
+
+ /* re-create attempts grab a new worker ref, drop the existing one */
+ io_worker_release(worker);
+ schedule_work(&worker->work);
+}
+
+static void io_workqueue_create(struct work_struct *work)
+{
+ struct io_worker *worker = container_of(work, struct io_worker, work);
+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
+
+ if (!io_queue_worker_create(worker, acct, create_worker_cont))
+ kfree(worker);
+}
+
+static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
+{
+ struct io_wqe_acct *acct = &wqe->acct[index];
+ struct io_worker *worker;
+ struct task_struct *tsk;
+
+ __set_current_state(TASK_RUNNING);
+
+ worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node);
+ if (!worker) {
+fail:
+ atomic_dec(&acct->nr_running);
+ raw_spin_lock(&wqe->lock);
+ acct->nr_workers--;
+ raw_spin_unlock(&wqe->lock);
+ io_worker_ref_put(wq);
+ return false;
+ }
+
+ refcount_set(&worker->ref, 1);
+ worker->wqe = wqe;
+ spin_lock_init(&worker->lock);
+ init_completion(&worker->ref_done);
+
+ if (index == IO_WQ_ACCT_BOUND)
+ worker->flags |= IO_WORKER_F_BOUND;
+
+ tsk = create_io_thread(io_wqe_worker, worker, wqe->node);
+ if (!IS_ERR(tsk)) {
+ io_init_new_worker(wqe, worker, tsk);
+ } else if (!io_should_retry_thread(PTR_ERR(tsk))) {
+ kfree(worker);
+ goto fail;
+ } else {
+ INIT_WORK(&worker->work, io_workqueue_create);
+ schedule_work(&worker->work);
+ }
+
+ return true;
+}
+
+/*
+ * Iterate the passed in list and call the specific function for each
+ * worker that isn't exiting
+ */
+static bool io_wq_for_each_worker(struct io_wqe *wqe,
+ bool (*func)(struct io_worker *, void *),
+ void *data)
+{
+ struct io_worker *worker;
+ bool ret = false;
+
+ list_for_each_entry_rcu(worker, &wqe->all_list, all_list) {
+ if (io_worker_get(worker)) {
+ /* no task if node is/was offline */
+ if (worker->task)
+ ret = func(worker, data);
+ io_worker_release(worker);
+ if (ret)
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static bool io_wq_worker_wake(struct io_worker *worker, void *data)
+{
+ set_notify_signal(worker->task);
+ wake_up_process(worker->task);
+ return false;
+}
+
+static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
+{
+ struct io_wq *wq = wqe->wq;
+
+ do {
+ work->flags |= IO_WQ_WORK_CANCEL;
+ wq->do_work(work);
+ work = wq->free_work(work);
+ } while (work);
+}
+
+static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work)
+{
+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
+ unsigned int hash;
+ struct io_wq_work *tail;
+
+ if (!io_wq_is_hashed(work)) {
+append:
+ wq_list_add_tail(&work->list, &acct->work_list);
+ return;
+ }
+
+ hash = io_get_work_hash(work);
+ tail = wqe->hash_tail[hash];
+ wqe->hash_tail[hash] = work;
+ if (!tail)
+ goto append;
+
+ wq_list_add_after(&work->list, &tail->list, &acct->work_list);
+}
+
+static bool io_wq_work_match_item(struct io_wq_work *work, void *data)
+{
+ return work == data;
+}
+
+static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
+{
+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
+ unsigned work_flags = work->flags;
+ bool do_create;
+
+ /*
+ * If io-wq is exiting for this task, or if the request has explicitly
+ * been marked as one that should not get executed, cancel it here.
+ */
+ if (test_bit(IO_WQ_BIT_EXIT, &wqe->wq->state) ||
+ (work->flags & IO_WQ_WORK_CANCEL)) {
+ io_run_cancel(work, wqe);
+ return;
+ }
+
+ raw_spin_lock(&wqe->lock);
+ io_wqe_insert_work(wqe, work);
+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
+
+ rcu_read_lock();
+ do_create = !io_wqe_activate_free_worker(wqe, acct);
+ rcu_read_unlock();
+
+ raw_spin_unlock(&wqe->lock);
+
+ if (do_create && ((work_flags & IO_WQ_WORK_CONCURRENT) ||
+ !atomic_read(&acct->nr_running))) {
+ bool did_create;
+
+ did_create = io_wqe_create_worker(wqe, acct);
+ if (likely(did_create))
+ return;
+
+ raw_spin_lock(&wqe->lock);
+ /* fatal condition, failed to create the first worker */
+ if (!acct->nr_workers) {
+ struct io_cb_cancel_data match = {
+ .fn = io_wq_work_match_item,
+ .data = work,
+ .cancel_all = false,
+ };
+
+ if (io_acct_cancel_pending_work(wqe, acct, &match))
+ raw_spin_lock(&wqe->lock);
+ }
+ raw_spin_unlock(&wqe->lock);
+ }
+}
+
+void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
+{
+ struct io_wqe *wqe = wq->wqes[numa_node_id()];
+
+ io_wqe_enqueue(wqe, work);
+}
+
+/*
+ * Work items that hash to the same value will not be done in parallel.
+ * Used to limit concurrent writes, generally hashed by inode.
+ */
+void io_wq_hash_work(struct io_wq_work *work, void *val)
+{
+ unsigned int bit;
+
+ bit = hash_ptr(val, IO_WQ_HASH_ORDER);
+ work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT));
+}
+
+static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
+{
+ struct io_cb_cancel_data *match = data;
+
+ /*
+ * Hold the lock to avoid ->cur_work going out of scope, caller
+ * may dereference the passed in work.
+ */
+ spin_lock(&worker->lock);
+ if (worker->cur_work &&
+ match->fn(worker->cur_work, match->data)) {
+ set_notify_signal(worker->task);
+ match->nr_running++;
+ }
+ spin_unlock(&worker->lock);
+
+ return match->nr_running && !match->cancel_all;
+}
+
+static inline void io_wqe_remove_pending(struct io_wqe *wqe,
+ struct io_wq_work *work,
+ struct io_wq_work_node *prev)
+{
+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
+ unsigned int hash = io_get_work_hash(work);
+ struct io_wq_work *prev_work = NULL;
+
+ if (io_wq_is_hashed(work) && work == wqe->hash_tail[hash]) {
+ if (prev)
+ prev_work = container_of(prev, struct io_wq_work, list);
+ if (prev_work && io_get_work_hash(prev_work) == hash)
+ wqe->hash_tail[hash] = prev_work;
+ else
+ wqe->hash_tail[hash] = NULL;
+ }
+ wq_list_del(&acct->work_list, &work->list, prev);
+}
+
+static bool io_acct_cancel_pending_work(struct io_wqe *wqe,
+ struct io_wqe_acct *acct,
+ struct io_cb_cancel_data *match)
+ __releases(wqe->lock)
+{
+ struct io_wq_work_node *node, *prev;
+ struct io_wq_work *work;
+
+ wq_list_for_each(node, prev, &acct->work_list) {
+ work = container_of(node, struct io_wq_work, list);
+ if (!match->fn(work, match->data))
+ continue;
+ io_wqe_remove_pending(wqe, work, prev);
+ raw_spin_unlock(&wqe->lock);
+ io_run_cancel(work, wqe);
+ match->nr_pending++;
+ /* not safe to continue after unlock */
+ return true;
+ }
+
+ return false;
+}
+
+static void io_wqe_cancel_pending_work(struct io_wqe *wqe,
+ struct io_cb_cancel_data *match)
+{
+ int i;
+retry:
+ raw_spin_lock(&wqe->lock);
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
+ struct io_wqe_acct *acct = io_get_acct(wqe, i == 0);
+
+ if (io_acct_cancel_pending_work(wqe, acct, match)) {
+ if (match->cancel_all)
+ goto retry;
+ return;
+ }
+ }
+ raw_spin_unlock(&wqe->lock);
+}
+
+static void io_wqe_cancel_running_work(struct io_wqe *wqe,
+ struct io_cb_cancel_data *match)
+{
+ rcu_read_lock();
+ io_wq_for_each_worker(wqe, io_wq_worker_cancel, match);
+ rcu_read_unlock();
+}
+
+enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
+ void *data, bool cancel_all)
+{
+ struct io_cb_cancel_data match = {
+ .fn = cancel,
+ .data = data,
+ .cancel_all = cancel_all,
+ };
+ int node;
+
+ /*
+ * First check pending list, if we're lucky we can just remove it
+ * from there. CANCEL_OK means that the work is returned as-new,
+ * no completion will be posted for it.
+ */
+ for_each_node(node) {
+ struct io_wqe *wqe = wq->wqes[node];
+
+ io_wqe_cancel_pending_work(wqe, &match);
+ if (match.nr_pending && !match.cancel_all)
+ return IO_WQ_CANCEL_OK;
+ }
+
+ /*
+ * Now check if a free (going busy) or busy worker has the work
+ * currently running. If we find it there, we'll return CANCEL_RUNNING
+ * as an indication that we attempt to signal cancellation. The
+ * completion will run normally in this case.
+ */
+ for_each_node(node) {
+ struct io_wqe *wqe = wq->wqes[node];
+
+ io_wqe_cancel_running_work(wqe, &match);
+ if (match.nr_running && !match.cancel_all)
+ return IO_WQ_CANCEL_RUNNING;
+ }
+
+ if (match.nr_running)
+ return IO_WQ_CANCEL_RUNNING;
+ if (match.nr_pending)
+ return IO_WQ_CANCEL_OK;
+ return IO_WQ_CANCEL_NOTFOUND;
+}
+
+static int io_wqe_hash_wake(struct wait_queue_entry *wait, unsigned mode,
+ int sync, void *key)
+{
+ struct io_wqe *wqe = container_of(wait, struct io_wqe, wait);
+ int i;
+
+ list_del_init(&wait->entry);
+
+ rcu_read_lock();
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
+ struct io_wqe_acct *acct = &wqe->acct[i];
+
+ if (test_and_clear_bit(IO_ACCT_STALLED_BIT, &acct->flags))
+ io_wqe_activate_free_worker(wqe, acct);
+ }
+ rcu_read_unlock();
+ return 1;
+}
+
+struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
+{
+ int ret, node, i;
+ struct io_wq *wq;
+
+ if (WARN_ON_ONCE(!data->free_work || !data->do_work))
+ return ERR_PTR(-EINVAL);
+ if (WARN_ON_ONCE(!bounded))
+ return ERR_PTR(-EINVAL);
+
+ wq = kzalloc(struct_size(wq, wqes, nr_node_ids), GFP_KERNEL);
+ if (!wq)
+ return ERR_PTR(-ENOMEM);
+ ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node);
+ if (ret)
+ goto err_wq;
+
+ refcount_inc(&data->hash->refs);
+ wq->hash = data->hash;
+ wq->free_work = data->free_work;
+ wq->do_work = data->do_work;
+
+ ret = -ENOMEM;
+ for_each_node(node) {
+ struct io_wqe *wqe;
+ int alloc_node = node;
+
+ if (!node_online(alloc_node))
+ alloc_node = NUMA_NO_NODE;
+ wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node);
+ if (!wqe)
+ goto err;
+ wq->wqes[node] = wqe;
+ if (!alloc_cpumask_var(&wqe->cpu_mask, GFP_KERNEL))
+ goto err;
+ cpumask_copy(wqe->cpu_mask, cpumask_of_node(node));
+ wqe->node = alloc_node;
+ wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
+ wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers =
+ task_rlimit(current, RLIMIT_NPROC);
+ INIT_LIST_HEAD(&wqe->wait.entry);
+ wqe->wait.func = io_wqe_hash_wake;
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
+ struct io_wqe_acct *acct = &wqe->acct[i];
+
+ acct->index = i;
+ atomic_set(&acct->nr_running, 0);
+ INIT_WQ_LIST(&acct->work_list);
+ }
+ wqe->wq = wq;
+ raw_spin_lock_init(&wqe->lock);
+ INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0);
+ INIT_LIST_HEAD(&wqe->all_list);
+ }
+
+ wq->task = get_task_struct(data->task);
+ atomic_set(&wq->worker_refs, 1);
+ init_completion(&wq->worker_done);
+ return wq;
+err:
+ io_wq_put_hash(data->hash);
+ cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
+ for_each_node(node) {
+ if (!wq->wqes[node])
+ continue;
+ free_cpumask_var(wq->wqes[node]->cpu_mask);
+ kfree(wq->wqes[node]);
+ }
+err_wq:
+ kfree(wq);
+ return ERR_PTR(ret);
+}
+
+static bool io_task_work_match(struct callback_head *cb, void *data)
+{
+ struct io_worker *worker;
+
+ if (cb->func != create_worker_cb && cb->func != create_worker_cont)
+ return false;
+ worker = container_of(cb, struct io_worker, create_work);
+ return worker->wqe->wq == data;
+}
+
+void io_wq_exit_start(struct io_wq *wq)
+{
+ set_bit(IO_WQ_BIT_EXIT, &wq->state);
+}
+
+static void io_wq_cancel_tw_create(struct io_wq *wq)
+{
+ struct callback_head *cb;
+
+ while ((cb = task_work_cancel_match(wq->task, io_task_work_match, wq)) != NULL) {
+ struct io_worker *worker;
+
+ worker = container_of(cb, struct io_worker, create_work);
+ io_worker_cancel_cb(worker);
+ }
+}
+
+static void io_wq_exit_workers(struct io_wq *wq)
+{
+ int node;
+
+ if (!wq->task)
+ return;
+
+ io_wq_cancel_tw_create(wq);
+
+ rcu_read_lock();
+ for_each_node(node) {
+ struct io_wqe *wqe = wq->wqes[node];
+
+ io_wq_for_each_worker(wqe, io_wq_worker_wake, NULL);
+ }
+ rcu_read_unlock();
+ io_worker_ref_put(wq);
+ wait_for_completion(&wq->worker_done);
+
+ for_each_node(node) {
+ spin_lock_irq(&wq->hash->wait.lock);
+ list_del_init(&wq->wqes[node]->wait.entry);
+ spin_unlock_irq(&wq->hash->wait.lock);
+ }
+ put_task_struct(wq->task);
+ wq->task = NULL;
+}
+
+static void io_wq_destroy(struct io_wq *wq)
+{
+ int node;
+
+ cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
+
+ for_each_node(node) {
+ struct io_wqe *wqe = wq->wqes[node];
+ struct io_cb_cancel_data match = {
+ .fn = io_wq_work_match_all,
+ .cancel_all = true,
+ };
+ io_wqe_cancel_pending_work(wqe, &match);
+ free_cpumask_var(wqe->cpu_mask);
+ kfree(wqe);
+ }
+ io_wq_put_hash(wq->hash);
+ kfree(wq);
+}
+
+void io_wq_put_and_exit(struct io_wq *wq)
+{
+ WARN_ON_ONCE(!test_bit(IO_WQ_BIT_EXIT, &wq->state));
+
+ io_wq_exit_workers(wq);
+ io_wq_destroy(wq);
+}
+
+struct online_data {
+ unsigned int cpu;
+ bool online;
+};
+
+static bool io_wq_worker_affinity(struct io_worker *worker, void *data)
+{
+ struct online_data *od = data;
+
+ if (od->online)
+ cpumask_set_cpu(od->cpu, worker->wqe->cpu_mask);
+ else
+ cpumask_clear_cpu(od->cpu, worker->wqe->cpu_mask);
+ return false;
+}
+
+static int __io_wq_cpu_online(struct io_wq *wq, unsigned int cpu, bool online)
+{
+ struct online_data od = {
+ .cpu = cpu,
+ .online = online
+ };
+ int i;
+
+ rcu_read_lock();
+ for_each_node(i)
+ io_wq_for_each_worker(wq->wqes[i], io_wq_worker_affinity, &od);
+ rcu_read_unlock();
+ return 0;
+}
+
+static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node)
+{
+ struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node);
+
+ return __io_wq_cpu_online(wq, cpu, true);
+}
+
+static int io_wq_cpu_offline(unsigned int cpu, struct hlist_node *node)
+{
+ struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node);
+
+ return __io_wq_cpu_online(wq, cpu, false);
+}
+
+int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask)
+{
+ int i;
+
+ rcu_read_lock();
+ for_each_node(i) {
+ struct io_wqe *wqe = wq->wqes[i];
+
+ if (mask)
+ cpumask_copy(wqe->cpu_mask, mask);
+ else
+ cpumask_copy(wqe->cpu_mask, cpumask_of_node(i));
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+/*
+ * Set max number of unbounded workers, returns old value. If new_count is 0,
+ * then just return the old value.
+ */
+int io_wq_max_workers(struct io_wq *wq, int *new_count)
+{
+ int prev[IO_WQ_ACCT_NR];
+ bool first_node = true;
+ int i, node;
+
+ BUILD_BUG_ON((int) IO_WQ_ACCT_BOUND != (int) IO_WQ_BOUND);
+ BUILD_BUG_ON((int) IO_WQ_ACCT_UNBOUND != (int) IO_WQ_UNBOUND);
+ BUILD_BUG_ON((int) IO_WQ_ACCT_NR != 2);
+
+ for (i = 0; i < 2; i++) {
+ if (new_count[i] > task_rlimit(current, RLIMIT_NPROC))
+ new_count[i] = task_rlimit(current, RLIMIT_NPROC);
+ }
+
+ for (i = 0; i < IO_WQ_ACCT_NR; i++)
+ prev[i] = 0;
+
+ rcu_read_lock();
+ for_each_node(node) {
+ struct io_wqe *wqe = wq->wqes[node];
+ struct io_wqe_acct *acct;
+
+ raw_spin_lock(&wqe->lock);
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
+ acct = &wqe->acct[i];
+ if (first_node)
+ prev[i] = max_t(int, acct->max_workers, prev[i]);
+ if (new_count[i])
+ acct->max_workers = new_count[i];
+ }
+ raw_spin_unlock(&wqe->lock);
+ first_node = false;
+ }
+ rcu_read_unlock();
+
+ for (i = 0; i < IO_WQ_ACCT_NR; i++)
+ new_count[i] = prev[i];
+
+ return 0;
+}
+
+static __init int io_wq_init(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "io-wq/online",
+ io_wq_cpu_online, io_wq_cpu_offline);
+ if (ret < 0)
+ return ret;
+ io_wq_online = ret;
+ return 0;
+}
+subsys_initcall(io_wq_init);
--- /dev/null
+++ b/io_uring/io-wq.h
@@ -0,0 +1,160 @@
+#ifndef INTERNAL_IO_WQ_H
+#define INTERNAL_IO_WQ_H
+
+#include <linux/refcount.h>
+
+struct io_wq;
+
+enum {
+ IO_WQ_WORK_CANCEL = 1,
+ IO_WQ_WORK_HASHED = 2,
+ IO_WQ_WORK_UNBOUND = 4,
+ IO_WQ_WORK_CONCURRENT = 16,
+
+ IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */
+};
+
+enum io_wq_cancel {
+ IO_WQ_CANCEL_OK, /* cancelled before started */
+ IO_WQ_CANCEL_RUNNING, /* found, running, and attempted cancelled */
+ IO_WQ_CANCEL_NOTFOUND, /* work not found */
+};
+
+struct io_wq_work_node {
+ struct io_wq_work_node *next;
+};
+
+struct io_wq_work_list {
+ struct io_wq_work_node *first;
+ struct io_wq_work_node *last;
+};
+
+static inline void wq_list_add_after(struct io_wq_work_node *node,
+ struct io_wq_work_node *pos,
+ struct io_wq_work_list *list)
+{
+ struct io_wq_work_node *next = pos->next;
+
+ pos->next = node;
+ node->next = next;
+ if (!next)
+ list->last = node;
+}
+
+static inline void wq_list_add_tail(struct io_wq_work_node *node,
+ struct io_wq_work_list *list)
+{
+ node->next = NULL;
+ if (!list->first) {
+ list->last = node;
+ WRITE_ONCE(list->first, node);
+ } else {
+ list->last->next = node;
+ list->last = node;
+ }
+}
+
+static inline void wq_list_cut(struct io_wq_work_list *list,
+ struct io_wq_work_node *last,
+ struct io_wq_work_node *prev)
+{
+ /* first in the list, if prev==NULL */
+ if (!prev)
+ WRITE_ONCE(list->first, last->next);
+ else
+ prev->next = last->next;
+
+ if (last == list->last)
+ list->last = prev;
+ last->next = NULL;
+}
+
+static inline void wq_list_del(struct io_wq_work_list *list,
+ struct io_wq_work_node *node,
+ struct io_wq_work_node *prev)
+{
+ wq_list_cut(list, node, prev);
+}
+
+#define wq_list_for_each(pos, prv, head) \
+ for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
+
+#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL)
+#define INIT_WQ_LIST(list) do { \
+ (list)->first = NULL; \
+ (list)->last = NULL; \
+} while (0)
+
+struct io_wq_work {
+ struct io_wq_work_node list;
+ unsigned flags;
+};
+
+static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
+{
+ if (!work->list.next)
+ return NULL;
+
+ return container_of(work->list.next, struct io_wq_work, list);
+}
+
+typedef struct io_wq_work *(free_work_fn)(struct io_wq_work *);
+typedef void (io_wq_work_fn)(struct io_wq_work *);
+
+struct io_wq_hash {
+ refcount_t refs;
+ unsigned long map;
+ struct wait_queue_head wait;
+};
+
+static inline void io_wq_put_hash(struct io_wq_hash *hash)
+{
+ if (refcount_dec_and_test(&hash->refs))
+ kfree(hash);
+}
+
+struct io_wq_data {
+ struct io_wq_hash *hash;
+ struct task_struct *task;
+ io_wq_work_fn *do_work;
+ free_work_fn *free_work;
+};
+
+struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
+void io_wq_exit_start(struct io_wq *wq);
+void io_wq_put_and_exit(struct io_wq *wq);
+
+void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
+void io_wq_hash_work(struct io_wq_work *work, void *val);
+
+int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask);
+int io_wq_max_workers(struct io_wq *wq, int *new_count);
+
+static inline bool io_wq_is_hashed(struct io_wq_work *work)
+{
+ return work->flags & IO_WQ_WORK_HASHED;
+}
+
+typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
+
+enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
+ void *data, bool cancel_all);
+
+#if defined(CONFIG_IO_WQ)
+extern void io_wq_worker_sleeping(struct task_struct *);
+extern void io_wq_worker_running(struct task_struct *);
+#else
+static inline void io_wq_worker_sleeping(struct task_struct *tsk)
+{
+}
+static inline void io_wq_worker_running(struct task_struct *tsk)
+{
+}
+#endif
+
+static inline bool io_wq_current_is_worker(void)
+{
+ return in_task() && (current->flags & PF_IO_WORKER) &&
+ current->pf_io_worker;
+}
+#endif
--- /dev/null
+++ b/io_uring/io_uring.c
@@ -0,0 +1,10945 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shared application/kernel submission and completion ring pairs, for
+ * supporting fast/efficient IO.
+ *
+ * A note on the read/write ordering memory barriers that are matched between
+ * the application and kernel side.
+ *
+ * After the application reads the CQ ring tail, it must use an
+ * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
+ * before writing the tail (using smp_load_acquire to read the tail will
+ * do). It also needs a smp_mb() before updating CQ head (ordering the
+ * entry load(s) with the head store), pairing with an implicit barrier
+ * through a control-dependency in io_get_cqe (smp_store_release to
+ * store head will do). Failure to do so could lead to reading invalid
+ * CQ entries.
+ *
+ * Likewise, the application must use an appropriate smp_wmb() before
+ * writing the SQ tail (ordering SQ entry stores with the tail store),
+ * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
+ * to store the tail will do). And it needs a barrier ordering the SQ
+ * head load before writing new SQ entries (smp_load_acquire to read
+ * head will do).
+ *
+ * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
+ * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
+ * updating the SQ tail; a full memory barrier smp_mb() is needed
+ * between.
+ *
+ * Also see the examples in the liburing library:
+ *
+ * git://git.kernel.dk/liburing
+ *
+ * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
+ * from data shared between the kernel and application. This is done both
+ * for ordering purposes, but also to ensure that once a value is loaded from
+ * data that the application could potentially modify, it remains stable.
+ *
+ * Copyright (C) 2018-2019 Jens Axboe
+ * Copyright (c) 2018-2019 Christoph Hellwig
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/syscalls.h>
+#include <linux/compat.h>
+#include <net/compat.h>
+#include <linux/refcount.h>
+#include <linux/uio.h>
+#include <linux/bits.h>
+
+#include <linux/sched/signal.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/bvec.h>
+#include <linux/net.h>
+#include <net/sock.h>
+#include <net/af_unix.h>
+#include <net/scm.h>
+#include <linux/anon_inodes.h>
+#include <linux/sched/mm.h>
+#include <linux/uaccess.h>
+#include <linux/nospec.h>
+#include <linux/sizes.h>
+#include <linux/hugetlb.h>
+#include <linux/highmem.h>
+#include <linux/namei.h>
+#include <linux/fsnotify.h>
+#include <linux/fadvise.h>
+#include <linux/eventpoll.h>
+#include <linux/splice.h>
+#include <linux/task_work.h>
+#include <linux/pagemap.h>
+#include <linux/io_uring.h>
+#include <linux/tracehook.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "../fs/internal.h"
+#include "io-wq.h"
+
+#define IORING_MAX_ENTRIES 32768
+#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
+#define IORING_SQPOLL_CAP_ENTRIES_VALUE 8
+
+/* only define max */
+#define IORING_MAX_FIXED_FILES (1U << 15)
+#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
+ IORING_REGISTER_LAST + IORING_OP_LAST)
+
+#define IO_RSRC_TAG_TABLE_SHIFT (PAGE_SHIFT - 3)
+#define IO_RSRC_TAG_TABLE_MAX (1U << IO_RSRC_TAG_TABLE_SHIFT)
+#define IO_RSRC_TAG_TABLE_MASK (IO_RSRC_TAG_TABLE_MAX - 1)
+
+#define IORING_MAX_REG_BUFFERS (1U << 14)
+
+#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
+ IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
+ IOSQE_BUFFER_SELECT)
+#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \
+ REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS)
+
+#define IO_TCTX_REFS_CACHE_NR (1U << 10)
+
+struct io_uring {
+ u32 head ____cacheline_aligned_in_smp;
+ u32 tail ____cacheline_aligned_in_smp;
+};
+
+/*
+ * This data is shared with the application through the mmap at offsets
+ * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
+ *
+ * The offsets to the member fields are published through struct
+ * io_sqring_offsets when calling io_uring_setup.
+ */
+struct io_rings {
+ /*
+ * Head and tail offsets into the ring; the offsets need to be
+ * masked to get valid indices.
+ *
+ * The kernel controls head of the sq ring and the tail of the cq ring,
+ * and the application controls tail of the sq ring and the head of the
+ * cq ring.
+ */
+ struct io_uring sq, cq;
+ /*
+ * Bitmasks to apply to head and tail offsets (constant, equals
+ * ring_entries - 1)
+ */
+ u32 sq_ring_mask, cq_ring_mask;
+ /* Ring sizes (constant, power of 2) */
+ u32 sq_ring_entries, cq_ring_entries;
+ /*
+ * Number of invalid entries dropped by the kernel due to
+ * invalid index stored in array
+ *
+ * Written by the kernel, shouldn't be modified by the
+ * application (i.e. get number of "new events" by comparing to
+ * cached value).
+ *
+ * After a new SQ head value was read by the application this
+ * counter includes all submissions that were dropped reaching
+ * the new SQ head (and possibly more).
+ */
+ u32 sq_dropped;
+ /*
+ * Runtime SQ flags
+ *
+ * Written by the kernel, shouldn't be modified by the
+ * application.
+ *
+ * The application needs a full memory barrier before checking
+ * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
+ */
+ u32 sq_flags;
+ /*
+ * Runtime CQ flags
+ *
+ * Written by the application, shouldn't be modified by the
+ * kernel.
+ */
+ u32 cq_flags;
+ /*
+ * Number of completion events lost because the queue was full;
+ * this should be avoided by the application by making sure
+ * there are not more requests pending than there is space in
+ * the completion queue.
+ *
+ * Written by the kernel, shouldn't be modified by the
+ * application (i.e. get number of "new events" by comparing to
+ * cached value).
+ *
+ * As completion events come in out of order this counter is not
+ * ordered with any other data.
+ */
+ u32 cq_overflow;
+ /*
+ * Ring buffer of completion events.
+ *
+ * The kernel writes completion events fresh every time they are
+ * produced, so the application is allowed to modify pending
+ * entries.
+ */
+ struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
+};
+
+enum io_uring_cmd_flags {
+ IO_URING_F_NONBLOCK = 1,
+ IO_URING_F_COMPLETE_DEFER = 2,
+};
+
+struct io_mapped_ubuf {
+ u64 ubuf;
+ u64 ubuf_end;
+ unsigned int nr_bvecs;
+ unsigned long acct_pages;
+ struct bio_vec bvec[];
+};
+
+struct io_ring_ctx;
+
+struct io_overflow_cqe {
+ struct io_uring_cqe cqe;
+ struct list_head list;
+};
+
+struct io_fixed_file {
+ /* file * with additional FFS_* flags */
+ unsigned long file_ptr;
+};
+
+struct io_rsrc_put {
+ struct list_head list;
+ u64 tag;
+ union {
+ void *rsrc;
+ struct file *file;
+ struct io_mapped_ubuf *buf;
+ };
+};
+
+struct io_file_table {
+ struct io_fixed_file *files;
+};
+
+struct io_rsrc_node {
+ struct percpu_ref refs;
+ struct list_head node;
+ struct list_head rsrc_list;
+ struct io_rsrc_data *rsrc_data;
+ struct llist_node llist;
+ bool done;
+};
+
+typedef void (rsrc_put_fn)(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
+
+struct io_rsrc_data {
+ struct io_ring_ctx *ctx;
+
+ u64 **tags;
+ unsigned int nr;
+ rsrc_put_fn *do_put;
+ atomic_t refs;
+ struct completion done;
+ bool quiesce;
+};
+
+struct io_buffer {
+ struct list_head list;
+ __u64 addr;
+ __u32 len;
+ __u16 bid;
+};
+
+struct io_restriction {
+ DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
+ DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
+ u8 sqe_flags_allowed;
+ u8 sqe_flags_required;
+ bool registered;
+};
+
+enum {
+ IO_SQ_THREAD_SHOULD_STOP = 0,
+ IO_SQ_THREAD_SHOULD_PARK,
+};
+
+struct io_sq_data {
+ refcount_t refs;
+ atomic_t park_pending;
+ struct mutex lock;
+
+ /* ctx's that are using this sqd */
+ struct list_head ctx_list;
+
+ struct task_struct *thread;
+ struct wait_queue_head wait;
+
+ unsigned sq_thread_idle;
+ int sq_cpu;
+ pid_t task_pid;
+ pid_t task_tgid;
+
+ unsigned long state;
+ struct completion exited;
+};
+
+#define IO_COMPL_BATCH 32
+#define IO_REQ_CACHE_SIZE 32
+#define IO_REQ_ALLOC_BATCH 8
+
+struct io_submit_link {
+ struct io_kiocb *head;
+ struct io_kiocb *last;
+};
+
+struct io_submit_state {
+ struct blk_plug plug;
+ struct io_submit_link link;
+
+ /*
+ * io_kiocb alloc cache
+ */
+ void *reqs[IO_REQ_CACHE_SIZE];
+ unsigned int free_reqs;
+
+ bool plug_started;
+
+ /*
+ * Batch completion logic
+ */
+ struct io_kiocb *compl_reqs[IO_COMPL_BATCH];
+ unsigned int compl_nr;
+ /* inline/task_work completion list, under ->uring_lock */
+ struct list_head free_list;
+
+ unsigned int ios_left;
+};
+
+struct io_ring_ctx {
+ /* const or read-mostly hot data */
+ struct {
+ struct percpu_ref refs;
+
+ struct io_rings *rings;
+ unsigned int flags;
+ unsigned int compat: 1;
+ unsigned int drain_next: 1;
+ unsigned int eventfd_async: 1;
+ unsigned int restricted: 1;
+ unsigned int off_timeout_used: 1;
+ unsigned int drain_active: 1;
+ } ____cacheline_aligned_in_smp;
+
+ /* submission data */
+ struct {
+ struct mutex uring_lock;
+
+ /*
+ * Ring buffer of indices into array of io_uring_sqe, which is
+ * mmapped by the application using the IORING_OFF_SQES offset.
+ *
+ * This indirection could e.g. be used to assign fixed
+ * io_uring_sqe entries to operations and only submit them to
+ * the queue when needed.
+ *
+ * The kernel modifies neither the indices array nor the entries
+ * array.
+ */
+ u32 *sq_array;
+ struct io_uring_sqe *sq_sqes;
+ unsigned cached_sq_head;
+ unsigned sq_entries;
+ struct list_head defer_list;
+
+ /*
+ * Fixed resources fast path, should be accessed only under
+ * uring_lock, and updated through io_uring_register(2)
+ */
+ struct io_rsrc_node *rsrc_node;
+ struct io_file_table file_table;
+ unsigned nr_user_files;
+ unsigned nr_user_bufs;
+ struct io_mapped_ubuf **user_bufs;
+
+ struct io_submit_state submit_state;
+ struct list_head timeout_list;
+ struct list_head ltimeout_list;
+ struct list_head cq_overflow_list;
+ struct xarray io_buffers;
+ struct xarray personalities;
+ u32 pers_next;
+ unsigned sq_thread_idle;
+ } ____cacheline_aligned_in_smp;
+
+ /* IRQ completion list, under ->completion_lock */
+ struct list_head locked_free_list;
+ unsigned int locked_free_nr;
+
+ const struct cred *sq_creds; /* cred used for __io_sq_thread() */
+ struct io_sq_data *sq_data; /* if using sq thread polling */
+
+ struct wait_queue_head sqo_sq_wait;
+ struct list_head sqd_list;
+
+ unsigned long check_cq_overflow;
+
+ struct {
+ unsigned cached_cq_tail;
+ unsigned cq_entries;
+ struct eventfd_ctx *cq_ev_fd;
+ struct wait_queue_head poll_wait;
+ struct wait_queue_head cq_wait;
+ unsigned cq_extra;
+ atomic_t cq_timeouts;
+ unsigned cq_last_tm_flush;
+ } ____cacheline_aligned_in_smp;
+
+ struct {
+ spinlock_t completion_lock;
+
+ spinlock_t timeout_lock;
+
+ /*
+ * ->iopoll_list is protected by the ctx->uring_lock for
+ * io_uring instances that don't use IORING_SETUP_SQPOLL.
+ * For SQPOLL, only the single threaded io_sq_thread() will
+ * manipulate the list, hence no extra locking is needed there.
