* [PATCH 2/2] io_uring: encapsulate task_work state
2023-03-27 15:38 [PATCH 0/2] introduce tw state Pavel Begunkov
2023-03-27 15:38 ` [PATCH 1/2] io_uring: remove extra tw trylocks Pavel Begunkov
@ 2023-03-27 15:38 ` Pavel Begunkov
2023-03-27 19:15 ` [PATCH 0/2] introduce tw state Jens Axboe
2 siblings, 0 replies; 4+ messages in thread
From: Pavel Begunkov @ 2023-03-27 15:38 UTC (permalink / raw)
To: io-uring; +Cc: Jens Axboe, asml.silence
For task works we're passing around a bool pointer for whether the
current ring is locked or not, let's wrap it in a structure, that
will make it more opaque preventing abuse and will also help us
to pass more info in the future if needed.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
include/linux/io_uring_types.h | 7 +++-
io_uring/io_uring.c | 71 +++++++++++++++++-----------------
io_uring/io_uring.h | 14 +++----
io_uring/notif.c | 4 +-
io_uring/poll.c | 32 +++++++--------
io_uring/rw.c | 6 +--
io_uring/timeout.c | 14 +++----
io_uring/uring_cmd.c | 2 +-
8 files changed, 78 insertions(+), 72 deletions(-)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 3d152bdcd30a..561fa421c453 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -367,6 +367,11 @@ struct io_ring_ctx {
unsigned evfd_last_cq_tail;
};
+struct io_tw_state {
+ /* ->uring_lock is taken, callbacks can use io_tw_lock to lock it */
+ bool locked;
+};
+
enum {
REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
@@ -473,7 +478,7 @@ enum {
REQ_F_HASH_LOCKED = BIT(REQ_F_HASH_LOCKED_BIT),
};
-typedef void (*io_req_tw_func_t)(struct io_kiocb *req, bool *locked);
+typedef void (*io_req_tw_func_t)(struct io_kiocb *req, struct io_tw_state *ts);
struct io_task_work {
struct llist_node node;
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 2669aca0ba39..536940675c67 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -247,12 +247,12 @@ static __cold void io_fallback_req_func(struct work_struct *work)
fallback_work.work);
struct llist_node *node = llist_del_all(&ctx->fallback_llist);
struct io_kiocb *req, *tmp;
- bool locked = true;
+ struct io_tw_state ts = { .locked = true, };
mutex_lock(&ctx->uring_lock);
llist_for_each_entry_safe(req, tmp, node, io_task_work.node)
- req->io_task_work.func(req, &locked);
- if (WARN_ON_ONCE(!locked))
+ req->io_task_work.func(req, &ts);
+ if (WARN_ON_ONCE(!ts.locked))
return;
io_submit_flush_completions(ctx);
mutex_unlock(&ctx->uring_lock);
@@ -457,7 +457,7 @@ static void io_prep_async_link(struct io_kiocb *req)
}
}
-void io_queue_iowq(struct io_kiocb *req, bool *dont_use)
+void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use)
{
struct io_kiocb *link = io_prep_linked_timeout(req);
struct io_uring_task *tctx = req->task->io_uring;
@@ -1153,22 +1153,23 @@ static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
return nxt;
}
-static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
+static void ctx_flush_and_put(struct io_ring_ctx *ctx, struct io_tw_state *ts)
{
if (!ctx)
return;
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
- if (*locked) {
+ if (ts->locked) {
io_submit_flush_completions(ctx);
mutex_unlock(&ctx->uring_lock);
- *locked = false;
+ ts->locked = false;
}
percpu_ref_put(&ctx->refs);
}
static unsigned int handle_tw_list(struct llist_node *node,
- struct io_ring_ctx **ctx, bool *locked,
+ struct io_ring_ctx **ctx,
+ struct io_tw_state *ts,
struct llist_node *last)
{
unsigned int count = 0;
@@ -1181,17 +1182,17 @@ static unsigned int handle_tw_list(struct llist_node *node,
prefetch(container_of(next, struct io_kiocb, io_task_work.node));
if (req->ctx != *ctx) {
- ctx_flush_and_put(*ctx, locked);
+ ctx_flush_and_put(*ctx, ts);
*ctx = req->ctx;
/* if not contended, grab and improve batching */
- *locked = mutex_trylock(&(*ctx)->uring_lock);
+ ts->locked = mutex_trylock(&(*ctx)->uring_lock);
percpu_ref_get(&(*ctx)->refs);