+ */
+ struct list_head iopoll_list;
+ struct hlist_head *cancel_hash;
+ unsigned cancel_hash_bits;
+ bool poll_multi_queue;
+ } ____cacheline_aligned_in_smp;
+
+ struct io_restriction restrictions;
+
+ /* slow path rsrc auxilary data, used by update/register */
+ struct {
+ struct io_rsrc_node *rsrc_backup_node;
+ struct io_mapped_ubuf *dummy_ubuf;
+ struct io_rsrc_data *file_data;
+ struct io_rsrc_data *buf_data;
+
+ struct delayed_work rsrc_put_work;
+ struct llist_head rsrc_put_llist;
+ struct list_head rsrc_ref_list;
+ spinlock_t rsrc_ref_lock;
+ };
+
+ /* Keep this last, we don't need it for the fast path */
+ struct {
+ #if defined(CONFIG_UNIX)
+ struct socket *ring_sock;
+ #endif
+ /* hashed buffered write serialization */
+ struct io_wq_hash *hash_map;
+
+ /* Only used for accounting purposes */
+ struct user_struct *user;
+ struct mm_struct *mm_account;
+
+ /* ctx exit and cancelation */
+ struct llist_head fallback_llist;
+ struct delayed_work fallback_work;
+ struct work_struct exit_work;
+ struct list_head tctx_list;
+ struct completion ref_comp;
+ u32 iowq_limits[2];
+ bool iowq_limits_set;
+ };
+};
+
+struct io_uring_task {
+ /* submission side */
+ int cached_refs;
+ struct xarray xa;
+ struct wait_queue_head wait;
+ const struct io_ring_ctx *last;
+ struct io_wq *io_wq;
+ struct percpu_counter inflight;
+ atomic_t inflight_tracked;
+ atomic_t in_idle;
+
+ spinlock_t task_lock;
+ struct io_wq_work_list task_list;
+ struct callback_head task_work;
+ bool task_running;
+};
+
+/*
+ * First field must be the file pointer in all the
+ * iocb unions! See also 'struct kiocb' in <linux/fs.h>
+ */
+struct io_poll_iocb {
+ struct file *file;
+ struct wait_queue_head *head;
+ __poll_t events;
+ struct wait_queue_entry wait;
+};
+
+struct io_poll_update {
+ struct file *file;
+ u64 old_user_data;
+ u64 new_user_data;
+ __poll_t events;
+ bool update_events;
+ bool update_user_data;
+};
+
+struct io_close {
+ struct file *file;
+ int fd;
+ u32 file_slot;
+};
+
+struct io_timeout_data {
+ struct io_kiocb *req;
+ struct hrtimer timer;
+ struct timespec64 ts;
+ enum hrtimer_mode mode;
+ u32 flags;
+};
+
+struct io_accept {
+ struct file *file;
+ struct sockaddr __user *addr;
+ int __user *addr_len;
+ int flags;
+ u32 file_slot;
+ unsigned long nofile;
+};
+
+struct io_sync {
+ struct file *file;
+ loff_t len;
+ loff_t off;
+ int flags;
+ int mode;
+};
+
+struct io_cancel {
+ struct file *file;
+ u64 addr;
+};
+
+struct io_timeout {
+ struct file *file;
+ u32 off;
+ u32 target_seq;
+ struct list_head list;
+ /* head of the link, used by linked timeouts only */
+ struct io_kiocb *head;
+ /* for linked completions */
+ struct io_kiocb *prev;
+};
+
+struct io_timeout_rem {
+ struct file *file;
+ u64 addr;
+
+ /* timeout update */
+ struct timespec64 ts;
+ u32 flags;
+ bool ltimeout;
+};
+
+struct io_rw {
+ /* NOTE: kiocb has the file as the first member, so don't do it here */
+ struct kiocb kiocb;
+ u64 addr;
+ u64 len;
+};
+
+struct io_connect {
+ struct file *file;
+ struct sockaddr __user *addr;
+ int addr_len;
+};
+
+struct io_sr_msg {
+ struct file *file;
+ union {
+ struct compat_msghdr __user *umsg_compat;
+ struct user_msghdr __user *umsg;
+ void __user *buf;
+ };
+ int msg_flags;
+ int bgid;
+ size_t len;
+ struct io_buffer *kbuf;
+};
+
+struct io_open {
+ struct file *file;
+ int dfd;
+ u32 file_slot;
+ struct filename *filename;
+ struct open_how how;
+ unsigned long nofile;
+};
+
+struct io_rsrc_update {
+ struct file *file;
+ u64 arg;
+ u32 nr_args;
+ u32 offset;
+};
+
+struct io_fadvise {
+ struct file *file;
+ u64 offset;
+ u32 len;
+ u32 advice;
+};
+
+struct io_madvise {
+ struct file *file;
+ u64 addr;
+ u32 len;
+ u32 advice;
+};
+
+struct io_epoll {
+ struct file *file;
+ int epfd;
+ int op;
+ int fd;
+ struct epoll_event event;
+};
+
+struct io_splice {
+ struct file *file_out;
+ loff_t off_out;
+ loff_t off_in;
+ u64 len;
+ int splice_fd_in;
+ unsigned int flags;
+};
+
+struct io_provide_buf {
+ struct file *file;
+ __u64 addr;
+ __u32 len;
+ __u32 bgid;
+ __u16 nbufs;
+ __u16 bid;
+};
+
+struct io_statx {
+ struct file *file;
+ int dfd;
+ unsigned int mask;
+ unsigned int flags;
+ const char __user *filename;
+ struct statx __user *buffer;
+};
+
+struct io_shutdown {
+ struct file *file;
+ int how;
+};
+
+struct io_rename {
+ struct file *file;
+ int old_dfd;
+ int new_dfd;
+ struct filename *oldpath;
+ struct filename *newpath;
+ int flags;
+};
+
+struct io_unlink {
+ struct file *file;
+ int dfd;
+ int flags;
+ struct filename *filename;
+};
+
+struct io_mkdir {
+ struct file *file;
+ int dfd;
+ umode_t mode;
+ struct filename *filename;
+};
+
+struct io_symlink {
+ struct file *file;
+ int new_dfd;
+ struct filename *oldpath;
+ struct filename *newpath;
+};
+
+struct io_hardlink {
+ struct file *file;
+ int old_dfd;
+ int new_dfd;
+ struct filename *oldpath;
+ struct filename *newpath;
+ int flags;
+};
+
+struct io_completion {
+ struct file *file;
+ u32 cflags;
+};
+
+struct io_async_connect {
+ struct sockaddr_storage address;
+};
+
+struct io_async_msghdr {
+ struct iovec fast_iov[UIO_FASTIOV];
+ /* points to an allocated iov, if NULL we use fast_iov instead */
+ struct iovec *free_iov;
+ struct sockaddr __user *uaddr;
+ struct msghdr msg;
+ struct sockaddr_storage addr;
+};
+
+struct io_async_rw {
+ struct iovec fast_iov[UIO_FASTIOV];
+ const struct iovec *free_iovec;
+ struct iov_iter iter;
+ struct iov_iter_state iter_state;
+ size_t bytes_done;
+ struct wait_page_queue wpq;
+};
+
+enum {
+ REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
+ REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
+ REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
+ REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
+ REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
+ REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
+
+ /* first byte is taken by user flags, shift it to not overlap */
+ REQ_F_FAIL_BIT = 8,
+ REQ_F_INFLIGHT_BIT,
+ REQ_F_CUR_POS_BIT,
+ REQ_F_NOWAIT_BIT,
+ REQ_F_LINK_TIMEOUT_BIT,
+ REQ_F_NEED_CLEANUP_BIT,
+ REQ_F_POLLED_BIT,
+ REQ_F_BUFFER_SELECTED_BIT,
+ REQ_F_COMPLETE_INLINE_BIT,
+ REQ_F_REISSUE_BIT,
+ REQ_F_CREDS_BIT,
+ REQ_F_REFCOUNT_BIT,
+ REQ_F_ARM_LTIMEOUT_BIT,
+ /* keep async read/write and isreg together and in order */
+ REQ_F_NOWAIT_READ_BIT,
+ REQ_F_NOWAIT_WRITE_BIT,
+ REQ_F_ISREG_BIT,
+
+ /* not a real bit, just to check we're not overflowing the space */
+ __REQ_F_LAST_BIT,
+};
+
+enum {
+ /* ctx owns file */
+ REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
+ /* drain existing IO first */
+ REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
+ /* linked sqes */
+ REQ_F_LINK = BIT(REQ_F_LINK_BIT),
+ /* doesn't sever on completion < 0 */
+ REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
+ /* IOSQE_ASYNC */
+ REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
+ /* IOSQE_BUFFER_SELECT */
+ REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
+
+ /* fail rest of links */
+ REQ_F_FAIL = BIT(REQ_F_FAIL_BIT),
+ /* on inflight list, should be cancelled and waited on exit reliably */
+ REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
+ /* read/write uses file position */
+ REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
+ /* must not punt to workers */
+ REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
+ /* has or had linked timeout */
+ REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
+ /* needs cleanup */
+ REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
+ /* already went through poll handler */
+ REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
+ /* buffer already selected */
+ REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
+ /* completion is deferred through io_comp_state */
+ REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT),
+ /* caller should reissue async */
+ REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT),
+ /* supports async reads */
+ REQ_F_NOWAIT_READ = BIT(REQ_F_NOWAIT_READ_BIT),
+ /* supports async writes */
+ REQ_F_NOWAIT_WRITE = BIT(REQ_F_NOWAIT_WRITE_BIT),
+ /* regular file */
+ REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
+ /* has creds assigned */
+ REQ_F_CREDS = BIT(REQ_F_CREDS_BIT),
+ /* skip refcounting if not set */
+ REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT),
+ /* there is a linked timeout that has to be armed */
+ REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT),
+};
+
+struct async_poll {
+ struct io_poll_iocb poll;
+ struct io_poll_iocb *double_poll;
+};
+
+typedef void (*io_req_tw_func_t)(struct io_kiocb *req, bool *locked);
+
+struct io_task_work {
+ union {
+ struct io_wq_work_node node;
+ struct llist_node fallback_node;
+ };
+ io_req_tw_func_t func;
+};
+
+enum {
+ IORING_RSRC_FILE = 0,
+ IORING_RSRC_BUFFER = 1,
+};
+
+/*
+ * NOTE! Each of the iocb union members has the file pointer
+ * as the first entry in their struct definition. So you can
+ * access the file pointer through any of the sub-structs,
+ * or directly as just 'ki_filp' in this struct.
+ */
+struct io_kiocb {
+ union {
+ struct file *file;
+ struct io_rw rw;
+ struct io_poll_iocb poll;
+ struct io_poll_update poll_update;
+ struct io_accept accept;
+ struct io_sync sync;
+ struct io_cancel cancel;
+ struct io_timeout timeout;
+ struct io_timeout_rem timeout_rem;
+ struct io_connect connect;
+ struct io_sr_msg sr_msg;
+ struct io_open open;
+ struct io_close close;
+ struct io_rsrc_update rsrc_update;
+ struct io_fadvise fadvise;
+ struct io_madvise madvise;
+ struct io_epoll epoll;
+ struct io_splice splice;
+ struct io_provide_buf pbuf;
+ struct io_statx statx;
+ struct io_shutdown shutdown;
+ struct io_rename rename;
+ struct io_unlink unlink;
+ struct io_mkdir mkdir;
+ struct io_symlink symlink;
+ struct io_hardlink hardlink;
+ /* use only after cleaning per-op data, see io_clean_op() */
+ struct io_completion compl;
+ };
+
+ /* opcode allocated if it needs to store data for async defer */
+ void *async_data;
+ u8 opcode;
+ /* polled IO has completed */
+ u8 iopoll_completed;
+
+ u16 buf_index;
+ u32 result;
+
+ struct io_ring_ctx *ctx;
+ unsigned int flags;
+ atomic_t refs;
+ struct task_struct *task;
+ u64 user_data;
+
+ struct io_kiocb *link;
+ struct percpu_ref *fixed_rsrc_refs;
+
+ /* used with ctx->iopoll_list with reads/writes */
+ struct list_head inflight_entry;
+ struct io_task_work io_task_work;
+ /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
+ struct hlist_node hash_node;
+ struct async_poll *apoll;
+ struct io_wq_work work;
+ const struct cred *creds;
+
+ /* store used ubuf, so we can prevent reloading */
+ struct io_mapped_ubuf *imu;
+ /* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */
+ struct io_buffer *kbuf;
+ atomic_t poll_refs;
+};
+
+struct io_tctx_node {
+ struct list_head ctx_node;
+ struct task_struct *task;
+ struct io_ring_ctx *ctx;
+};
+
+struct io_defer_entry {
+ struct list_head list;
+ struct io_kiocb *req;
+ u32 seq;
+};
+
+struct io_op_def {
+ /* needs req->file assigned */
+ unsigned needs_file : 1;
+ /* hash wq insertion if file is a regular file */
+ unsigned hash_reg_file : 1;
+ /* unbound wq insertion if file is a non-regular file */
+ unsigned unbound_nonreg_file : 1;
+ /* opcode is not supported by this kernel */
+ unsigned not_supported : 1;
+ /* set if opcode supports polled "wait" */
+ unsigned pollin : 1;
+ unsigned pollout : 1;
+ /* op supports buffer selection */
+ unsigned buffer_select : 1;
+ /* do prep async if is going to be punted */
+ unsigned needs_async_setup : 1;
+ /* should block plug */
+ unsigned plug : 1;
+ /* size of async data needed, if any */
+ unsigned short async_size;
+};
+
+static const struct io_op_def io_op_defs[] = {
+ [IORING_OP_NOP] = {},
+ [IORING_OP_READV] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ .needs_async_setup = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_WRITEV] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .needs_async_setup = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_FSYNC] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_READ_FIXED] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_WRITE_FIXED] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_POLL_ADD] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_POLL_REMOVE] = {},
+ [IORING_OP_SYNC_FILE_RANGE] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_SENDMSG] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .needs_async_setup = 1,
+ .async_size = sizeof(struct io_async_msghdr),
+ },
+ [IORING_OP_RECVMSG] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ .needs_async_setup = 1,
+ .async_size = sizeof(struct io_async_msghdr),
+ },
+ [IORING_OP_TIMEOUT] = {
+ .async_size = sizeof(struct io_timeout_data),
+ },
+ [IORING_OP_TIMEOUT_REMOVE] = {
+ /* used by timeout updates' prep() */
+ },
+ [IORING_OP_ACCEPT] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ },
+ [IORING_OP_ASYNC_CANCEL] = {},
+ [IORING_OP_LINK_TIMEOUT] = {
+ .async_size = sizeof(struct io_timeout_data),
+ },
+ [IORING_OP_CONNECT] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .needs_async_setup = 1,
+ .async_size = sizeof(struct io_async_connect),
+ },
+ [IORING_OP_FALLOCATE] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_OPENAT] = {},
+ [IORING_OP_CLOSE] = {},
+ [IORING_OP_FILES_UPDATE] = {},
+ [IORING_OP_STATX] = {},
+ [IORING_OP_READ] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_WRITE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_FADVISE] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_MADVISE] = {},
+ [IORING_OP_SEND] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ },
+ [IORING_OP_RECV] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ },
+ [IORING_OP_OPENAT2] = {
+ },
+ [IORING_OP_EPOLL_CTL] = {
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_SPLICE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_PROVIDE_BUFFERS] = {},
+ [IORING_OP_REMOVE_BUFFERS] = {},
+ [IORING_OP_TEE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_SHUTDOWN] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_RENAMEAT] = {},
+ [IORING_OP_UNLINKAT] = {},
+};
+
+/* requests with any of those set should undergo io_disarm_next() */
+#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)
+
+static bool io_disarm_next(struct io_kiocb *req);
+static void io_uring_del_tctx_node(unsigned long index);
+static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
+ struct task_struct *task,
+ bool cancel_all);
+static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
+
+static void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags);
+
+static void io_put_req(struct io_kiocb *req);
+static void io_put_req_deferred(struct io_kiocb *req);
+static void io_dismantle_req(struct io_kiocb *req);
+static void io_queue_linked_timeout(struct io_kiocb *req);
+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args);
+static void io_clean_op(struct io_kiocb *req);
+static struct file *io_file_get(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd, bool fixed);
+static void __io_queue_sqe(struct io_kiocb *req);
+static void io_rsrc_put_work(struct work_struct *work);
+
+static void io_req_task_queue(struct io_kiocb *req);
+static void io_submit_flush_completions(struct io_ring_ctx *ctx);
+static int io_req_prep_async(struct io_kiocb *req);
+
+static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
+ unsigned int issue_flags, u32 slot_index);
+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags);
+
+static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer);
+
+static struct kmem_cache *req_cachep;
+
+static const struct file_operations io_uring_fops;
+
+struct sock *io_uring_get_socket(struct file *file)
+{
+#if defined(CONFIG_UNIX)
+ if (file->f_op == &io_uring_fops) {
+ struct io_ring_ctx *ctx = file->private_data;
+
+ return ctx->ring_sock->sk;
+ }
+#endif
+ return NULL;
+}
+EXPORT_SYMBOL(io_uring_get_socket);
+
+static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
+{
+ if (!*locked) {
+ mutex_lock(&ctx->uring_lock);
+ *locked = true;
+ }
+}
+
+#define io_for_each_link(pos, head) \
+ for (pos = (head); pos; pos = pos->link)
+
+/*
+ * Shamelessly stolen from the mm implementation of page reference checking,
+ * see commit f958d7b528b1 for details.
+ */
+#define req_ref_zero_or_close_to_overflow(req) \
+ ((unsigned int) atomic_read(&(req->refs)) + 127u <= 127u)
+
+static inline bool req_ref_inc_not_zero(struct io_kiocb *req)
+{
+ WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT));
+ return atomic_inc_not_zero(&req->refs);
+}
+
+static inline bool req_ref_put_and_test(struct io_kiocb *req)
+{
+ if (likely(!(req->flags & REQ_F_REFCOUNT)))
+ return true;
+
+ WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
+ return atomic_dec_and_test(&req->refs);
+}
+
+static inline void req_ref_get(struct io_kiocb *req)
+{
+ WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT));
+ WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
+ atomic_inc(&req->refs);
+}
+
+static inline void __io_req_set_refcount(struct io_kiocb *req, int nr)
+{
+ if (!(req->flags & REQ_F_REFCOUNT)) {
+ req->flags |= REQ_F_REFCOUNT;
+ atomic_set(&req->refs, nr);
+ }
+}
+
+static inline void io_req_set_refcount(struct io_kiocb *req)
+{
+ __io_req_set_refcount(req, 1);
+}
+
+static inline void io_req_set_rsrc_node(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!req->fixed_rsrc_refs) {
+ req->fixed_rsrc_refs = &ctx->rsrc_node->refs;
+ percpu_ref_get(req->fixed_rsrc_refs);
+ }
+}
+
+static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl)
+{
+ bool got = percpu_ref_tryget(ref);
+
+ /* already at zero, wait for ->release() */
+ if (!got)
+ wait_for_completion(compl);
+ percpu_ref_resurrect(ref);
+ if (got)
+ percpu_ref_put(ref);
+}
+
+static bool io_match_task(struct io_kiocb *head, struct task_struct *task,
+ bool cancel_all)
+ __must_hold(&req->ctx->timeout_lock)
+{
+ struct io_kiocb *req;
+
+ if (task && head->task != task)
+ return false;
+ if (cancel_all)
+ return true;
+
+ io_for_each_link(req, head) {
+ if (req->flags & REQ_F_INFLIGHT)
+ return true;
+ }
+ return false;
+}
+
+static bool io_match_linked(struct io_kiocb *head)
+{
+ struct io_kiocb *req;
+
+ io_for_each_link(req, head) {
+ if (req->flags & REQ_F_INFLIGHT)
+ return true;
+ }
+ return false;
+}
+
+/*
+ * As io_match_task() but protected against racing with linked timeouts.
+ * User must not hold timeout_lock.
+ */
+static bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
+ bool cancel_all)
+{
+ bool matched;
+
+ if (task && head->task != task)
+ return false;
+ if (cancel_all)
+ return true;
+
+ if (head->flags & REQ_F_LINK_TIMEOUT) {
+ struct io_ring_ctx *ctx = head->ctx;
+
+ /* protect against races with linked timeouts */
+ spin_lock_irq(&ctx->timeout_lock);
+ matched = io_match_linked(head);
+ spin_unlock_irq(&ctx->timeout_lock);
+ } else {
+ matched = io_match_linked(head);
+ }
+ return matched;
+}
+
+static inline void req_set_fail(struct io_kiocb *req)
+{
+ req->flags |= REQ_F_FAIL;
+}
+
+static inline void req_fail_link_node(struct io_kiocb *req, int res)
+{
+ req_set_fail(req);
+ req->result = res;
+}
+
+static void io_ring_ctx_ref_free(struct percpu_ref *ref)
+{
+ struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
+
+ complete(&ctx->ref_comp);
+}
+
+static inline bool io_is_timeout_noseq(struct io_kiocb *req)
+{
+ return !req->timeout.off;
+}
+
+static void io_fallback_req_func(struct work_struct *work)
+{
+ struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
+ fallback_work.work);
+ struct llist_node *node = llist_del_all(&ctx->fallback_llist);
+ struct io_kiocb *req, *tmp;
+ bool locked = false;
+
+ percpu_ref_get(&ctx->refs);
+ llist_for_each_entry_safe(req, tmp, node, io_task_work.fallback_node)
+ req->io_task_work.func(req, &locked);
+
+ if (locked) {
+ if (ctx->submit_state.compl_nr)
+ io_submit_flush_completions(ctx);
+ mutex_unlock(&ctx->uring_lock);
+ }
+ percpu_ref_put(&ctx->refs);
+
+}
+
+static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
+{
+ struct io_ring_ctx *ctx;
+ int hash_bits;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ /*
+ * Use 5 bits less than the max cq entries, that should give us around
+ * 32 entries per hash list if totally full and uniformly spread.
+ */
+ hash_bits = ilog2(p->cq_entries);
+ hash_bits -= 5;
+ if (hash_bits <= 0)
+ hash_bits = 1;
+ ctx->cancel_hash_bits = hash_bits;
+ ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
+ GFP_KERNEL);
+ if (!ctx->cancel_hash)
+ goto err;
+ __hash_init(ctx->cancel_hash, 1U << hash_bits);
+
+ ctx->dummy_ubuf = kzalloc(sizeof(*ctx->dummy_ubuf), GFP_KERNEL);
+ if (!ctx->dummy_ubuf)
+ goto err;
+ /* set invalid range, so io_import_fixed() fails meeting it */
+ ctx->dummy_ubuf->ubuf = -1UL;
+
+ if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
+ PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
+ goto err;
+
+ ctx->flags = p->flags;
+ init_waitqueue_head(&ctx->sqo_sq_wait);
+ INIT_LIST_HEAD(&ctx->sqd_list);
+ init_waitqueue_head(&ctx->poll_wait);
+ INIT_LIST_HEAD(&ctx->cq_overflow_list);
+ init_completion(&ctx->ref_comp);
+ xa_init_flags(&ctx->io_buffers, XA_FLAGS_ALLOC1);
+ xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
+ mutex_init(&ctx->uring_lock);
+ init_waitqueue_head(&ctx->cq_wait);
+ spin_lock_init(&ctx->completion_lock);
+ spin_lock_init(&ctx->timeout_lock);
+ INIT_LIST_HEAD(&ctx->iopoll_list);
+ INIT_LIST_HEAD(&ctx->defer_list);
+ INIT_LIST_HEAD(&ctx->timeout_list);
+ INIT_LIST_HEAD(&ctx->ltimeout_list);
+ spin_lock_init(&ctx->rsrc_ref_lock);
+ INIT_LIST_HEAD(&ctx->rsrc_ref_list);
+ INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
+ init_llist_head(&ctx->rsrc_put_llist);
+ INIT_LIST_HEAD(&ctx->tctx_list);
+ INIT_LIST_HEAD(&ctx->submit_state.free_list);
+ INIT_LIST_HEAD(&ctx->locked_free_list);
+ INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
+ return ctx;
+err:
+ kfree(ctx->dummy_ubuf);
+ kfree(ctx->cancel_hash);
+ kfree(ctx);
+ return NULL;
+}
+
+static void io_account_cq_overflow(struct io_ring_ctx *ctx)
+{
+ struct io_rings *r = ctx->rings;
+
+ WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1);
+ ctx->cq_extra--;
+}
+
+static bool req_need_defer(struct io_kiocb *req, u32 seq)
+{
+ if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
+ struct io_ring_ctx *ctx = req->ctx;
+
+ return seq + READ_ONCE(ctx->cq_extra) != ctx->cached_cq_tail;
+ }
+
+ return false;
+}
+
+#define FFS_ASYNC_READ 0x1UL
+#define FFS_ASYNC_WRITE 0x2UL
+#ifdef CONFIG_64BIT
+#define FFS_ISREG 0x4UL
+#else
+#define FFS_ISREG 0x0UL
+#endif
+#define FFS_MASK ~(FFS_ASYNC_READ|FFS_ASYNC_WRITE|FFS_ISREG)
+
+static inline bool io_req_ffs_set(struct io_kiocb *req)
+{
+ return IS_ENABLED(CONFIG_64BIT) && (req->flags & REQ_F_FIXED_FILE);
+}
+
+static void io_req_track_inflight(struct io_kiocb *req)
+{
+ if (!(req->flags & REQ_F_INFLIGHT)) {
+ req->flags |= REQ_F_INFLIGHT;
+ atomic_inc(&req->task->io_uring->inflight_tracked);
+ }
+}
+
+static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req)
+{
+ if (WARN_ON_ONCE(!req->link))
+ return NULL;
+
+ req->flags &= ~REQ_F_ARM_LTIMEOUT;
+ req->flags |= REQ_F_LINK_TIMEOUT;
+
+ /* linked timeouts should have two refs once prep'ed */
+ io_req_set_refcount(req);
+ __io_req_set_refcount(req->link, 2);
+ return req->link;
+}
+
+static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
+{
+ if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT)))
+ return NULL;
+ return __io_prep_linked_timeout(req);
+}
+
+static void io_prep_async_work(struct io_kiocb *req)
+{
+ const struct io_op_def *def = &io_op_defs[req->opcode];
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!(req->flags & REQ_F_CREDS)) {
+ req->flags |= REQ_F_CREDS;
+ req->creds = get_current_cred();
+ }
+
+ req->work.list.next = NULL;
+ req->work.flags = 0;
+ if (req->flags & REQ_F_FORCE_ASYNC)
+ req->work.flags |= IO_WQ_WORK_CONCURRENT;
+
+ if (req->flags & REQ_F_ISREG) {
+ if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
+ io_wq_hash_work(&req->work, file_inode(req->file));
+ } else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
+ if (def->unbound_nonreg_file)
+ req->work.flags |= IO_WQ_WORK_UNBOUND;
+ }
+}
+
+static void io_prep_async_link(struct io_kiocb *req)
+{
+ struct io_kiocb *cur;
+
+ if (req->flags & REQ_F_LINK_TIMEOUT) {
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ io_for_each_link(cur, req)
+ io_prep_async_work(cur);
+ spin_unlock_irq(&ctx->timeout_lock);
+ } else {
+ io_for_each_link(cur, req)
+ io_prep_async_work(cur);
+ }
+}
+
+static void io_queue_async_work(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_kiocb *link = io_prep_linked_timeout(req);
+ struct io_uring_task *tctx = req->task->io_uring;
+
+ /* must not take the lock, NULL it as a precaution */
+ locked = NULL;
+
+ BUG_ON(!tctx);
+ BUG_ON(!tctx->io_wq);
+
+ /* init ->work of the whole link before punting */
+ io_prep_async_link(req);
+
+ /*
+ * Not expected to happen, but if we do have a bug where this _can_
+ * happen, catch it here and ensure the request is marked as
+ * canceled. That will make io-wq go through the usual work cancel
+ * procedure rather than attempt to run this request (or create a new
+ * worker for it).
+ */
+ if (WARN_ON_ONCE(!same_thread_group(req->task, current)))
+ req->work.flags |= IO_WQ_WORK_CANCEL;
+
+ trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
+ &req->work, req->flags);
+ io_wq_enqueue(tctx->io_wq, &req->work);
+ if (link)
+ io_queue_linked_timeout(link);
+}
+
+static void io_kill_timeout(struct io_kiocb *req, int status)
+ __must_hold(&req->ctx->completion_lock)
+ __must_hold(&req->ctx->timeout_lock)
+{
+ struct io_timeout_data *io = req->async_data;
+
+ if (hrtimer_try_to_cancel(&io->timer) != -1) {
+ if (status)
+ req_set_fail(req);
+ atomic_set(&req->ctx->cq_timeouts,
+ atomic_read(&req->ctx->cq_timeouts) + 1);
+ list_del_init(&req->timeout.list);
+ io_fill_cqe_req(req, status, 0);
+ io_put_req_deferred(req);
+ }
+}
+
+static void io_queue_deferred(struct io_ring_ctx *ctx)
+{
+ while (!list_empty(&ctx->defer_list)) {
+ struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
+ struct io_defer_entry, list);
+
+ if (req_need_defer(de->req, de->seq))
+ break;
+ list_del_init(&de->list);
+ io_req_task_queue(de->req);
+ kfree(de);
+ }
+}
+
+static void io_flush_timeouts(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->completion_lock)
+{
+ u32 seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
+ struct io_kiocb *req, *tmp;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
+ u32 events_needed, events_got;
+
+ if (io_is_timeout_noseq(req))
+ break;
+
+ /*
+ * Since seq can easily wrap around over time, subtract
+ * the last seq at which timeouts were flushed before comparing.
+ * Assuming not more than 2^31-1 events have happened since,
+ * these subtractions won't have wrapped, so we can check if
+ * target is in [last_seq, current_seq] by comparing the two.
+ */
+ events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush;
+ events_got = seq - ctx->cq_last_tm_flush;
+ if (events_got < events_needed)
+ break;
+
+ io_kill_timeout(req, 0);
+ }
+ ctx->cq_last_tm_flush = seq;
+ spin_unlock_irq(&ctx->timeout_lock);
+}
+
+static void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
+{
+ if (ctx->off_timeout_used)
+ io_flush_timeouts(ctx);
+ if (ctx->drain_active)
+ io_queue_deferred(ctx);
+}
+
+static inline void io_commit_cqring(struct io_ring_ctx *ctx)
+{
+ if (unlikely(ctx->off_timeout_used || ctx->drain_active))
+ __io_commit_cqring_flush(ctx);
+ /* order cqe stores with ring update */
+ smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
+}
+
+static inline bool io_sqring_full(struct io_ring_ctx *ctx)
+{
+ struct io_rings *r = ctx->rings;
+
+ return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
+}
+
+static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
+{
+ return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
+}
+
+static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
+{
+ struct io_rings *rings = ctx->rings;
+ unsigned tail, mask = ctx->cq_entries - 1;
+
+ /*
+ * writes to the cq entry need to come after reading head; the
+ * control dependency is enough as we're using WRITE_ONCE to
+ * fill the cq entry
+ */
+ if (__io_cqring_events(ctx) == ctx->cq_entries)
+ return NULL;
+
+ tail = ctx->cached_cq_tail++;
+ return &rings->cqes[tail & mask];
+}
+
+static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
+{
+ if (likely(!ctx->cq_ev_fd))
+ return false;
+ if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
+ return false;
+ return !ctx->eventfd_async || io_wq_current_is_worker();
+}
+
+/*
+ * This should only get called when at least one event has been posted.
+ * Some applications rely on the eventfd notification count only changing
+ * IFF a new CQE has been added to the CQ ring. There's no depedency on
+ * 1:1 relationship between how many times this function is called (and
+ * hence the eventfd count) and number of CQEs posted to the CQ ring.
+ */
+static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
+{
+ /*
+ * wake_up_all() may seem excessive, but io_wake_function() and
+ * io_should_wake() handle the termination of the loop and only
+ * wake as many waiters as we need to.
+ */
+ if (wq_has_sleeper(&ctx->cq_wait))
+ wake_up_all(&ctx->cq_wait);
+ if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait))
+ wake_up(&ctx->sq_data->wait);
+ if (io_should_trigger_evfd(ctx))
+ eventfd_signal(ctx->cq_ev_fd, 1);
+ if (waitqueue_active(&ctx->poll_wait))
+ wake_up_interruptible(&ctx->poll_wait);
+}
+
+static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
+{
+ /* see waitqueue_active() comment */
+ smp_mb();
+
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ if (waitqueue_active(&ctx->cq_wait))
+ wake_up_all(&ctx->cq_wait);
+ }
+ if (io_should_trigger_evfd(ctx))
+ eventfd_signal(ctx->cq_ev_fd, 1);
+ if (waitqueue_active(&ctx->poll_wait))
+ wake_up_interruptible(&ctx->poll_wait);
+}
+
+/* Returns true if there are no backlogged entries after the flush */
+static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
+{
+ bool all_flushed, posted;
+
+ if (!force && __io_cqring_events(ctx) == ctx->cq_entries)
+ return false;
+
+ posted = false;
+ spin_lock(&ctx->completion_lock);
+ while (!list_empty(&ctx->cq_overflow_list)) {
+ struct io_uring_cqe *cqe = io_get_cqe(ctx);
+ struct io_overflow_cqe *ocqe;
+
+ if (!cqe && !force)
+ break;
+ ocqe = list_first_entry(&ctx->cq_overflow_list,
+ struct io_overflow_cqe, list);
+ if (cqe)
+ memcpy(cqe, &ocqe->cqe, sizeof(*cqe));
+ else
+ io_account_cq_overflow(ctx);
+
+ posted = true;
+ list_del(&ocqe->list);
+ kfree(ocqe);
+ }
+
+ all_flushed = list_empty(&ctx->cq_overflow_list);
+ if (all_flushed) {
+ clear_bit(0, &ctx->check_cq_overflow);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags & ~IORING_SQ_CQ_OVERFLOW);
+ }
+
+ if (posted)
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (posted)
+ io_cqring_ev_posted(ctx);
+ return all_flushed;
+}
+
+static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx)
+{
+ bool ret = true;
+
+ if (test_bit(0, &ctx->check_cq_overflow)) {
+ /* iopoll syncs against uring_lock, not completion_lock */
+ if (ctx->flags & IORING_SETUP_IOPOLL)
+ mutex_lock(&ctx->uring_lock);
+ ret = __io_cqring_overflow_flush(ctx, false);
+ if (ctx->flags & IORING_SETUP_IOPOLL)
+ mutex_unlock(&ctx->uring_lock);
+ }
+
+ return ret;
+}
+
+/* must to be called somewhat shortly after putting a request */
+static inline void io_put_task(struct task_struct *task, int nr)
+{
+ struct io_uring_task *tctx = task->io_uring;
+
+ if (likely(task == current)) {
+ tctx->cached_refs += nr;
+ } else {
+ percpu_counter_sub(&tctx->inflight, nr);
+ if (unlikely(atomic_read(&tctx->in_idle)))
+ wake_up(&tctx->wait);
+ put_task_struct_many(task, nr);
+ }
+}
+
+static void io_task_refs_refill(struct io_uring_task *tctx)
+{
+ unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;
+
+ percpu_counter_add(&tctx->inflight, refill);
+ refcount_add(refill, ¤t->usage);
+ tctx->cached_refs += refill;
+}
+
+static inline void io_get_task_refs(int nr)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ tctx->cached_refs -= nr;
+ if (unlikely(tctx->cached_refs < 0))
+ io_task_refs_refill(tctx);
+}
+
+static __cold void io_uring_drop_tctx_refs(struct task_struct *task)
+{
+ struct io_uring_task *tctx = task->io_uring;
+ unsigned int refs = tctx->cached_refs;
+
+ if (refs) {
+ tctx->cached_refs = 0;
+ percpu_counter_sub(&tctx->inflight, refs);
+ put_task_struct_many(task, refs);
+ }
+}
+
+static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
+ s32 res, u32 cflags)
+{
+ struct io_overflow_cqe *ocqe;
+
+ ocqe = kmalloc(sizeof(*ocqe), GFP_ATOMIC | __GFP_ACCOUNT);
+ if (!ocqe) {
+ /*
+ * If we're in ring overflow flush mode, or in task cancel mode,
+ * or cannot allocate an overflow entry, then we need to drop it
+ * on the floor.
+ */
+ io_account_cq_overflow(ctx);
+ return false;
+ }
+ if (list_empty(&ctx->cq_overflow_list)) {
+ set_bit(0, &ctx->check_cq_overflow);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags | IORING_SQ_CQ_OVERFLOW);
+
+ }
+ ocqe->cqe.user_data = user_data;
+ ocqe->cqe.res = res;
+ ocqe->cqe.flags = cflags;
+ list_add_tail(&ocqe->list, &ctx->cq_overflow_list);
+ return true;
+}
+
+static inline bool __io_fill_cqe(struct io_ring_ctx *ctx, u64 user_data,
+ s32 res, u32 cflags)
+{
+ struct io_uring_cqe *cqe;
+
+ trace_io_uring_complete(ctx, user_data, res, cflags);
+
+ /*
+ * If we can't get a cq entry, userspace overflowed the
+ * submission (by quite a lot). Increment the overflow count in
+ * the ring.
+ */
+ cqe = io_get_cqe(ctx);
+ if (likely(cqe)) {
+ WRITE_ONCE(cqe->user_data, user_data);
+ WRITE_ONCE(cqe->res, res);
+ WRITE_ONCE(cqe->flags, cflags);
+ return true;
+ }
+ return io_cqring_event_overflow(ctx, user_data, res, cflags);
+}
+
+static noinline void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags)
+{
+ __io_fill_cqe(req->ctx, req->user_data, res, cflags);
+}
+
+static noinline bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data,
+ s32 res, u32 cflags)
+{
+ ctx->cq_extra++;
+ return __io_fill_cqe(ctx, user_data, res, cflags);
+}
+
+static void io_req_complete_post(struct io_kiocb *req, s32 res,
+ u32 cflags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock(&ctx->completion_lock);
+ __io_fill_cqe(ctx, req->user_data, res, cflags);
+ /*
+ * If we're the last reference to this request, add to our locked
+ * free_list cache.
+ */
+ if (req_ref_put_and_test(req)) {
+ if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
+ if (req->flags & IO_DISARM_MASK)
+ io_disarm_next(req);
+ if (req->link) {
+ io_req_task_queue(req->link);
+ req->link = NULL;
+ }
+ }
+ io_dismantle_req(req);
+ io_put_task(req->task, 1);
+ list_add(&req->inflight_entry, &ctx->locked_free_list);
+ ctx->locked_free_nr++;
+ } else {
+ if (!percpu_ref_tryget(&ctx->refs))
+ req = NULL;
+ }
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+
+ if (req) {
+ io_cqring_ev_posted(ctx);
+ percpu_ref_put(&ctx->refs);
+ }
+}
+
+static inline bool io_req_needs_clean(struct io_kiocb *req)
+{
+ return req->flags & IO_REQ_CLEAN_FLAGS;
+}
+
+static inline void io_req_complete_state(struct io_kiocb *req, s32 res,
+ u32 cflags)
+{
+ if (io_req_needs_clean(req))
+ io_clean_op(req);
+ req->result = res;
+ req->compl.cflags = cflags;
+ req->flags |= REQ_F_COMPLETE_INLINE;
+}
+
+static inline void __io_req_complete(struct io_kiocb *req, unsigned issue_flags,
+ s32 res, u32 cflags)
+{
+ if (issue_flags & IO_URING_F_COMPLETE_DEFER)
+ io_req_complete_state(req, res, cflags);
+ else
+ io_req_complete_post(req, res, cflags);
+}
+
+static inline void io_req_complete(struct io_kiocb *req, s32 res)
+{
+ __io_req_complete(req, 0, res, 0);
+}
+
+static void io_req_complete_failed(struct io_kiocb *req, s32 res)
+{
+ req_set_fail(req);
+ io_req_complete_post(req, res, 0);
+}
+
+static void io_req_complete_fail_submit(struct io_kiocb *req)
+{
+ /*
+ * We don't submit, fail them all, for that replace hardlinks with
+ * normal links. Extra REQ_F_LINK is tolerated.
+ */
+ req->flags &= ~REQ_F_HARDLINK;
+ req->flags |= REQ_F_LINK;
+ io_req_complete_failed(req, req->result);
+}
+
+/*
+ * Don't initialise the fields below on every allocation, but do that in
+ * advance and keep them valid across allocations.
+ */
+static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
+{
+ req->ctx = ctx;
+ req->link = NULL;
+ req->async_data = NULL;
+ /* not necessary, but safer to zero */
+ req->result = 0;
+}
+
+static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
+ struct io_submit_state *state)
+{
+ spin_lock(&ctx->completion_lock);
+ list_splice_init(&ctx->locked_free_list, &state->free_list);
+ ctx->locked_free_nr = 0;
+ spin_unlock(&ctx->completion_lock);
+}
+
+/* Returns true IFF there are requests in the cache */
+static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+ int nr;
+
+ /*
+ * If we have more than a batch's worth of requests in our IRQ side
+ * locked cache, grab the lock and move them over to our submission
+ * side cache.
+ */
+ if (READ_ONCE(ctx->locked_free_nr) > IO_COMPL_BATCH)
+ io_flush_cached_locked_reqs(ctx, state);
+
+ nr = state->free_reqs;
+ while (!list_empty(&state->free_list)) {
+ struct io_kiocb *req = list_first_entry(&state->free_list,
+ struct io_kiocb, inflight_entry);
+
+ list_del(&req->inflight_entry);
+ state->reqs[nr++] = req;
+ if (nr == ARRAY_SIZE(state->reqs))
+ break;
+ }
+
+ state->free_reqs = nr;
+ return nr != 0;
+}
+
+/*
+ * A request might get retired back into the request caches even before opcode
+ * handlers and io_issue_sqe() are done with it, e.g. inline completion path.
+ * Because of that, io_alloc_req() should be called only under ->uring_lock
+ * and with extra caution to not get a request that is still worked on.
+ */
+static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+ gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
+ int ret, i;
+
+ BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH);
+
+ if (likely(state->free_reqs || io_flush_cached_reqs(ctx)))
+ goto got_req;
+
+ ret = kmem_cache_alloc_bulk(req_cachep, gfp, IO_REQ_ALLOC_BATCH,
+ state->reqs);
+
+ /*
+ * Bulk alloc is all-or-nothing. If we fail to get a batch,
+ * retry single alloc to be on the safe side.
+ */
+ if (unlikely(ret <= 0)) {
+ state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
+ if (!state->reqs[0])
+ return NULL;
+ ret = 1;
+ }
+
+ for (i = 0; i < ret; i++)
+ io_preinit_req(state->reqs[i], ctx);
+ state->free_reqs = ret;
+got_req:
+ state->free_reqs--;
+ return state->reqs[state->free_reqs];
+}
+
+static inline void io_put_file(struct file *file)
+{
+ if (file)
+ fput(file);
+}
+
+static void io_dismantle_req(struct io_kiocb *req)
+{
+ unsigned int flags = req->flags;
+
+ if (io_req_needs_clean(req))
+ io_clean_op(req);
+ if (!(flags & REQ_F_FIXED_FILE))
+ io_put_file(req->file);
+ if (req->fixed_rsrc_refs)
+ percpu_ref_put(req->fixed_rsrc_refs);
+ if (req->async_data) {
+ kfree(req->async_data);
+ req->async_data = NULL;
+ }
+}
+
+static void __io_free_req(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ io_dismantle_req(req);
+ io_put_task(req->task, 1);
+
+ spin_lock(&ctx->completion_lock);
+ list_add(&req->inflight_entry, &ctx->locked_free_list);
+ ctx->locked_free_nr++;
+ spin_unlock(&ctx->completion_lock);
+
+ percpu_ref_put(&ctx->refs);
+}
+
+static inline void io_remove_next_linked(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt = req->link;
+
+ req->link = nxt->link;
+ nxt->link = NULL;
+}
+
+static bool io_kill_linked_timeout(struct io_kiocb *req)
+ __must_hold(&req->ctx->completion_lock)
+ __must_hold(&req->ctx->timeout_lock)
+{
+ struct io_kiocb *link = req->link;
+
+ if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
+ struct io_timeout_data *io = link->async_data;
+
+ io_remove_next_linked(req);
+ link->timeout.head = NULL;
+ if (hrtimer_try_to_cancel(&io->timer) != -1) {
+ list_del(&link->timeout.list);
+ io_fill_cqe_req(link, -ECANCELED, 0);
+ io_put_req_deferred(link);
+ return true;
+ }
+ }
+ return false;
+}
+
+static void io_fail_links(struct io_kiocb *req)
+ __must_hold(&req->ctx->completion_lock)
+{
+ struct io_kiocb *nxt, *link = req->link;
+
+ req->link = NULL;
+ while (link) {
+ long res = -ECANCELED;
+
+ if (link->flags & REQ_F_FAIL)
+ res = link->result;
+
+ nxt = link->link;
+ link->link = NULL;
+
+ trace_io_uring_fail_link(req, link);
+ io_fill_cqe_req(link, res, 0);
+ io_put_req_deferred(link);
+ link = nxt;
+ }
+}
+
+static bool io_disarm_next(struct io_kiocb *req)
+ __must_hold(&req->ctx->completion_lock)
+{
+ bool posted = false;
+
+ if (req->flags & REQ_F_ARM_LTIMEOUT) {
+ struct io_kiocb *link = req->link;
+
+ req->flags &= ~REQ_F_ARM_LTIMEOUT;
+ if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
+ io_remove_next_linked(req);
+ io_fill_cqe_req(link, -ECANCELED, 0);
+ io_put_req_deferred(link);
+ posted = true;
+ }
+ } else if (req->flags & REQ_F_LINK_TIMEOUT) {
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ posted = io_kill_linked_timeout(req);
+ spin_unlock_irq(&ctx->timeout_lock);
+ }
+ if (unlikely((req->flags & REQ_F_FAIL) &&
+ !(req->flags & REQ_F_HARDLINK))) {
+ posted |= (req->link != NULL);
+ io_fail_links(req);
+ }
+ return posted;
+}
+
+static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt;
+
+ /*
+ * If LINK is set, we have dependent requests in this chain. If we
+ * didn't fail this request, queue the first one up, moving any other
+ * dependencies to the next request. In case of failure, fail the rest
+ * of the chain.
+ */
+ if (req->flags & IO_DISARM_MASK) {
+ struct io_ring_ctx *ctx = req->ctx;
+ bool posted;
+
+ spin_lock(&ctx->completion_lock);
+ posted = io_disarm_next(req);
+ if (posted)
+ io_commit_cqring(req->ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (posted)
+ io_cqring_ev_posted(ctx);
+ }
+ nxt = req->link;
+ req->link = NULL;
+ return nxt;
+}
+
+static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
+{
+ if (likely(!(req->flags & (REQ_F_LINK|REQ_F_HARDLINK))))
+ return NULL;
+ return __io_req_find_next(req);
+}
+
+static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
+{
+ if (!ctx)
+ return;
+ if (*locked) {
+ if (ctx->submit_state.compl_nr)
+ io_submit_flush_completions(ctx);
+ mutex_unlock(&ctx->uring_lock);
+ *locked = false;
+ }
+ percpu_ref_put(&ctx->refs);
+}
+
+static void tctx_task_work(struct callback_head *cb)
+{
+ bool locked = false;
+ struct io_ring_ctx *ctx = NULL;
+ struct io_uring_task *tctx = container_of(cb, struct io_uring_task,
+ task_work);
+
+ while (1) {
+ struct io_wq_work_node *node;
+
+ if (!tctx->task_list.first && locked && ctx->submit_state.compl_nr)
+ io_submit_flush_completions(ctx);
+
+ spin_lock_irq(&tctx->task_lock);
+ node = tctx->task_list.first;
+ INIT_WQ_LIST(&tctx->task_list);
+ if (!node)
+ tctx->task_running = false;
+ spin_unlock_irq(&tctx->task_lock);
+ if (!node)
+ break;
+
+ do {
+ struct io_wq_work_node *next = node->next;
+ struct io_kiocb *req = container_of(node, struct io_kiocb,
+ io_task_work.node);
+
+ if (req->ctx != ctx) {
+ ctx_flush_and_put(ctx, &locked);
+ ctx = req->ctx;
+ /* if not contended, grab and improve batching */
+ locked = mutex_trylock(&ctx->uring_lock);
+ percpu_ref_get(&ctx->refs);
+ }
+ req->io_task_work.func(req, &locked);
+ node = next;
+ } while (node);
+
+ cond_resched();
+ }
+
+ ctx_flush_and_put(ctx, &locked);
+
+ /* relaxed read is enough as only the task itself sets ->in_idle */
+ if (unlikely(atomic_read(&tctx->in_idle)))
+ io_uring_drop_tctx_refs(current);
+}
+
+static void io_req_task_work_add(struct io_kiocb *req)
+{
+ struct task_struct *tsk = req->task;
+ struct io_uring_task *tctx = tsk->io_uring;
+ enum task_work_notify_mode notify;
+ struct io_wq_work_node *node;
+ unsigned long flags;
+ bool running;
+
+ WARN_ON_ONCE(!tctx);
+
+ spin_lock_irqsave(&tctx->task_lock, flags);
+ wq_list_add_tail(&req->io_task_work.node, &tctx->task_list);
+ running = tctx->task_running;
+ if (!running)
+ tctx->task_running = true;
+ spin_unlock_irqrestore(&tctx->task_lock, flags);
+
+ /* task_work already pending, we're done */
+ if (running)
+ return;
+
+ /*
+ * SQPOLL kernel thread doesn't need notification, just a wakeup. For
+ * all other cases, use TWA_SIGNAL unconditionally to ensure we're
+ * processing task_work. There's no reliable way to tell if TWA_RESUME
+ * will do the job.
+ */
+ notify = (req->ctx->flags & IORING_SETUP_SQPOLL) ? TWA_NONE : TWA_SIGNAL;
+ if (!task_work_add(tsk, &tctx->task_work, notify)) {
+ wake_up_process(tsk);
+ return;
+ }
+
+ spin_lock_irqsave(&tctx->task_lock, flags);
+ tctx->task_running = false;
+ node = tctx->task_list.first;
+ INIT_WQ_LIST(&tctx->task_list);
+ spin_unlock_irqrestore(&tctx->task_lock, flags);
+
+ while (node) {
+ req = container_of(node, struct io_kiocb, io_task_work.node);
+ node = node->next;
+ if (llist_add(&req->io_task_work.fallback_node,
+ &req->ctx->fallback_llist))
+ schedule_delayed_work(&req->ctx->fallback_work, 1);
+ }
+}
+
+static void io_req_task_cancel(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ /* not needed for normal modes, but SQPOLL depends on it */
+ io_tw_lock(ctx, locked);
+ io_req_complete_failed(req, req->result);
+}
+
+static void io_req_task_submit(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ io_tw_lock(ctx, locked);
+ /* req->task == current here, checking PF_EXITING is safe */
+ if (likely(!(req->task->flags & PF_EXITING)))
+ __io_queue_sqe(req);
+ else
+ io_req_complete_failed(req, -EFAULT);
+}
+
+static void io_req_task_queue_fail(struct io_kiocb *req, int ret)
+{
+ req->result = ret;
+ req->io_task_work.func = io_req_task_cancel;
+ io_req_task_work_add(req);
+}
+
+static void io_req_task_queue(struct io_kiocb *req)
+{
+ req->io_task_work.func = io_req_task_submit;
+ io_req_task_work_add(req);
+}
+
+static void io_req_task_queue_reissue(struct io_kiocb *req)
+{
+ req->io_task_work.func = io_queue_async_work;
+ io_req_task_work_add(req);
+}
+
+static inline void io_queue_next(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt = io_req_find_next(req);
+
+ if (nxt)
+ io_req_task_queue(nxt);
+}
+
+static void io_free_req(struct io_kiocb *req)
+{
+ io_queue_next(req);
+ __io_free_req(req);
+}
+
+static void io_free_req_work(struct io_kiocb *req, bool *locked)
+{
+ io_free_req(req);
+}
+
+struct req_batch {
+ struct task_struct *task;
+ int task_refs;
+ int ctx_refs;
+};
+
+static inline void io_init_req_batch(struct req_batch *rb)
+{
+ rb->task_refs = 0;
+ rb->ctx_refs = 0;
+ rb->task = NULL;
+}
+
+static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
+ struct req_batch *rb)
+{
+ if (rb->ctx_refs)
+ percpu_ref_put_many(&ctx->refs, rb->ctx_refs);
+ if (rb->task)
+ io_put_task(rb->task, rb->task_refs);
+}
+
+static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req,
+ struct io_submit_state *state)
+{
+ io_queue_next(req);
+ io_dismantle_req(req);
+
+ if (req->task != rb->task) {
+ if (rb->task)
+ io_put_task(rb->task, rb->task_refs);
+ rb->task = req->task;
+ rb->task_refs = 0;
+ }
+ rb->task_refs++;
+ rb->ctx_refs++;
+
+ if (state->free_reqs != ARRAY_SIZE(state->reqs))
+ state->reqs[state->free_reqs++] = req;
+ else
+ list_add(&req->inflight_entry, &state->free_list);
+}
+
+static void io_submit_flush_completions(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+ int i, nr = state->compl_nr;
+ struct req_batch rb;
+
+ spin_lock(&ctx->completion_lock);
+ for (i = 0; i < nr; i++) {
+ struct io_kiocb *req = state->compl_reqs[i];
+
+ __io_fill_cqe(ctx, req->user_data, req->result,
+ req->compl.cflags);
+ }
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ io_cqring_ev_posted(ctx);
+
+ io_init_req_batch(&rb);
+ for (i = 0; i < nr; i++) {
+ struct io_kiocb *req = state->compl_reqs[i];
+
+ if (req_ref_put_and_test(req))
+ io_req_free_batch(&rb, req, &ctx->submit_state);
+ }
+
+ io_req_free_batch_finish(ctx, &rb);
+ state->compl_nr = 0;
+}
+
+/*
+ * Drop reference to request, return next in chain (if there is one) if this
+ * was the last reference to this request.
+ */
+static inline struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt = NULL;
+
+ if (req_ref_put_and_test(req)) {
+ nxt = io_req_find_next(req);
+ __io_free_req(req);
+ }
+ return nxt;
+}
+
+static inline void io_put_req(struct io_kiocb *req)
+{
+ if (req_ref_put_and_test(req))
+ io_free_req(req);
+}
+
+static inline void io_put_req_deferred(struct io_kiocb *req)
+{
+ if (req_ref_put_and_test(req)) {
+ req->io_task_work.func = io_free_req_work;
+ io_req_task_work_add(req);
+ }
+}
+
+static unsigned io_cqring_events(struct io_ring_ctx *ctx)
+{
+ /* See comment at the top of this file */
+ smp_rmb();
+ return __io_cqring_events(ctx);
+}
+
+static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
+{
+ struct io_rings *rings = ctx->rings;
+
+ /* make sure SQ entry isn't read before tail */
+ return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
+}
+
+static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
+{
+ unsigned int cflags;
+
+ cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
+ cflags |= IORING_CQE_F_BUFFER;
+ req->flags &= ~REQ_F_BUFFER_SELECTED;
+ kfree(kbuf);
+ return cflags;
+}
+
+static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
+{
+ struct io_buffer *kbuf;
+
+ if (likely(!(req->flags & REQ_F_BUFFER_SELECTED)))
+ return 0;
+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+ return io_put_kbuf(req, kbuf);
+}
+
+static inline bool io_run_task_work(void)
+{
+ if (test_thread_flag(TIF_NOTIFY_SIGNAL) || current->task_works) {
+ __set_current_state(TASK_RUNNING);
+ tracehook_notify_signal();
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * Find and free completed poll iocbs
+ */
+static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
+ struct list_head *done)
+{
+ struct req_batch rb;
+ struct io_kiocb *req;
+
+ /* order with ->result store in io_complete_rw_iopoll() */
+ smp_rmb();
+
+ io_init_req_batch(&rb);
+ while (!list_empty(done)) {
+ req = list_first_entry(done, struct io_kiocb, inflight_entry);
+ list_del(&req->inflight_entry);
+
+ io_fill_cqe_req(req, req->result, io_put_rw_kbuf(req));
+ (*nr_events)++;
+
+ if (req_ref_put_and_test(req))
+ io_req_free_batch(&rb, req, &ctx->submit_state);
+ }
+
+ io_commit_cqring(ctx);
+ io_cqring_ev_posted_iopoll(ctx);
+ io_req_free_batch_finish(ctx, &rb);
+}
+
+static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
+ long min)
+{
+ struct io_kiocb *req, *tmp;
+ LIST_HEAD(done);
+ bool spin;
+
+ /*
+ * Only spin for completions if we don't have multiple devices hanging
+ * off our complete list, and we're under the requested amount.
+ */
+ spin = !ctx->poll_multi_queue && *nr_events < min;
+
+ list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) {
+ struct kiocb *kiocb = &req->rw.kiocb;
+ int ret;
+
+ /*
+ * Move completed and retryable entries to our local lists.
+ * If we find a request that requires polling, break out
+ * and complete those lists first, if we have entries there.
+ */
+ if (READ_ONCE(req->iopoll_completed)) {
+ list_move_tail(&req->inflight_entry, &done);
+ continue;
+ }
+ if (!list_empty(&done))
+ break;
+
+ ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
+ if (unlikely(ret < 0))
+ return ret;
+ else if (ret)
+ spin = false;
+
+ /* iopoll may have completed current req */
+ if (READ_ONCE(req->iopoll_completed))
+ list_move_tail(&req->inflight_entry, &done);
+ }
+
+ if (!list_empty(&done))
+ io_iopoll_complete(ctx, nr_events, &done);
+
+ return 0;
+}
+
+/*
+ * We can't just wait for polled events to come to us, we have to actively
+ * find and complete them.
+ */
+static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
+{
+ if (!(ctx->flags & IORING_SETUP_IOPOLL))
+ return;
+
+ mutex_lock(&ctx->uring_lock);
+ while (!list_empty(&ctx->iopoll_list)) {
+ unsigned int nr_events = 0;
+
+ io_do_iopoll(ctx, &nr_events, 0);
+
+ /* let it sleep and repeat later if can't complete a request */
+ if (nr_events == 0)
+ break;
+ /*
+ * Ensure we allow local-to-the-cpu processing to take place,
+ * in this case we need to ensure that we reap all events.
+ * Also let task_work, etc. to progress by releasing the mutex
+ */
+ if (need_resched()) {
+ mutex_unlock(&ctx->uring_lock);
+ cond_resched();
+ mutex_lock(&ctx->uring_lock);
+ }
+ }
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
+{
+ unsigned int nr_events = 0;
+ int ret = 0;
+
+ /*
+ * We disallow the app entering submit/complete with polling, but we
+ * still need to lock the ring to prevent racing with polled issue
+ * that got punted to a workqueue.
+ */
+ mutex_lock(&ctx->uring_lock);
+ /*
+ * Don't enter poll loop if we already have events pending.
+ * If we do, we can potentially be spinning for commands that
+ * already triggered a CQE (eg in error).
+ */
+ if (test_bit(0, &ctx->check_cq_overflow))
+ __io_cqring_overflow_flush(ctx, false);
+ if (io_cqring_events(ctx))
+ goto out;
+ do {
+ /*
+ * If a submit got punted to a workqueue, we can have the
+ * application entering polling for a command before it gets
+ * issued. That app will hold the uring_lock for the duration
+ * of the poll right here, so we need to take a breather every
+ * now and then to ensure that the issue has a chance to add
+ * the poll to the issued list. Otherwise we can spin here
+ * forever, while the workqueue is stuck trying to acquire the
+ * very same mutex.
+ */
+ if (list_empty(&ctx->iopoll_list)) {
+ u32 tail = ctx->cached_cq_tail;
+
+ mutex_unlock(&ctx->uring_lock);
+ io_run_task_work();
+ mutex_lock(&ctx->uring_lock);
+
+ /* some requests don't go through iopoll_list */
+ if (tail != ctx->cached_cq_tail ||
+ list_empty(&ctx->iopoll_list))
+ break;
+ }
+ ret = io_do_iopoll(ctx, &nr_events, min);
+ } while (!ret && nr_events < min && !need_resched());
+out:
+ mutex_unlock(&ctx->uring_lock);
+ return ret;
+}
+
+static void kiocb_end_write(struct io_kiocb *req)
+{
+ /*
+ * Tell lockdep we inherited freeze protection from submission
+ * thread.
+ */
+ if (req->flags & REQ_F_ISREG) {
+ struct super_block *sb = file_inode(req->file)->i_sb;
+
+ __sb_writers_acquired(sb, SB_FREEZE_WRITE);
+ sb_end_write(sb);
+ }
+}
+
+#ifdef CONFIG_BLOCK
+static bool io_resubmit_prep(struct io_kiocb *req)
+{
+ struct io_async_rw *rw = req->async_data;
+
+ if (!rw)
+ return !io_req_prep_async(req);
+ iov_iter_restore(&rw->iter, &rw->iter_state);
+ return true;
+}
+
+static bool io_rw_should_reissue(struct io_kiocb *req)
+{
+ umode_t mode = file_inode(req->file)->i_mode;
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!S_ISBLK(mode) && !S_ISREG(mode))
+ return false;
+ if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() &&
+ !(ctx->flags & IORING_SETUP_IOPOLL)))
+ return false;
+ /*
+ * If ref is dying, we might be running poll reap from the exit work.
+ * Don't attempt to reissue from that path, just let it fail with
+ * -EAGAIN.
+ */
+ if (percpu_ref_is_dying(&ctx->refs))
+ return false;
+ /*
+ * Play it safe and assume not safe to re-import and reissue if we're
+ * not in the original thread group (or in task context).
+ */
+ if (!same_thread_group(req->task, current) || !in_task())
+ return false;
+ return true;
+}
+#else
+static bool io_resubmit_prep(struct io_kiocb *req)
+{
+ return false;
+}
+static bool io_rw_should_reissue(struct io_kiocb *req)
+{
+ return false;
+}
+#endif
+
+static bool __io_complete_rw_common(struct io_kiocb *req, long res)
+{
+ if (req->rw.kiocb.ki_flags & IOCB_WRITE) {
+ kiocb_end_write(req);
+ fsnotify_modify(req->file);
+ } else {
+ fsnotify_access(req->file);
+ }
+ if (res != req->result) {
+ if ((res == -EAGAIN || res == -EOPNOTSUPP) &&
+ io_rw_should_reissue(req)) {
+ req->flags |= REQ_F_REISSUE;
+ return true;
+ }
+ req_set_fail(req);
+ req->result = res;
+ }
+ return false;
+}
+
+static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res)
+{
+ struct io_async_rw *io = req->async_data;
+
+ /* add previously done IO, if any */
+ if (io && io->bytes_done > 0) {
+ if (res < 0)
+ res = io->bytes_done;
+ else
+ res += io->bytes_done;
+ }
+ return res;
+}
+
+static void io_req_task_complete(struct io_kiocb *req, bool *locked)
+{
+ unsigned int cflags = io_put_rw_kbuf(req);
+ int res = req->result;
+
+ if (*locked) {
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_submit_state *state = &ctx->submit_state;
+
+ io_req_complete_state(req, res, cflags);
+ state->compl_reqs[state->compl_nr++] = req;
+ if (state->compl_nr == ARRAY_SIZE(state->compl_reqs))
+ io_submit_flush_completions(ctx);
+ } else {
+ io_req_complete_post(req, res, cflags);
+ }
+}
+
+static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
+ unsigned int issue_flags)
+{
+ if (__io_complete_rw_common(req, res))
+ return;
+ __io_req_complete(req, issue_flags, io_fixup_rw_res(req, res), io_put_rw_kbuf(req));
+}
+
+static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
+{
+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+
+ if (__io_complete_rw_common(req, res))
+ return;
+ req->result = io_fixup_rw_res(req, res);
+ req->io_task_work.func = io_req_task_complete;
+ io_req_task_work_add(req);
+}
+
+static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
+{
+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+
+ if (kiocb->ki_flags & IOCB_WRITE)
+ kiocb_end_write(req);
+ if (unlikely(res != req->result)) {
+ if (res == -EAGAIN && io_rw_should_reissue(req)) {
+ req->flags |= REQ_F_REISSUE;
+ return;
+ }
+ }
+
+ WRITE_ONCE(req->result, res);
+ /* order with io_iopoll_complete() checking ->result */
+ smp_wmb();
+ WRITE_ONCE(req->iopoll_completed, 1);
+}
+
+/*
+ * After the iocb has been issued, it's safe to be found on the poll list.
+ * Adding the kiocb to the list AFTER submission ensures that we don't
+ * find it from a io_do_iopoll() thread before the issuer is done
+ * accessing the kiocb cookie.
+ */
+static void io_iopoll_req_issued(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ const bool in_async = io_wq_current_is_worker();
+
+ /* workqueue context doesn't hold uring_lock, grab it now */
+ if (unlikely(in_async))
+ mutex_lock(&ctx->uring_lock);
+
+ /*
+ * Track whether we have multiple files in our lists. This will impact
+ * how we do polling eventually, not spinning if we're on potentially
+ * different devices.
+ */
+ if (list_empty(&ctx->iopoll_list)) {
+ ctx->poll_multi_queue = false;
+ } else if (!ctx->poll_multi_queue) {
+ struct io_kiocb *list_req;
+ unsigned int queue_num0, queue_num1;
+
+ list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
+ inflight_entry);
+
+ if (list_req->file != req->file) {
+ ctx->poll_multi_queue = true;
+ } else {
+ queue_num0 = blk_qc_t_to_queue_num(list_req->rw.kiocb.ki_cookie);
+ queue_num1 = blk_qc_t_to_queue_num(req->rw.kiocb.ki_cookie);
+ if (queue_num0 != queue_num1)
+ ctx->poll_multi_queue = true;
+ }
+ }
+
+ /*
+ * For fast devices, IO may have already completed. If it has, add
+ * it to the front so we find it first.
+ */
+ if (READ_ONCE(req->iopoll_completed))
+ list_add(&req->inflight_entry, &ctx->iopoll_list);
+ else
+ list_add_tail(&req->inflight_entry, &ctx->iopoll_list);
+
+ if (unlikely(in_async)) {
+ /*
+ * If IORING_SETUP_SQPOLL is enabled, sqes are either handle
+ * in sq thread task context or in io worker task context. If
+ * current task context is sq thread, we don't need to check
+ * whether should wake up sq thread.
+ */
+ if ((ctx->flags & IORING_SETUP_SQPOLL) &&
+ wq_has_sleeper(&ctx->sq_data->wait))
+ wake_up(&ctx->sq_data->wait);
+
+ mutex_unlock(&ctx->uring_lock);
+ }
+}
+
+static bool io_bdev_nowait(struct block_device *bdev)
+{
+ return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
+}
+
+/*
+ * If we tracked the file through the SCM inflight mechanism, we could support
+ * any file. For now, just ensure that anything potentially problematic is done
+ * inline.
+ */
+static bool __io_file_supports_nowait(struct file *file, int rw)
+{
+ umode_t mode = file_inode(file)->i_mode;
+
+ if (S_ISBLK(mode)) {
+ if (IS_ENABLED(CONFIG_BLOCK) &&
+ io_bdev_nowait(I_BDEV(file->f_mapping->host)))
+ return true;
+ return false;
+ }
+ if (S_ISSOCK(mode))
+ return true;
+ if (S_ISREG(mode)) {
+ if (IS_ENABLED(CONFIG_BLOCK) &&
+ io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
+ file->f_op != &io_uring_fops)
+ return true;
+ return false;
+ }
+
+ /* any ->read/write should understand O_NONBLOCK */
+ if (file->f_flags & O_NONBLOCK)
+ return true;
+
+ if (!(file->f_mode & FMODE_NOWAIT))
+ return false;
+
+ if (rw == READ)
+ return file->f_op->read_iter != NULL;
+
+ return file->f_op->write_iter != NULL;
+}
+
+static bool io_file_supports_nowait(struct io_kiocb *req, int rw)
+{
+ if (rw == READ && (req->flags & REQ_F_NOWAIT_READ))
+ return true;
+ else if (rw == WRITE && (req->flags & REQ_F_NOWAIT_WRITE))
+ return true;
+
+ return __io_file_supports_nowait(req->file, rw);
+}
+
+static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
+ int rw)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct file *file = req->file;
+ unsigned ioprio;
+ int ret;
+
+ if (!io_req_ffs_set(req) && S_ISREG(file_inode(file)->i_mode))
+ req->flags |= REQ_F_ISREG;
+
+ kiocb->ki_pos = READ_ONCE(sqe->off);
+ if (kiocb->ki_pos == -1) {
+ if (!(file->f_mode & FMODE_STREAM)) {
+ req->flags |= REQ_F_CUR_POS;
+ kiocb->ki_pos = file->f_pos;
+ } else {
+ kiocb->ki_pos = 0;
+ }
+ }
+ kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
+ kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
+ ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
+ if (unlikely(ret))
+ return ret;
+
+ /*
+ * If the file is marked O_NONBLOCK, still allow retry for it if it
+ * supports async. Otherwise it's impossible to use O_NONBLOCK files
+ * reliably. If not, or it IOCB_NOWAIT is set, don't retry.
+ */
+ if ((kiocb->ki_flags & IOCB_NOWAIT) ||
+ ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw)))
+ req->flags |= REQ_F_NOWAIT;
+
+ ioprio = READ_ONCE(sqe->ioprio);
+ if (ioprio) {
+ ret = ioprio_check_cap(ioprio);
+ if (ret)
+ return ret;
+
+ kiocb->ki_ioprio = ioprio;
+ } else
+ kiocb->ki_ioprio = get_current_ioprio();
+
+ if (ctx->flags & IORING_SETUP_IOPOLL) {
+ if (!(kiocb->ki_flags & IOCB_DIRECT) ||
+ !kiocb->ki_filp->f_op->iopoll)
+ return -EOPNOTSUPP;
+
+ kiocb->ki_flags |= IOCB_HIPRI;
+ kiocb->ki_complete = io_complete_rw_iopoll;
+ req->iopoll_completed = 0;
+ } else {
+ if (kiocb->ki_flags & IOCB_HIPRI)
+ return -EINVAL;
+ kiocb->ki_complete = io_complete_rw;
+ }
+
+ /* used for fixed read/write too - just read unconditionally */
+ req->buf_index = READ_ONCE(sqe->buf_index);
+ req->imu = NULL;
+
+ if (req->opcode == IORING_OP_READ_FIXED ||
+ req->opcode == IORING_OP_WRITE_FIXED) {
+ struct io_ring_ctx *ctx = req->ctx;
+ u16 index;
+
+ if (unlikely(req->buf_index >= ctx->nr_user_bufs))
+ return -EFAULT;
+ index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
+ req->imu = ctx->user_bufs[index];
+ io_req_set_rsrc_node(req);
+ }
+
+ req->rw.addr = READ_ONCE(sqe->addr);
+ req->rw.len = READ_ONCE(sqe->len);
+ return 0;
+}
+
+static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
+{
+ switch (ret) {
+ case -EIOCBQUEUED:
+ break;
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ case -ERESTARTNOHAND:
+ case -ERESTART_RESTARTBLOCK:
+ /*
+ * We can't just restart the syscall, since previously
+ * submitted sqes may already be in progress. Just fail this
+ * IO with EINTR.
+ */
+ ret = -EINTR;
+ fallthrough;
+ default:
+ kiocb->ki_complete(kiocb, ret, 0);
+ }
+}
+
+static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
+ unsigned int issue_flags)
+{
+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+
+ if (req->flags & REQ_F_CUR_POS)
+ req->file->f_pos = kiocb->ki_pos;
+ if (ret >= 0 && (kiocb->ki_complete == io_complete_rw))
+ __io_complete_rw(req, ret, 0, issue_flags);
+ else
+ io_rw_done(kiocb, ret);
+
+ if (req->flags & REQ_F_REISSUE) {
+ req->flags &= ~REQ_F_REISSUE;
+ if (io_resubmit_prep(req)) {
+ io_req_task_queue_reissue(req);
+ } else {
+ unsigned int cflags = io_put_rw_kbuf(req);
+ struct io_ring_ctx *ctx = req->ctx;
+
+ ret = io_fixup_rw_res(req, ret);
+ req_set_fail(req);
+ if (!(issue_flags & IO_URING_F_NONBLOCK)) {
+ mutex_lock(&ctx->uring_lock);
+ __io_req_complete(req, issue_flags, ret, cflags);
+ mutex_unlock(&ctx->uring_lock);
+ } else {
+ __io_req_complete(req, issue_flags, ret, cflags);
+ }
+ }
+ }
+}
+
+static int __io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter,
+ struct io_mapped_ubuf *imu)
+{
+ size_t len = req->rw.len;
+ u64 buf_end, buf_addr = req->rw.addr;
+ size_t offset;
+
+ if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
+ return -EFAULT;
+ /* not inside the mapped region */
+ if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
+ return -EFAULT;
+
+ /*
+ * May not be a start of buffer, set size appropriately
+ * and advance us to the beginning.
+ */
+ offset = buf_addr - imu->ubuf;
+ iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
+
+ if (offset) {
+ /*
+ * Don't use iov_iter_advance() here, as it's really slow for
+ * using the latter parts of a big fixed buffer - it iterates
+ * over each segment manually. We can cheat a bit here, because
+ * we know that:
+ *
+ * 1) it's a BVEC iter, we set it up
+ * 2) all bvecs are PAGE_SIZE in size, except potentially the
+ * first and last bvec
+ *
+ * So just find our index, and adjust the iterator afterwards.
+ * If the offset is within the first bvec (or the whole first
+ * bvec, just use iov_iter_advance(). This makes it easier
+ * since we can just skip the first segment, which may not
+ * be PAGE_SIZE aligned.
+ */
+ const struct bio_vec *bvec = imu->bvec;
+
+ if (offset <= bvec->bv_len) {
+ iov_iter_advance(iter, offset);
+ } else {
+ unsigned long seg_skip;
+
+ /* skip first vec */
+ offset -= bvec->bv_len;
+ seg_skip = 1 + (offset >> PAGE_SHIFT);
+
+ iter->bvec = bvec + seg_skip;
+ iter->nr_segs -= seg_skip;
+ iter->count -= bvec->bv_len + offset;
+ iter->iov_offset = offset & ~PAGE_MASK;
+ }
+ }
+
+ return 0;
+}
+
+static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter)
+{
+ if (WARN_ON_ONCE(!req->imu))
+ return -EFAULT;
+ return __io_import_fixed(req, rw, iter, req->imu);
+}
+
+static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
+{
+ if (needs_lock)
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
+{
+ /*
+ * "Normal" inline submissions always hold the uring_lock, since we
+ * grab it from the system call. Same is true for the SQPOLL offload.
+ * The only exception is when we've detached the request and issue it
+ * from an async worker thread, grab the lock for that case.
+ */
+ if (needs_lock)
+ mutex_lock(&ctx->uring_lock);
+}
+
+static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
+ int bgid, struct io_buffer *kbuf,
+ bool needs_lock)
+{
+ struct io_buffer *head;
+
+ if (req->flags & REQ_F_BUFFER_SELECTED)
+ return kbuf;
+
+ io_ring_submit_lock(req->ctx, needs_lock);
+
+ lockdep_assert_held(&req->ctx->uring_lock);
+
+ head = xa_load(&req->ctx->io_buffers, bgid);
+ if (head) {
+ if (!list_empty(&head->list)) {
+ kbuf = list_last_entry(&head->list, struct io_buffer,
+ list);
+ list_del(&kbuf->list);
+ } else {
+ kbuf = head;
+ xa_erase(&req->ctx->io_buffers, bgid);
+ }
+ if (*len > kbuf->len)
+ *len = kbuf->len;
+ } else {
+ kbuf = ERR_PTR(-ENOBUFS);
+ }
+
+ io_ring_submit_unlock(req->ctx, needs_lock);
+
+ return kbuf;
+}
+
+static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
+ bool needs_lock)
+{
+ struct io_buffer *kbuf;
+ u16 bgid;
+
+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+ bgid = req->buf_index;
+ kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
+ if (IS_ERR(kbuf))
+ return kbuf;
+ req->rw.addr = (u64) (unsigned long) kbuf;
+ req->flags |= REQ_F_BUFFER_SELECTED;
+ return u64_to_user_ptr(kbuf->addr);
+}
+
+#ifdef CONFIG_COMPAT
+static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
+ bool needs_lock)
+{
+ struct compat_iovec __user *uiov;
+ compat_ssize_t clen;
+ void __user *buf;
+ ssize_t len;
+
+ uiov = u64_to_user_ptr(req->rw.addr);
+ if (!access_ok(uiov, sizeof(*uiov)))
+ return -EFAULT;
+ if (__get_user(clen, &uiov->iov_len))
+ return -EFAULT;
+ if (clen < 0)
+ return -EINVAL;
+
+ len = clen;
+ buf = io_rw_buffer_select(req, &len, needs_lock);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ iov[0].iov_base = buf;
+ iov[0].iov_len = (compat_size_t) len;
+ return 0;
+}
+#endif
+
+static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+ bool needs_lock)
+{
+ struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
+ void __user *buf;
+ ssize_t len;
+
+ if (copy_from_user(iov, uiov, sizeof(*uiov)))
+ return -EFAULT;
+
+ len = iov[0].iov_len;
+ if (len < 0)
+ return -EINVAL;
+ buf = io_rw_buffer_select(req, &len, needs_lock);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ return 0;
+}
+
+static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+ bool needs_lock)
+{
+ if (req->flags & REQ_F_BUFFER_SELECTED) {
+ struct io_buffer *kbuf;
+
+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+ iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
+ iov[0].iov_len = kbuf->len;
+ return 0;
+ }
+ if (req->rw.len != 1)
+ return -EINVAL;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ return io_compat_import(req, iov, needs_lock);
+#endif
+
+ return __io_iov_buffer_select(req, iov, needs_lock);
+}
+
+static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec,
+ struct iov_iter *iter, bool needs_lock)
+{
+ void __user *buf = u64_to_user_ptr(req->rw.addr);
+ size_t sqe_len = req->rw.len;
+ u8 opcode = req->opcode;
+ ssize_t ret;
+
+ if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
+ *iovec = NULL;
+ return io_import_fixed(req, rw, iter);
+ }
+
+ /* buffer index only valid with fixed read/write, or buffer select */
+ if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
+ return -EINVAL;
+
+ if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ req->rw.len = sqe_len;
+ }
+
+ ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
+ *iovec = NULL;
+ return ret;
+ }
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ ret = io_iov_buffer_select(req, *iovec, needs_lock);
+ if (!ret)
+ iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len);
+ *iovec = NULL;
+ return ret;
+ }
+
+ return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
+ req->ctx->compat);
+}
+
+static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
+{
+ return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
+}
+
+/*
+ * For files that don't have ->read_iter() and ->write_iter(), handle them
+ * by looping over ->read() or ->write() manually.
+ */
+static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
+{
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct file *file = req->file;
+ ssize_t ret = 0;
+
+ /*
+ * Don't support polled IO through this interface, and we can't
+ * support non-blocking either. For the latter, this just causes
+ * the kiocb to be handled from an async context.
+ */
+ if (kiocb->ki_flags & IOCB_HIPRI)
+ return -EOPNOTSUPP;
+ if (kiocb->ki_flags & IOCB_NOWAIT)
+ return -EAGAIN;
+
+ while (iov_iter_count(iter)) {
+ struct iovec iovec;
+ ssize_t nr;
+
+ if (!iov_iter_is_bvec(iter)) {
+ iovec = iov_iter_iovec(iter);
+ } else {
+ iovec.iov_base = u64_to_user_ptr(req->rw.addr);
+ iovec.iov_len = req->rw.len;
+ }
+
+ if (rw == READ) {
+ nr = file->f_op->read(file, iovec.iov_base,
+ iovec.iov_len, io_kiocb_ppos(kiocb));
+ } else {
+ nr = file->f_op->write(file, iovec.iov_base,
+ iovec.iov_len, io_kiocb_ppos(kiocb));
+ }
+
+ if (nr < 0) {
+ if (!ret)
+ ret = nr;
+ break;
+ }
+ ret += nr;
+ if (!iov_iter_is_bvec(iter)) {
+ iov_iter_advance(iter, nr);
+ } else {
+ req->rw.addr += nr;
+ req->rw.len -= nr;
+ if (!req->rw.len)
+ break;
+ }
+ if (nr != iovec.iov_len)
+ break;
+ }
+
+ return ret;
+}
+
+static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
+ const struct iovec *fast_iov, struct iov_iter *iter)
+{
+ struct io_async_rw *rw = req->async_data;
+
+ memcpy(&rw->iter, iter, sizeof(*iter));
+ rw->free_iovec = iovec;
+ rw->bytes_done = 0;
+ /* can only be fixed buffers, no need to do anything */
+ if (iov_iter_is_bvec(iter))
+ return;
+ if (!iovec) {
+ unsigned iov_off = 0;
+
+ rw->iter.iov = rw->fast_iov;
+ if (iter->iov != fast_iov) {
+ iov_off = iter->iov - fast_iov;
+ rw->iter.iov += iov_off;
+ }
+ if (rw->fast_iov != fast_iov)
+ memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
+ sizeof(struct iovec) * iter->nr_segs);
+ } else {
+ req->flags |= REQ_F_NEED_CLEANUP;
+ }
+}
+
+static inline int io_alloc_async_data(struct io_kiocb *req)
+{
+ WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
+ req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL);
+ return req->async_data == NULL;
+}
+
+static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
+ const struct iovec *fast_iov,
+ struct iov_iter *iter, bool force)
+{
+ if (!force && !io_op_defs[req->opcode].needs_async_setup)
+ return 0;
+ if (!req->async_data) {
+ struct io_async_rw *iorw;
+
+ if (io_alloc_async_data(req)) {
+ kfree(iovec);
+ return -ENOMEM;
+ }
+
+ io_req_map_rw(req, iovec, fast_iov, iter);
+ iorw = req->async_data;
+ /* we've copied and mapped the iter, ensure state is saved */
+ iov_iter_save_state(&iorw->iter, &iorw->iter_state);
+ }
+ return 0;
+}
+
+static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
+{
+ struct io_async_rw *iorw = req->async_data;
+ struct iovec *iov = iorw->fast_iov;
+ int ret;
+
+ ret = io_import_iovec(rw, req, &iov, &iorw->iter, false);
+ if (unlikely(ret < 0))
+ return ret;
+
+ iorw->bytes_done = 0;
+ iorw->free_iovec = iov;
+ if (iov)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ iov_iter_save_state(&iorw->iter, &iorw->iter_state);
+ return 0;
+}
+
+static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(!(req->file->f_mode & FMODE_READ)))
+ return -EBADF;
+ return io_prep_rw(req, sqe, READ);
+}
+
+/*
+ * This is our waitqueue callback handler, registered through lock_page_async()
+ * when we initially tried to do the IO with the iocb armed our waitqueue.
+ * This gets called when the page is unlocked, and we generally expect that to
+ * happen when the page IO is completed and the page is now uptodate. This will
+ * queue a task_work based retry of the operation, attempting to copy the data
+ * again. If the latter fails because the page was NOT uptodate, then we will
+ * do a thread based blocking retry of the operation. That's the unexpected
+ * slow path.
+ */
+static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
+ int sync, void *arg)
+{
+ struct wait_page_queue *wpq;
+ struct io_kiocb *req = wait->private;
+ struct wait_page_key *key = arg;
+
+ wpq = container_of(wait, struct wait_page_queue, wait);
+
+ if (!wake_page_match(wpq, key))
+ return 0;
+
+ req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
+ list_del_init(&wait->entry);
+ io_req_task_queue(req);
+ return 1;
+}
+
+/*
+ * This controls whether a given IO request should be armed for async page
+ * based retry. If we return false here, the request is handed to the async
+ * worker threads for retry. If we're doing buffered reads on a regular file,
+ * we prepare a private wait_page_queue entry and retry the operation. This
+ * will either succeed because the page is now uptodate and unlocked, or it
+ * will register a callback when the page is unlocked at IO completion. Through
+ * that callback, io_uring uses task_work to setup a retry of the operation.
+ * That retry will attempt the buffered read again. The retry will generally
+ * succeed, or in rare cases where it fails, we then fall back to using the
+ * async worker threads for a blocking retry.