}
- req->io_task_work.func(req, locked);
+ req->io_task_work.func(req, ts);
node = next;
count++;
if (unlikely(need_resched())) {
- ctx_flush_and_put(*ctx, locked);
+ ctx_flush_and_put(*ctx, ts);
*ctx = NULL;
cond_resched();
}
@@ -1232,7 +1233,7 @@ static inline struct llist_node *io_llist_cmpxchg(struct llist_head *head,
void tctx_task_work(struct callback_head *cb)
{
- bool uring_locked = false;
+ struct io_tw_state ts = {};
struct io_ring_ctx *ctx = NULL;
struct io_uring_task *tctx = container_of(cb, struct io_uring_task,
task_work);
@@ -1249,12 +1250,12 @@ void tctx_task_work(struct callback_head *cb)
do {
loops++;
node = io_llist_xchg(&tctx->task_list, &fake);
- count += handle_tw_list(node, &ctx, &uring_locked, &fake);
+ count += handle_tw_list(node, &ctx, &ts, &fake);
/* skip expensive cmpxchg if there are items in the list */
if (READ_ONCE(tctx->task_list.first) != &fake)
continue;
- if (uring_locked && !wq_list_empty(&ctx->submit_state.compl_reqs)) {
+ if (ts.locked && !wq_list_empty(&ctx->submit_state.compl_reqs)) {
io_submit_flush_completions(ctx);
if (READ_ONCE(tctx->task_list.first) != &fake)
continue;
@@ -1262,7 +1263,7 @@ void tctx_task_work(struct callback_head *cb)
node = io_llist_cmpxchg(&tctx->task_list, &fake, NULL);
} while (node != &fake);
- ctx_flush_and_put(ctx, &uring_locked);
+ ctx_flush_and_put(ctx, &ts);
/* relaxed read is enough as only the task itself sets ->in_cancel */
if (unlikely(atomic_read(&tctx->in_cancel)))
@@ -1351,7 +1352,7 @@ static void __cold io_move_task_work_from_local(struct io_ring_ctx *ctx)
}
}
-static int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked)
+static int __io_run_local_work(struct io_ring_ctx *ctx, struct io_tw_state *ts)
{
struct llist_node *node;
unsigned int loops = 0;
@@ -1368,7 +1369,7 @@ static int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked)
struct io_kiocb *req = container_of(node, struct io_kiocb,
io_task_work.node);
prefetch(container_of(next, struct io_kiocb, io_task_work.node));
- req->io_task_work.func(req, locked);
+ req->io_task_work.func(req, ts);
ret++;
node = next;
}
@@ -1376,7 +1377,7 @@ static int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked)
if (!llist_empty(&ctx->work_llist))
goto again;
- if (*locked) {
+ if (ts->locked) {
io_submit_flush_completions(ctx);
if (!llist_empty(&ctx->work_llist))
goto again;
@@ -1387,46 +1388,46 @@ static int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked)
static inline int io_run_local_work_locked(struct io_ring_ctx *ctx)
{
- bool locked;
+ struct io_tw_state ts = { .locked = true, };
int ret;
if (llist_empty(&ctx->work_llist))
return 0;
- locked = true;
- ret = __io_run_local_work(ctx, &locked);
+ ret = __io_run_local_work(ctx, &ts);
/* shouldn't happen! */
- if (WARN_ON_ONCE(!locked))
+ if (WARN_ON_ONCE(!ts.locked))
mutex_lock(&ctx->uring_lock);
return ret;
}
static int io_run_local_work(struct io_ring_ctx *ctx)
{
- bool locked = mutex_trylock(&ctx->uring_lock);
+ struct io_tw_state ts = {};
int ret;
- ret = __io_run_local_work(ctx, &locked);
- if (locked)
+ ts.locked = mutex_trylock(&ctx->uring_lock);
+ ret = __io_run_local_work(ctx, &ts);
+ if (ts.locked)
mutex_unlock(&ctx->uring_lock);
return ret;
}
-static void io_req_task_cancel(struct io_kiocb *req, bool *locked)
+static void io_req_task_cancel(struct io_kiocb *req, struct io_tw_state *ts)
{
- io_tw_lock(req->ctx, locked);
+ io_tw_lock(req->ctx, ts);
io_req_defer_failed(req, req->cqe.res);
}
-void io_req_task_submit(struct io_kiocb *req, bool *locked)
+void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts)
{
- io_tw_lock(req->ctx, locked);
+ io_tw_lock(req->ctx, ts);
/* req->task == current here, checking PF_EXITING is safe */
if (unlikely(req->task->flags & PF_EXITING))
io_req_defer_failed(req, -EFAULT);
else if (req->flags & REQ_F_FORCE_ASYNC)