+ */
+static bool io_rw_should_retry(struct io_kiocb *req)
+{
+ struct io_async_rw *rw = req->async_data;
+ struct wait_page_queue *wait = &rw->wpq;
+ struct kiocb *kiocb = &req->rw.kiocb;
+
+ /* never retry for NOWAIT, we just complete with -EAGAIN */
+ if (req->flags & REQ_F_NOWAIT)
+ return false;
+
+ /* Only for buffered IO */
+ if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
+ return false;
+
+ /*
+ * just use poll if we can, and don't attempt if the fs doesn't
+ * support callback based unlocks
+ */
+ if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
+ return false;
+
+ wait->wait.func = io_async_buf_func;
+ wait->wait.private = req;
+ wait->wait.flags = 0;
+ INIT_LIST_HEAD(&wait->wait.entry);
+ kiocb->ki_flags |= IOCB_WAITQ;
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ kiocb->ki_waitq = wait;
+ return true;
+}
+
+static inline int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
+{
+ if (req->file->f_op->read_iter)
+ return call_read_iter(req->file, &req->rw.kiocb, iter);
+ else if (req->file->f_op->read)
+ return loop_rw_iter(READ, req, iter);
+ else
+ return -EINVAL;
+}
+
+static bool need_read_all(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_ISREG ||
+ S_ISBLK(file_inode(req->file)->i_mode);
+}
+
+static int io_read(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct iov_iter __iter, *iter = &__iter;
+ struct io_async_rw *rw = req->async_data;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ struct iov_iter_state __state, *state;
+ ssize_t ret, ret2;
+
+ if (rw) {
+ iter = &rw->iter;
+ state = &rw->iter_state;
+ /*
+ * We come here from an earlier attempt, restore our state to
+ * match in case it doesn't. It's cheap enough that we don't
+ * need to make this conditional.
+ */
+ iov_iter_restore(iter, state);
+ iovec = NULL;
+ } else {
+ ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
+ if (ret < 0)
+ return ret;
+ state = &__state;
+ iov_iter_save_state(iter, state);
+ }
+ req->result = iov_iter_count(iter);
+
+ /* Ensure we clear previously set non-block flag */
+ if (!force_nonblock)
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ else
+ kiocb->ki_flags |= IOCB_NOWAIT;
+
+ /* If the file doesn't support async, just async punt */
+ if (force_nonblock && !io_file_supports_nowait(req, READ)) {
+ ret = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
+ return ret ?: -EAGAIN;
+ }
+
+ ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result);
+ if (unlikely(ret)) {
+ kfree(iovec);
+ return ret;
+ }
+
+ ret = io_iter_do_read(req, iter);
+
+ if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) {
+ req->flags &= ~REQ_F_REISSUE;
+ /* IOPOLL retry should happen for io-wq threads */
+ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
+ goto done;
+ /* no retry on NONBLOCK nor RWF_NOWAIT */
+ if (req->flags & REQ_F_NOWAIT)
+ goto done;
+ ret = 0;
+ } else if (ret == -EIOCBQUEUED) {
+ goto out_free;
+ } else if (ret <= 0 || ret == req->result || !force_nonblock ||
+ (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) {
+ /* read all, failed, already did sync or don't want to retry */
+ goto done;
+ }
+
+ /*
+ * Don't depend on the iter state matching what was consumed, or being
+ * untouched in case of error. Restore it and we'll advance it
+ * manually if we need to.
+ */
+ iov_iter_restore(iter, state);
+
+ ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
+ if (ret2)
+ return ret2;
+
+ iovec = NULL;
+ rw = req->async_data;
+ /*
+ * Now use our persistent iterator and state, if we aren't already.
+ * We've restored and mapped the iter to match.
+ */
+ if (iter != &rw->iter) {
+ iter = &rw->iter;
+ state = &rw->iter_state;
+ }
+
+ do {
+ /*
+ * We end up here because of a partial read, either from
+ * above or inside this loop. Advance the iter by the bytes
+ * that were consumed.
+ */
+ iov_iter_advance(iter, ret);
+ if (!iov_iter_count(iter))
+ break;
+ rw->bytes_done += ret;
+ iov_iter_save_state(iter, state);
+
+ /* if we can retry, do so with the callbacks armed */
+ if (!io_rw_should_retry(req)) {
+ kiocb->ki_flags &= ~IOCB_WAITQ;
+ return -EAGAIN;
+ }
+
+ req->result = iov_iter_count(iter);
+ /*
+ * Now retry read with the IOCB_WAITQ parts set in the iocb. If
+ * we get -EIOCBQUEUED, then we'll get a notification when the
+ * desired page gets unlocked. We can also get a partial read
+ * here, and if we do, then just retry at the new offset.
+ */
+ ret = io_iter_do_read(req, iter);
+ if (ret == -EIOCBQUEUED)
+ return 0;
+ /* we got some bytes, but not all. retry. */
+ kiocb->ki_flags &= ~IOCB_WAITQ;
+ iov_iter_restore(iter, state);
+ } while (ret > 0);
+done:
+ kiocb_done(kiocb, ret, issue_flags);
+out_free:
+ /* it's faster to check here then delegate to kfree */
+ if (iovec)
+ kfree(iovec);
+ return 0;
+}
+
+static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
+ return -EBADF;
+ return io_prep_rw(req, sqe, WRITE);
+}
+
+static int io_write(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct iov_iter __iter, *iter = &__iter;
+ struct io_async_rw *rw = req->async_data;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ struct iov_iter_state __state, *state;
+ ssize_t ret, ret2;
+
+ if (rw) {
+ iter = &rw->iter;
+ state = &rw->iter_state;
+ iov_iter_restore(iter, state);
+ iovec = NULL;
+ } else {
+ ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
+ if (ret < 0)
+ return ret;
+ state = &__state;
+ iov_iter_save_state(iter, state);
+ }
+ req->result = iov_iter_count(iter);
+
+ /* Ensure we clear previously set non-block flag */
+ if (!force_nonblock)
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ else
+ kiocb->ki_flags |= IOCB_NOWAIT;
+
+ /* If the file doesn't support async, just async punt */
+ if (force_nonblock && !io_file_supports_nowait(req, WRITE))
+ goto copy_iov;
+
+ /* file path doesn't support NOWAIT for non-direct_IO */
+ if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
+ (req->flags & REQ_F_ISREG))
+ goto copy_iov;
+
+ ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result);
+ if (unlikely(ret))
+ goto out_free;
+
+ /*
+ * Open-code file_start_write here to grab freeze protection,
+ * which will be released by another thread in
+ * io_complete_rw(). Fool lockdep by telling it the lock got
+ * released so that it doesn't complain about the held lock when
+ * we return to userspace.
+ */
+ if (req->flags & REQ_F_ISREG) {
+ sb_start_write(file_inode(req->file)->i_sb);
+ __sb_writers_release(file_inode(req->file)->i_sb,
+ SB_FREEZE_WRITE);
+ }
+ kiocb->ki_flags |= IOCB_WRITE;
+
+ if (req->file->f_op->write_iter)
+ ret2 = call_write_iter(req->file, kiocb, iter);
+ else if (req->file->f_op->write)
+ ret2 = loop_rw_iter(WRITE, req, iter);
+ else
+ ret2 = -EINVAL;
+
+ if (req->flags & REQ_F_REISSUE) {
+ req->flags &= ~REQ_F_REISSUE;
+ ret2 = -EAGAIN;
+ }
+
+ /*
+ * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
+ * retry them without IOCB_NOWAIT.
+ */
+ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
+ ret2 = -EAGAIN;
+ /* no retry on NONBLOCK nor RWF_NOWAIT */
+ if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT))
+ goto done;
+ if (!force_nonblock || ret2 != -EAGAIN) {
+ /* IOPOLL retry should happen for io-wq threads */
+ if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
+ goto copy_iov;
+done:
+ kiocb_done(kiocb, ret2, issue_flags);
+ } else {
+copy_iov:
+ iov_iter_restore(iter, state);
+ ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
+ if (!ret) {
+ if (kiocb->ki_flags & IOCB_WRITE)
+ kiocb_end_write(req);
+ return -EAGAIN;
+ }
+ return ret;
+ }
+out_free:
+ /* it's reportedly faster than delegating the null check to kfree() */
+ if (iovec)
+ kfree(iovec);
+ return ret;
+}
+
+static int io_renameat_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_rename *ren = &req->rename;
+ const char __user *oldf, *newf;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ ren->old_dfd = READ_ONCE(sqe->fd);
+ oldf = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ newf = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ ren->new_dfd = READ_ONCE(sqe->len);
+ ren->flags = READ_ONCE(sqe->rename_flags);
+
+ ren->oldpath = getname(oldf);
+ if (IS_ERR(ren->oldpath))
+ return PTR_ERR(ren->oldpath);
+
+ ren->newpath = getname(newf);
+ if (IS_ERR(ren->newpath)) {
+ putname(ren->oldpath);
+ return PTR_ERR(ren->newpath);
+ }
+
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+static int io_renameat(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_rename *ren = &req->rename;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd,
+ ren->newpath, ren->flags);
+
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_unlinkat_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_unlink *un = &req->unlink;
+ const char __user *fname;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ un->dfd = READ_ONCE(sqe->fd);
+
+ un->flags = READ_ONCE(sqe->unlink_flags);
+ if (un->flags & ~AT_REMOVEDIR)
+ return -EINVAL;
+
+ fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ un->filename = getname(fname);
+ if (IS_ERR(un->filename))
+ return PTR_ERR(un->filename);
+
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+static int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_unlink *un = &req->unlink;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ if (un->flags & AT_REMOVEDIR)
+ ret = do_rmdir(un->dfd, un->filename);
+ else
+ ret = do_unlinkat(un->dfd, un->filename);
+
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_shutdown_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_NET)
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->ioprio || sqe->off || sqe->addr || sqe->rw_flags ||
+ sqe->buf_index || sqe->splice_fd_in))
+ return -EINVAL;
+
+ req->shutdown.how = READ_ONCE(sqe->len);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
+{
+#if defined(CONFIG_NET)
+ struct socket *sock;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ ret = __sys_shutdown_sock(sock, req->shutdown.how);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int __io_splice_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_splice *sp = &req->splice;
+ unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ sp->len = READ_ONCE(sqe->len);
+ sp->flags = READ_ONCE(sqe->splice_flags);
+ if (unlikely(sp->flags & ~valid_flags))
+ return -EINVAL;
+ sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);
+ return 0;
+}
+
+static int io_tee_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
+ return -EINVAL;
+ return __io_splice_prep(req, sqe);
+}
+
+static int io_tee(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_splice *sp = &req->splice;
+ struct file *out = sp->file_out;
+ unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
+ struct file *in;
+ long ret = 0;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ in = io_file_get(req->ctx, req, sp->splice_fd_in,
+ (sp->flags & SPLICE_F_FD_IN_FIXED));
+ if (!in) {
+ ret = -EBADF;
+ goto done;
+ }
+
+ if (sp->len)
+ ret = do_tee(in, out, sp->len, flags);
+
+ if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
+ io_put_file(in);
+done:
+ if (ret != sp->len)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_splice *sp = &req->splice;
+
+ sp->off_in = READ_ONCE(sqe->splice_off_in);
+ sp->off_out = READ_ONCE(sqe->off);
+ return __io_splice_prep(req, sqe);
+}
+
+static int io_splice(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_splice *sp = &req->splice;
+ struct file *out = sp->file_out;
+ unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
+ loff_t *poff_in, *poff_out;
+ struct file *in;
+ long ret = 0;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ in = io_file_get(req->ctx, req, sp->splice_fd_in,
+ (sp->flags & SPLICE_F_FD_IN_FIXED));
+ if (!in) {
+ ret = -EBADF;
+ goto done;
+ }
+
+ poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
+ poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
+
+ if (sp->len)
+ ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
+
+ if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
+ io_put_file(in);
+done:
+ if (ret != sp->len)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+/*
+ * IORING_OP_NOP just posts a completion event, nothing else.
+ */
+static int io_nop(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ __io_req_complete(req, issue_flags, 0, 0);
+ return 0;
+}
+
+static int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
+ sqe->splice_fd_in))
+ return -EINVAL;
+
+ req->sync.flags = READ_ONCE(sqe->fsync_flags);
+ if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
+ return -EINVAL;
+
+ req->sync.off = READ_ONCE(sqe->off);
+ req->sync.len = READ_ONCE(sqe->len);
+ return 0;
+}
+
+static int io_fsync(struct io_kiocb *req, unsigned int issue_flags)
+{
+ loff_t end = req->sync.off + req->sync.len;
+ int ret;
+
+ /* fsync always requires a blocking context */
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = vfs_fsync_range(req->file, req->sync.off,
+ end > 0 ? end : LLONG_MAX,
+ req->sync.flags & IORING_FSYNC_DATASYNC);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_fallocate_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (sqe->ioprio || sqe->buf_index || sqe->rw_flags ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->sync.off = READ_ONCE(sqe->off);
+ req->sync.len = READ_ONCE(sqe->addr);
+ req->sync.mode = READ_ONCE(sqe->len);
+ return 0;
+}
+
+static int io_fallocate(struct io_kiocb *req, unsigned int issue_flags)
+{
+ int ret;
+
+ /* fallocate always requiring blocking context */
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+ ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
+ req->sync.len);
+ if (ret < 0)
+ req_set_fail(req);
+ else
+ fsnotify_modify(req->file);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ const char __user *fname;
+ int ret;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->ioprio || sqe->buf_index))
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ /* open.how should be already initialised */
+ if (!(req->open.how.flags & O_PATH) && force_o_largefile())
+ req->open.how.flags |= O_LARGEFILE;
+
+ req->open.dfd = READ_ONCE(sqe->fd);
+ fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ req->open.filename = getname(fname);
+ if (IS_ERR(req->open.filename)) {
+ ret = PTR_ERR(req->open.filename);
+ req->open.filename = NULL;
+ return ret;
+ }
+
+ req->open.file_slot = READ_ONCE(sqe->file_index);
+ if (req->open.file_slot && (req->open.how.flags & O_CLOEXEC))
+ return -EINVAL;
+
+ req->open.nofile = rlimit(RLIMIT_NOFILE);
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ u64 mode = READ_ONCE(sqe->len);
+ u64 flags = READ_ONCE(sqe->open_flags);
+
+ req->open.how = build_open_how(flags, mode);
+ return __io_openat_prep(req, sqe);
+}
+
+static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct open_how __user *how;
+ size_t len;
+ int ret;
+
+ how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ len = READ_ONCE(sqe->len);
+ if (len < OPEN_HOW_SIZE_VER0)
+ return -EINVAL;
+
+ ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
+ len);
+ if (ret)
+ return ret;
+
+ return __io_openat_prep(req, sqe);
+}
+
+static int io_openat2(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct open_flags op;
+ struct file *file;
+ bool resolve_nonblock, nonblock_set;
+ bool fixed = !!req->open.file_slot;
+ int ret;
+
+ ret = build_open_flags(&req->open.how, &op);
+ if (ret)
+ goto err;
+ nonblock_set = op.open_flag & O_NONBLOCK;
+ resolve_nonblock = req->open.how.resolve & RESOLVE_CACHED;
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ /*
+ * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open,
+ * it'll always -EAGAIN
+ */
+ if (req->open.how.flags & (O_TRUNC | O_CREAT | O_TMPFILE))
+ return -EAGAIN;
+ op.lookup_flags |= LOOKUP_CACHED;
+ op.open_flag |= O_NONBLOCK;
+ }
+
+ if (!fixed) {
+ ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
+ if (ret < 0)
+ goto err;
+ }
+
+ file = do_filp_open(req->open.dfd, req->open.filename, &op);
+ if (IS_ERR(file)) {
+ /*
+ * We could hang on to this 'fd' on retrying, but seems like
+ * marginal gain for something that is now known to be a slower
+ * path. So just put it, and we'll get a new one when we retry.
+ */
+ if (!fixed)
+ put_unused_fd(ret);
+
+ ret = PTR_ERR(file);
+ /* only retry if RESOLVE_CACHED wasn't already set by application */
+ if (ret == -EAGAIN &&
+ (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK)))
+ return -EAGAIN;
+ goto err;
+ }
+
+ if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set)
+ file->f_flags &= ~O_NONBLOCK;
+ fsnotify_open(file);
+
+ if (!fixed)
+ fd_install(ret, file);
+ else
+ ret = io_install_fixed_file(req, file, issue_flags,
+ req->open.file_slot - 1);
+err:
+ putname(req->open.filename);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_openat(struct io_kiocb *req, unsigned int issue_flags)
+{
+ return io_openat2(req, issue_flags);
+}
+
+static int io_remove_buffers_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_provide_buf *p = &req->pbuf;
+ u64 tmp;
+
+ if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+
+ tmp = READ_ONCE(sqe->fd);
+ if (!tmp || tmp > USHRT_MAX)
+ return -EINVAL;
+
+ memset(p, 0, sizeof(*p));
+ p->nbufs = tmp;
+ p->bgid = READ_ONCE(sqe->buf_group);
+ return 0;
+}
+
+static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
+ int bgid, unsigned nbufs)
+{
+ unsigned i = 0;
+
+ /* shouldn't happen */
+ if (!nbufs)
+ return 0;
+
+ /* the head kbuf is the list itself */
+ while (!list_empty(&buf->list)) {
+ struct io_buffer *nxt;
+
+ nxt = list_first_entry(&buf->list, struct io_buffer, list);
+ list_del(&nxt->list);
+ kfree(nxt);
+ if (++i == nbufs)
+ return i;
+ cond_resched();
+ }
+ i++;
+ kfree(buf);
+ xa_erase(&ctx->io_buffers, bgid);
+
+ return i;
+}
+
+static int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_provide_buf *p = &req->pbuf;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_buffer *head;
+ int ret = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ io_ring_submit_lock(ctx, !force_nonblock);
+
+ lockdep_assert_held(&ctx->uring_lock);
+
+ ret = -ENOENT;
+ head = xa_load(&ctx->io_buffers, p->bgid);
+ if (head)
+ ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
+ if (ret < 0)
+ req_set_fail(req);
+
+ /* complete before unlock, IOPOLL may need the lock */
+ __io_req_complete(req, issue_flags, ret, 0);
+ io_ring_submit_unlock(ctx, !force_nonblock);
+ return 0;
+}
+
+static int io_provide_buffers_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ unsigned long size, tmp_check;
+ struct io_provide_buf *p = &req->pbuf;
+ u64 tmp;
+
+ if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
+ return -EINVAL;
+
+ tmp = READ_ONCE(sqe->fd);
+ if (!tmp || tmp > USHRT_MAX)
+ return -E2BIG;
+ p->nbufs = tmp;
+ p->addr = READ_ONCE(sqe->addr);
+ p->len = READ_ONCE(sqe->len);
+
+ if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs,
+ &size))
+ return -EOVERFLOW;
+ if (check_add_overflow((unsigned long)p->addr, size, &tmp_check))
+ return -EOVERFLOW;
+
+ size = (unsigned long)p->len * p->nbufs;
+ if (!access_ok(u64_to_user_ptr(p->addr), size))
+ return -EFAULT;
+
+ p->bgid = READ_ONCE(sqe->buf_group);
+ tmp = READ_ONCE(sqe->off);
+ if (tmp > USHRT_MAX)
+ return -E2BIG;
+ p->bid = tmp;
+ return 0;
+}
+
+static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
+{
+ struct io_buffer *buf;
+ u64 addr = pbuf->addr;
+ int i, bid = pbuf->bid;
+
+ for (i = 0; i < pbuf->nbufs; i++) {
+ buf = kmalloc(sizeof(*buf), GFP_KERNEL_ACCOUNT);
+ if (!buf)
+ break;
+
+ buf->addr = addr;
+ buf->len = min_t(__u32, pbuf->len, MAX_RW_COUNT);
+ buf->bid = bid;
+ addr += pbuf->len;
+ bid++;
+ if (!*head) {
+ INIT_LIST_HEAD(&buf->list);
+ *head = buf;
+ } else {
+ list_add_tail(&buf->list, &(*head)->list);
+ }
+ cond_resched();
+ }
+
+ return i ? i : -ENOMEM;
+}
+
+static int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_provide_buf *p = &req->pbuf;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_buffer *head, *list;
+ int ret = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ io_ring_submit_lock(ctx, !force_nonblock);
+
+ lockdep_assert_held(&ctx->uring_lock);
+
+ list = head = xa_load(&ctx->io_buffers, p->bgid);
+
+ ret = io_add_buffers(p, &head);
+ if (ret >= 0 && !list) {
+ ret = xa_insert(&ctx->io_buffers, p->bgid, head,
+ GFP_KERNEL_ACCOUNT);
+ if (ret < 0)
+ __io_remove_buffers(ctx, head, p->bgid, -1U);
+ }
+ if (ret < 0)
+ req_set_fail(req);
+ /* complete before unlock, IOPOLL may need the lock */
+ __io_req_complete(req, issue_flags, ret, 0);
+ io_ring_submit_unlock(ctx, !force_nonblock);
+ return 0;
+}
+
+static int io_epoll_ctl_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_EPOLL)
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->epoll.epfd = READ_ONCE(sqe->fd);
+ req->epoll.op = READ_ONCE(sqe->len);
+ req->epoll.fd = READ_ONCE(sqe->off);
+
+ if (ep_op_has_event(req->epoll.op)) {
+ struct epoll_event __user *ev;
+
+ ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
+ return -EFAULT;
+ }
+
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
+{
+#if defined(CONFIG_EPOLL)
+ struct io_epoll *ie = &req->epoll;
+ int ret;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
+ if (force_nonblock && ret == -EAGAIN)
+ return -EAGAIN;
+
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+ if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->madvise.addr = READ_ONCE(sqe->addr);
+ req->madvise.len = READ_ONCE(sqe->len);
+ req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_madvise(struct io_kiocb *req, unsigned int issue_flags)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+ struct io_madvise *ma = &req->madvise;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (sqe->ioprio || sqe->buf_index || sqe->addr || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->fadvise.offset = READ_ONCE(sqe->off);
+ req->fadvise.len = READ_ONCE(sqe->len);
+ req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
+ return 0;
+}
+
+static int io_fadvise(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_fadvise *fa = &req->fadvise;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ switch (fa->advice) {
+ case POSIX_FADV_NORMAL:
+ case POSIX_FADV_RANDOM:
+ case POSIX_FADV_SEQUENTIAL:
+ break;
+ default:
+ return -EAGAIN;
+ }
+ }
+
+ ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ if (req->flags & REQ_F_FIXED_FILE)
+ return -EBADF;
+
+ req->statx.dfd = READ_ONCE(sqe->fd);
+ req->statx.mask = READ_ONCE(sqe->len);
+ req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ req->statx.flags = READ_ONCE(sqe->statx_flags);
+
+ return 0;
+}
+
+static int io_statx(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_statx *ctx = &req->statx;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
+ ctx->buffer);
+
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
+ sqe->rw_flags || sqe->buf_index)
+ return -EINVAL;
+ if (req->flags & REQ_F_FIXED_FILE)
+ return -EBADF;
+
+ req->close.fd = READ_ONCE(sqe->fd);
+ req->close.file_slot = READ_ONCE(sqe->file_index);
+ if (req->close.file_slot && req->close.fd)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int io_close(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct files_struct *files = current->files;
+ struct io_close *close = &req->close;
+ struct fdtable *fdt;
+ struct file *file = NULL;
+ int ret = -EBADF;
+
+ if (req->close.file_slot) {
+ ret = io_close_fixed(req, issue_flags);
+ goto err;
+ }
+
+ spin_lock(&files->file_lock);
+ fdt = files_fdtable(files);
+ if (close->fd >= fdt->max_fds) {
+ spin_unlock(&files->file_lock);
+ goto err;
+ }
+ file = fdt->fd[close->fd];
+ if (!file || file->f_op == &io_uring_fops) {
+ spin_unlock(&files->file_lock);
+ file = NULL;
+ goto err;
+ }
+
+ /* if the file has a flush method, be safe and punt to async */
+ if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) {
+ spin_unlock(&files->file_lock);
+ return -EAGAIN;
+ }
+
+ ret = __close_fd_get_file(close->fd, &file);
+ spin_unlock(&files->file_lock);
+ if (ret < 0) {
+ if (ret == -ENOENT)
+ ret = -EBADF;
+ goto err;
+ }
+
+ /* No ->flush() or already async, safely close from here */
+ ret = filp_close(file, current->files);
+err:
+ if (ret < 0)
+ req_set_fail(req);
+ if (file)
+ fput(file);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
+ sqe->splice_fd_in))
+ return -EINVAL;
+
+ req->sync.off = READ_ONCE(sqe->off);
+ req->sync.len = READ_ONCE(sqe->len);
+ req->sync.flags = READ_ONCE(sqe->sync_range_flags);
+ return 0;
+}
+
+static int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags)
+{
+ int ret;
+
+ /* sync_file_range always requires a blocking context */
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = sync_file_range(req->file, req->sync.off, req->sync.len,
+ req->sync.flags);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+#if defined(CONFIG_NET)
+static int io_setup_async_msg(struct io_kiocb *req,
+ struct io_async_msghdr *kmsg)
+{
+ struct io_async_msghdr *async_msg = req->async_data;
+
+ if (async_msg)
+ return -EAGAIN;
+ if (io_alloc_async_data(req)) {
+ kfree(kmsg->free_iov);
+ return -ENOMEM;
+ }
+ async_msg = req->async_data;
+ req->flags |= REQ_F_NEED_CLEANUP;
+ memcpy(async_msg, kmsg, sizeof(*kmsg));
+ if (async_msg->msg.msg_name)
+ async_msg->msg.msg_name = &async_msg->addr;
+ /* if were using fast_iov, set it to the new one */
+ if (!async_msg->free_iov)
+ async_msg->msg.msg_iter.iov = async_msg->fast_iov;
+
+ return -EAGAIN;
+}
+
+static int io_sendmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ iomsg->msg.msg_name = &iomsg->addr;
+ iomsg->free_iov = iomsg->fast_iov;
+ return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
+ req->sr_msg.msg_flags, &iomsg->free_iov);
+}
+
+static int io_sendmsg_prep_async(struct io_kiocb *req)
+{
+ int ret;
+
+ ret = io_sendmsg_copy_hdr(req, req->async_data);
+ if (!ret)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return ret;
+}
+
+static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio))
+ return -EINVAL;
+
+ sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ sr->len = READ_ONCE(sqe->len);
+ sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
+ if (sr->msg_flags & MSG_DONTWAIT)
+ req->flags |= REQ_F_NOWAIT;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ sr->msg_flags |= MSG_CMSG_COMPAT;
+#endif
+ return 0;
+}
+
+static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_async_msghdr iomsg, *kmsg;
+ struct socket *sock;
+ unsigned flags;
+ int min_ret = 0;
+ int ret;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ kmsg = req->async_data;
+ if (!kmsg) {
+ ret = io_sendmsg_copy_hdr(req, &iomsg);
+ if (ret)
+ return ret;
+ kmsg = &iomsg;
+ }
+
+ flags = req->sr_msg.msg_flags;
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+ ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
+ if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
+ return io_setup_async_msg(req, kmsg);
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+
+ /* fast path, check for non-NULL to avoid function call */
+ if (kmsg->free_iov)
+ kfree(kmsg->free_iov);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < min_ret)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_send(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct msghdr msg;
+ struct iovec iov;
+ struct socket *sock;
+ unsigned flags;
+ int min_ret = 0;
+ int ret;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
+ if (unlikely(ret))
+ return ret;
+
+ msg.msg_name = NULL;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_namelen = 0;
+
+ flags = req->sr_msg.msg_flags;
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&msg.msg_iter);
+
+ msg.msg_flags = flags;
+ ret = sock_sendmsg(sock, &msg);
+ if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
+ return -EAGAIN;
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+
+ if (ret < min_ret)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct iovec __user *uiov;
+ size_t iov_len;
+ int ret;
+
+ ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
+ &iomsg->uaddr, &uiov, &iov_len);
+ if (ret)
+ return ret;
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ if (iov_len > 1)
+ return -EINVAL;
+ if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov)))
+ return -EFAULT;
+ sr->len = iomsg->fast_iov[0].iov_len;
+ iomsg->free_iov = NULL;
+ } else {
+ iomsg->free_iov = iomsg->fast_iov;
+ ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
+ &iomsg->free_iov, &iomsg->msg.msg_iter,
+ false);
+ if (ret > 0)
+ ret = 0;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct compat_iovec __user *uiov;
+ compat_uptr_t ptr;
+ compat_size_t len;
+ int ret;
+
+ ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr,
+ &ptr, &len);
+ if (ret)
+ return ret;
+
+ uiov = compat_ptr(ptr);
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ compat_ssize_t clen;
+
+ if (len > 1)
+ return -EINVAL;
+ if (!access_ok(uiov, sizeof(*uiov)))
+ return -EFAULT;
+ if (__get_user(clen, &uiov->iov_len))
+ return -EFAULT;
+ if (clen < 0)
+ return -EINVAL;
+ sr->len = clen;
+ iomsg->free_iov = NULL;
+ } else {
+ iomsg->free_iov = iomsg->fast_iov;
+ ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
+ UIO_FASTIOV, &iomsg->free_iov,
+ &iomsg->msg.msg_iter, true);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
+static int io_recvmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ iomsg->msg.msg_name = &iomsg->addr;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ return __io_compat_recvmsg_copy_hdr(req, iomsg);
+#endif
+
+ return __io_recvmsg_copy_hdr(req, iomsg);
+}
+
+static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
+ bool needs_lock)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct io_buffer *kbuf;
+
+ kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
+ if (IS_ERR(kbuf))
+ return kbuf;
+
+ sr->kbuf = kbuf;
+ req->flags |= REQ_F_BUFFER_SELECTED;
+ return kbuf;
+}
+
+static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
+{
+ return io_put_kbuf(req, req->sr_msg.kbuf);
+}
+
+static int io_recvmsg_prep_async(struct io_kiocb *req)
+{
+ int ret;
+
+ ret = io_recvmsg_copy_hdr(req, req->async_data);
+ if (!ret)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return ret;
+}
+
+static int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio))
+ return -EINVAL;
+
+ sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ sr->len = READ_ONCE(sqe->len);
+ sr->bgid = READ_ONCE(sqe->buf_group);
+ sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
+ if (sr->msg_flags & MSG_DONTWAIT)
+ req->flags |= REQ_F_NOWAIT;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ sr->msg_flags |= MSG_CMSG_COMPAT;
+#endif
+ return 0;
+}
+
+static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_async_msghdr iomsg, *kmsg;
+ struct socket *sock;
+ struct io_buffer *kbuf;
+ unsigned flags;
+ int min_ret = 0;
+ int ret, cflags = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ kmsg = req->async_data;
+ if (!kmsg) {
+ ret = io_recvmsg_copy_hdr(req, &iomsg);
+ if (ret)
+ return ret;
+ kmsg = &iomsg;
+ }
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ kbuf = io_recv_buffer_select(req, !force_nonblock);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+ kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
+ kmsg->fast_iov[0].iov_len = req->sr_msg.len;
+ iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov,
+ 1, req->sr_msg.len);
+ }
+
+ flags = req->sr_msg.msg_flags;
+ if (force_nonblock)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+ ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
+ kmsg->uaddr, flags);
+ if (force_nonblock && ret == -EAGAIN)
+ return io_setup_async_msg(req, kmsg);
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+
+ if (req->flags & REQ_F_BUFFER_SELECTED)
+ cflags = io_put_recv_kbuf(req);
+ /* fast path, check for non-NULL to avoid function call */
+ if (kmsg->free_iov)
+ kfree(kmsg->free_iov);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, cflags);
+ return 0;
+}
+
+static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_buffer *kbuf;
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct msghdr msg;
+ void __user *buf = sr->buf;
+ struct socket *sock;
+ struct iovec iov;
+ unsigned flags;
+ int min_ret = 0;
+ int ret, cflags = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ kbuf = io_recv_buffer_select(req, !force_nonblock);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+ buf = u64_to_user_ptr(kbuf->addr);
+ }
+
+ ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
+ if (unlikely(ret))
+ goto out_free;
+
+ msg.msg_name = NULL;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_namelen = 0;
+ msg.msg_iocb = NULL;
+ msg.msg_flags = 0;
+
+ flags = req->sr_msg.msg_flags;
+ if (force_nonblock)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&msg.msg_iter);
+
+ ret = sock_recvmsg(sock, &msg, flags);
+ if (force_nonblock && ret == -EAGAIN)
+ return -EAGAIN;
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+out_free:
+ if (req->flags & REQ_F_BUFFER_SELECTED)
+ cflags = io_put_recv_kbuf(req);
+ if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, cflags);
+ return 0;
+}
+
+static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_accept *accept = &req->accept;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->len || sqe->buf_index)
+ return -EINVAL;
+
+ accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ accept->flags = READ_ONCE(sqe->accept_flags);
+ accept->nofile = rlimit(RLIMIT_NOFILE);
+
+ accept->file_slot = READ_ONCE(sqe->file_index);
+ if (accept->file_slot && (accept->flags & SOCK_CLOEXEC))
+ return -EINVAL;
+ if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
+ return -EINVAL;
+ if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
+ accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+ return 0;
+}
+
+static int io_accept(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_accept *accept = &req->accept;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
+ bool fixed = !!accept->file_slot;
+ struct file *file;
+ int ret, fd;
+
+ if (req->file->f_flags & O_NONBLOCK)
+ req->flags |= REQ_F_NOWAIT;
+
+ if (!fixed) {
+ fd = __get_unused_fd_flags(accept->flags, accept->nofile);
+ if (unlikely(fd < 0))
+ return fd;
+ }
+ file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
+ accept->flags);
+
+ if (IS_ERR(file)) {
+ if (!fixed)
+ put_unused_fd(fd);
+ ret = PTR_ERR(file);
+ if (ret == -EAGAIN && force_nonblock)
+ return -EAGAIN;
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+ req_set_fail(req);
+ } else if (!fixed) {
+ fd_install(fd, file);
+ ret = fd;
+ } else {
+ ret = io_install_fixed_file(req, file, issue_flags,
+ accept->file_slot - 1);
+ }
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_connect_prep_async(struct io_kiocb *req)
+{
+ struct io_async_connect *io = req->async_data;
+ struct io_connect *conn = &req->connect;
+
+ return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
+}
+
+static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_connect *conn = &req->connect;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+
+ conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ conn->addr_len = READ_ONCE(sqe->addr2);
+ return 0;
+}
+
+static int io_connect(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_async_connect __io, *io;
+ unsigned file_flags;
+ int ret;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ if (req->async_data) {
+ io = req->async_data;
+ } else {
+ ret = move_addr_to_kernel(req->connect.addr,
+ req->connect.addr_len,
+ &__io.address);
+ if (ret)
+ goto out;
+ io = &__io;
+ }
+
+ file_flags = force_nonblock ? O_NONBLOCK : 0;
+
+ ret = __sys_connect_file(req->file, &io->address,
+ req->connect.addr_len, file_flags);
+ if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
+ if (req->async_data)
+ return -EAGAIN;
+ if (io_alloc_async_data(req)) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ memcpy(req->async_data, &__io, sizeof(__io));
+ return -EAGAIN;
+ }
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+out:
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+#else /* !CONFIG_NET */
+#define IO_NETOP_FN(op) \
+static int io_##op(struct io_kiocb *req, unsigned int issue_flags) \
+{ \
+ return -EOPNOTSUPP; \
+}
+
+#define IO_NETOP_PREP(op) \
+IO_NETOP_FN(op) \
+static int io_##op##_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) \
+{ \
+ return -EOPNOTSUPP; \
+} \
+
+#define IO_NETOP_PREP_ASYNC(op) \
+IO_NETOP_PREP(op) \
+static int io_##op##_prep_async(struct io_kiocb *req) \
+{ \
+ return -EOPNOTSUPP; \
+}
+
+IO_NETOP_PREP_ASYNC(sendmsg);
+IO_NETOP_PREP_ASYNC(recvmsg);
+IO_NETOP_PREP_ASYNC(connect);
+IO_NETOP_PREP(accept);
+IO_NETOP_FN(send);
+IO_NETOP_FN(recv);
+#endif /* CONFIG_NET */
+
+struct io_poll_table {
+ struct poll_table_struct pt;
+ struct io_kiocb *req;
+ int nr_entries;
+ int error;
+};
+
+#define IO_POLL_CANCEL_FLAG BIT(31)
+#define IO_POLL_RETRY_FLAG BIT(30)
+#define IO_POLL_REF_MASK GENMASK(29, 0)
+
+/*
+ * We usually have 1-2 refs taken, 128 is more than enough and we want to
+ * maximise the margin between this amount and the moment when it overflows.
+ */
+#define IO_POLL_REF_BIAS 128
+
+static bool io_poll_get_ownership_slowpath(struct io_kiocb *req)
+{
+ int v;
+
+ /*
+ * poll_refs are already elevated and we don't have much hope for
+ * grabbing the ownership. Instead of incrementing set a retry flag
+ * to notify the loop that there might have been some change.
+ */
+ v = atomic_fetch_or(IO_POLL_RETRY_FLAG, &req->poll_refs);
+ if (v & IO_POLL_REF_MASK)
+ return false;
+ return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK);
+}
+
+/*
+ * If refs part of ->poll_refs (see IO_POLL_REF_MASK) is 0, it's free. We can
+ * bump it and acquire ownership. It's disallowed to modify requests while not
+ * owning it, that prevents from races for enqueueing task_work's and b/w
+ * arming poll and wakeups.
+ */
+static inline bool io_poll_get_ownership(struct io_kiocb *req)
+{
+ if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))
+ return io_poll_get_ownership_slowpath(req);
+ return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK);
+}
+
+static void io_poll_mark_cancelled(struct io_kiocb *req)
+{
+ atomic_or(IO_POLL_CANCEL_FLAG, &req->poll_refs);
+}
+
+static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
+{
+ /* pure poll stashes this in ->async_data, poll driven retry elsewhere */
+ if (req->opcode == IORING_OP_POLL_ADD)
+ return req->async_data;
+ return req->apoll->double_poll;
+}
+
+static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
+{
+ if (req->opcode == IORING_OP_POLL_ADD)
+ return &req->poll;
+ return &req->apoll->poll;
+}
+
+static void io_poll_req_insert(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct hlist_head *list;
+
+ list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
+ hlist_add_head(&req->hash_node, list);
+}
+
+static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
+ wait_queue_func_t wake_func)
+{
+ poll->head = NULL;
+#define IO_POLL_UNMASK (EPOLLERR|EPOLLHUP|EPOLLNVAL|EPOLLRDHUP)
+ /* mask in events that we always want/need */
+ poll->events = events | IO_POLL_UNMASK;
+ INIT_LIST_HEAD(&poll->wait.entry);
+ init_waitqueue_func_entry(&poll->wait, wake_func);
+}
+
+static inline void io_poll_remove_entry(struct io_poll_iocb *poll)
+{
+ struct wait_queue_head *head = smp_load_acquire(&poll->head);
+
+ if (head) {
+ spin_lock_irq(&head->lock);
+ list_del_init(&poll->wait.entry);
+ poll->head = NULL;
+ spin_unlock_irq(&head->lock);
+ }
+}
+
+static void io_poll_remove_entries(struct io_kiocb *req)
+{
+ struct io_poll_iocb *poll = io_poll_get_single(req);
+ struct io_poll_iocb *poll_double = io_poll_get_double(req);
+
+ /*
+ * While we hold the waitqueue lock and the waitqueue is nonempty,
+ * wake_up_pollfree() will wait for us. However, taking the waitqueue
+ * lock in the first place can race with the waitqueue being freed.