- io_queue_iowq(req, locked);
+ io_queue_iowq(req, ts);
else
io_queue_sqe(req);
}
@@ -1652,9 +1653,9 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
return ret;
}
-void io_req_task_complete(struct io_kiocb *req, bool *locked)
+void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts)
{
- if (*locked)
+ if (ts->locked)
io_req_complete_defer(req);
else
io_req_complete_post(req, IO_URING_F_UNLOCKED);
@@ -1933,9 +1934,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
return 0;
}
-int io_poll_issue(struct io_kiocb *req, bool *locked)
+int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts)
{
- io_tw_lock(req->ctx, locked);
+ io_tw_lock(req->ctx, ts);
return io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_MULTISHOT|
IO_URING_F_COMPLETE_DEFER);
}
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 2711865f1e19..c33f719731ac 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -52,16 +52,16 @@ void __io_req_task_work_add(struct io_kiocb *req, bool allow_local);
bool io_is_uring_fops(struct file *file);
bool io_alloc_async_data(struct io_kiocb *req);
void io_req_task_queue(struct io_kiocb *req);
-void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
-void io_req_task_complete(struct io_kiocb *req, bool *locked);
+void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use);
+void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts);
void io_req_task_queue_fail(struct io_kiocb *req, int ret);
-void io_req_task_submit(struct io_kiocb *req, bool *locked);
+void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts);
void tctx_task_work(struct callback_head *cb);
__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
int io_uring_alloc_task_context(struct task_struct *task,
struct io_ring_ctx *ctx);
-int io_poll_issue(struct io_kiocb *req, bool *locked);
+int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts);
int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr);
int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin);
void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node);
@@ -299,11 +299,11 @@ static inline bool io_task_work_pending(struct io_ring_ctx *ctx)
return task_work_pending(current) || !wq_list_empty(&ctx->work_llist);
}
-static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
+static inline void io_tw_lock(struct io_ring_ctx *ctx, struct io_tw_state *ts)
{
- if (!*locked) {
+ if (!ts->locked) {
mutex_lock(&ctx->uring_lock);
- *locked = true;
+ ts->locked = true;
}
}
diff --git a/io_uring/notif.c b/io_uring/notif.c
index 09dfd0832d19..172105eb347d 100644
--- a/io_uring/notif.c
+++ b/io_uring/notif.c
@@ -9,7 +9,7 @@
#include "notif.h"
#include "rsrc.h"
-static void io_notif_complete_tw_ext(struct io_kiocb *notif, bool *locked)
+static void io_notif_complete_tw_ext(struct io_kiocb *notif, struct io_tw_state *ts)
{
struct io_notif_data *nd = io_notif_to_data(notif);
struct io_ring_ctx *ctx = notif->ctx;
@@ -21,7 +21,7 @@ static void io_notif_complete_tw_ext(struct io_kiocb *notif, bool *locked)
__io_unaccount_mem(ctx->user, nd->account_pages);
nd->account_pages = 0;
}
- io_req_task_complete(notif, locked);
+ io_req_task_complete(notif, ts);
}
static void io_tx_ubuf_callback(struct sk_buff *skb, struct ubuf_info *uarg,
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 795facbd0e9f..37513fb38fad 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -148,7 +148,7 @@ static void io_poll_req_insert_locked(struct io_kiocb *req)
hlist_add_head(&req->hash_node, &table->hbs[index].list);
}
-static void io_poll_tw_hash_eject(struct io_kiocb *req, bool *locked)
+static void io_poll_tw_hash_eject(struct io_kiocb *req, struct io_tw_state *ts)
{
struct io_ring_ctx *ctx = req->ctx;
@@ -159,7 +159,7 @@ static void io_poll_tw_hash_eject(struct io_kiocb *req, bool *locked)
* already grabbed the mutex for us, but there is a chance it
* failed.
*/
- io_tw_lock(ctx, locked);
+ io_tw_lock(ctx, ts);
hash_del(&req->hash_node);
req->flags &= ~REQ_F_HASH_LOCKED;
} else {
@@ -238,7 +238,7 @@ enum {
* req->cqe.res. IOU_POLL_REMOVE_POLL_USE_RES indicates to remove multishot
* poll and that the result is stored in req->cqe.
*/
-static int io_poll_check_events(struct io_kiocb *req, bool *locked)
+static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts)
{
int v;
@@ -300,13 +300,13 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked)
__poll_t mask = mangle_poll(req->cqe.res &
req->apoll_events);
- if (!io_aux_cqe(req->ctx, *locked, req->cqe.user_data,
+ if (!io_aux_cqe(req->ctx, ts->locked, req->cqe.user_data,
mask, IORING_CQE_F_MORE, false)) {
io_req_set_res(req, mask, 0);
return IOU_POLL_REMOVE_POLL_USE_RES;
}
} else {
- int ret = io_poll_issue(req, locked);
+ int ret = io_poll_issue(req, ts);
if (ret == IOU_STOP_MULTISHOT)
return IOU_POLL_REMOVE_POLL_USE_RES;
if (ret < 0)
@@ -326,15 +326,15 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked)
return IOU_POLL_NO_ACTION;
}
-static void io_poll_task_func(struct io_kiocb *req, bool *locked)
+static void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts)
{
int ret;
- ret = io_poll_check_events(req, locked);
+ ret = io_poll_check_events(req, ts);
if (ret == IOU_POLL_NO_ACTION)
return;
io_poll_remove_entries(req);
- io_poll_tw_hash_eject(req, locked);
+ io_poll_tw_hash_eject(req, ts);
if (req->opcode == IORING_OP_POLL_ADD) {
if (ret == IOU_POLL_DONE) {
@@ -343,7 +343,7 @@ static void io_poll_task_func(struct io_kiocb *req, bool *locked)
poll = io_kiocb_to_cmd(req, struct io_poll);
req->cqe.res = mangle_poll(req->cqe.res & poll->events);
} else if (ret == IOU_POLL_REISSUE) {
- io_req_task_submit(req, locked);
+ io_req_task_submit(req, ts);
return;
} else if (ret != IOU_POLL_REMOVE_POLL_USE_RES) {
req->cqe.res = ret;
@@ -351,14 +351,14 @@ static void io_poll_task_func(struct io_kiocb *req, bool *locked)
}
io_req_set_res(req, req->cqe.res, 0);
- io_req_task_complete(req, locked);
+ io_req_task_complete(req, ts);
} else {
- io_tw_lock(req->ctx, locked);
+ io_tw_lock(req->ctx, ts);
if (ret == IOU_POLL_REMOVE_POLL_USE_RES)
- io_req_task_complete(req, locked);
+ io_req_task_complete(req, ts);
else if (ret == IOU_POLL_DONE || ret == IOU_POLL_REISSUE)
- io_req_task_submit(req, locked);
+ io_req_task_submit(req, ts);
else
io_req_defer_failed(req, ret);
}
@@ -976,7 +976,7 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags)
struct io_hash_bucket *bucket;
struct io_kiocb *preq;
int ret2, ret = 0;
- bool locked;
+ struct io_tw_state ts = {};
preq = io_poll_find(ctx, true, &cd, &ctx->cancel_table, &bucket);
ret2 = io_poll_disarm(preq);
@@ -1026,8 +1026,8 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags)
req_set_fail(preq);
io_req_set_res(preq, -ECANCELED, 0);
- locked = !(issue_flags & IO_URING_F_UNLOCKED);
- io_req_task_complete(preq, &locked);
+ ts.locked = !(issue_flags & IO_URING_F_UNLOCKED);