+ *
+ * We solve this as eventpoll does: by taking advantage of the fact that
+ * all users of wake_up_pollfree() will RCU-delay the actual free. If
+ * we enter rcu_read_lock() and see that the pointer to the queue is
+ * non-NULL, we can then lock it without the memory being freed out from
+ * under us.
+ *
+ * Keep holding rcu_read_lock() as long as we hold the queue lock, in
+ * case the caller deletes the entry from the queue, leaving it empty.
+ * In that case, only RCU prevents the queue memory from being freed.
+ */
+ rcu_read_lock();
+ io_poll_remove_entry(poll);
+ if (poll_double)
+ io_poll_remove_entry(poll_double);
+ rcu_read_unlock();
+}
+
+/*
+ * All poll tw should go through this. Checks for poll events, manages
+ * references, does rewait, etc.
+ *
+ * Returns a negative error on failure. >0 when no action require, which is
+ * either spurious wakeup or multishot CQE is served. 0 when it's done with
+ * the request, then the mask is stored in req->result.
+ */
+static int io_poll_check_events(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_poll_iocb *poll = io_poll_get_single(req);
+ int v;
+
+ /* req->task == current here, checking PF_EXITING is safe */
+ if (unlikely(req->task->flags & PF_EXITING))
+ io_poll_mark_cancelled(req);
+
+ do {
+ v = atomic_read(&req->poll_refs);
+
+ /* tw handler should be the owner, and so have some references */
+ if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK)))
+ return 0;
+ if (v & IO_POLL_CANCEL_FLAG)
+ return -ECANCELED;
+ /*
+ * cqe.res contains only events of the first wake up
+ * and all others are be lost. Redo vfs_poll() to get
+ * up to date state.
+ */
+ if ((v & IO_POLL_REF_MASK) != 1)
+ req->result = 0;
+ if (v & IO_POLL_RETRY_FLAG) {
+ req->result = 0;
+ /*
+ * We won't find new events that came in between
+ * vfs_poll and the ref put unless we clear the
+ * flag in advance.
+ */
+ atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs);
+ v &= ~IO_POLL_RETRY_FLAG;
+ }
+
+ if (!req->result) {
+ struct poll_table_struct pt = { ._key = poll->events };
+
+ req->result = vfs_poll(req->file, &pt) & poll->events;
+ }
+
+ /* multishot, just fill an CQE and proceed */
+ if (req->result && !(poll->events & EPOLLONESHOT)) {
+ __poll_t mask = mangle_poll(req->result & poll->events);
+ bool filled;
+
+ spin_lock(&ctx->completion_lock);
+ filled = io_fill_cqe_aux(ctx, req->user_data, mask,
+ IORING_CQE_F_MORE);
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (unlikely(!filled))
+ return -ECANCELED;
+ io_cqring_ev_posted(ctx);
+ } else if (req->result) {
+ return 0;
+ }
+
+ /* force the next iteration to vfs_poll() */
+ req->result = 0;
+
+ /*
+ * Release all references, retry if someone tried to restart
+ * task_work while we were executing it.
+ */
+ } while (atomic_sub_return(v & IO_POLL_REF_MASK, &req->poll_refs) &
+ IO_POLL_REF_MASK);
+
+ return 1;
+}
+
+static void io_poll_task_func(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ ret = io_poll_check_events(req);
+ if (ret > 0)
+ return;
+
+ if (!ret) {
+ req->result = mangle_poll(req->result & req->poll.events);
+ } else {
+ req->result = ret;
+ req_set_fail(req);
+ }
+
+ io_poll_remove_entries(req);
+ spin_lock(&ctx->completion_lock);
+ hash_del(&req->hash_node);
+ spin_unlock(&ctx->completion_lock);
+ io_req_complete_post(req, req->result, 0);
+}
+
+static void io_apoll_task_func(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ ret = io_poll_check_events(req);
+ if (ret > 0)
+ return;
+
+ io_poll_remove_entries(req);
+ spin_lock(&ctx->completion_lock);
+ hash_del(&req->hash_node);
+ spin_unlock(&ctx->completion_lock);
+
+ if (!ret)
+ io_req_task_submit(req, locked);
+ else
+ io_req_complete_failed(req, ret);
+}
+
+static void __io_poll_execute(struct io_kiocb *req, int mask)
+{
+ req->result = mask;
+ if (req->opcode == IORING_OP_POLL_ADD)
+ req->io_task_work.func = io_poll_task_func;
+ else
+ req->io_task_work.func = io_apoll_task_func;
+
+ trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
+ io_req_task_work_add(req);
+}
+
+static inline void io_poll_execute(struct io_kiocb *req, int res)
+{
+ if (io_poll_get_ownership(req))
+ __io_poll_execute(req, res);
+}
+
+static void io_poll_cancel_req(struct io_kiocb *req)
+{
+ io_poll_mark_cancelled(req);
+ /* kick tw, which should complete the request */
+ io_poll_execute(req, 0);
+}
+
+static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
+ void *key)
+{
+ struct io_kiocb *req = wait->private;
+ struct io_poll_iocb *poll = container_of(wait, struct io_poll_iocb,
+ wait);
+ __poll_t mask = key_to_poll(key);
+
+ if (unlikely(mask & POLLFREE)) {
+ io_poll_mark_cancelled(req);
+ /* we have to kick tw in case it's not already */
+ io_poll_execute(req, 0);
+
+ /*
+ * If the waitqueue is being freed early but someone is already
+ * holds ownership over it, we have to tear down the request as
+ * best we can. That means immediately removing the request from
+ * its waitqueue and preventing all further accesses to the
+ * waitqueue via the request.
+ */
+ list_del_init(&poll->wait.entry);
+
+ /*
+ * Careful: this *must* be the last step, since as soon
+ * as req->head is NULL'ed out, the request can be
+ * completed and freed, since aio_poll_complete_work()
+ * will no longer need to take the waitqueue lock.
+ */
+ smp_store_release(&poll->head, NULL);
+ return 1;
+ }
+
+ /* for instances that support it check for an event match first */
+ if (mask && !(mask & poll->events))
+ return 0;
+
+ if (io_poll_get_ownership(req))
+ __io_poll_execute(req, mask);
+ return 1;
+}
+
+static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
+ struct wait_queue_head *head,
+ struct io_poll_iocb **poll_ptr)
+{
+ struct io_kiocb *req = pt->req;
+
+ /*
+ * The file being polled uses multiple waitqueues for poll handling
+ * (e.g. one for read, one for write). Setup a separate io_poll_iocb
+ * if this happens.
+ */
+ if (unlikely(pt->nr_entries)) {
+ struct io_poll_iocb *first = poll;
+
+ /* double add on the same waitqueue head, ignore */
+ if (first->head == head)
+ return;
+ /* already have a 2nd entry, fail a third attempt */
+ if (*poll_ptr) {
+ if ((*poll_ptr)->head == head)
+ return;
+ pt->error = -EINVAL;
+ return;
+ }
+
+ poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
+ if (!poll) {
+ pt->error = -ENOMEM;
+ return;
+ }
+ io_init_poll_iocb(poll, first->events, first->wait.func);
+ *poll_ptr = poll;
+ }
+
+ pt->nr_entries++;
+ poll->head = head;
+ poll->wait.private = req;
+
+ if (poll->events & EPOLLEXCLUSIVE)
+ add_wait_queue_exclusive(head, &poll->wait);
+ else
+ add_wait_queue(head, &poll->wait);
+}
+
+static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
+ struct poll_table_struct *p)
+{
+ struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
+
+ __io_queue_proc(&pt->req->poll, pt, head,
+ (struct io_poll_iocb **) &pt->req->async_data);
+}
+
+static int __io_arm_poll_handler(struct io_kiocb *req,
+ struct io_poll_iocb *poll,
+ struct io_poll_table *ipt, __poll_t mask)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ INIT_HLIST_NODE(&req->hash_node);
+ io_init_poll_iocb(poll, mask, io_poll_wake);
+ poll->file = req->file;
+ poll->wait.private = req;
+
+ ipt->pt._key = mask;
+ ipt->req = req;
+ ipt->error = 0;
+ ipt->nr_entries = 0;
+
+ /*
+ * Take the ownership to delay any tw execution up until we're done
+ * with poll arming. see io_poll_get_ownership().
+ */
+ atomic_set(&req->poll_refs, 1);
+ mask = vfs_poll(req->file, &ipt->pt) & poll->events;
+
+ if (mask && (poll->events & EPOLLONESHOT)) {
+ io_poll_remove_entries(req);
+ /* no one else has access to the req, forget about the ref */
+ return mask;
+ }
+ if (!mask && unlikely(ipt->error || !ipt->nr_entries)) {
+ io_poll_remove_entries(req);
+ if (!ipt->error)
+ ipt->error = -EINVAL;
+ return 0;
+ }
+
+ spin_lock(&ctx->completion_lock);
+ io_poll_req_insert(req);
+ spin_unlock(&ctx->completion_lock);
+
+ if (mask) {
+ /* can't multishot if failed, just queue the event we've got */
+ if (unlikely(ipt->error || !ipt->nr_entries)) {
+ poll->events |= EPOLLONESHOT;
+ ipt->error = 0;
+ }
+ __io_poll_execute(req, mask);
+ return 0;
+ }
+
+ /*
+ * Try to release ownership. If we see a change of state, e.g.
+ * poll was waken up, queue up a tw, it'll deal with it.
+ */
+ if (atomic_cmpxchg(&req->poll_refs, 1, 0) != 1)
+ __io_poll_execute(req, 0);
+ return 0;
+}
+
+static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
+ struct poll_table_struct *p)
+{
+ struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
+ struct async_poll *apoll = pt->req->apoll;
+
+ __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
+}
+
+enum {
+ IO_APOLL_OK,
+ IO_APOLL_ABORTED,
+ IO_APOLL_READY
+};
+
+static int io_arm_poll_handler(struct io_kiocb *req)
+{
+ const struct io_op_def *def = &io_op_defs[req->opcode];
+ struct io_ring_ctx *ctx = req->ctx;
+ struct async_poll *apoll;
+ struct io_poll_table ipt;
+ __poll_t mask = EPOLLONESHOT | POLLERR | POLLPRI;
+ int ret;
+
+ if (!req->file || !file_can_poll(req->file))
+ return IO_APOLL_ABORTED;
+ if (req->flags & REQ_F_POLLED)
+ return IO_APOLL_ABORTED;
+ if (!def->pollin && !def->pollout)
+ return IO_APOLL_ABORTED;
+
+ if (def->pollin) {
+ mask |= POLLIN | POLLRDNORM;
+
+ /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
+ if ((req->opcode == IORING_OP_RECVMSG) &&
+ (req->sr_msg.msg_flags & MSG_ERRQUEUE))
+ mask &= ~POLLIN;
+ } else {
+ mask |= POLLOUT | POLLWRNORM;
+ }
+
+ apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
+ if (unlikely(!apoll))
+ return IO_APOLL_ABORTED;
+ apoll->double_poll = NULL;
+ req->apoll = apoll;
+ req->flags |= REQ_F_POLLED;
+ ipt.pt._qproc = io_async_queue_proc;
+
+ ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask);
+ if (ret || ipt.error)
+ return ret ? IO_APOLL_READY : IO_APOLL_ABORTED;
+
+ trace_io_uring_poll_arm(ctx, req, req->opcode, req->user_data,
+ mask, apoll->poll.events);
+ return IO_APOLL_OK;
+}
+
+/*
+ * Returns true if we found and killed one or more poll requests
+ */
+static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
+ bool cancel_all)
+{
+ struct hlist_node *tmp;
+ struct io_kiocb *req;
+ bool found = false;
+ int i;
+
+ spin_lock(&ctx->completion_lock);
+ for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
+ struct hlist_head *list;
+
+ list = &ctx->cancel_hash[i];
+ hlist_for_each_entry_safe(req, tmp, list, hash_node) {
+ if (io_match_task_safe(req, tsk, cancel_all)) {
+ hlist_del_init(&req->hash_node);
+ io_poll_cancel_req(req);
+ found = true;
+ }
+ }
+ }
+ spin_unlock(&ctx->completion_lock);
+ return found;
+}
+
+static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, __u64 sqe_addr,
+ bool poll_only)
+ __must_hold(&ctx->completion_lock)
+{
+ struct hlist_head *list;
+ struct io_kiocb *req;
+
+ list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
+ hlist_for_each_entry(req, list, hash_node) {
+ if (sqe_addr != req->user_data)
+ continue;
+ if (poll_only && req->opcode != IORING_OP_POLL_ADD)
+ continue;
+ return req;
+ }
+ return NULL;
+}
+
+static bool io_poll_disarm(struct io_kiocb *req)
+ __must_hold(&ctx->completion_lock)
+{
+ if (!io_poll_get_ownership(req))
+ return false;
+ io_poll_remove_entries(req);
+ hash_del(&req->hash_node);
+ return true;
+}
+
+static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr,
+ bool poll_only)
+ __must_hold(&ctx->completion_lock)
+{
+ struct io_kiocb *req = io_poll_find(ctx, sqe_addr, poll_only);
+
+ if (!req)
+ return -ENOENT;
+ io_poll_cancel_req(req);
+ return 0;
+}
+
+static __poll_t io_poll_parse_events(const struct io_uring_sqe *sqe,
+ unsigned int flags)
+{
+ u32 events;
+
+ events = READ_ONCE(sqe->poll32_events);
+#ifdef __BIG_ENDIAN
+ events = swahw32(events);
+#endif
+ if (!(flags & IORING_POLL_ADD_MULTI))
+ events |= EPOLLONESHOT;
+ return demangle_poll(events) | (events & (EPOLLEXCLUSIVE|EPOLLONESHOT));
+}
+
+static int io_poll_update_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_poll_update *upd = &req->poll_update;
+ u32 flags;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ flags = READ_ONCE(sqe->len);
+ if (flags & ~(IORING_POLL_UPDATE_EVENTS | IORING_POLL_UPDATE_USER_DATA |
+ IORING_POLL_ADD_MULTI))
+ return -EINVAL;
+ /* meaningless without update */
+ if (flags == IORING_POLL_ADD_MULTI)
+ return -EINVAL;
+
+ upd->old_user_data = READ_ONCE(sqe->addr);
+ upd->update_events = flags & IORING_POLL_UPDATE_EVENTS;
+ upd->update_user_data = flags & IORING_POLL_UPDATE_USER_DATA;
+
+ upd->new_user_data = READ_ONCE(sqe->off);
+ if (!upd->update_user_data && upd->new_user_data)
+ return -EINVAL;
+ if (upd->update_events)
+ upd->events = io_poll_parse_events(sqe, flags);
+ else if (sqe->poll32_events)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_poll_iocb *poll = &req->poll;
+ u32 flags;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->addr)
+ return -EINVAL;
+ flags = READ_ONCE(sqe->len);
+ if (flags & ~IORING_POLL_ADD_MULTI)
+ return -EINVAL;
+
+ io_req_set_refcount(req);
+ poll->events = io_poll_parse_events(sqe, flags);
+ return 0;
+}
+
+static int io_poll_add(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_poll_iocb *poll = &req->poll;
+ struct io_poll_table ipt;
+ int ret;
+
+ ipt.pt._qproc = io_poll_queue_proc;
+
+ ret = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events);
+ if (!ret && ipt.error)
+ req_set_fail(req);
+ ret = ret ?: ipt.error;
+ if (ret)
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_poll_update(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_kiocb *preq;
+ int ret2, ret = 0;
+
+ spin_lock(&ctx->completion_lock);
+ preq = io_poll_find(ctx, req->poll_update.old_user_data, true);
+ if (!preq || !io_poll_disarm(preq)) {
+ spin_unlock(&ctx->completion_lock);
+ ret = preq ? -EALREADY : -ENOENT;
+ goto out;
+ }
+ spin_unlock(&ctx->completion_lock);
+
+ if (req->poll_update.update_events || req->poll_update.update_user_data) {
+ /* only mask one event flags, keep behavior flags */
+ if (req->poll_update.update_events) {
+ preq->poll.events &= ~0xffff;
+ preq->poll.events |= req->poll_update.events & 0xffff;
+ preq->poll.events |= IO_POLL_UNMASK;
+ }
+ if (req->poll_update.update_user_data)
+ preq->user_data = req->poll_update.new_user_data;
+
+ ret2 = io_poll_add(preq, issue_flags);
+ /* successfully updated, don't complete poll request */
+ if (!ret2)
+ goto out;
+ }
+ req_set_fail(preq);
+ io_req_complete(preq, -ECANCELED);
+out:
+ if (ret < 0)
+ req_set_fail(req);
+ /* complete update request, we're done with it */
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static void io_req_task_timeout(struct io_kiocb *req, bool *locked)
+{
+ req_set_fail(req);
+ io_req_complete_post(req, -ETIME, 0);
+}
+
+static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
+{
+ struct io_timeout_data *data = container_of(timer,
+ struct io_timeout_data, timer);
+ struct io_kiocb *req = data->req;
+ struct io_ring_ctx *ctx = req->ctx;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->timeout_lock, flags);
+ list_del_init(&req->timeout.list);
+ atomic_set(&req->ctx->cq_timeouts,
+ atomic_read(&req->ctx->cq_timeouts) + 1);
+ spin_unlock_irqrestore(&ctx->timeout_lock, flags);
+
+ req->io_task_work.func = io_req_task_timeout;
+ io_req_task_work_add(req);
+ return HRTIMER_NORESTART;
+}
+
+static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,
+ __u64 user_data)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_timeout_data *io;
+ struct io_kiocb *req;
+ bool found = false;
+
+ list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
+ found = user_data == req->user_data;
+ if (found)
+ break;
+ }
+ if (!found)
+ return ERR_PTR(-ENOENT);
+
+ io = req->async_data;
+ if (hrtimer_try_to_cancel(&io->timer) == -1)
+ return ERR_PTR(-EALREADY);
+ list_del_init(&req->timeout.list);
+ return req;
+}
+
+static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
+ __must_hold(&ctx->completion_lock)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_kiocb *req = io_timeout_extract(ctx, user_data);
+
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ req_set_fail(req);
+ io_fill_cqe_req(req, -ECANCELED, 0);
+ io_put_req_deferred(req);
+ return 0;
+}
+
+static clockid_t io_timeout_get_clock(struct io_timeout_data *data)
+{
+ switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {
+ case IORING_TIMEOUT_BOOTTIME:
+ return CLOCK_BOOTTIME;
+ case IORING_TIMEOUT_REALTIME:
+ return CLOCK_REALTIME;
+ default:
+ /* can't happen, vetted at prep time */
+ WARN_ON_ONCE(1);
+ fallthrough;
+ case 0:
+ return CLOCK_MONOTONIC;
+ }
+}
+
+static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
+ struct timespec64 *ts, enum hrtimer_mode mode)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_timeout_data *io;
+ struct io_kiocb *req;
+ bool found = false;
+
+ list_for_each_entry(req, &ctx->ltimeout_list, timeout.list) {
+ found = user_data == req->user_data;
+ if (found)
+ break;
+ }
+ if (!found)
+ return -ENOENT;
+
+ io = req->async_data;
+ if (hrtimer_try_to_cancel(&io->timer) == -1)
+ return -EALREADY;
+ hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);
+ io->timer.function = io_link_timeout_fn;
+ hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);
+ return 0;
+}
+
+static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
+ struct timespec64 *ts, enum hrtimer_mode mode)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_kiocb *req = io_timeout_extract(ctx, user_data);
+ struct io_timeout_data *data;
+
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ req->timeout.off = 0; /* noseq */
+ data = req->async_data;
+ list_add_tail(&req->timeout.list, &ctx->timeout_list);
+ hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);
+ data->timer.function = io_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);
+ return 0;
+}
+
+static int io_timeout_remove_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_timeout_rem *tr = &req->timeout_rem;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->splice_fd_in)
+ return -EINVAL;
+
+ tr->ltimeout = false;
+ tr->addr = READ_ONCE(sqe->addr);
+ tr->flags = READ_ONCE(sqe->timeout_flags);
+ if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {
+ if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
+ return -EINVAL;
+ if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)
+ tr->ltimeout = true;
+ if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))
+ return -EINVAL;
+ if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
+ return -EFAULT;
+ } else if (tr->flags) {
+ /* timeout removal doesn't support flags */
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags)
+{
+ return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS
+ : HRTIMER_MODE_REL;
+}
+
+/*
+ * Remove or update an existing timeout command
+ */
+static int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_timeout_rem *tr = &req->timeout_rem;
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ if (!(req->timeout_rem.flags & IORING_TIMEOUT_UPDATE)) {
+ spin_lock(&ctx->completion_lock);
+ spin_lock_irq(&ctx->timeout_lock);
+ ret = io_timeout_cancel(ctx, tr->addr);
+ spin_unlock_irq(&ctx->timeout_lock);
+ spin_unlock(&ctx->completion_lock);
+ } else {
+ enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags);
+
+ spin_lock_irq(&ctx->timeout_lock);
+ if (tr->ltimeout)
+ ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);
+ else
+ ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
+ spin_unlock_irq(&ctx->timeout_lock);
+ }
+
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete_post(req, ret, 0);
+ return 0;
+}
+
+static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
+ bool is_timeout_link)
+{
+ struct io_timeout_data *data;
+ unsigned flags;
+ u32 off = READ_ONCE(sqe->off);
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->len != 1 ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+ if (off && is_timeout_link)
+ return -EINVAL;
+ flags = READ_ONCE(sqe->timeout_flags);
+ if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK))
+ return -EINVAL;
+ /* more than one clock specified is invalid, obviously */
+ if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&req->timeout.list);
+ req->timeout.off = off;
+ if (unlikely(off && !req->ctx->off_timeout_used))
+ req->ctx->off_timeout_used = true;
+
+ if (!req->async_data && io_alloc_async_data(req))
+ return -ENOMEM;
+
+ data = req->async_data;
+ data->req = req;
+ data->flags = flags;
+
+ if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
+ return -EFAULT;
+
+ INIT_LIST_HEAD(&req->timeout.list);
+ data->mode = io_translate_timeout_mode(flags);
+ hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);
+
+ if (is_timeout_link) {
+ struct io_submit_link *link = &req->ctx->submit_state.link;
+
+ if (!link->head)
+ return -EINVAL;
+ if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
+ return -EINVAL;
+ req->timeout.head = link->last;
+ link->last->flags |= REQ_F_ARM_LTIMEOUT;
+ }
+ return 0;
+}
+
+static int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_timeout_data *data = req->async_data;
+ struct list_head *entry;
+ u32 tail, off = req->timeout.off;
+
+ spin_lock_irq(&ctx->timeout_lock);
+
+ /*
+ * sqe->off holds how many events that need to occur for this
+ * timeout event to be satisfied. If it isn't set, then this is
+ * a pure timeout request, sequence isn't used.
+ */
+ if (io_is_timeout_noseq(req)) {
+ entry = ctx->timeout_list.prev;
+ goto add;
+ }
+
+ tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
+ req->timeout.target_seq = tail + off;
+
+ /* Update the last seq here in case io_flush_timeouts() hasn't.
+ * This is safe because ->completion_lock is held, and submissions
+ * and completions are never mixed in the same ->completion_lock section.
+ */
+ ctx->cq_last_tm_flush = tail;
+
+ /*
+ * Insertion sort, ensuring the first entry in the list is always
+ * the one we need first.
+ */
+ list_for_each_prev(entry, &ctx->timeout_list) {
+ struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
+ timeout.list);
+
+ if (io_is_timeout_noseq(nxt))
+ continue;
+ /* nxt.seq is behind @tail, otherwise would've been completed */
+ if (off >= nxt->timeout.target_seq - tail)
+ break;
+ }
+add:
+ list_add(&req->timeout.list, entry);
+ data->timer.function = io_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
+ spin_unlock_irq(&ctx->timeout_lock);
+ return 0;
+}
+
+struct io_cancel_data {
+ struct io_ring_ctx *ctx;
+ u64 user_data;
+};
+
+static bool io_cancel_cb(struct io_wq_work *work, void *data)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+ struct io_cancel_data *cd = data;
+
+ return req->ctx == cd->ctx && req->user_data == cd->user_data;
+}
+
+static int io_async_cancel_one(struct io_uring_task *tctx, u64 user_data,
+ struct io_ring_ctx *ctx)
+{
+ struct io_cancel_data data = { .ctx = ctx, .user_data = user_data, };
+ enum io_wq_cancel cancel_ret;
+ int ret = 0;
+
+ if (!tctx || !tctx->io_wq)
+ return -ENOENT;
+
+ cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, &data, false);
+ switch (cancel_ret) {
+ case IO_WQ_CANCEL_OK:
+ ret = 0;
+ break;
+ case IO_WQ_CANCEL_RUNNING:
+ ret = -EALREADY;
+ break;
+ case IO_WQ_CANCEL_NOTFOUND:
+ ret = -ENOENT;
+ break;
+ }
+
+ return ret;
+}
+
+static int io_try_cancel_userdata(struct io_kiocb *req, u64 sqe_addr)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ WARN_ON_ONCE(!io_wq_current_is_worker() && req->task != current);
+
+ ret = io_async_cancel_one(req->task->io_uring, sqe_addr, ctx);
+ if (ret != -ENOENT)
+ return ret;
+
+ spin_lock(&ctx->completion_lock);
+ spin_lock_irq(&ctx->timeout_lock);
+ ret = io_timeout_cancel(ctx, sqe_addr);
+ spin_unlock_irq(&ctx->timeout_lock);
+ if (ret != -ENOENT)
+ goto out;
+ ret = io_poll_cancel(ctx, sqe_addr, false);
+out:
+ spin_unlock(&ctx->completion_lock);
+ return ret;
+}
+
+static int io_async_cancel_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+
+ req->cancel.addr = READ_ONCE(sqe->addr);
+ return 0;
+}
+
+static int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ u64 sqe_addr = req->cancel.addr;
+ struct io_tctx_node *node;
+ int ret;
+
+ ret = io_try_cancel_userdata(req, sqe_addr);
+ if (ret != -ENOENT)
+ goto done;
+
+ /* slow path, try all io-wq's */
+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ ret = -ENOENT;
+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
+ struct io_uring_task *tctx = node->task->io_uring;
+
+ ret = io_async_cancel_one(tctx, req->cancel.addr, ctx);
+ if (ret != -ENOENT)
+ break;
+ }
+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+done:
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete_post(req, ret, 0);
+ return 0;
+}
+
+static int io_rsrc_update_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
+ return -EINVAL;
+
+ req->rsrc_update.offset = READ_ONCE(sqe->off);
+ req->rsrc_update.nr_args = READ_ONCE(sqe->len);
+ if (!req->rsrc_update.nr_args)
+ return -EINVAL;
+ req->rsrc_update.arg = READ_ONCE(sqe->addr);
+ return 0;
+}
+
+static int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_uring_rsrc_update2 up;
+ int ret;
+
+ up.offset = req->rsrc_update.offset;
+ up.data = req->rsrc_update.arg;
+ up.nr = 0;
+ up.tags = 0;
+ up.resv = 0;
+ up.resv2 = 0;
+
+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE,
+ &up, req->rsrc_update.nr_args);
+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ switch (req->opcode) {
+ case IORING_OP_NOP:
+ return 0;
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ return io_read_prep(req, sqe);
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ case IORING_OP_WRITE:
+ return io_write_prep(req, sqe);
+ case IORING_OP_POLL_ADD:
+ return io_poll_add_prep(req, sqe);
+ case IORING_OP_POLL_REMOVE:
+ return io_poll_update_prep(req, sqe);
+ case IORING_OP_FSYNC:
+ return io_fsync_prep(req, sqe);
+ case IORING_OP_SYNC_FILE_RANGE:
+ return io_sfr_prep(req, sqe);
+ case IORING_OP_SENDMSG:
+ case IORING_OP_SEND:
+ return io_sendmsg_prep(req, sqe);
+ case IORING_OP_RECVMSG:
+ case IORING_OP_RECV:
+ return io_recvmsg_prep(req, sqe);
+ case IORING_OP_CONNECT:
+ return io_connect_prep(req, sqe);
+ case IORING_OP_TIMEOUT:
+ return io_timeout_prep(req, sqe, false);
+ case IORING_OP_TIMEOUT_REMOVE:
+ return io_timeout_remove_prep(req, sqe);
+ case IORING_OP_ASYNC_CANCEL:
+ return io_async_cancel_prep(req, sqe);
+ case IORING_OP_LINK_TIMEOUT:
+ return io_timeout_prep(req, sqe, true);
+ case IORING_OP_ACCEPT:
+ return io_accept_prep(req, sqe);
+ case IORING_OP_FALLOCATE:
+ return io_fallocate_prep(req, sqe);
+ case IORING_OP_OPENAT:
+ return io_openat_prep(req, sqe);
+ case IORING_OP_CLOSE:
+ return io_close_prep(req, sqe);
+ case IORING_OP_FILES_UPDATE:
+ return io_rsrc_update_prep(req, sqe);
+ case IORING_OP_STATX:
+ return io_statx_prep(req, sqe);
+ case IORING_OP_FADVISE:
+ return io_fadvise_prep(req, sqe);
+ case IORING_OP_MADVISE:
+ return io_madvise_prep(req, sqe);
+ case IORING_OP_OPENAT2:
+ return io_openat2_prep(req, sqe);
+ case IORING_OP_EPOLL_CTL:
+ return io_epoll_ctl_prep(req, sqe);
+ case IORING_OP_SPLICE:
+ return io_splice_prep(req, sqe);
+ case IORING_OP_PROVIDE_BUFFERS:
+ return io_provide_buffers_prep(req, sqe);
+ case IORING_OP_REMOVE_BUFFERS:
+ return io_remove_buffers_prep(req, sqe);
+ case IORING_OP_TEE:
+ return io_tee_prep(req, sqe);
+ case IORING_OP_SHUTDOWN:
+ return io_shutdown_prep(req, sqe);
+ case IORING_OP_RENAMEAT:
+ return io_renameat_prep(req, sqe);
+ case IORING_OP_UNLINKAT:
+ return io_unlinkat_prep(req, sqe);
+ }
+
+ printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
+ req->opcode);
+ return -EINVAL;
+}
+
+static int io_req_prep_async(struct io_kiocb *req)
+{
+ if (!io_op_defs[req->opcode].needs_async_setup)
+ return 0;
+ if (WARN_ON_ONCE(req->async_data))
+ return -EFAULT;
+ if (io_alloc_async_data(req))
+ return -EAGAIN;
+
+ switch (req->opcode) {
+ case IORING_OP_READV:
+ return io_rw_prep_async(req, READ);
+ case IORING_OP_WRITEV:
+ return io_rw_prep_async(req, WRITE);
+ case IORING_OP_SENDMSG:
+ return io_sendmsg_prep_async(req);
+ case IORING_OP_RECVMSG:
+ return io_recvmsg_prep_async(req);
+ case IORING_OP_CONNECT:
+ return io_connect_prep_async(req);
+ }
+ printk_once(KERN_WARNING "io_uring: prep_async() bad opcode %d\n",
+ req->opcode);
+ return -EFAULT;
+}
+
+static u32 io_get_sequence(struct io_kiocb *req)
+{
+ u32 seq = req->ctx->cached_sq_head;
+
+ /* need original cached_sq_head, but it was increased for each req */
+ io_for_each_link(req, req)
+ seq--;
+ return seq;
+}
+
+static bool io_drain_req(struct io_kiocb *req)
+{
+ struct io_kiocb *pos;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_defer_entry *de;
+ int ret;
+ u32 seq;
+
+ if (req->flags & REQ_F_FAIL) {
+ io_req_complete_fail_submit(req);
+ return true;
+ }
+
+ /*
+ * If we need to drain a request in the middle of a link, drain the
+ * head request and the next request/link after the current link.
+ * Considering sequential execution of links, IOSQE_IO_DRAIN will be
+ * maintained for every request of our link.
+ */
+ if (ctx->drain_next) {
+ req->flags |= REQ_F_IO_DRAIN;
+ ctx->drain_next = false;
+ }
+ /* not interested in head, start from the first linked */
+ io_for_each_link(pos, req->link) {
+ if (pos->flags & REQ_F_IO_DRAIN) {
+ ctx->drain_next = true;
+ req->flags |= REQ_F_IO_DRAIN;
+ break;
+ }
+ }
+
+ /* Still need defer if there is pending req in defer list. */
+ spin_lock(&ctx->completion_lock);
+ if (likely(list_empty_careful(&ctx->defer_list) &&
+ !(req->flags & REQ_F_IO_DRAIN))) {
+ spin_unlock(&ctx->completion_lock);
+ ctx->drain_active = false;
+ return false;
+ }
+ spin_unlock(&ctx->completion_lock);
+
+ seq = io_get_sequence(req);
+ /* Still a chance to pass the sequence check */
+ if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
+ return false;
+
+ ret = io_req_prep_async(req);
+ if (ret)
+ goto fail;
+ io_prep_async_link(req);
+ de = kmalloc(sizeof(*de), GFP_KERNEL);
+ if (!de) {
+ ret = -ENOMEM;
+fail:
+ io_req_complete_failed(req, ret);
+ return true;
+ }
+
+ spin_lock(&ctx->completion_lock);
+ if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
+ spin_unlock(&ctx->completion_lock);
+ kfree(de);
+ io_queue_async_work(req, NULL);
+ return true;
+ }
+
+ trace_io_uring_defer(ctx, req, req->user_data);
+ de->req = req;
+ de->seq = seq;
+ list_add_tail(&de->list, &ctx->defer_list);
+ spin_unlock(&ctx->completion_lock);
+ return true;
+}
+
+static void io_clean_op(struct io_kiocb *req)
+{
+ if (req->flags & REQ_F_BUFFER_SELECTED) {
+ switch (req->opcode) {
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ kfree((void *)(unsigned long)req->rw.addr);
+ break;
+ case IORING_OP_RECVMSG:
+ case IORING_OP_RECV:
+ kfree(req->sr_msg.kbuf);
+ break;
+ }
+ }
+
+ if (req->flags & REQ_F_NEED_CLEANUP) {
+ switch (req->opcode) {
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ case IORING_OP_WRITE: {
+ struct io_async_rw *io = req->async_data;
+
+ kfree(io->free_iovec);
+ break;
+ }
+ case IORING_OP_RECVMSG:
+ case IORING_OP_SENDMSG: {
+ struct io_async_msghdr *io = req->async_data;
+
+ kfree(io->free_iov);
+ break;
+ }
+ case IORING_OP_OPENAT:
+ case IORING_OP_OPENAT2:
+ if (req->open.filename)
+ putname(req->open.filename);
+ break;
+ case IORING_OP_RENAMEAT:
+ putname(req->rename.oldpath);
+ putname(req->rename.newpath);
+ break;
+ case IORING_OP_UNLINKAT:
+ putname(req->unlink.filename);
+ break;
+ }
+ }
+ if ((req->flags & REQ_F_POLLED) && req->apoll) {
+ kfree(req->apoll->double_poll);
+ kfree(req->apoll);
+ req->apoll = NULL;
+ }
+ if (req->flags & REQ_F_INFLIGHT) {
+ struct io_uring_task *tctx = req->task->io_uring;
+
+ atomic_dec(&tctx->inflight_tracked);
+ }
+ if (req->flags & REQ_F_CREDS)
+ put_cred(req->creds);
+
+ req->flags &= ~IO_REQ_CLEAN_FLAGS;
+}
+
+static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ const struct cred *creds = NULL;
+ int ret;
+
+ if ((req->flags & REQ_F_CREDS) && req->creds != current_cred())
+ creds = override_creds(req->creds);
+
+ switch (req->opcode) {
+ case IORING_OP_NOP:
+ ret = io_nop(req, issue_flags);
+ break;
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ ret = io_read(req, issue_flags);
+ break;
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ case IORING_OP_WRITE:
+ ret = io_write(req, issue_flags);
+ break;
+ case IORING_OP_FSYNC:
+ ret = io_fsync(req, issue_flags);
+ break;
+ case IORING_OP_POLL_ADD:
+ ret = io_poll_add(req, issue_flags);
+ break;
+ case IORING_OP_POLL_REMOVE:
+ ret = io_poll_update(req, issue_flags);
+ break;
+ case IORING_OP_SYNC_FILE_RANGE:
+ ret = io_sync_file_range(req, issue_flags);
+ break;
+ case IORING_OP_SENDMSG:
+ ret = io_sendmsg(req, issue_flags);
+ break;
+ case IORING_OP_SEND:
+ ret = io_send(req, issue_flags);
+ break;
+ case IORING_OP_RECVMSG:
+ ret = io_recvmsg(req, issue_flags);
+ break;
+ case IORING_OP_RECV:
+ ret = io_recv(req, issue_flags);
+ break;
+ case IORING_OP_TIMEOUT:
+ ret = io_timeout(req, issue_flags);
+ break;
+ case IORING_OP_TIMEOUT_REMOVE:
+ ret = io_timeout_remove(req, issue_flags);
+ break;
+ case IORING_OP_ACCEPT:
+ ret = io_accept(req, issue_flags);
+ break;
+ case IORING_OP_CONNECT:
+ ret = io_connect(req, issue_flags);
+ break;
+ case IORING_OP_ASYNC_CANCEL:
+ ret = io_async_cancel(req, issue_flags);
+ break;
+ case IORING_OP_FALLOCATE:
+ ret = io_fallocate(req, issue_flags);
+ break;
+ case IORING_OP_OPENAT:
+ ret = io_openat(req, issue_flags);
+ break;
+ case IORING_OP_CLOSE:
+ ret = io_close(req, issue_flags);
+ break;
+ case IORING_OP_FILES_UPDATE:
+ ret = io_files_update(req, issue_flags);
+ break;
+ case IORING_OP_STATX:
+ ret = io_statx(req, issue_flags);
+ break;
+ case IORING_OP_FADVISE:
+ ret = io_fadvise(req, issue_flags);
+ break;
+ case IORING_OP_MADVISE:
+ ret = io_madvise(req, issue_flags);
+ break;
+ case IORING_OP_OPENAT2:
+ ret = io_openat2(req, issue_flags);
+ break;
+ case IORING_OP_EPOLL_CTL:
+ ret = io_epoll_ctl(req, issue_flags);
+ break;
+ case IORING_OP_SPLICE:
+ ret = io_splice(req, issue_flags);
+ break;
+ case IORING_OP_PROVIDE_BUFFERS:
+ ret = io_provide_buffers(req, issue_flags);
+ break;
+ case IORING_OP_REMOVE_BUFFERS:
+ ret = io_remove_buffers(req, issue_flags);
+ break;
+ case IORING_OP_TEE:
+ ret = io_tee(req, issue_flags);
+ break;
+ case IORING_OP_SHUTDOWN:
+ ret = io_shutdown(req, issue_flags);
+ break;
+ case IORING_OP_RENAMEAT:
+ ret = io_renameat(req, issue_flags);
+ break;
+ case IORING_OP_UNLINKAT:
+ ret = io_unlinkat(req, issue_flags);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (creds)
+ revert_creds(creds);
+ if (ret)
+ return ret;
+ /* If the op doesn't have a file, we're not polling for it */
+ if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file)
+ io_iopoll_req_issued(req);
+
+ return 0;
+}
+
+static struct io_wq_work *io_wq_free_work(struct io_wq_work *work)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+
+ req = io_put_req_find_next(req);
+ return req ? &req->work : NULL;
+}
+
+static void io_wq_submit_work(struct io_wq_work *work)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+ struct io_kiocb *timeout;
+ int ret = 0;
+
+ /* one will be dropped by ->io_free_work() after returning to io-wq */
+ if (!(req->flags & REQ_F_REFCOUNT))
+ __io_req_set_refcount(req, 2);
+ else
+ req_ref_get(req);
+
+ timeout = io_prep_linked_timeout(req);
+ if (timeout)
+ io_queue_linked_timeout(timeout);
+
+ /* either cancelled or io-wq is dying, so don't touch tctx->iowq */
+ if (work->flags & IO_WQ_WORK_CANCEL)
+ ret = -ECANCELED;
+
+ if (!ret) {
+ do {
+ ret = io_issue_sqe(req, 0);
+ /*
+ * We can get EAGAIN for polled IO even though we're
+ * forcing a sync submission from here, since we can't
+ * wait for request slots on the block side.