+ io_req_task_complete(preq, &ts);
out:
if (ret < 0) {
req_set_fail(req);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 8f3b86c20075..0200f563a98f 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -283,16 +283,16 @@ static inline int io_fixup_rw_res(struct io_kiocb *req, long res)
return res;
}
-static void io_req_rw_complete(struct io_kiocb *req, bool *locked)
+static void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts)
{
io_req_io_end(req);
if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) {
- unsigned issue_flags = *locked ? 0 : IO_URING_F_UNLOCKED;
+ unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED;
req->cqe.flags |= io_put_kbuf(req, issue_flags);
}
- io_req_task_complete(req, locked);
+ io_req_task_complete(req, ts);
}
static void io_complete_rw(struct kiocb *kiocb, long res)
diff --git a/io_uring/timeout.c b/io_uring/timeout.c
index 826a51bca3e4..5c6c6f720809 100644
--- a/io_uring/timeout.c
+++ b/io_uring/timeout.c
@@ -101,9 +101,9 @@ __cold void io_flush_timeouts(struct io_ring_ctx *ctx)
spin_unlock_irq(&ctx->timeout_lock);
}
-static void io_req_tw_fail_links(struct io_kiocb *link, bool *locked)
+static void io_req_tw_fail_links(struct io_kiocb *link, struct io_tw_state *ts)
{
- io_tw_lock(link->ctx, locked);
+ io_tw_lock(link->ctx, ts);
while (link) {
struct io_kiocb *nxt = link->link;
long res = -ECANCELED;
@@ -112,7 +112,7 @@ static void io_req_tw_fail_links(struct io_kiocb *link, bool *locked)
res = link->cqe.res;
link->link = NULL;
io_req_set_res(link, res, 0);
- io_req_task_complete(link, locked);
+ io_req_task_complete(link, ts);
link = nxt;
}
}
@@ -265,9 +265,9 @@ int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
return 0;
}
-static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked)
+static void io_req_task_link_timeout(struct io_kiocb *req, struct io_tw_state *ts)
{
- unsigned issue_flags = *locked ? 0 : IO_URING_F_UNLOCKED;
+ unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED;
struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
struct io_kiocb *prev = timeout->prev;
int ret = -ENOENT;
@@ -282,11 +282,11 @@ static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked)
ret = io_try_cancel(req->task->io_uring, &cd, issue_flags);
}
io_req_set_res(req, ret ?: -ETIME, 0);
- io_req_task_complete(req, locked);
+ io_req_task_complete(req, ts);
io_put_req(prev);
} else {
io_req_set_res(req, -ETIME, 0);
- io_req_task_complete(req, locked);
+ io_req_task_complete(req, ts);
}
}
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 2e4c483075d3..871ce53fe833 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -12,7 +12,7 @@
#include "rsrc.h"
#include "uring_cmd.h"
-static void io_uring_cmd_work(struct io_kiocb *req, bool *locked)
+static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
{
struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
--
2.39.1
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