+ */
+ if (ret != -EAGAIN || !(req->ctx->flags & IORING_SETUP_IOPOLL))
+ break;
+ cond_resched();
+ } while (1);
+ }
+
+ /* avoid locking problems by failing it from a clean context */
+ if (ret)
+ io_req_task_queue_fail(req, ret);
+}
+
+static inline struct io_fixed_file *io_fixed_file_slot(struct io_file_table *table,
+ unsigned i)
+{
+ return &table->files[i];
+}
+
+static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
+ int index)
+{
+ struct io_fixed_file *slot = io_fixed_file_slot(&ctx->file_table, index);
+
+ return (struct file *) (slot->file_ptr & FFS_MASK);
+}
+
+static void io_fixed_file_set(struct io_fixed_file *file_slot, struct file *file)
+{
+ unsigned long file_ptr = (unsigned long) file;
+
+ if (__io_file_supports_nowait(file, READ))
+ file_ptr |= FFS_ASYNC_READ;
+ if (__io_file_supports_nowait(file, WRITE))
+ file_ptr |= FFS_ASYNC_WRITE;
+ if (S_ISREG(file_inode(file)->i_mode))
+ file_ptr |= FFS_ISREG;
+ file_slot->file_ptr = file_ptr;
+}
+
+static inline struct file *io_file_get_fixed(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd)
+{
+ struct file *file;
+ unsigned long file_ptr;
+
+ if (unlikely((unsigned int)fd >= ctx->nr_user_files))
+ return NULL;
+ fd = array_index_nospec(fd, ctx->nr_user_files);
+ file_ptr = io_fixed_file_slot(&ctx->file_table, fd)->file_ptr;
+ file = (struct file *) (file_ptr & FFS_MASK);
+ file_ptr &= ~FFS_MASK;
+ /* mask in overlapping REQ_F and FFS bits */
+ req->flags |= (file_ptr << REQ_F_NOWAIT_READ_BIT);
+ io_req_set_rsrc_node(req);
+ return file;
+}
+
+static struct file *io_file_get_normal(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd)
+{
+ struct file *file = fget(fd);
+
+ trace_io_uring_file_get(ctx, fd);
+
+ /* we don't allow fixed io_uring files */
+ if (file && unlikely(file->f_op == &io_uring_fops))
+ io_req_track_inflight(req);
+ return file;
+}
+
+static inline struct file *io_file_get(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd, bool fixed)
+{
+ if (fixed)
+ return io_file_get_fixed(ctx, req, fd);
+ else
+ return io_file_get_normal(ctx, req, fd);
+}
+
+static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked)
+{
+ struct io_kiocb *prev = req->timeout.prev;
+ int ret = -ENOENT;
+
+ if (prev) {
+ if (!(req->task->flags & PF_EXITING))
+ ret = io_try_cancel_userdata(req, prev->user_data);
+ io_req_complete_post(req, ret ?: -ETIME, 0);
+ io_put_req(prev);
+ } else {
+ io_req_complete_post(req, -ETIME, 0);
+ }
+}
+
+static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
+{
+ struct io_timeout_data *data = container_of(timer,
+ struct io_timeout_data, timer);
+ struct io_kiocb *prev, *req = data->req;
+ struct io_ring_ctx *ctx = req->ctx;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->timeout_lock, flags);
+ prev = req->timeout.head;
+ req->timeout.head = NULL;
+
+ /*
+ * We don't expect the list to be empty, that will only happen if we
+ * race with the completion of the linked work.
+ */
+ if (prev) {
+ io_remove_next_linked(prev);
+ if (!req_ref_inc_not_zero(prev))
+ prev = NULL;
+ }
+ list_del(&req->timeout.list);
+ req->timeout.prev = prev;
+ spin_unlock_irqrestore(&ctx->timeout_lock, flags);
+
+ req->io_task_work.func = io_req_task_link_timeout;
+ io_req_task_work_add(req);
+ return HRTIMER_NORESTART;
+}
+
+static void io_queue_linked_timeout(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ /*
+ * If the back reference is NULL, then our linked request finished
+ * before we got a chance to setup the timer
+ */
+ if (req->timeout.head) {
+ struct io_timeout_data *data = req->async_data;
+
+ data->timer.function = io_link_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
+ data->mode);
+ list_add_tail(&req->timeout.list, &ctx->ltimeout_list);
+ }
+ spin_unlock_irq(&ctx->timeout_lock);
+ /* drop submission reference */
+ io_put_req(req);
+}
+
+static void __io_queue_sqe(struct io_kiocb *req)
+ __must_hold(&req->ctx->uring_lock)
+{
+ struct io_kiocb *linked_timeout;
+ int ret;
+
+issue_sqe:
+ ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER);
+
+ /*
+ * We async punt it if the file wasn't marked NOWAIT, or if the file
+ * doesn't support non-blocking read/write attempts
+ */
+ if (likely(!ret)) {
+ if (req->flags & REQ_F_COMPLETE_INLINE) {
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_submit_state *state = &ctx->submit_state;
+
+ state->compl_reqs[state->compl_nr++] = req;
+ if (state->compl_nr == ARRAY_SIZE(state->compl_reqs))
+ io_submit_flush_completions(ctx);
+ return;
+ }
+
+ linked_timeout = io_prep_linked_timeout(req);
+ if (linked_timeout)
+ io_queue_linked_timeout(linked_timeout);
+ } else if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
+ linked_timeout = io_prep_linked_timeout(req);
+
+ switch (io_arm_poll_handler(req)) {
+ case IO_APOLL_READY:
+ if (linked_timeout)
+ io_queue_linked_timeout(linked_timeout);
+ goto issue_sqe;
+ case IO_APOLL_ABORTED:
+ /*
+ * Queued up for async execution, worker will release
+ * submit reference when the iocb is actually submitted.
+ */
+ io_queue_async_work(req, NULL);
+ break;
+ }
+
+ if (linked_timeout)
+ io_queue_linked_timeout(linked_timeout);
+ } else {
+ io_req_complete_failed(req, ret);
+ }
+}
+
+static inline void io_queue_sqe(struct io_kiocb *req)
+ __must_hold(&req->ctx->uring_lock)
+{
+ if (unlikely(req->ctx->drain_active) && io_drain_req(req))
+ return;
+
+ if (likely(!(req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)))) {
+ __io_queue_sqe(req);
+ } else if (req->flags & REQ_F_FAIL) {
+ io_req_complete_fail_submit(req);
+ } else {
+ int ret = io_req_prep_async(req);
+
+ if (unlikely(ret))
+ io_req_complete_failed(req, ret);
+ else
+ io_queue_async_work(req, NULL);
+ }
+}
+
+/*
+ * Check SQE restrictions (opcode and flags).
+ *
+ * Returns 'true' if SQE is allowed, 'false' otherwise.
+ */
+static inline bool io_check_restriction(struct io_ring_ctx *ctx,
+ struct io_kiocb *req,
+ unsigned int sqe_flags)
+{
+ if (likely(!ctx->restricted))
+ return true;
+
+ if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
+ return false;
+
+ if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
+ ctx->restrictions.sqe_flags_required)
+ return false;
+
+ if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
+ ctx->restrictions.sqe_flags_required))
+ return false;
+
+ return true;
+}
+
+static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_state *state;
+ unsigned int sqe_flags;
+ int personality, ret = 0;
+
+ /* req is partially pre-initialised, see io_preinit_req() */
+ req->opcode = READ_ONCE(sqe->opcode);
+ /* same numerical values with corresponding REQ_F_*, safe to copy */
+ req->flags = sqe_flags = READ_ONCE(sqe->flags);
+ req->user_data = READ_ONCE(sqe->user_data);
+ req->file = NULL;
+ req->fixed_rsrc_refs = NULL;
+ req->task = current;
+
+ /* enforce forwards compatibility on users */
+ if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
+ return -EINVAL;
+ if (unlikely(req->opcode >= IORING_OP_LAST))
+ return -EINVAL;
+ if (!io_check_restriction(ctx, req, sqe_flags))
+ return -EACCES;
+
+ if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
+ !io_op_defs[req->opcode].buffer_select)
+ return -EOPNOTSUPP;
+ if (unlikely(sqe_flags & IOSQE_IO_DRAIN))
+ ctx->drain_active = true;
+
+ personality = READ_ONCE(sqe->personality);
+ if (personality) {
+ req->creds = xa_load(&ctx->personalities, personality);
+ if (!req->creds)
+ return -EINVAL;
+ get_cred(req->creds);
+ req->flags |= REQ_F_CREDS;
+ }
+ state = &ctx->submit_state;
+
+ /*
+ * Plug now if we have more than 1 IO left after this, and the target
+ * is potentially a read/write to block based storage.
+ */
+ if (!state->plug_started && state->ios_left > 1 &&
+ io_op_defs[req->opcode].plug) {
+ blk_start_plug(&state->plug);
+ state->plug_started = true;
+ }
+
+ if (io_op_defs[req->opcode].needs_file) {
+ req->file = io_file_get(ctx, req, READ_ONCE(sqe->fd),
+ (sqe_flags & IOSQE_FIXED_FILE));
+ if (unlikely(!req->file))
+ ret = -EBADF;
+ }
+
+ state->ios_left--;
+ return ret;
+}
+
+static int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_link *link = &ctx->submit_state.link;
+ int ret;
+
+ ret = io_init_req(ctx, req, sqe);
+ if (unlikely(ret)) {
+fail_req:
+ /* fail even hard links since we don't submit */
+ if (link->head) {
+ /*
+ * we can judge a link req is failed or cancelled by if
+ * REQ_F_FAIL is set, but the head is an exception since
+ * it may be set REQ_F_FAIL because of other req's failure
+ * so let's leverage req->result to distinguish if a head
+ * is set REQ_F_FAIL because of its failure or other req's
+ * failure so that we can set the correct ret code for it.
+ * init result here to avoid affecting the normal path.
+ */
+ if (!(link->head->flags & REQ_F_FAIL))
+ req_fail_link_node(link->head, -ECANCELED);
+ } else if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
+ /*
+ * the current req is a normal req, we should return
+ * error and thus break the submittion loop.
+ */
+ io_req_complete_failed(req, ret);
+ return ret;
+ }
+ req_fail_link_node(req, ret);
+ } else {
+ ret = io_req_prep(req, sqe);
+ if (unlikely(ret))
+ goto fail_req;
+ }
+
+ /* don't need @sqe from now on */
+ trace_io_uring_submit_sqe(ctx, req, req->opcode, req->user_data,
+ req->flags, true,
+ ctx->flags & IORING_SETUP_SQPOLL);
+
+ /*
+ * If we already have a head request, queue this one for async
+ * submittal once the head completes. If we don't have a head but
+ * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
+ * submitted sync once the chain is complete. If none of those
+ * conditions are true (normal request), then just queue it.
+ */
+ if (link->head) {
+ struct io_kiocb *head = link->head;
+
+ if (!(req->flags & REQ_F_FAIL)) {
+ ret = io_req_prep_async(req);
+ if (unlikely(ret)) {
+ req_fail_link_node(req, ret);
+ if (!(head->flags & REQ_F_FAIL))
+ req_fail_link_node(head, -ECANCELED);
+ }
+ }
+ trace_io_uring_link(ctx, req, head);
+ link->last->link = req;
+ link->last = req;
+
+ /* last request of a link, enqueue the link */
+ if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
+ link->head = NULL;
+ io_queue_sqe(head);
+ }
+ } else {
+ if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
+ link->head = req;
+ link->last = req;
+ } else {
+ io_queue_sqe(req);
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Batched submission is done, ensure local IO is flushed out.
+ */
+static void io_submit_state_end(struct io_submit_state *state,
+ struct io_ring_ctx *ctx)
+{
+ if (state->link.head)
+ io_queue_sqe(state->link.head);
+ if (state->compl_nr)
+ io_submit_flush_completions(ctx);
+ if (state->plug_started)
+ blk_finish_plug(&state->plug);
+}
+
+/*
+ * Start submission side cache.
+ */
+static void io_submit_state_start(struct io_submit_state *state,
+ unsigned int max_ios)
+{
+ state->plug_started = false;
+ state->ios_left = max_ios;
+ /* set only head, no need to init link_last in advance */
+ state->link.head = NULL;
+}
+
+static void io_commit_sqring(struct io_ring_ctx *ctx)
+{
+ struct io_rings *rings = ctx->rings;
+
+ /*
+ * Ensure any loads from the SQEs are done at this point,
+ * since once we write the new head, the application could
+ * write new data to them.
+ */
+ smp_store_release(&rings->sq.head, ctx->cached_sq_head);
+}
+
+/*
+ * Fetch an sqe, if one is available. Note this returns a pointer to memory
+ * that is mapped by userspace. This means that care needs to be taken to
+ * ensure that reads are stable, as we cannot rely on userspace always
+ * being a good citizen. If members of the sqe are validated and then later
+ * used, it's important that those reads are done through READ_ONCE() to
+ * prevent a re-load down the line.
+ */
+static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
+{
+ unsigned head, mask = ctx->sq_entries - 1;
+ unsigned sq_idx = ctx->cached_sq_head++ & mask;
+
+ /*
+ * The cached sq head (or cq tail) serves two purposes:
+ *
+ * 1) allows us to batch the cost of updating the user visible
+ * head updates.
+ * 2) allows the kernel side to track the head on its own, even
+ * though the application is the one updating it.
+ */
+ head = READ_ONCE(ctx->sq_array[sq_idx]);
+ if (likely(head < ctx->sq_entries))
+ return &ctx->sq_sqes[head];
+
+ /* drop invalid entries */
+ ctx->cq_extra--;
+ WRITE_ONCE(ctx->rings->sq_dropped,
+ READ_ONCE(ctx->rings->sq_dropped) + 1);
+ return NULL;
+}
+
+static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
+ __must_hold(&ctx->uring_lock)
+{
+ int submitted = 0;
+
+ /* make sure SQ entry isn't read before tail */
+ nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
+ if (!percpu_ref_tryget_many(&ctx->refs, nr))
+ return -EAGAIN;
+ io_get_task_refs(nr);
+
+ io_submit_state_start(&ctx->submit_state, nr);
+ while (submitted < nr) {
+ const struct io_uring_sqe *sqe;
+ struct io_kiocb *req;
+
+ req = io_alloc_req(ctx);
+ if (unlikely(!req)) {
+ if (!submitted)
+ submitted = -EAGAIN;
+ break;
+ }
+ sqe = io_get_sqe(ctx);
+ if (unlikely(!sqe)) {
+ list_add(&req->inflight_entry, &ctx->submit_state.free_list);
+ break;
+ }
+ /* will complete beyond this point, count as submitted */
+ submitted++;
+ if (io_submit_sqe(ctx, req, sqe))
+ break;
+ }
+
+ if (unlikely(submitted != nr)) {
+ int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
+ int unused = nr - ref_used;
+
+ current->io_uring->cached_refs += unused;
+ percpu_ref_put_many(&ctx->refs, unused);
+ }
+
+ io_submit_state_end(&ctx->submit_state, ctx);
+ /* Commit SQ ring head once we've consumed and submitted all SQEs */
+ io_commit_sqring(ctx);
+
+ return submitted;
+}
+
+static inline bool io_sqd_events_pending(struct io_sq_data *sqd)
+{
+ return READ_ONCE(sqd->state);
+}
+
+static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
+{
+ /* Tell userspace we may need a wakeup call */
+ spin_lock(&ctx->completion_lock);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags | IORING_SQ_NEED_WAKEUP);
+ spin_unlock(&ctx->completion_lock);
+}
+
+static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
+{
+ spin_lock(&ctx->completion_lock);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags & ~IORING_SQ_NEED_WAKEUP);
+ spin_unlock(&ctx->completion_lock);
+}
+
+static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
+{
+ unsigned int to_submit;
+ int ret = 0;
+
+ to_submit = io_sqring_entries(ctx);
+ /* if we're handling multiple rings, cap submit size for fairness */
+ if (cap_entries && to_submit > IORING_SQPOLL_CAP_ENTRIES_VALUE)
+ to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE;
+
+ if (!list_empty(&ctx->iopoll_list) || to_submit) {
+ unsigned nr_events = 0;
+ const struct cred *creds = NULL;
+
+ if (ctx->sq_creds != current_cred())
+ creds = override_creds(ctx->sq_creds);
+
+ mutex_lock(&ctx->uring_lock);
+ if (!list_empty(&ctx->iopoll_list))
+ io_do_iopoll(ctx, &nr_events, 0);
+
+ /*
+ * Don't submit if refs are dying, good for io_uring_register(),
+ * but also it is relied upon by io_ring_exit_work()
+ */
+ if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) &&
+ !(ctx->flags & IORING_SETUP_R_DISABLED))
+ ret = io_submit_sqes(ctx, to_submit);
+ mutex_unlock(&ctx->uring_lock);
+
+ if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait))
+ wake_up(&ctx->sqo_sq_wait);
+ if (creds)
+ revert_creds(creds);
+ }
+
+ return ret;
+}
+
+static void io_sqd_update_thread_idle(struct io_sq_data *sqd)
+{
+ struct io_ring_ctx *ctx;
+ unsigned sq_thread_idle = 0;
+
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ sq_thread_idle = max(sq_thread_idle, ctx->sq_thread_idle);
+ sqd->sq_thread_idle = sq_thread_idle;
+}
+
+static bool io_sqd_handle_event(struct io_sq_data *sqd)
+{
+ bool did_sig = false;
+ struct ksignal ksig;
+
+ if (test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) ||
+ signal_pending(current)) {
+ mutex_unlock(&sqd->lock);
+ if (signal_pending(current))
+ did_sig = get_signal(&ksig);
+ cond_resched();
+ mutex_lock(&sqd->lock);
+ }
+ return did_sig || test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state);
+}
+
+static int io_sq_thread(void *data)
+{
+ struct io_sq_data *sqd = data;
+ struct io_ring_ctx *ctx;
+ unsigned long timeout = 0;
+ char buf[TASK_COMM_LEN];
+ DEFINE_WAIT(wait);
+
+ snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid);
+ set_task_comm(current, buf);
+
+ if (sqd->sq_cpu != -1)
+ set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu));
+ else
+ set_cpus_allowed_ptr(current, cpu_online_mask);
+ current->flags |= PF_NO_SETAFFINITY;
+
+ mutex_lock(&sqd->lock);
+ while (1) {
+ bool cap_entries, sqt_spin = false;
+
+ if (io_sqd_events_pending(sqd) || signal_pending(current)) {
+ if (io_sqd_handle_event(sqd))
+ break;
+ timeout = jiffies + sqd->sq_thread_idle;
+ }
+
+ cap_entries = !list_is_singular(&sqd->ctx_list);
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
+ int ret = __io_sq_thread(ctx, cap_entries);
+
+ if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list)))
+ sqt_spin = true;
+ }
+ if (io_run_task_work())
+ sqt_spin = true;
+
+ if (sqt_spin || !time_after(jiffies, timeout)) {
+ cond_resched();
+ if (sqt_spin)
+ timeout = jiffies + sqd->sq_thread_idle;
+ continue;
+ }
+
+ prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE);
+ if (!io_sqd_events_pending(sqd) && !current->task_works) {
+ bool needs_sched = true;
+
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
+ io_ring_set_wakeup_flag(ctx);
+
+ if ((ctx->flags & IORING_SETUP_IOPOLL) &&
+ !list_empty_careful(&ctx->iopoll_list)) {
+ needs_sched = false;
+ break;
+ }
+ if (io_sqring_entries(ctx)) {
+ needs_sched = false;
+ break;
+ }
+ }
+
+ if (needs_sched) {
+ mutex_unlock(&sqd->lock);
+ schedule();
+ mutex_lock(&sqd->lock);
+ }
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ io_ring_clear_wakeup_flag(ctx);
+ }
+
+ finish_wait(&sqd->wait, &wait);
+ timeout = jiffies + sqd->sq_thread_idle;
+ }
+
+ io_uring_cancel_generic(true, sqd);
+ sqd->thread = NULL;
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ io_ring_set_wakeup_flag(ctx);
+ io_run_task_work();
+ mutex_unlock(&sqd->lock);
+
+ complete(&sqd->exited);
+ do_exit(0);
+}
+
+struct io_wait_queue {
+ struct wait_queue_entry wq;
+ struct io_ring_ctx *ctx;
+ unsigned cq_tail;
+ unsigned nr_timeouts;
+};
+
+static inline bool io_should_wake(struct io_wait_queue *iowq)
+{
+ struct io_ring_ctx *ctx = iowq->ctx;
+ int dist = ctx->cached_cq_tail - (int) iowq->cq_tail;
+
+ /*
+ * Wake up if we have enough events, or if a timeout occurred since we
+ * started waiting. For timeouts, we always want to return to userspace,
+ * regardless of event count.
+ */
+ return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
+}
+
+static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
+ int wake_flags, void *key)
+{
+ struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
+ wq);
+
+ /*
+ * Cannot safely flush overflowed CQEs from here, ensure we wake up
+ * the task, and the next invocation will do it.
+ */
+ if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->check_cq_overflow))
+ return autoremove_wake_function(curr, mode, wake_flags, key);
+ return -1;
+}
+
+static int io_run_task_work_sig(void)
+{
+ if (io_run_task_work())
+ return 1;
+ if (!signal_pending(current))
+ return 0;
+ if (test_thread_flag(TIF_NOTIFY_SIGNAL))
+ return -ERESTARTSYS;
+ return -EINTR;
+}
+
+/* when returns >0, the caller should retry */
+static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq,
+ ktime_t timeout)
+{
+ int ret;
+
+ /* make sure we run task_work before checking for signals */
+ ret = io_run_task_work_sig();
+ if (ret || io_should_wake(iowq))
+ return ret;
+ /* let the caller flush overflows, retry */
+ if (test_bit(0, &ctx->check_cq_overflow))
+ return 1;
+
+ if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS))
+ return -ETIME;
+ return 1;
+}
+
+/*
+ * Wait until events become available, if we don't already have some. The
+ * application must reap them itself, as they reside on the shared cq ring.
+ */
+static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
+ const sigset_t __user *sig, size_t sigsz,
+ struct __kernel_timespec __user *uts)
+{
+ struct io_wait_queue iowq;
+ struct io_rings *rings = ctx->rings;
+ ktime_t timeout = KTIME_MAX;
+ int ret;
+
+ do {
+ io_cqring_overflow_flush(ctx);
+ if (io_cqring_events(ctx) >= min_events)
+ return 0;
+ if (!io_run_task_work())
+ break;
+ } while (1);
+
+ if (uts) {
+ struct timespec64 ts;
+
+ if (get_timespec64(&ts, uts))
+ return -EFAULT;
+ timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
+ }
+
+ if (sig) {
+#ifdef CONFIG_COMPAT
+ if (in_compat_syscall())
+ ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
+ sigsz);
+ else
+#endif
+ ret = set_user_sigmask(sig, sigsz);
+
+ if (ret)
+ return ret;
+ }
+
+ init_waitqueue_func_entry(&iowq.wq, io_wake_function);
+ iowq.wq.private = current;
+ INIT_LIST_HEAD(&iowq.wq.entry);
+ iowq.ctx = ctx;
+ iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
+ iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events;
+
+ trace_io_uring_cqring_wait(ctx, min_events);
+ do {
+ /* if we can't even flush overflow, don't wait for more */
+ if (!io_cqring_overflow_flush(ctx)) {
+ ret = -EBUSY;
+ break;
+ }
+ prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
+ TASK_INTERRUPTIBLE);
+ ret = io_cqring_wait_schedule(ctx, &iowq, timeout);
+ finish_wait(&ctx->cq_wait, &iowq.wq);
+ cond_resched();
+ } while (ret > 0);
+
+ restore_saved_sigmask_unless(ret == -EINTR);
+
+ return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
+}
+
+static void io_free_page_table(void **table, size_t size)
+{
+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
+
+ for (i = 0; i < nr_tables; i++)
+ kfree(table[i]);
+ kfree(table);
+}
+
+static void **io_alloc_page_table(size_t size)
+{
+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
+ size_t init_size = size;
+ void **table;
+
+ table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT);
+ if (!table)
+ return NULL;
+
+ for (i = 0; i < nr_tables; i++) {
+ unsigned int this_size = min_t(size_t, size, PAGE_SIZE);
+
+ table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT);
+ if (!table[i]) {
+ io_free_page_table(table, init_size);
+ return NULL;
+ }
+ size -= this_size;
+ }
+ return table;
+}
+
+static void io_rsrc_node_destroy(struct io_rsrc_node *ref_node)
+{
+ percpu_ref_exit(&ref_node->refs);
+ kfree(ref_node);
+}
+
+static void io_rsrc_node_ref_zero(struct percpu_ref *ref)
+{
+ struct io_rsrc_node *node = container_of(ref, struct io_rsrc_node, refs);
+ struct io_ring_ctx *ctx = node->rsrc_data->ctx;
+ unsigned long flags;
+ bool first_add = false;
+ unsigned long delay = HZ;
+
+ spin_lock_irqsave(&ctx->rsrc_ref_lock, flags);
+ node->done = true;
+
+ /* if we are mid-quiesce then do not delay */
+ if (node->rsrc_data->quiesce)
+ delay = 0;
+
+ while (!list_empty(&ctx->rsrc_ref_list)) {
+ node = list_first_entry(&ctx->rsrc_ref_list,
+ struct io_rsrc_node, node);
+ /* recycle ref nodes in order */
+ if (!node->done)
+ break;
+ list_del(&node->node);
+ first_add |= llist_add(&node->llist, &ctx->rsrc_put_llist);
+ }
+ spin_unlock_irqrestore(&ctx->rsrc_ref_lock, flags);
+
+ if (first_add)
+ mod_delayed_work(system_wq, &ctx->rsrc_put_work, delay);
+}
+
+static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx)
+{
+ struct io_rsrc_node *ref_node;
+
+ ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
+ if (!ref_node)
+ return NULL;
+
+ if (percpu_ref_init(&ref_node->refs, io_rsrc_node_ref_zero,
+ 0, GFP_KERNEL)) {
+ kfree(ref_node);
+ return NULL;
+ }
+ INIT_LIST_HEAD(&ref_node->node);
+ INIT_LIST_HEAD(&ref_node->rsrc_list);
+ ref_node->done = false;
+ return ref_node;
+}
+
+static void io_rsrc_node_switch(struct io_ring_ctx *ctx,
+ struct io_rsrc_data *data_to_kill)
+{
+ WARN_ON_ONCE(!ctx->rsrc_backup_node);
+ WARN_ON_ONCE(data_to_kill && !ctx->rsrc_node);
+
+ if (data_to_kill) {
+ struct io_rsrc_node *rsrc_node = ctx->rsrc_node;
+
+ rsrc_node->rsrc_data = data_to_kill;
+ spin_lock_irq(&ctx->rsrc_ref_lock);
+ list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list);
+ spin_unlock_irq(&ctx->rsrc_ref_lock);
+
+ atomic_inc(&data_to_kill->refs);
+ percpu_ref_kill(&rsrc_node->refs);
+ ctx->rsrc_node = NULL;
+ }
+
+ if (!ctx->rsrc_node) {
+ ctx->rsrc_node = ctx->rsrc_backup_node;
+ ctx->rsrc_backup_node = NULL;
+ }
+}
+
+static int io_rsrc_node_switch_start(struct io_ring_ctx *ctx)
+{
+ if (ctx->rsrc_backup_node)
+ return 0;
+ ctx->rsrc_backup_node = io_rsrc_node_alloc(ctx);
+ return ctx->rsrc_backup_node ? 0 : -ENOMEM;
+}
+
+static int io_rsrc_ref_quiesce(struct io_rsrc_data *data, struct io_ring_ctx *ctx)
+{
+ int ret;
+
+ /* As we may drop ->uring_lock, other task may have started quiesce */
+ if (data->quiesce)
+ return -ENXIO;
+
+ data->quiesce = true;
+ do {
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ break;
+ io_rsrc_node_switch(ctx, data);
+
+ /* kill initial ref, already quiesced if zero */
+ if (atomic_dec_and_test(&data->refs))
+ break;
+ mutex_unlock(&ctx->uring_lock);
+ flush_delayed_work(&ctx->rsrc_put_work);
+ ret = wait_for_completion_interruptible(&data->done);
+ if (!ret) {
+ mutex_lock(&ctx->uring_lock);
+ if (atomic_read(&data->refs) > 0) {
+ /*
+ * it has been revived by another thread while
+ * we were unlocked
+ */
+ mutex_unlock(&ctx->uring_lock);
+ } else {
+ break;
+ }
+ }
+
+ atomic_inc(&data->refs);
+ /* wait for all works potentially completing data->done */
+ flush_delayed_work(&ctx->rsrc_put_work);
+ reinit_completion(&data->done);
+
+ ret = io_run_task_work_sig();
+ mutex_lock(&ctx->uring_lock);
+ } while (ret >= 0);
+ data->quiesce = false;
+
+ return ret;
+}
+
+static u64 *io_get_tag_slot(struct io_rsrc_data *data, unsigned int idx)
+{
+ unsigned int off = idx & IO_RSRC_TAG_TABLE_MASK;
+ unsigned int table_idx = idx >> IO_RSRC_TAG_TABLE_SHIFT;
+
+ return &data->tags[table_idx][off];
+}
+
+static void io_rsrc_data_free(struct io_rsrc_data *data)
+{
+ size_t size = data->nr * sizeof(data->tags[0][0]);
+
+ if (data->tags)
+ io_free_page_table((void **)data->tags, size);
+ kfree(data);
+}
+
+static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_put,
+ u64 __user *utags, unsigned nr,
+ struct io_rsrc_data **pdata)
+{
+ struct io_rsrc_data *data;
+ int ret = -ENOMEM;
+ unsigned i;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0]));
+ if (!data->tags) {
+ kfree(data);
+ return -ENOMEM;
+ }
+
+ data->nr = nr;
+ data->ctx = ctx;
+ data->do_put = do_put;
+ if (utags) {
+ ret = -EFAULT;
+ for (i = 0; i < nr; i++) {
+ u64 *tag_slot = io_get_tag_slot(data, i);
+
+ if (copy_from_user(tag_slot, &utags[i],
+ sizeof(*tag_slot)))
+ goto fail;
+ }
+ }
+
+ atomic_set(&data->refs, 1);
+ init_completion(&data->done);
+ *pdata = data;
+ return 0;
+fail:
+ io_rsrc_data_free(data);
+ return ret;
+}
+
+static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)
+{
+ table->files = kvcalloc(nr_files, sizeof(table->files[0]),
+ GFP_KERNEL_ACCOUNT);
+ return !!table->files;
+}
+
+static void io_free_file_tables(struct io_file_table *table)
+{
+ kvfree(table->files);
+ table->files = NULL;
+}
+
+static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
+{
+#if defined(CONFIG_UNIX)
+ if (ctx->ring_sock) {
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
+ kfree_skb(skb);
+ }
+#else
+ int i;
+
+ for (i = 0; i < ctx->nr_user_files; i++) {
+ struct file *file;
+
+ file = io_file_from_index(ctx, i);
+ if (file)
+ fput(file);
+ }
+#endif
+ io_free_file_tables(&ctx->file_table);
+ io_rsrc_data_free(ctx->file_data);
+ ctx->file_data = NULL;
+ ctx->nr_user_files = 0;
+}
+
+static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned nr = ctx->nr_user_files;
+ int ret;
+
+ if (!ctx->file_data)
+ return -ENXIO;
+
+ /*
+ * Quiesce may unlock ->uring_lock, and while it's not held
+ * prevent new requests using the table.
+ */
+ ctx->nr_user_files = 0;
+ ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);
+ ctx->nr_user_files = nr;
+ if (!ret)
+ __io_sqe_files_unregister(ctx);
+ return ret;
+}
+
+static void io_sq_thread_unpark(struct io_sq_data *sqd)
+ __releases(&sqd->lock)
+{
+ WARN_ON_ONCE(sqd->thread == current);
+
+ /*
+ * Do the dance but not conditional clear_bit() because it'd race with
+ * other threads incrementing park_pending and setting the bit.
+ */
+ clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
+ if (atomic_dec_return(&sqd->park_pending))
+ set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
+ mutex_unlock(&sqd->lock);
+}
+
+static void io_sq_thread_park(struct io_sq_data *sqd)
+ __acquires(&sqd->lock)
+{
+ WARN_ON_ONCE(sqd->thread == current);
+
+ atomic_inc(&sqd->park_pending);
+ set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
+ mutex_lock(&sqd->lock);
+ if (sqd->thread)
+ wake_up_process(sqd->thread);
+}
+
+static void io_sq_thread_stop(struct io_sq_data *sqd)
+{
+ WARN_ON_ONCE(sqd->thread == current);
+ WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state));
+
+ set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state);
+ mutex_lock(&sqd->lock);
+ if (sqd->thread)
+ wake_up_process(sqd->thread);
+ mutex_unlock(&sqd->lock);
+ wait_for_completion(&sqd->exited);
+}
+
+static void io_put_sq_data(struct io_sq_data *sqd)
+{
+ if (refcount_dec_and_test(&sqd->refs)) {
+ WARN_ON_ONCE(atomic_read(&sqd->park_pending));
+
+ io_sq_thread_stop(sqd);
+ kfree(sqd);
+ }
+}
+
+static void io_sq_thread_finish(struct io_ring_ctx *ctx)
+{
+ struct io_sq_data *sqd = ctx->sq_data;
+
+ if (sqd) {
+ io_sq_thread_park(sqd);
+ list_del_init(&ctx->sqd_list);
+ io_sqd_update_thread_idle(sqd);
+ io_sq_thread_unpark(sqd);
+
+ io_put_sq_data(sqd);
+ ctx->sq_data = NULL;
+ }
+}
+
+static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p)
+{
+ struct io_ring_ctx *ctx_attach;
+ struct io_sq_data *sqd;
+ struct fd f;
+
+ f = fdget(p->wq_fd);
+ if (!f.file)
+ return ERR_PTR(-ENXIO);
+ if (f.file->f_op != &io_uring_fops) {
+ fdput(f);
+ return ERR_PTR(-EINVAL);
+ }
+
+ ctx_attach = f.file->private_data;
+ sqd = ctx_attach->sq_data;
+ if (!sqd) {
+ fdput(f);
+ return ERR_PTR(-EINVAL);
+ }
+ if (sqd->task_tgid != current->tgid) {
+ fdput(f);
+ return ERR_PTR(-EPERM);
+ }
+
+ refcount_inc(&sqd->refs);
+ fdput(f);
+ return sqd;
+}
+
+static struct io_sq_data *io_get_sq_data(struct io_uring_params *p,
+ bool *attached)
+{
+ struct io_sq_data *sqd;
+
+ *attached = false;
+ if (p->flags & IORING_SETUP_ATTACH_WQ) {
+ sqd = io_attach_sq_data(p);
+ if (!IS_ERR(sqd)) {
+ *attached = true;
+ return sqd;
+ }
+ /* fall through for EPERM case, setup new sqd/task */
+ if (PTR_ERR(sqd) != -EPERM)
+ return sqd;
+ }
+
+ sqd = kzalloc(sizeof(*sqd), GFP_KERNEL);
+ if (!sqd)
+ return ERR_PTR(-ENOMEM);
+
+ atomic_set(&sqd->park_pending, 0);
+ refcount_set(&sqd->refs, 1);
+ INIT_LIST_HEAD(&sqd->ctx_list);
+ mutex_init(&sqd->lock);
+ init_waitqueue_head(&sqd->wait);
+ init_completion(&sqd->exited);
+ return sqd;
+}
+
+#if defined(CONFIG_UNIX)
+/*
+ * Ensure the UNIX gc is aware of our file set, so we are certain that
+ * the io_uring can be safely unregistered on process exit, even if we have
+ * loops in the file referencing.
+ */
+static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
+{
+ struct sock *sk = ctx->ring_sock->sk;
+ struct scm_fp_list *fpl;
+ struct sk_buff *skb;
+ int i, nr_files;
+
+ fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
+ if (!fpl)
+ return -ENOMEM;
+
+ skb = alloc_skb(0, GFP_KERNEL);
+ if (!skb) {
+ kfree(fpl);
+ return -ENOMEM;
+ }
+
+ skb->sk = sk;
+ skb->scm_io_uring = 1;
+
+ nr_files = 0;
+ fpl->user = get_uid(current_user());
+ for (i = 0; i < nr; i++) {
+ struct file *file = io_file_from_index(ctx, i + offset);
+
+ if (!file)
+ continue;
+ fpl->fp[nr_files] = get_file(file);
+ unix_inflight(fpl->user, fpl->fp[nr_files]);
+ nr_files++;
+ }
+
+ if (nr_files) {
+ fpl->max = SCM_MAX_FD;
+ fpl->count = nr_files;
+ UNIXCB(skb).fp = fpl;
+ skb->destructor = unix_destruct_scm;
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
+ skb_queue_head(&sk->sk_receive_queue, skb);
+
+ for (i = 0; i < nr; i++) {
+ struct file *file = io_file_from_index(ctx, i + offset);
+
+ if (file)
+ fput(file);
+ }
+ } else {
+ kfree_skb(skb);
+ free_uid(fpl->user);
+ kfree(fpl);
+ }
+
+ return 0;
+}
+
+/*
+ * If UNIX sockets are enabled, fd passing can cause a reference cycle which
+ * causes regular reference counting to break down. We rely on the UNIX
+ * garbage collection to take care of this problem for us.
+ */
+static int io_sqe_files_scm(struct io_ring_ctx *ctx)
+{
+ unsigned left, total;
+ int ret = 0;
+
+ total = 0;
+ left = ctx->nr_user_files;
+ while (left) {
+ unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
+
+ ret = __io_sqe_files_scm(ctx, this_files, total);
+ if (ret)
+ break;
+ left -= this_files;
+ total += this_files;
+ }
+
+ if (!ret)
+ return 0;
+
+ while (total < ctx->nr_user_files) {
+ struct file *file = io_file_from_index(ctx, total);
+
+ if (file)
+ fput(file);
+ total++;
+ }
+
+ return ret;
+}
+#else
+static int io_sqe_files_scm(struct io_ring_ctx *ctx)
+{
+ return 0;
+}
+#endif
+
+static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+ struct file *file = prsrc->file;
+#if defined(CONFIG_UNIX)
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff_head list, *head = &sock->sk_receive_queue;
+ struct sk_buff *skb;
+ int i;
+
+ __skb_queue_head_init(&list);
+
+ /*
+ * Find the skb that holds this file in its SCM_RIGHTS. When found,
+ * remove this entry and rearrange the file array.
+ */
+ skb = skb_dequeue(head);
+ while (skb) {
+ struct scm_fp_list *fp;
+
+ fp = UNIXCB(skb).fp;
+ for (i = 0; i < fp->count; i++) {
+ int left;
+
+ if (fp->fp[i] != file)
+ continue;
+
+ unix_notinflight(fp->user, fp->fp[i]);
+ left = fp->count - 1 - i;
+ if (left) {
+ memmove(&fp->fp[i], &fp->fp[i + 1],
+ left * sizeof(struct file *));
+ }
+ fp->count--;
+ if (!fp->count) {
+ kfree_skb(skb);
+ skb = NULL;
+ } else {
+ __skb_queue_tail(&list, skb);
+ }
+ fput(file);
+ file = NULL;
+ break;
+ }
+
+ if (!file)
+ break;
+
+ __skb_queue_tail(&list, skb);
+
+ skb = skb_dequeue(head);
+ }
+
+ if (skb_peek(&list)) {
+ spin_lock_irq(&head->lock);
+ while ((skb = __skb_dequeue(&list)) != NULL)
+ __skb_queue_tail(head, skb);
+ spin_unlock_irq(&head->lock);
+ }
+#else
+ fput(file);
+#endif
+}
+
+static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
+{
+ struct io_rsrc_data *rsrc_data = ref_node->rsrc_data;
+ struct io_ring_ctx *ctx = rsrc_data->ctx;
+ struct io_rsrc_put *prsrc, *tmp;
+
+ list_for_each_entry_safe(prsrc, tmp, &ref_node->rsrc_list, list) {
+ list_del(&prsrc->list);
+
+ if (prsrc->tag) {
+ bool lock_ring = ctx->flags & IORING_SETUP_IOPOLL;
+
+ io_ring_submit_lock(ctx, lock_ring);
+ spin_lock(&ctx->completion_lock);
+ io_fill_cqe_aux(ctx, prsrc->tag, 0, 0);
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ io_cqring_ev_posted(ctx);
+ io_ring_submit_unlock(ctx, lock_ring);
+ }
+
+ rsrc_data->do_put(ctx, prsrc);
+ kfree(prsrc);
+ }
+
+ io_rsrc_node_destroy(ref_node);
+ if (atomic_dec_and_test(&rsrc_data->refs))
+ complete(&rsrc_data->done);
+}
+
+static void io_rsrc_put_work(struct work_struct *work)
+{
+ struct io_ring_ctx *ctx;
+ struct llist_node *node;
+
+ ctx = container_of(work, struct io_ring_ctx, rsrc_put_work.work);
+ node = llist_del_all(&ctx->rsrc_put_llist);
+
+ while (node) {
+ struct io_rsrc_node *ref_node;
+ struct llist_node *next = node->next;
+
+ ref_node = llist_entry(node, struct io_rsrc_node, llist);
+ __io_rsrc_put_work(ref_node);
+ node = next;
+ }
+}
+
+static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned nr_args, u64 __user *tags)
+{
+ __s32 __user *fds = (__s32 __user *) arg;
+ struct file *file;
+ int fd, ret;
+ unsigned i;
+
+ if (ctx->file_data)
+ return -EBUSY;
+ if (!nr_args)
+ return -EINVAL;
+ if (nr_args > IORING_MAX_FIXED_FILES)
+ return -EMFILE;
+ if (nr_args > rlimit(RLIMIT_NOFILE))
+ return -EMFILE;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ return ret;
+ ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args,
+ &ctx->file_data);
+ if (ret)
+ return ret;
+
+ ret = -ENOMEM;
+ if (!io_alloc_file_tables(&ctx->file_table, nr_args))
+ goto out_free;
+
+ for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
+ if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
+ ret = -EFAULT;
+ goto out_fput;
+ }
+ /* allow sparse sets */
+ if (fd == -1) {
+ ret = -EINVAL;
+ if (unlikely(*io_get_tag_slot(ctx->file_data, i)))
+ goto out_fput;
+ continue;
+ }
+
+ file = fget(fd);
+ ret = -EBADF;
+ if (unlikely(!file))
+ goto out_fput;
+
+ /*
+ * Don't allow io_uring instances to be registered. If UNIX
+ * isn't enabled, then this causes a reference cycle and this
+ * instance can never get freed. If UNIX is enabled we'll
+ * handle it just fine, but there's still no point in allowing
+ * a ring fd as it doesn't support regular read/write anyway.
+ */
+ if (file->f_op == &io_uring_fops) {
+ fput(file);
+ goto out_fput;
+ }
+ io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);
+ }
+
+ ret = io_sqe_files_scm(ctx);
+ if (ret) {
+ __io_sqe_files_unregister(ctx);
+ return ret;
+ }
+
+ io_rsrc_node_switch(ctx, NULL);
+ return ret;
+out_fput:
+ for (i = 0; i < ctx->nr_user_files; i++) {
+ file = io_file_from_index(ctx, i);
+ if (file)
+ fput(file);
+ }
+ io_free_file_tables(&ctx->file_table);
+ ctx->nr_user_files = 0;
+out_free:
+ io_rsrc_data_free(ctx->file_data);
+ ctx->file_data = NULL;
+ return ret;
+}
+
+static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
+ int index)
+{
+#if defined(CONFIG_UNIX)
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff_head *head = &sock->sk_receive_queue;
+ struct sk_buff *skb;
+
+ /*
+ * See if we can merge this file into an existing skb SCM_RIGHTS
+ * file set. If there's no room, fall back to allocating a new skb
+ * and filling it in.
+ */
+ spin_lock_irq(&head->lock);
+ skb = skb_peek(head);
+ if (skb) {
+ struct scm_fp_list *fpl = UNIXCB(skb).fp;
+
+ if (fpl->count < SCM_MAX_FD) {
+ __skb_unlink(skb, head);
+ spin_unlock_irq(&head->lock);
+ fpl->fp[fpl->count] = get_file(file);
+ unix_inflight(fpl->user, fpl->fp[fpl->count]);
+ fpl->count++;
+ spin_lock_irq(&head->lock);
+ __skb_queue_head(head, skb);
+ } else {
+ skb = NULL;
+ }
+ }
+ spin_unlock_irq(&head->lock);
+
+ if (skb) {
+ fput(file);
+ return 0;
+ }
+
+ return __io_sqe_files_scm(ctx, 1, index);
+#else
+ return 0;
+#endif
+}
+
+static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx,
+ struct io_rsrc_node *node, void *rsrc)
+{
+ u64 *tag_slot = io_get_tag_slot(data, idx);
+ struct io_rsrc_put *prsrc;
+
+ prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL);
+ if (!prsrc)
+ return -ENOMEM;
+
+ prsrc->tag = *tag_slot;
+ *tag_slot = 0;
+ prsrc->rsrc = rsrc;
+ list_add(&prsrc->list, &node->rsrc_list);
+ return 0;
+}
+
+static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
+ unsigned int issue_flags, u32 slot_index)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ bool needs_switch = false;
+ struct io_fixed_file *file_slot;
+ int ret = -EBADF;
+
+ io_ring_submit_lock(ctx, !force_nonblock);
+ if (file->f_op == &io_uring_fops)
+ goto err;
+ ret = -ENXIO;
+ if (!ctx->file_data)
+ goto err;
+ ret = -EINVAL;
+ if (slot_index >= ctx->nr_user_files)
+ goto err;
+
+ slot_index = array_index_nospec(slot_index, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, slot_index);
+
+ if (file_slot->file_ptr) {
+ struct file *old_file;
+
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ goto err;
+
+ old_file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ ret = io_queue_rsrc_removal(ctx->file_data, slot_index,
+ ctx->rsrc_node, old_file);
+ if (ret)
+ goto err;
+ file_slot->file_ptr = 0;
+ needs_switch = true;
+ }
+
+ *io_get_tag_slot(ctx->file_data, slot_index) = 0;
+ io_fixed_file_set(file_slot, file);
+ ret = io_sqe_file_register(ctx, file, slot_index);
+ if (ret) {
+ file_slot->file_ptr = 0;
+ goto err;
+ }
+
+ ret = 0;
+err:
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, ctx->file_data);
+ io_ring_submit_unlock(ctx, !force_nonblock);
+ if (ret)
+ fput(file);
+ return ret;
+}
+
+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags)
+{
+ unsigned int offset = req->close.file_slot - 1;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_fixed_file *file_slot;
+ struct file *file;
+ int ret;
+
+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ ret = -ENXIO;
+ if (unlikely(!ctx->file_data))
+ goto out;
+ ret = -EINVAL;
+ if (offset >= ctx->nr_user_files)
+ goto out;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ goto out;
+
+ offset = array_index_nospec(offset, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, offset);
+ ret = -EBADF;
+ if (!file_slot->file_ptr)
+ goto out;
+
+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file);
+ if (ret)
+ goto out;
+
+ file_slot->file_ptr = 0;
+ io_rsrc_node_switch(ctx, ctx->file_data);
+ ret = 0;
+out:
+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ return ret;
+}
+
+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args)
+{
+ u64 __user *tags = u64_to_user_ptr(up->tags);
+ __s32 __user *fds = u64_to_user_ptr(up->data);
+ struct io_rsrc_data *data = ctx->file_data;
+ struct io_fixed_file *file_slot;
+ struct file *file;
+ int fd, i, err = 0;
+ unsigned int done;
+ bool needs_switch = false;
+
+ if (!ctx->file_data)
+ return -ENXIO;
+ if (up->offset + nr_args > ctx->nr_user_files)
+ return -EINVAL;
+
+ for (done = 0; done < nr_args; done++) {
+ u64 tag = 0;
+
+ if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) ||
+ copy_from_user(&fd, &fds[done], sizeof(fd))) {
+ err = -EFAULT;
+ break;
+ }
+ if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) {
+ err = -EINVAL;
+ break;
+ }
+ if (fd == IORING_REGISTER_FILES_SKIP)
+ continue;
+
+ i = array_index_nospec(up->offset + done, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, i);
+
+ if (file_slot->file_ptr) {
+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ err = io_queue_rsrc_removal(data, i, ctx->rsrc_node, file);
+ if (err)
+ break;
+ file_slot->file_ptr = 0;
+ needs_switch = true;
+ }
+ if (fd != -1) {
+ file = fget(fd);
+ if (!file) {
+ err = -EBADF;
+ break;
+ }
+ /*
+ * Don't allow io_uring instances to be registered. If
+ * UNIX isn't enabled, then this causes a reference
+ * cycle and this instance can never get freed. If UNIX
+ * is enabled we'll handle it just fine, but there's
+ * still no point in allowing a ring fd as it doesn't
+ * support regular read/write anyway.
+ */
+ if (file->f_op == &io_uring_fops) {
+ fput(file);
+ err = -EBADF;
+ break;
+ }
+ *io_get_tag_slot(data, i) = tag;
+ io_fixed_file_set(file_slot, file);
+ err = io_sqe_file_register(ctx, file, i);
+ if (err) {
+ file_slot->file_ptr = 0;
+ fput(file);
+ break;
+ }
+ }
+ }
+
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, data);
+ return done ? done : err;
+}
+
+static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx,
+ struct task_struct *task)
+{
+ struct io_wq_hash *hash;
+ struct io_wq_data data;
+ unsigned int concurrency;
+
+ mutex_lock(&ctx->uring_lock);
+ hash = ctx->hash_map;
+ if (!hash) {
+ hash = kzalloc(sizeof(*hash), GFP_KERNEL);
+ if (!hash) {
+ mutex_unlock(&ctx->uring_lock);
+ return ERR_PTR(-ENOMEM);
+ }
+ refcount_set(&hash->refs, 1);
+ init_waitqueue_head(&hash->wait);
+ ctx->hash_map = hash;
+ }
+ mutex_unlock(&ctx->uring_lock);
+
+ data.hash = hash;
+ data.task = task;
+ data.free_work = io_wq_free_work;
+ data.do_work = io_wq_submit_work;
+
+ /* Do QD, or 4 * CPUS, whatever is smallest */
+ concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
+
+ return io_wq_create(concurrency, &data);
+}
+
+static int io_uring_alloc_task_context(struct task_struct *task,
+ struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx;
+ int ret;
+
+ tctx = kzalloc(sizeof(*tctx), GFP_KERNEL);
+ if (unlikely(!tctx))
+ return -ENOMEM;
+
+ ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
+ if (unlikely(ret)) {
+ kfree(tctx);
+ return ret;
+ }
+
+ tctx->io_wq = io_init_wq_offload(ctx, task);
+ if (IS_ERR(tctx->io_wq)) {
+ ret = PTR_ERR(tctx->io_wq);
+ percpu_counter_destroy(&tctx->inflight);
+ kfree(tctx);
+ return ret;
+ }
+
+ xa_init(&tctx->xa);
+ init_waitqueue_head(&tctx->wait);
+ atomic_set(&tctx->in_idle, 0);
+ atomic_set(&tctx->inflight_tracked, 0);
+ task->io_uring = tctx;
+ spin_lock_init(&tctx->task_lock);
+ INIT_WQ_LIST(&tctx->task_list);
+ init_task_work(&tctx->task_work, tctx_task_work);
+ return 0;
+}
+
+void __io_uring_free(struct task_struct *tsk)
+{
+ struct io_uring_task *tctx = tsk->io_uring;
+
+ WARN_ON_ONCE(!xa_empty(&tctx->xa));
+ WARN_ON_ONCE(tctx->io_wq);
+ WARN_ON_ONCE(tctx->cached_refs);
+
+ percpu_counter_destroy(&tctx->inflight);
+ kfree(tctx);
+ tsk->io_uring = NULL;
+}
+
+static int io_sq_offload_create(struct io_ring_ctx *ctx,
+ struct io_uring_params *p)
+{
+ int ret;
+
+ /* Retain compatibility with failing for an invalid attach attempt */
+ if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) ==
+ IORING_SETUP_ATTACH_WQ) {
+ struct fd f;
+
+ f = fdget(p->wq_fd);
+ if (!f.file)
+ return -ENXIO;
+ if (f.file->f_op != &io_uring_fops) {
+ fdput(f);
+ return -EINVAL;
+ }
+ fdput(f);
+ }
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ struct task_struct *tsk;
+ struct io_sq_data *sqd;
+ bool attached;
+
+ sqd = io_get_sq_data(p, &attached);
+ if (IS_ERR(sqd)) {
+ ret = PTR_ERR(sqd);
+ goto err;
+ }
+
+ ctx->sq_creds = get_current_cred();
+ ctx->sq_data = sqd;
+ ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
+ if (!ctx->sq_thread_idle)
+ ctx->sq_thread_idle = HZ;
+
+ io_sq_thread_park(sqd);
+ list_add(&ctx->sqd_list, &sqd->ctx_list);
+ io_sqd_update_thread_idle(sqd);
+ /* don't attach to a dying SQPOLL thread, would be racy */
+ ret = (attached && !sqd->thread) ? -ENXIO : 0;
+ io_sq_thread_unpark(sqd);
+
+ if (ret < 0)
+ goto err;
+ if (attached)
+ return 0;
+
+ if (p->flags & IORING_SETUP_SQ_AFF) {
+ int cpu = p->sq_thread_cpu;
+
+ ret = -EINVAL;
+ if (cpu >= nr_cpu_ids || !cpu_online(cpu))
+ goto err_sqpoll;
+ sqd->sq_cpu = cpu;
+ } else {
+ sqd->sq_cpu = -1;
+ }
+
+ sqd->task_pid = current->pid;
+ sqd->task_tgid = current->tgid;
+ tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE);
+ if (IS_ERR(tsk)) {
+ ret = PTR_ERR(tsk);
+ goto err_sqpoll;
+ }
+
+ sqd->thread = tsk;
+ ret = io_uring_alloc_task_context(tsk, ctx);
+ wake_up_new_task(tsk);
+ if (ret)
+ goto err;
+ } else if (p->flags & IORING_SETUP_SQ_AFF) {
+ /* Can't have SQ_AFF without SQPOLL */
+ ret = -EINVAL;
+ goto err;
+ }
+
+ return 0;
+err_sqpoll:
+ complete(&ctx->sq_data->exited);
+err:
+ io_sq_thread_finish(ctx);
+ return ret;
+}
+
+static inline void __io_unaccount_mem(struct user_struct *user,
+ unsigned long nr_pages)
+{
+ atomic_long_sub(nr_pages, &user->locked_vm);
+}
+
+static inline int __io_account_mem(struct user_struct *user,
+ unsigned long nr_pages)
+{
+ unsigned long page_limit, cur_pages, new_pages;
+
+ /* Don't allow more pages than we can safely lock */
+ page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+ do {
+ cur_pages = atomic_long_read(&user->locked_vm);
+ new_pages = cur_pages + nr_pages;
+ if (new_pages > page_limit)
+ return -ENOMEM;
+ } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
+ new_pages) != cur_pages);
+
+ return 0;
+}
+
+static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
+{
+ if (ctx->user)
+ __io_unaccount_mem(ctx->user, nr_pages);
+
+ if (ctx->mm_account)
+ atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
+}
+
+static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
+{
+ int ret;
+
+ if (ctx->user) {
+ ret = __io_account_mem(ctx->user, nr_pages);
+ if (ret)
+ return ret;
+ }
+
+ if (ctx->mm_account)
+ atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
+
+ return 0;
+}
+
+static void io_mem_free(void *ptr)
+{
+ struct page *page;
+
+ if (!ptr)
+ return;
+
+ page = virt_to_head_page(ptr);
+ if (put_page_testzero(page))
+ free_compound_page(page);
+}
+
+static void *io_mem_alloc(size_t size)
+{
+ gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP;
+
+ return (void *) __get_free_pages(gfp, get_order(size));
+}
+
+static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
+ size_t *sq_offset)
+{
+ struct io_rings *rings;
+ size_t off, sq_array_size;
+
+ off = struct_size(rings, cqes, cq_entries);
+ if (off == SIZE_MAX)
+ return SIZE_MAX;
+
+#ifdef CONFIG_SMP
+ off = ALIGN(off, SMP_CACHE_BYTES);
+ if (off == 0)
+ return SIZE_MAX;
+#endif
+
+ if (sq_offset)
+ *sq_offset = off;
+
+ sq_array_size = array_size(sizeof(u32), sq_entries);
+ if (sq_array_size == SIZE_MAX)
+ return SIZE_MAX;
+
+ if (check_add_overflow(off, sq_array_size, &off))
+ return SIZE_MAX;
+
+ return off;
+}
+
+static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slot)
+{
+ struct io_mapped_ubuf *imu = *slot;
+ unsigned int i;
+
+ if (imu != ctx->dummy_ubuf) {
+ for (i = 0; i < imu->nr_bvecs; i++)
+ unpin_user_page(imu->bvec[i].bv_page);
+ if (imu->acct_pages)
+ io_unaccount_mem(ctx, imu->acct_pages);
+ kvfree(imu);
+ }
+ *slot = NULL;
+}
+
+static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+ io_buffer_unmap(ctx, &prsrc->buf);
+ prsrc->buf = NULL;
+}
+
+static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned int i;
+
+ for (i = 0; i < ctx->nr_user_bufs; i++)
+ io_buffer_unmap(ctx, &ctx->user_bufs[i]);
+ kfree(ctx->user_bufs);
+ io_rsrc_data_free(ctx->buf_data);
+ ctx->user_bufs = NULL;
+ ctx->buf_data = NULL;
+ ctx->nr_user_bufs = 0;
+}
+
+static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned nr = ctx->nr_user_bufs;
+ int ret;
+
+ if (!ctx->buf_data)
+ return -ENXIO;
+
+ /*
+ * Quiesce may unlock ->uring_lock, and while it's not held
+ * prevent new requests using the table.
+ */
+ ctx->nr_user_bufs = 0;
+ ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx);
+ ctx->nr_user_bufs = nr;
+ if (!ret)
+ __io_sqe_buffers_unregister(ctx);
+ return ret;
+}
+
+static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
+ void __user *arg, unsigned index)
+{
+ struct iovec __user *src;
+
+#ifdef CONFIG_COMPAT
+ if (ctx->compat) {
+ struct compat_iovec __user *ciovs;
+ struct compat_iovec ciov;
+
+ ciovs = (struct compat_iovec __user *) arg;
+ if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
+ return -EFAULT;
+
+ dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
+ dst->iov_len = ciov.iov_len;
+ return 0;
+ }
+#endif
+ src = (struct iovec __user *) arg;
+ if (copy_from_user(dst, &src[index], sizeof(*dst)))
+ return -EFAULT;
+ return 0;
+}
+
+/*
+ * Not super efficient, but this is just a registration time. And we do cache
+ * the last compound head, so generally we'll only do a full search if we don't
+ * match that one.
+ *
+ * We check if the given compound head page has already been accounted, to
+ * avoid double accounting it. This allows us to account the full size of the
+ * page, not just the constituent pages of a huge page.
+ */
+static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
+ int nr_pages, struct page *hpage)
+{
+ int i, j;
+
+ /* check current page array */
+ for (i = 0; i < nr_pages; i++) {
+ if (!PageCompound(pages[i]))
+ continue;
+ if (compound_head(pages[i]) == hpage)
+ return true;
+ }
+
+ /* check previously registered pages */
+ for (i = 0; i < ctx->nr_user_bufs; i++) {
+ struct io_mapped_ubuf *imu = ctx->user_bufs[i];
+
+ for (j = 0; j < imu->nr_bvecs; j++) {
+ if (!PageCompound(imu->bvec[j].bv_page))
+ continue;
+ if (compound_head(imu->bvec[j].bv_page) == hpage)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
+ int nr_pages, struct io_mapped_ubuf *imu,
+ struct page **last_hpage)
+{
+ int i, ret;
+
+ imu->acct_pages = 0;
+ for (i = 0; i < nr_pages; i++) {
+ if (!PageCompound(pages[i])) {
+ imu->acct_pages++;
+ } else {
+ struct page *hpage;
+
+ hpage = compound_head(pages[i]);
+ if (hpage == *last_hpage)
+ continue;
+ *last_hpage = hpage;
+ if (headpage_already_acct(ctx, pages, i, hpage))
+ continue;
+ imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
+ }
+ }
+
+ if (!imu->acct_pages)
+ return 0;
+
+ ret = io_account_mem(ctx, imu->acct_pages);
+ if (ret)
+ imu->acct_pages = 0;
+ return ret;
+}
+
+static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
+ struct io_mapped_ubuf **pimu,
+ struct page **last_hpage)
+{
+ struct io_mapped_ubuf *imu = NULL;
+ struct vm_area_struct **vmas = NULL;
+ struct page **pages = NULL;
+ unsigned long off, start, end, ubuf;
+ size_t size;
+ int ret, pret, nr_pages, i;
+
+ if (!iov->iov_base) {
+ *pimu = ctx->dummy_ubuf;
+ return 0;
+ }
+
+ ubuf = (unsigned long) iov->iov_base;
+ end = (ubuf + iov->iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ start = ubuf >> PAGE_SHIFT;
+ nr_pages = end - start;
+
+ *pimu = NULL;
+ ret = -ENOMEM;
+
+ pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!pages)
+ goto done;
+
+ vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
+ GFP_KERNEL);
+ if (!vmas)
+ goto done;
+
+ imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL);
+ if (!imu)
+ goto done;
+
+ ret = 0;
+ mmap_read_lock(current->mm);
+ pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
+ pages, vmas);
+ if (pret == nr_pages) {
+ /* don't support file backed memory */
+ for (i = 0; i < nr_pages; i++) {
+ struct vm_area_struct *vma = vmas[i];
+
+ if (vma_is_shmem(vma))
+ continue;
+ if (vma->vm_file &&
+ !is_file_hugepages(vma->vm_file)) {
+ ret = -EOPNOTSUPP;
+ break;
+ }
+ }
+ } else {
+ ret = pret < 0 ? pret : -EFAULT;
+ }
+ mmap_read_unlock(current->mm);
+ if (ret) {
+ /*
+ * if we did partial map, or found file backed vmas,
+ * release any pages we did get
+ */
+ if (pret > 0)
+ unpin_user_pages(pages, pret);
+ goto done;
+ }
+
+ ret = io_buffer_account_pin(ctx, pages, pret, imu, last_hpage);
+ if (ret) {
+ unpin_user_pages(pages, pret);
+ goto done;
+ }
+
+ off = ubuf & ~PAGE_MASK;
+ size = iov->iov_len;
+ for (i = 0; i < nr_pages; i++) {
+ size_t vec_len;
+
+ vec_len = min_t(size_t, size, PAGE_SIZE - off);
+ imu->bvec[i].bv_page = pages[i];
+ imu->bvec[i].bv_len = vec_len;
+ imu->bvec[i].bv_offset = off;
+ off = 0;
+ size -= vec_len;
+ }
+ /* store original address for later verification */
+ imu->ubuf = ubuf;
+ imu->ubuf_end = ubuf + iov->iov_len;
+ imu->nr_bvecs = nr_pages;
+ *pimu = imu;
+ ret = 0;
+done:
+ if (ret)
+ kvfree(imu);
+ kvfree(pages);
+ kvfree(vmas);
+ return ret;
+}
+
+static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args)
+{
+ ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL);
+ return ctx->user_bufs ? 0 : -ENOMEM;
+}
+
+static int io_buffer_validate(struct iovec *iov)
+{
+ unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1);
+
+ /*
+ * Don't impose further limits on the size and buffer
+ * constraints here, we'll -EINVAL later when IO is
+ * submitted if they are wrong.
+ */
+ if (!iov->iov_base)
+ return iov->iov_len ? -EFAULT : 0;
+ if (!iov->iov_len)
+ return -EFAULT;
+
+ /* arbitrary limit, but we need something */
+ if (iov->iov_len > SZ_1G)
+ return -EFAULT;
+
+ if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp))
+ return -EOVERFLOW;
+
+ return 0;
+}
+
+static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int nr_args, u64 __user *tags)
+{
+ struct page *last_hpage = NULL;
+ struct io_rsrc_data *data;
+ int i, ret;
+ struct iovec iov;
+
+ if (ctx->user_bufs)
+ return -EBUSY;
+ if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS)
+ return -EINVAL;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ return ret;
+ ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data);
+ if (ret)
+ return ret;
+ ret = io_buffers_map_alloc(ctx, nr_args);
+ if (ret) {
+ io_rsrc_data_free(data);
+ return ret;
+ }
+
+ for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
+ ret = io_copy_iov(ctx, &iov, arg, i);
+ if (ret)
+ break;
+ ret = io_buffer_validate(&iov);
+ if (ret)
+ break;
+ if (!iov.iov_base && *io_get_tag_slot(data, i)) {
+ ret = -EINVAL;
+ break;
+ }
+
+ ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
+ &last_hpage);
+ if (ret)
+ break;
+ }
+
+ WARN_ON_ONCE(ctx->buf_data);
+
+ ctx->buf_data = data;
+ if (ret)
+ __io_sqe_buffers_unregister(ctx);
+ else
+ io_rsrc_node_switch(ctx, NULL);
+ return ret;
+}
+
+static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
+ struct io_uring_rsrc_update2 *up,
+ unsigned int nr_args)
+{
+ u64 __user *tags = u64_to_user_ptr(up->tags);
+ struct iovec iov, __user *iovs = u64_to_user_ptr(up->data);
+ struct page *last_hpage = NULL;
+ bool needs_switch = false;
+ __u32 done;
+ int i, err;
+
+ if (!ctx->buf_data)
+ return -ENXIO;
+ if (up->offset + nr_args > ctx->nr_user_bufs)
+ return -EINVAL;
+
+ for (done = 0; done < nr_args; done++) {
+ struct io_mapped_ubuf *imu;
+ int offset = up->offset + done;
+ u64 tag = 0;
+
+ err = io_copy_iov(ctx, &iov, iovs, done);
+ if (err)
+ break;
+ if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) {
+ err = -EFAULT;
+ break;
+ }
+ err = io_buffer_validate(&iov);
+ if (err)
+ break;
+ if (!iov.iov_base && tag) {
+ err = -EINVAL;
+ break;
+ }
+ err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
+ if (err)
+ break;
+
+ i = array_index_nospec(offset, ctx->nr_user_bufs);
+ if (ctx->user_bufs[i] != ctx->dummy_ubuf) {
+ err = io_queue_rsrc_removal(ctx->buf_data, i,
+ ctx->rsrc_node, ctx->user_bufs[i]);
+ if (unlikely(err)) {
+ io_buffer_unmap(ctx, &imu);
+ break;
+ }
+ ctx->user_bufs[i] = NULL;
+ needs_switch = true;
+ }
+
+ ctx->user_bufs[i] = imu;
+ *io_get_tag_slot(ctx->buf_data, offset) = tag;
+ }
+
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, ctx->buf_data);
+ return done ? done : err;
+}
+
+static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
+{
+ __s32 __user *fds = arg;
+ int fd;
+
+ if (ctx->cq_ev_fd)
+ return -EBUSY;
+
+ if (copy_from_user(&fd, fds, sizeof(*fds)))
+ return -EFAULT;
+
+ ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
+ if (IS_ERR(ctx->cq_ev_fd)) {
+ int ret = PTR_ERR(ctx->cq_ev_fd);
+
+ ctx->cq_ev_fd = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
+static int io_eventfd_unregister(struct io_ring_ctx *ctx)
+{
+ if (ctx->cq_ev_fd) {
+ eventfd_ctx_put(ctx->cq_ev_fd);
+ ctx->cq_ev_fd = NULL;
+ return 0;
+ }
+
+ return -ENXIO;
+}
+
+static void io_destroy_buffers(struct io_ring_ctx *ctx)
+{
+ struct io_buffer *buf;
+ unsigned long index;
+
+ xa_for_each(&ctx->io_buffers, index, buf)
+ __io_remove_buffers(ctx, buf, index, -1U);
+}
+
+static void io_req_cache_free(struct list_head *list)
+{
+ struct io_kiocb *req, *nxt;
+
+ list_for_each_entry_safe(req, nxt, list, inflight_entry) {
+ list_del(&req->inflight_entry);
+ kmem_cache_free(req_cachep, req);
+ }
+}
+
+static void io_req_caches_free(struct io_ring_ctx *ctx)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+
+ mutex_lock(&ctx->uring_lock);
+
+ if (state->free_reqs) {
+ kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
+ state->free_reqs = 0;
+ }
+
+ io_flush_cached_locked_reqs(ctx, state);
+ io_req_cache_free(&state->free_list);
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_wait_rsrc_data(struct io_rsrc_data *data)
+{
+ if (data && !atomic_dec_and_test(&data->refs))
+ wait_for_completion(&data->done);
+}
+
+static void io_ring_ctx_free(struct io_ring_ctx *ctx)
+{
+ io_sq_thread_finish(ctx);
+
+ /* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */
+ io_wait_rsrc_data(ctx->buf_data);
+ io_wait_rsrc_data(ctx->file_data);
+
+ mutex_lock(&ctx->uring_lock);
+ if (ctx->buf_data)
+ __io_sqe_buffers_unregister(ctx);
+ if (ctx->file_data)
+ __io_sqe_files_unregister(ctx);
+ if (ctx->rings)
+ __io_cqring_overflow_flush(ctx, true);
+ mutex_unlock(&ctx->uring_lock);
+ io_eventfd_unregister(ctx);
+ io_destroy_buffers(ctx);
+ if (ctx->sq_creds)
+ put_cred(ctx->sq_creds);
+
+ /* there are no registered resources left, nobody uses it */
+ if (ctx->rsrc_node)
+ io_rsrc_node_destroy(ctx->rsrc_node);
+ if (ctx->rsrc_backup_node)
+ io_rsrc_node_destroy(ctx->rsrc_backup_node);
+ flush_delayed_work(&ctx->rsrc_put_work);
+
+ WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
+ WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));
+
+#if defined(CONFIG_UNIX)
+ if (ctx->ring_sock) {
+ ctx->ring_sock->file = NULL; /* so that iput() is called */
+ sock_release(ctx->ring_sock);
+ }
+#endif
+ WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
+
+ if (ctx->mm_account) {
+ mmdrop(ctx->mm_account);
+ ctx->mm_account = NULL;
+ }
+
+ io_mem_free(ctx->rings);
+ io_mem_free(ctx->sq_sqes);
+
+ percpu_ref_exit(&ctx->refs);
+ free_uid(ctx->user);
+ io_req_caches_free(ctx);
+ if (ctx->hash_map)
+ io_wq_put_hash(ctx->hash_map);
+ kfree(ctx->cancel_hash);
+ kfree(ctx->dummy_ubuf);
+ kfree(ctx);
+}
+
+static __poll_t io_uring_poll(struct file *file, poll_table *wait)
+{
+ struct io_ring_ctx *ctx = file->private_data;
+ __poll_t mask = 0;
+
+ poll_wait(file, &ctx->poll_wait, wait);
+ /*
+ * synchronizes with barrier from wq_has_sleeper call in
+ * io_commit_cqring
+ */
+ smp_rmb();
+ if (!io_sqring_full(ctx))
+ mask |= EPOLLOUT | EPOLLWRNORM;
+
+ /*
+ * Don't flush cqring overflow list here, just do a simple check.
+ * Otherwise there could possible be ABBA deadlock:
+ * CPU0 CPU1
+ * ---- ----
+ * lock(&ctx->uring_lock);
+ * lock(&ep->mtx);
+ * lock(&ctx->uring_lock);
+ * lock(&ep->mtx);
+ *
+ * Users may get EPOLLIN meanwhile seeing nothing in cqring, this
+ * pushs them to do the flush.
+ */
+ if (io_cqring_events(ctx) || test_bit(0, &ctx->check_cq_overflow))
+ mask |= EPOLLIN | EPOLLRDNORM;
+
+ return mask;
+}
+
+static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
+{
+ const struct cred *creds;
+
+ creds = xa_erase(&ctx->personalities, id);
+ if (creds) {
+ put_cred(creds);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+struct io_tctx_exit {
+ struct callback_head task_work;
+ struct completion completion;
+ struct io_ring_ctx *ctx;
+};
+
+static void io_tctx_exit_cb(struct callback_head *cb)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_exit *work;
+
+ work = container_of(cb, struct io_tctx_exit, task_work);
+ /*
+ * When @in_idle, we're in cancellation and it's racy to remove the
+ * node. It'll be removed by the end of cancellation, just ignore it.
+ * tctx can be NULL if the queueing of this task_work raced with
+ * work cancelation off the exec path.
+ */
+ if (tctx && !atomic_read(&tctx->in_idle))
+ io_uring_del_tctx_node((unsigned long)work->ctx);
+ complete(&work->completion);
+}
+
+static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+
+ return req->ctx == data;
+}
+
+static void io_ring_exit_work(struct work_struct *work)
+{
+ struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work);
+ unsigned long timeout = jiffies + HZ * 60 * 5;
+ unsigned long interval = HZ / 20;
+ struct io_tctx_exit exit;
+ struct io_tctx_node *node;
+ int ret;
+
+ /*
+ * If we're doing polled IO and end up having requests being
+ * submitted async (out-of-line), then completions can come in while
+ * we're waiting for refs to drop. We need to reap these manually,
+ * as nobody else will be looking for them.
+ */
+ do {
+ io_uring_try_cancel_requests(ctx, NULL, true);
+ if (ctx->sq_data) {
+ struct io_sq_data *sqd = ctx->sq_data;
+ struct task_struct *tsk;
+
+ io_sq_thread_park(sqd);
+ tsk = sqd->thread;
+ if (tsk && tsk->io_uring && tsk->io_uring->io_wq)
+ io_wq_cancel_cb(tsk->io_uring->io_wq,
+ io_cancel_ctx_cb, ctx, true);
+ io_sq_thread_unpark(sqd);
+ }
+
+ if (WARN_ON_ONCE(time_after(jiffies, timeout))) {
+ /* there is little hope left, don't run it too often */
+ interval = HZ * 60;
+ }
+ } while (!wait_for_completion_timeout(&ctx->ref_comp, interval));
+
+ init_completion(&exit.completion);
+ init_task_work(&exit.task_work, io_tctx_exit_cb);
+ exit.ctx = ctx;
+ /*
+ * Some may use context even when all refs and requests have been put,
+ * and they are free to do so while still holding uring_lock or
+ * completion_lock, see io_req_task_submit(). Apart from other work,
+ * this lock/unlock section also waits them to finish.
+ */
+ mutex_lock(&ctx->uring_lock);
+ while (!list_empty(&ctx->tctx_list)) {
+ WARN_ON_ONCE(time_after(jiffies, timeout));
+
+ node = list_first_entry(&ctx->tctx_list, struct io_tctx_node,
+ ctx_node);
+ /* don't spin on a single task if cancellation failed */
+ list_rotate_left(&ctx->tctx_list);
+ ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL);
+ if (WARN_ON_ONCE(ret))
+ continue;
+ wake_up_process(node->task);
+
+ mutex_unlock(&ctx->uring_lock);
+ wait_for_completion(&exit.completion);
+ mutex_lock(&ctx->uring_lock);
+ }
+ mutex_unlock(&ctx->uring_lock);
+ spin_lock(&ctx->completion_lock);
+ spin_unlock(&ctx->completion_lock);
+
+ io_ring_ctx_free(ctx);
+}
+
+/* Returns true if we found and killed one or more timeouts */
+static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
+ bool cancel_all)
+{
+ struct io_kiocb *req, *tmp;
+ int canceled = 0;
+
+ spin_lock(&ctx->completion_lock);
+ spin_lock_irq(&ctx->timeout_lock);
+ list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
+ if (io_match_task(req, tsk, cancel_all)) {
+ io_kill_timeout(req, -ECANCELED);
+ canceled++;
+ }
+ }
+ spin_unlock_irq(&ctx->timeout_lock);
+ if (canceled != 0)
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (canceled != 0)
+ io_cqring_ev_posted(ctx);
+ return canceled != 0;
+}
+
+static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
+{
+ unsigned long index;
+ struct creds *creds;
+
+ mutex_lock(&ctx->uring_lock);
+ percpu_ref_kill(&ctx->refs);
+ if (ctx->rings)
+ __io_cqring_overflow_flush(ctx, true);
+ xa_for_each(&ctx->personalities, index, creds)
+ io_unregister_personality(ctx, index);
+ mutex_unlock(&ctx->uring_lock);
+
+ io_kill_timeouts(ctx, NULL, true);
+ io_poll_remove_all(ctx, NULL, true);
+
+ /* if we failed setting up the ctx, we might not have any rings */
+ io_iopoll_try_reap_events(ctx);
+
+ INIT_WORK(&ctx->exit_work, io_ring_exit_work);
+ /*
+ * Use system_unbound_wq to avoid spawning tons of event kworkers
+ * if we're exiting a ton of rings at the same time. It just adds
+ * noise and overhead, there's no discernable change in runtime
+ * over using system_wq.
+ */
+ queue_work(system_unbound_wq, &ctx->exit_work);
+}
+
+static int io_uring_release(struct inode *inode, struct file *file)
+{
+ struct io_ring_ctx *ctx = file->private_data;
+
+ file->private_data = NULL;
+ io_ring_ctx_wait_and_kill(ctx);
+ return 0;
+}
+
+struct io_task_cancel {
+ struct task_struct *task;
+ bool all;
+};
+
+static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+ struct io_task_cancel *cancel = data;
+
+ return io_match_task_safe(req, cancel->task, cancel->all);
+}
+
+static bool io_cancel_defer_files(struct io_ring_ctx *ctx,
+ struct task_struct *task, bool cancel_all)
+{
+ struct io_defer_entry *de;
+ LIST_HEAD(list);
+
+ spin_lock(&ctx->completion_lock);
+ list_for_each_entry_reverse(de, &ctx->defer_list, list) {
+ if (io_match_task_safe(de->req, task, cancel_all)) {
+ list_cut_position(&list, &ctx->defer_list, &de->list);
+ break;
+ }
+ }
+ spin_unlock(&ctx->completion_lock);
+ if (list_empty(&list))
+ return false;
+
+ while (!list_empty(&list)) {
+ de = list_first_entry(&list, struct io_defer_entry, list);
+ list_del_init(&de->list);
+ io_req_complete_failed(de->req, -ECANCELED);
+ kfree(de);
+ }
+ return true;
+}
+
+static bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)
+{
+ struct io_tctx_node *node;
+ enum io_wq_cancel cret;
+ bool ret = false;
+
+ mutex_lock(&ctx->uring_lock);
+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
+ struct io_uring_task *tctx = node->task->io_uring;
+
+ /*
+ * io_wq will stay alive while we hold uring_lock, because it's
+ * killed after ctx nodes, which requires to take the lock.
+ */
+ if (!tctx || !tctx->io_wq)
+ continue;
+ cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true);
+ ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
+ }
+ mutex_unlock(&ctx->uring_lock);
+
+ return ret;
+}
+
+static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
+ struct task_struct *task,
+ bool cancel_all)
+{
+ struct io_task_cancel cancel = { .task = task, .all = cancel_all, };
+ struct io_uring_task *tctx = task ? task->io_uring : NULL;
+
+ while (1) {
+ enum io_wq_cancel cret;
+ bool ret = false;
+
+ if (!task) {
+ ret |= io_uring_try_cancel_iowq(ctx);
+ } else if (tctx && tctx->io_wq) {
+ /*
+ * Cancels requests of all rings, not only @ctx, but
+ * it's fine as the task is in exit/exec.
+ */
+ cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb,
+ &cancel, true);
+ ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
+ }
+
+ /* SQPOLL thread does its own polling */
+ if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) ||
+ (ctx->sq_data && ctx->sq_data->thread == current)) {
+ while (!list_empty_careful(&ctx->iopoll_list)) {
+ io_iopoll_try_reap_events(ctx);
+ ret = true;
+ }
+ }
+
+ ret |= io_cancel_defer_files(ctx, task, cancel_all);
+ ret |= io_poll_remove_all(ctx, task, cancel_all);
+ ret |= io_kill_timeouts(ctx, task, cancel_all);
+ if (task)
+ ret |= io_run_task_work();
+ if (!ret)
+ break;
+ cond_resched();
+ }
+}
+
+static int __io_uring_add_tctx_node(struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_node *node;
+ int ret;
+
+ if (unlikely(!tctx)) {
+ ret = io_uring_alloc_task_context(current, ctx);
+ if (unlikely(ret))
+ return ret;
+
+ tctx = current->io_uring;
+ if (ctx->iowq_limits_set) {
+ unsigned int limits[2] = { ctx->iowq_limits[0],
+ ctx->iowq_limits[1], };
+
+ ret = io_wq_max_workers(tctx->io_wq, limits);
+ if (ret)
+ return ret;
+ }
+ }
+ if (!xa_load(&tctx->xa, (unsigned long)ctx)) {
+ node = kmalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return -ENOMEM;
+ node->ctx = ctx;
+ node->task = current;
+
+ ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx,
+ node, GFP_KERNEL));
+ if (ret) {
+ kfree(node);
+ return ret;
+ }
+
+ mutex_lock(&ctx->uring_lock);
+ list_add(&node->ctx_node, &ctx->tctx_list);
+ mutex_unlock(&ctx->uring_lock);
+ }
+ tctx->last = ctx;
+ return 0;
+}
+
+/*
+ * Note that this task has used io_uring. We use it for cancelation purposes.
+ */
+static inline int io_uring_add_tctx_node(struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ if (likely(tctx && tctx->last == ctx))
+ return 0;
+ return __io_uring_add_tctx_node(ctx);
+}
+
+/*
+ * Remove this io_uring_file -> task mapping.
+ */
+static void io_uring_del_tctx_node(unsigned long index)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_node *node;
+
+ if (!tctx)
+ return;
+ node = xa_erase(&tctx->xa, index);
+ if (!node)
+ return;
+
+ WARN_ON_ONCE(current != node->task);
+ WARN_ON_ONCE(list_empty(&node->ctx_node));
+
+ mutex_lock(&node->ctx->uring_lock);
+ list_del(&node->ctx_node);
+ mutex_unlock(&node->ctx->uring_lock);
+
+ if (tctx->last == node->ctx)
+ tctx->last = NULL;
+ kfree(node);
+}
+
+static void io_uring_clean_tctx(struct io_uring_task *tctx)
+{
+ struct io_wq *wq = tctx->io_wq;
+ struct io_tctx_node *node;
+ unsigned long index;
+
+ xa_for_each(&tctx->xa, index, node) {
+ io_uring_del_tctx_node(index);
+ cond_resched();
+ }
+ if (wq) {
+ /*
+ * Must be after io_uring_del_task_file() (removes nodes under
+ * uring_lock) to avoid race with io_uring_try_cancel_iowq().
+ */
+ io_wq_put_and_exit(wq);
+ tctx->io_wq = NULL;
+ }
+}
+
+static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked)
+{
+ if (tracked)
+ return atomic_read(&tctx->inflight_tracked);
+ return percpu_counter_sum(&tctx->inflight);
+}
+
+/*
+ * Find any io_uring ctx that this task has registered or done IO on, and cancel
+ * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation.
+ */
+static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_ring_ctx *ctx;
+ s64 inflight;
+ DEFINE_WAIT(wait);
+
+ WARN_ON_ONCE(sqd && sqd->thread != current);
+
+ if (!current->io_uring)
+ return;
+ if (tctx->io_wq)
+ io_wq_exit_start(tctx->io_wq);
+
+ atomic_inc(&tctx->in_idle);
+ do {
+ io_uring_drop_tctx_refs(current);
+ /* read completions before cancelations */
+ inflight = tctx_inflight(tctx, !cancel_all);
+ if (!inflight)
+ break;
+
+ if (!sqd) {
+ struct io_tctx_node *node;
+ unsigned long index;
+
+ xa_for_each(&tctx->xa, index, node) {
+ /* sqpoll task will cancel all its requests */
+ if (node->ctx->sq_data)
+ continue;
+ io_uring_try_cancel_requests(node->ctx, current,
+ cancel_all);
+ }
+ } else {
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ io_uring_try_cancel_requests(ctx, current,
+ cancel_all);
+ }
+
+ prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE);
+ io_run_task_work();
+ io_uring_drop_tctx_refs(current);
+
+ /*
+ * If we've seen completions, retry without waiting. This
+ * avoids a race where a completion comes in before we did
+ * prepare_to_wait().
+ */
+ if (inflight == tctx_inflight(tctx, !cancel_all))
+ schedule();
+ finish_wait(&tctx->wait, &wait);
+ } while (1);
+
+ io_uring_clean_tctx(tctx);
+ if (cancel_all) {
+ /*
+ * We shouldn't run task_works after cancel, so just leave
+ * ->in_idle set for normal exit.
+ */
+ atomic_dec(&tctx->in_idle);
+ /* for exec all current's requests should be gone, kill tctx */
+ __io_uring_free(current);
+ }
+}
+
+void __io_uring_cancel(bool cancel_all)
+{
+ io_uring_cancel_generic(cancel_all, NULL);
+}
+
+static void *io_uring_validate_mmap_request(struct file *file,
+ loff_t pgoff, size_t sz)
+{
+ struct io_ring_ctx *ctx = file->private_data;
+ loff_t offset = pgoff << PAGE_SHIFT;
+ struct page *page;
+ void *ptr;
+
+ switch (offset) {
+ case IORING_OFF_SQ_RING:
+ case IORING_OFF_CQ_RING:
+ ptr = ctx->rings;
+ break;
+ case IORING_OFF_SQES:
+ ptr = ctx->sq_sqes;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ page = virt_to_head_page(ptr);
+ if (sz > page_size(page))
+ return ERR_PTR(-EINVAL);
+
+ return ptr;
+}
+
+#ifdef CONFIG_MMU
+
+static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ size_t sz = vma->vm_end - vma->vm_start;
+ unsigned long pfn;
+ void *ptr;
+
+ ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+
+ pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
+ return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
+}
+
+#else /* !CONFIG_MMU */
+
+static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
+}
+
+static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
+{
+ return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
+}
+
+static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
+ unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+ void *ptr;
+
+ ptr = io_uring_validate_mmap_request(file, pgoff, len);
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+
+ return (unsigned long) ptr;
+}
+
+#endif /* !CONFIG_MMU */
+
+static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
+{
+ DEFINE_WAIT(wait);
+
+ do {
+ if (!io_sqring_full(ctx))
+ break;
+ prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);
+
+ if (!io_sqring_full(ctx))
+ break;
+ schedule();
+ } while (!signal_pending(current));
+
+ finish_wait(&ctx->sqo_sq_wait, &wait);
+ return 0;
+}
+
+static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz,
+ struct __kernel_timespec __user **ts,
+ const sigset_t __user **sig)
+{
+ struct io_uring_getevents_arg arg;
+
+ /*
+ * If EXT_ARG isn't set, then we have no timespec and the argp pointer
+ * is just a pointer to the sigset_t.
+ */
+ if (!(flags & IORING_ENTER_EXT_ARG)) {
+ *sig = (const sigset_t __user *) argp;
+ *ts = NULL;
+ return 0;
+ }
+
+ /*
+ * EXT_ARG is set - ensure we agree on the size of it and copy in our
+ * timespec and sigset_t pointers if good.
+ */
+ if (*argsz != sizeof(arg))
+ return -EINVAL;
+ if (copy_from_user(&arg, argp, sizeof(arg)))
+ return -EFAULT;
+ if (arg.pad)
+ return -EINVAL;
+ *sig = u64_to_user_ptr(arg.sigmask);
+ *argsz = arg.sigmask_sz;
+ *ts = u64_to_user_ptr(arg.ts);
+ return 0;
+}
+
+SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
+ u32, min_complete, u32, flags, const void __user *, argp,
+ size_t, argsz)
+{
+ struct io_ring_ctx *ctx;
+ int submitted = 0;
+ struct fd f;
+ long ret;
+
+ io_run_task_work();
+
+ if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
+ IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG)))
+ return -EINVAL;
+
+ f = fdget(fd);
+ if (unlikely(!f.file))
+ return -EBADF;
+
+ ret = -EOPNOTSUPP;
+ if (unlikely(f.file->f_op != &io_uring_fops))
+ goto out_fput;
+
+ ret = -ENXIO;
+ ctx = f.file->private_data;
+ if (unlikely(!percpu_ref_tryget(&ctx->refs)))
+ goto out_fput;
+
+ ret = -EBADFD;
+ if (unlikely(ctx->flags & IORING_SETUP_R_DISABLED))
+ goto out;
+
+ /*
+ * For SQ polling, the thread will do all submissions and completions.
+ * Just return the requested submit count, and wake the thread if
+ * we were asked to.
+ */
+ ret = 0;
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ io_cqring_overflow_flush(ctx);
+
+ if (unlikely(ctx->sq_data->thread == NULL)) {
+ ret = -EOWNERDEAD;
+ goto out;
+ }
+ if (flags & IORING_ENTER_SQ_WAKEUP)
+ wake_up(&ctx->sq_data->wait);
+ if (flags & IORING_ENTER_SQ_WAIT) {
+ ret = io_sqpoll_wait_sq(ctx);
+ if (ret)
+ goto out;
+ }
+ submitted = to_submit;
+ } else if (to_submit) {
+ ret = io_uring_add_tctx_node(ctx);
+ if (unlikely(ret))
+ goto out;
+ mutex_lock(&ctx->uring_lock);
+ submitted = io_submit_sqes(ctx, to_submit);
+ mutex_unlock(&ctx->uring_lock);
+
+ if (submitted != to_submit)
+ goto out;
+ }
+ if (flags & IORING_ENTER_GETEVENTS) {
+ const sigset_t __user *sig;
+ struct __kernel_timespec __user *ts;
+
+ ret = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);
+ if (unlikely(ret))
+ goto out;
+
+ min_complete = min(min_complete, ctx->cq_entries);
+
+ /*
+ * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
+ * space applications don't need to do io completion events
+ * polling again, they can rely on io_sq_thread to do polling
+ * work, which can reduce cpu usage and uring_lock contention.
+ */
+ if (ctx->flags & IORING_SETUP_IOPOLL &&
+ !(ctx->flags & IORING_SETUP_SQPOLL)) {
+ ret = io_iopoll_check(ctx, min_complete);
+ } else {
+ ret = io_cqring_wait(ctx, min_complete, sig, argsz, ts);
+ }
+ }
+
+out:
+ percpu_ref_put(&ctx->refs);
+out_fput:
+ fdput(f);
+ return submitted ? submitted : ret;
+}
+
+#ifdef CONFIG_PROC_FS
+static int io_uring_show_cred(struct seq_file *m, unsigned int id,
+ const struct cred *cred)
+{
+ struct user_namespace *uns = seq_user_ns(m);
+ struct group_info *gi;
+ kernel_cap_t cap;
+ unsigned __capi;
+ int g;
+
+ seq_printf(m, "%5d\n", id);
+ seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
+ seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
+ seq_puts(m, "\n\tGroups:\t");
+ gi = cred->group_info;
+ for (g = 0; g < gi->ngroups; g++) {
+ seq_put_decimal_ull(m, g ? " " : "",
+ from_kgid_munged(uns, gi->gid[g]));
+ }
+ seq_puts(m, "\n\tCapEff:\t");
+ cap = cred->cap_effective;
+ CAP_FOR_EACH_U32(__capi)
+ seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
+ seq_putc(m, '\n');
+ return 0;
+}
+
+static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
+{
+ struct io_sq_data *sq = NULL;
+ bool has_lock;
+ int i;
+
+ /*
+ * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
+ * since fdinfo case grabs it in the opposite direction of normal use
+ * cases. If we fail to get the lock, we just don't iterate any
+ * structures that could be going away outside the io_uring mutex.
+ */
+ has_lock = mutex_trylock(&ctx->uring_lock);
+
+ if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
+ sq = ctx->sq_data;
+ if (!sq->thread)
+ sq = NULL;
+ }
+
+ seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
+ seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
+ seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
+ for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
+ struct file *f = io_file_from_index(ctx, i);
+
+ if (f)
+ seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
+ else
+ seq_printf(m, "%5u: <none>\n", i);
+ }
+ seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
+ for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
+ struct io_mapped_ubuf *buf = ctx->user_bufs[i];
+ unsigned int len = buf->ubuf_end - buf->ubuf;
+
+ seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
+ }
+ if (has_lock && !xa_empty(&ctx->personalities)) {
+ unsigned long index;
+ const struct cred *cred;
+
+ seq_printf(m, "Personalities:\n");
+ xa_for_each(&ctx->personalities, index, cred)
+ io_uring_show_cred(m, index, cred);
+ }
+ seq_printf(m, "PollList:\n");
+ spin_lock(&ctx->completion_lock);
+ for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
+ struct hlist_head *list = &ctx->cancel_hash[i];
+ struct io_kiocb *req;
+
+ hlist_for_each_entry(req, list, hash_node)
+ seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
+ req->task->task_works != NULL);
+ }
+ spin_unlock(&ctx->completion_lock);
+ if (has_lock)
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
+{
+ struct io_ring_ctx *ctx = f->private_data;
+
+ if (percpu_ref_tryget(&ctx->refs)) {
+ __io_uring_show_fdinfo(ctx, m);
+ percpu_ref_put(&ctx->refs);
+ }
+}
+#endif
+
+static const struct file_operations io_uring_fops = {
+ .release = io_uring_release,
+ .mmap = io_uring_mmap,
+#ifndef CONFIG_MMU
+ .get_unmapped_area = io_uring_nommu_get_unmapped_area,
+ .mmap_capabilities = io_uring_nommu_mmap_capabilities,
+#endif
+ .poll = io_uring_poll,
+#ifdef CONFIG_PROC_FS
+ .show_fdinfo = io_uring_show_fdinfo,
+#endif
+};
+
+static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
+ struct io_uring_params *p)
+{
+ struct io_rings *rings;
+ size_t size, sq_array_offset;
+
+ /* make sure these are sane, as we already accounted them */
+ ctx->sq_entries = p->sq_entries;
+ ctx->cq_entries = p->cq_entries;
+
+ size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+
+ rings = io_mem_alloc(size);
+ if (!rings)
+ return -ENOMEM;
+
+ ctx->rings = rings;
+ ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
+ rings->sq_ring_mask = p->sq_entries - 1;
+ rings->cq_ring_mask = p->cq_entries - 1;
+ rings->sq_ring_entries = p->sq_entries;
+ rings->cq_ring_entries = p->cq_entries;
+
+ size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
+ if (size == SIZE_MAX) {
+ io_mem_free(ctx->rings);
+ ctx->rings = NULL;
+ return -EOVERFLOW;
+ }
+
+ ctx->sq_sqes = io_mem_alloc(size);
+ if (!ctx->sq_sqes) {
+ io_mem_free(ctx->rings);
+ ctx->rings = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
+{
+ int ret, fd;
+
+ fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+
+ ret = io_uring_add_tctx_node(ctx);
+ if (ret) {
+ put_unused_fd(fd);
+ return ret;
+ }
+ fd_install(fd, file);
+ return fd;
+}
+
+/*
+ * Allocate an anonymous fd, this is what constitutes the application
+ * visible backing of an io_uring instance. The application mmaps this
+ * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
+ * we have to tie this fd to a socket for file garbage collection purposes.
+ */
+static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
+{
+ struct file *file;
+#if defined(CONFIG_UNIX)
+ int ret;
+
+ ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
+ &ctx->ring_sock);
+ if (ret)
+ return ERR_PTR(ret);
+#endif
+
+ file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
+ O_RDWR | O_CLOEXEC);
+#if defined(CONFIG_UNIX)
+ if (IS_ERR(file)) {
+ sock_release(ctx->ring_sock);
+ ctx->ring_sock = NULL;
+ } else {
+ ctx->ring_sock->file = file;
+ }
+#endif
+ return file;
+}
+
+static int io_uring_create(unsigned entries, struct io_uring_params *p,
+ struct io_uring_params __user *params)
+{
+ struct io_ring_ctx *ctx;
+ struct file *file;
+ int ret;
+
+ if (!entries)
+ return -EINVAL;
+ if (entries > IORING_MAX_ENTRIES) {
+ if (!(p->flags & IORING_SETUP_CLAMP))
+ return -EINVAL;
+ entries = IORING_MAX_ENTRIES;
+ }
+
+ /*
+ * Use twice as many entries for the CQ ring. It's possible for the
+ * application to drive a higher depth than the size of the SQ ring,
+ * since the sqes are only used at submission time. This allows for
+ * some flexibility in overcommitting a bit. If the application has
+ * set IORING_SETUP_CQSIZE, it will have passed in the desired number
+ * of CQ ring entries manually.
+ */
+ p->sq_entries = roundup_pow_of_two(entries);
+ if (p->flags & IORING_SETUP_CQSIZE) {
+ /*
+ * If IORING_SETUP_CQSIZE is set, we do the same roundup
+ * to a power-of-two, if it isn't already. We do NOT impose
+ * any cq vs sq ring sizing.
+ */
+ if (!p->cq_entries)
+ return -EINVAL;
+ if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
+ if (!(p->flags & IORING_SETUP_CLAMP))
+ return -EINVAL;
+ p->cq_entries = IORING_MAX_CQ_ENTRIES;
+ }
+ p->cq_entries = roundup_pow_of_two(p->cq_entries);
+ if (p->cq_entries < p->sq_entries)
+ return -EINVAL;
+ } else {
+ p->cq_entries = 2 * p->sq_entries;
+ }
+
+ ctx = io_ring_ctx_alloc(p);
+ if (!ctx)
+ return -ENOMEM;
+ ctx->compat = in_compat_syscall();
+ if (!capable(CAP_IPC_LOCK))
+ ctx->user = get_uid(current_user());
+
+ /*
+ * This is just grabbed for accounting purposes. When a process exits,
+ * the mm is exited and dropped before the files, hence we need to hang
+ * on to this mm purely for the purposes of being able to unaccount
+ * memory (locked/pinned vm). It's not used for anything else.
+ */
+ mmgrab(current->mm);
+ ctx->mm_account = current->mm;
+
+ ret = io_allocate_scq_urings(ctx, p);
+ if (ret)
+ goto err;
+
+ ret = io_sq_offload_create(ctx, p);
+ if (ret)
+ goto err;
+ /* always set a rsrc node */
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ goto err;
+ io_rsrc_node_switch(ctx, NULL);
+
+ memset(&p->sq_off, 0, sizeof(p->sq_off));
+ p->sq_off.head = offsetof(struct io_rings, sq.head);
+ p->sq_off.tail = offsetof(struct io_rings, sq.tail);
+ p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
+ p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
+ p->sq_off.flags = offsetof(struct io_rings, sq_flags);
+ p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
+ p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
+
+ memset(&p->cq_off, 0, sizeof(p->cq_off));
+ p->cq_off.head = offsetof(struct io_rings, cq.head);
+ p->cq_off.tail = offsetof(struct io_rings, cq.tail);
+ p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
+ p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
+ p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
+ p->cq_off.cqes = offsetof(struct io_rings, cqes);
+ p->cq_off.flags = offsetof(struct io_rings, cq_flags);
+
+ p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
+ IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
+ IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
+ IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED |
+ IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS |
+ IORING_FEAT_RSRC_TAGS;
+
+ if (copy_to_user(params, p, sizeof(*p))) {
+ ret = -EFAULT;
+ goto err;
+ }
+
+ file = io_uring_get_file(ctx);
+ if (IS_ERR(file)) {
+ ret = PTR_ERR(file);
+ goto err;
+ }
+
+ /*
+ * Install ring fd as the very last thing, so we don't risk someone
+ * having closed it before we finish setup
+ */
+ ret = io_uring_install_fd(ctx, file);
+ if (ret < 0) {
+ /* fput will clean it up */
+ fput(file);
+ return ret;
+ }
+
+ trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
+ return ret;
+err:
+ io_ring_ctx_wait_and_kill(ctx);
+ return ret;
+}
+
+/*
+ * Sets up an aio uring context, and returns the fd. Applications asks for a
+ * ring size, we return the actual sq/cq ring sizes (among other things) in the
+ * params structure passed in.
+ */
+static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
+{
+ struct io_uring_params p;
+ int i;
+
+ if (copy_from_user(&p, params, sizeof(p)))
+ return -EFAULT;
+ for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
+ if (p.resv[i])
+ return -EINVAL;
+ }
+
+ if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
+ IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
+ IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
+ IORING_SETUP_R_DISABLED))
+ return -EINVAL;
+
+ return io_uring_create(entries, &p, params);
+}
+
+SYSCALL_DEFINE2(io_uring_setup, u32, entries,
+ struct io_uring_params __user *, params)
+{
+ return io_uring_setup(entries, params);
+}
+
+static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
+{
+ struct io_uring_probe *p;
+ size_t size;
+ int i, ret;
+
+ size = struct_size(p, ops, nr_args);
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+ p = kzalloc(size, GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ ret = -EFAULT;
+ if (copy_from_user(p, arg, size))
+ goto out;
+ ret = -EINVAL;
+ if (memchr_inv(p, 0, size))
+ goto out;
+
+ p->last_op = IORING_OP_LAST - 1;
+ if (nr_args > IORING_OP_LAST)
+ nr_args = IORING_OP_LAST;
+
+ for (i = 0; i < nr_args; i++) {
+ p->ops[i].op = i;
+ if (!io_op_defs[i].not_supported)
+ p->ops[i].flags = IO_URING_OP_SUPPORTED;
+ }
+ p->ops_len = i;
+
+ ret = 0;
+ if (copy_to_user(arg, p, size))
+ ret = -EFAULT;
+out:
+ kfree(p);
+ return ret;
+}
+
+static int io_register_personality(struct io_ring_ctx *ctx)
+{
+ const struct cred *creds;
+ u32 id;
+ int ret;
+
+ creds = get_current_cred();
+
+ ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds,
+ XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
+ if (ret < 0) {
+ put_cred(creds);
+ return ret;
+ }
+ return id;
+}
+
+static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int nr_args)
+{
+ struct io_uring_restriction *res;
+ size_t size;
+ int i, ret;
+
+ /* Restrictions allowed only if rings started disabled */
+ if (!(ctx->flags & IORING_SETUP_R_DISABLED))
+ return -EBADFD;
+
+ /* We allow only a single restrictions registration */
+ if (ctx->restrictions.registered)
+ return -EBUSY;
+
+ if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
+ return -EINVAL;
+
+ size = array_size(nr_args, sizeof(*res));
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+
+ res = memdup_user(arg, size);
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+
+ ret = 0;
+
+ for (i = 0; i < nr_args; i++) {
+ switch (res[i].opcode) {
+ case IORING_RESTRICTION_REGISTER_OP:
+ if (res[i].register_op >= IORING_REGISTER_LAST) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ __set_bit(res[i].register_op,
+ ctx->restrictions.register_op);
+ break;
+ case IORING_RESTRICTION_SQE_OP:
+ if (res[i].sqe_op >= IORING_OP_LAST) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ __set_bit(res[i].sqe_op, ctx->restrictions.sqe_op);
+ break;
+ case IORING_RESTRICTION_SQE_FLAGS_ALLOWED:
+ ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags;
+ break;
+ case IORING_RESTRICTION_SQE_FLAGS_REQUIRED:
+ ctx->restrictions.sqe_flags_required = res[i].sqe_flags;
+ break;
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+out:
+ /* Reset all restrictions if an error happened */
+ if (ret != 0)
+ memset(&ctx->restrictions, 0, sizeof(ctx->restrictions));
+ else
+ ctx->restrictions.registered = true;
+
+ kfree(res);
+ return ret;
+}
+
+static int io_register_enable_rings(struct io_ring_ctx *ctx)
+{
+ if (!(ctx->flags & IORING_SETUP_R_DISABLED))
+ return -EBADFD;
+
+ if (ctx->restrictions.registered)
+ ctx->restricted = 1;
+
+ ctx->flags &= ~IORING_SETUP_R_DISABLED;
+ if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait))
+ wake_up(&ctx->sq_data->wait);
+ return 0;
+}
+
+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args)
+{
+ __u32 tmp;
+ int err;
+
+ if (check_add_overflow(up->offset, nr_args, &tmp))
+ return -EOVERFLOW;
+ err = io_rsrc_node_switch_start(ctx);
+ if (err)
+ return err;
+
+ switch (type) {
+ case IORING_RSRC_FILE:
+ return __io_sqe_files_update(ctx, up, nr_args);
+ case IORING_RSRC_BUFFER:
+ return __io_sqe_buffers_update(ctx, up, nr_args);
+ }
+ return -EINVAL;
+}
+
+static int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned nr_args)
+{
+ struct io_uring_rsrc_update2 up;
+
+ if (!nr_args)
+ return -EINVAL;
+ memset(&up, 0, sizeof(up));
+ if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
+ return -EFAULT;
+ if (up.resv || up.resv2)
+ return -EINVAL;
+ return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
+}
+
+static int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned size, unsigned type)
+{
+ struct io_uring_rsrc_update2 up;
+
+ if (size != sizeof(up))
+ return -EINVAL;
+ if (copy_from_user(&up, arg, sizeof(up)))
+ return -EFAULT;
+ if (!up.nr || up.resv || up.resv2)
+ return -EINVAL;
+ return __io_register_rsrc_update(ctx, type, &up, up.nr);
+}
+
+static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int size, unsigned int type)
+{
+ struct io_uring_rsrc_register rr;
+
+ /* keep it extendible */
+ if (size != sizeof(rr))
+ return -EINVAL;
+
+ memset(&rr, 0, sizeof(rr));
+ if (copy_from_user(&rr, arg, size))
+ return -EFAULT;
+ if (!rr.nr || rr.resv || rr.resv2)
+ return -EINVAL;
+
+ switch (type) {
+ case IORING_RSRC_FILE:
+ return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data),
+ rr.nr, u64_to_user_ptr(rr.tags));
+ case IORING_RSRC_BUFFER:
+ return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data),
+ rr.nr, u64_to_user_ptr(rr.tags));
+ }
+ return -EINVAL;
+}
+
+static int io_register_iowq_aff(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned len)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ cpumask_var_t new_mask;
+ int ret;
+
+ if (!tctx || !tctx->io_wq)
+ return -EINVAL;
+
+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ cpumask_clear(new_mask);
+ if (len > cpumask_size())
+ len = cpumask_size();
+
+#ifdef CONFIG_COMPAT
+ if (in_compat_syscall()) {
+ ret = compat_get_bitmap(cpumask_bits(new_mask),
+ (const compat_ulong_t __user *)arg,
+ len * 8 /* CHAR_BIT */);
+ } else {
+ ret = copy_from_user(new_mask, arg, len);
+ }
+#else
+ ret = copy_from_user(new_mask, arg, len);
+#endif
+
+ if (ret) {
+ free_cpumask_var(new_mask);
+ return -EFAULT;
+ }
+
+ ret = io_wq_cpu_affinity(tctx->io_wq, new_mask);
+ free_cpumask_var(new_mask);
+ return ret;
+}
+
+static int io_unregister_iowq_aff(struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ if (!tctx || !tctx->io_wq)
+ return -EINVAL;
+
+ return io_wq_cpu_affinity(tctx->io_wq, NULL);
+}
+
+static int io_register_iowq_max_workers(struct io_ring_ctx *ctx,
+ void __user *arg)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_tctx_node *node;
+ struct io_uring_task *tctx = NULL;
+ struct io_sq_data *sqd = NULL;
+ __u32 new_count[2];
+ int i, ret;
+
+ if (copy_from_user(new_count, arg, sizeof(new_count)))
+ return -EFAULT;
+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
+ if (new_count[i] > INT_MAX)
+ return -EINVAL;
+
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ sqd = ctx->sq_data;
+ if (sqd) {
+ /*
+ * Observe the correct sqd->lock -> ctx->uring_lock
+ * ordering. Fine to drop uring_lock here, we hold
+ * a ref to the ctx.
+ */
+ refcount_inc(&sqd->refs);
+ mutex_unlock(&ctx->uring_lock);
+ mutex_lock(&sqd->lock);
+ mutex_lock(&ctx->uring_lock);
+ if (sqd->thread)
+ tctx = sqd->thread->io_uring;
+ }
+ } else {
+ tctx = current->io_uring;
+ }
+
+ BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits));
+
+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
+ if (new_count[i])
+ ctx->iowq_limits[i] = new_count[i];
+ ctx->iowq_limits_set = true;
+
+ ret = -EINVAL;
+ if (tctx && tctx->io_wq) {
+ ret = io_wq_max_workers(tctx->io_wq, new_count);
+ if (ret)
+ goto err;
+ } else {
+ memset(new_count, 0, sizeof(new_count));
+ }
+
+ if (sqd) {
+ mutex_unlock(&sqd->lock);
+ io_put_sq_data(sqd);
+ }
+
+ if (copy_to_user(arg, new_count, sizeof(new_count)))
+ return -EFAULT;
+
+ /* that's it for SQPOLL, only the SQPOLL task creates requests */
+ if (sqd)
+ return 0;
+
+ /* now propagate the restriction to all registered users */
+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
+ struct io_uring_task *tctx = node->task->io_uring;
+
+ if (WARN_ON_ONCE(!tctx->io_wq))
+ continue;
+
+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
+ new_count[i] = ctx->iowq_limits[i];
+ /* ignore errors, it always returns zero anyway */
+ (void)io_wq_max_workers(tctx->io_wq, new_count);
+ }
+ return 0;
+err:
+ if (sqd) {
+ mutex_unlock(&sqd->lock);
+ io_put_sq_data(sqd);
+ }
+ return ret;
+}
+
+static bool io_register_op_must_quiesce(int op)
+{
+ switch (op) {
+ case IORING_REGISTER_BUFFERS:
+ case IORING_UNREGISTER_BUFFERS:
+ case IORING_REGISTER_FILES:
+ case IORING_UNREGISTER_FILES:
+ case IORING_REGISTER_FILES_UPDATE:
+ case IORING_REGISTER_PROBE:
+ case IORING_REGISTER_PERSONALITY:
+ case IORING_UNREGISTER_PERSONALITY:
+ case IORING_REGISTER_FILES2:
+ case IORING_REGISTER_FILES_UPDATE2:
+ case IORING_REGISTER_BUFFERS2:
+ case IORING_REGISTER_BUFFERS_UPDATE:
+ case IORING_REGISTER_IOWQ_AFF:
+ case IORING_UNREGISTER_IOWQ_AFF:
+ case IORING_REGISTER_IOWQ_MAX_WORKERS:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static int io_ctx_quiesce(struct io_ring_ctx *ctx)
+{
+ long ret;
+
+ percpu_ref_kill(&ctx->refs);
+
+ /*
+ * Drop uring mutex before waiting for references to exit. If another
+ * thread is currently inside io_uring_enter() it might need to grab the
+ * uring_lock to make progress. If we hold it here across the drain
+ * wait, then we can deadlock. It's safe to drop the mutex here, since
+ * no new references will come in after we've killed the percpu ref.
+ */
+ mutex_unlock(&ctx->uring_lock);
+ do {
+ ret = wait_for_completion_interruptible(&ctx->ref_comp);
+ if (!ret)
+ break;
+ ret = io_run_task_work_sig();
+ } while (ret >= 0);
+ mutex_lock(&ctx->uring_lock);
+
+ if (ret)
+ io_refs_resurrect(&ctx->refs, &ctx->ref_comp);
+ return ret;
+}
+
+static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
+ void __user *arg, unsigned nr_args)
+ __releases(ctx->uring_lock)
+ __acquires(ctx->uring_lock)
+{
+ int ret;
+
+ /*
+ * We're inside the ring mutex, if the ref is already dying, then
+ * someone else killed the ctx or is already going through
+ * io_uring_register().
+ */
+ if (percpu_ref_is_dying(&ctx->refs))
+ return -ENXIO;
+
+ if (ctx->restricted) {
+ if (opcode >= IORING_REGISTER_LAST)
+ return -EINVAL;
+ opcode = array_index_nospec(opcode, IORING_REGISTER_LAST);
+ if (!test_bit(opcode, ctx->restrictions.register_op))
+ return -EACCES;
+ }
+
+ if (io_register_op_must_quiesce(opcode)) {
+ ret = io_ctx_quiesce(ctx);
+ if (ret)
+ return ret;
+ }
+
+ switch (opcode) {
+ case IORING_REGISTER_BUFFERS:
+ ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL);
+ break;
+ case IORING_UNREGISTER_BUFFERS:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_sqe_buffers_unregister(ctx);
+ break;
+ case IORING_REGISTER_FILES:
+ ret = io_sqe_files_register(ctx, arg, nr_args, NULL);
+ break;
+ case IORING_UNREGISTER_FILES:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_sqe_files_unregister(ctx);
+ break;
+ case IORING_REGISTER_FILES_UPDATE:
+ ret = io_register_files_update(ctx, arg, nr_args);
+ break;
+ case IORING_REGISTER_EVENTFD:
+ case IORING_REGISTER_EVENTFD_ASYNC:
+ ret = -EINVAL;
+ if (nr_args != 1)
+ break;
+ ret = io_eventfd_register(ctx, arg);
+ if (ret)
+ break;
+ if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
+ ctx->eventfd_async = 1;
+ else
+ ctx->eventfd_async = 0;
+ break;
+ case IORING_UNREGISTER_EVENTFD:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_eventfd_unregister(ctx);
+ break;
+ case IORING_REGISTER_PROBE:
+ ret = -EINVAL;
+ if (!arg || nr_args > 256)
+ break;
+ ret = io_probe(ctx, arg, nr_args);
+ break;
+ case IORING_REGISTER_PERSONALITY:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_register_personality(ctx);
+ break;
+ case IORING_UNREGISTER_PERSONALITY:
+ ret = -EINVAL;
+ if (arg)
+ break;
+ ret = io_unregister_personality(ctx, nr_args);
+ break;
+ case IORING_REGISTER_ENABLE_RINGS:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_register_enable_rings(ctx);
+ break;
+ case IORING_REGISTER_RESTRICTIONS:
+ ret = io_register_restrictions(ctx, arg, nr_args);
+ break;
+ case IORING_REGISTER_FILES2:
+ ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE);
+ break;
+ case IORING_REGISTER_FILES_UPDATE2:
+ ret = io_register_rsrc_update(ctx, arg, nr_args,
+ IORING_RSRC_FILE);
+ break;
+ case IORING_REGISTER_BUFFERS2:
+ ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER);
+ break;
+ case IORING_REGISTER_BUFFERS_UPDATE:
+ ret = io_register_rsrc_update(ctx, arg, nr_args,
+ IORING_RSRC_BUFFER);
+ break;
+ case IORING_REGISTER_IOWQ_AFF:
+ ret = -EINVAL;
+ if (!arg || !nr_args)
+ break;
+ ret = io_register_iowq_aff(ctx, arg, nr_args);
+ break;
+ case IORING_UNREGISTER_IOWQ_AFF:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_unregister_iowq_aff(ctx);
+ break;
+ case IORING_REGISTER_IOWQ_MAX_WORKERS:
+ ret = -EINVAL;
+ if (!arg || nr_args != 2)
+ break;
+ ret = io_register_iowq_max_workers(ctx, arg);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (io_register_op_must_quiesce(opcode)) {
+ /* bring the ctx back to life */
+ percpu_ref_reinit(&ctx->refs);
+ reinit_completion(&ctx->ref_comp);
+ }
+ return ret;
+}
+
+SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
+ void __user *, arg, unsigned int, nr_args)
+{
+ struct io_ring_ctx *ctx;
+ long ret = -EBADF;
+ struct fd f;
+
+ f = fdget(fd);
+ if (!f.file)
+ return -EBADF;
+
+ ret = -EOPNOTSUPP;
+ if (f.file->f_op != &io_uring_fops)
+ goto out_fput;
+
+ ctx = f.file->private_data;
+
+ io_run_task_work();
+
+ mutex_lock(&ctx->uring_lock);
+ ret = __io_uring_register(ctx, opcode, arg, nr_args);
+ mutex_unlock(&ctx->uring_lock);
+ trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
+ ctx->cq_ev_fd != NULL, ret);
+out_fput:
+ fdput(f);
+ return ret;
+}
+
+static int __init io_uring_init(void)
+{
+#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
+ BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
+ BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
+} while (0)
+
+#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
+ __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
+ BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
+ BUILD_BUG_SQE_ELEM(0, __u8, opcode);
+ BUILD_BUG_SQE_ELEM(1, __u8, flags);
+ BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
+ BUILD_BUG_SQE_ELEM(4, __s32, fd);
+ BUILD_BUG_SQE_ELEM(8, __u64, off);
+ BUILD_BUG_SQE_ELEM(8, __u64, addr2);
+ BUILD_BUG_SQE_ELEM(16, __u64, addr);
+ BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
+ BUILD_BUG_SQE_ELEM(24, __u32, len);
+ BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
+ BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
+ BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
+ BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
+ BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
+ BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
+ BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
+ BUILD_BUG_SQE_ELEM(32, __u64, user_data);
+ BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
+ BUILD_BUG_SQE_ELEM(40, __u16, buf_group);
+ BUILD_BUG_SQE_ELEM(42, __u16, personality);
+ BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
+ BUILD_BUG_SQE_ELEM(44, __u32, file_index);
+
+ BUILD_BUG_ON(sizeof(struct io_uring_files_update) !=
+ sizeof(struct io_uring_rsrc_update));
+ BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) >
+ sizeof(struct io_uring_rsrc_update2));
+
+ /* ->buf_index is u16 */
+ BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
+
+ /* should fit into one byte */
+ BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));
+
+ BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
+ BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int));
+
+ req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC |
+ SLAB_ACCOUNT);
+ return 0;
+};
+__initcall(io_uring_init);
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -763,7 +763,7 @@ void __noreturn do_exit(long code)
schedule();
}
- io_uring_files_cancel(tsk->files);
+ io_uring_files_cancel();
exit_signals(tsk); /* sets PF_EXITING */
/* sync mm's RSS info before statistics gathering */
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -926,6 +926,7 @@ static struct task_struct *dup_task_stru
tsk->splice_pipe = NULL;
tsk->task_frag.page = NULL;
tsk->wake_q.next = NULL;
+ tsk->pf_io_worker = NULL;
account_kernel_stack(tsk, 1);
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -21,7 +21,7 @@
#include <asm/tlb.h>
#include "../workqueue_internal.h"
-#include "../../fs/io-wq.h"
+#include "../../io_uring/io-wq.h"
#include "../smpboot.h"
#include "pelt.h"
^ permalink raw reply [flat|nested] 73+ messages in thread