[PATCH 5.13 243/351] io_uring: get rid of files in exit cancel

Greg Kroah-Hartman
2021-07-19T17:51:08Z

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit 3dd0c97a9e011b11ce6bd245bacf58c57f6f7875 ]

We don't match against files on cancellation anymore, so no need to drag
around files_struct anymore, just pass a flag telling whether only
inflight or all requests should be killed.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7bfc5409a78f8e2d6b27dec3293ec2d248677348.1621201931.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/io_uring.c | 63 +++++++++++++++++++++++++--------------------------
1 file changed, 31 insertions(+), 32 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index a949b2bdb718..2bf2aacb4c81 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1037,7 +1037,7 @@ static bool io_disarm_next(struct io_kiocb *req);
static void io_uring_del_task_file(unsigned long index);
static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
struct task_struct *task,
- struct files_struct *files);
+ bool cancel_all);
static void io_uring_cancel_sqpoll(struct io_sq_data *sqd);
static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx);

@@ -1106,15 +1106,14 @@ static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl)
percpu_ref_put(ref);
}

-static bool io_match_task(struct io_kiocb *head,
- struct task_struct *task,
- struct files_struct *files)
+static bool io_match_task(struct io_kiocb *head, struct task_struct *task,
+ bool cancel_all)
{
struct io_kiocb *req;

if (task && head->task != task)
return false;
- if (!files)
+ if (cancel_all)
return true;

io_for_each_link(req, head) {
@@ -5265,7 +5264,7 @@ static bool io_poll_remove_one(struct io_kiocb *req)
* 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)
+ bool cancel_all)
{
struct hlist_node *tmp;
struct io_kiocb *req;
@@ -5277,7 +5276,7 @@ static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,

list = &ctx->cancel_hash[i];
hlist_for_each_entry_safe(req, tmp, list, hash_node) {
- if (io_match_task(req, tsk, files))
+ if (io_match_task(req, tsk, cancel_all))
posted += io_poll_remove_one(req);
}
}
@@ -8747,7 +8746,7 @@ static void io_ring_exit_work(struct work_struct *work)
* as nobody else will be looking for them.
*/
do {
- io_uring_try_cancel_requests(ctx, NULL, NULL);
+ io_uring_try_cancel_requests(ctx, NULL, true);
if (ctx->sq_data) {
struct io_sq_data *sqd = ctx->sq_data;
struct task_struct *tsk;
@@ -8798,14 +8797,14 @@ static void io_ring_exit_work(struct work_struct *work)

/* 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)
+ bool cancel_all)
{
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)) {
+ if (io_match_task(req, tsk, cancel_all)) {
io_kill_timeout(req, -ECANCELED);
canceled++;
}
@@ -8831,8 +8830,8 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
io_unregister_personality(ctx, index);
mutex_unlock(&ctx->uring_lock);

- io_kill_timeouts(ctx, NULL, NULL);
- io_poll_remove_all(ctx, NULL, NULL);
+ 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);
@@ -8858,7 +8857,7 @@ static int io_uring_release(struct inode *inode, struct file *file)

struct io_task_cancel {
struct task_struct *task;
- struct files_struct *files;
+ bool all;
};

static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
@@ -8867,30 +8866,29 @@ static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
struct io_task_cancel *cancel = data;
bool ret;

- if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) {
+ if (!cancel->all && (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);
+ ret = io_match_task(req, cancel->task, cancel->all);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
} else {
- ret = io_match_task(req, cancel->task, cancel->files);
+ ret = io_match_task(req, cancel->task, cancel->all);
}
return ret;
}

static bool io_cancel_defer_files(struct io_ring_ctx *ctx,
- struct task_struct *task,
- struct files_struct *files)
+ struct task_struct *task, bool cancel_all)
{
struct io_defer_entry *de;
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)) {
+ if (io_match_task(de->req, task, cancel_all)) {
list_cut_position(&list, &ctx->defer_list, &de->list);
break;
}
@@ -8934,9 +8932,9 @@ static bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)

static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
struct task_struct *task,
- struct files_struct *files)
+ bool cancel_all)
{
- struct io_task_cancel cancel = { .task = task, .files = files, };
+ struct io_task_cancel cancel = { .task = task, .all = cancel_all, };
struct io_uring_task *tctx = task ? task->io_uring : NULL;

while (1) {
@@ -8956,7 +8954,7 @@ static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
}

/* SQPOLL thread does its own polling */
- if ((!(ctx->flags & IORING_SETUP_SQPOLL) && !files) ||
+ 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);
@@ -8964,9 +8962,9 @@ static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
}
}

- ret |= io_cancel_defer_files(ctx, task, files);
- ret |= io_poll_remove_all(ctx, task, files);
- ret |= io_kill_timeouts(ctx, task, files);
+ 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);
ret |= io_run_task_work();
ret |= io_run_ctx_fallback(ctx);
if (!ret)
@@ -9072,7 +9070,7 @@ static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked)
return percpu_counter_sum(&tctx->inflight);
}

-static void io_uring_try_cancel(struct files_struct *files)
+static void io_uring_try_cancel(bool cancel_all)
{
struct io_uring_task *tctx = current->io_uring;
struct io_tctx_node *node;
@@ -9083,7 +9081,7 @@ static void io_uring_try_cancel(struct files_struct *files)

/* sqpoll task will cancel all its requests */
if (!ctx->sq_data)
- io_uring_try_cancel_requests(ctx, current, files);
+ io_uring_try_cancel_requests(ctx, current, cancel_all);
}
}

@@ -9109,7 +9107,7 @@ static void io_uring_cancel_sqpoll(struct io_sq_data *sqd)
if (!inflight)
break;
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
- io_uring_try_cancel_requests(ctx, current, NULL);
+ io_uring_try_cancel_requests(ctx, current, true);

prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
/*
@@ -9133,6 +9131,7 @@ void __io_uring_cancel(struct files_struct *files)
struct io_uring_task *tctx = current->io_uring;
DEFINE_WAIT(wait);
s64 inflight;
+ bool cancel_all = !files;

if (tctx->io_wq)
io_wq_exit_start(tctx->io_wq);
@@ -9141,10 +9140,10 @@ void __io_uring_cancel(struct files_struct *files)
atomic_inc(&tctx->in_idle);
do {
/* read completions before cancelations */
- inflight = tctx_inflight(tctx, !!files);
+ inflight = tctx_inflight(tctx, !cancel_all);
if (!inflight)
break;
- io_uring_try_cancel(files);
+ io_uring_try_cancel(cancel_all);
prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);

/*
@@ -9152,14 +9151,14 @@ void __io_uring_cancel(struct files_struct *files)
* avoids a race where a completion comes in before we did
* prepare_to_wait().
*/
- if (inflight == tctx_inflight(tctx, !!files))
+ if (inflight == tctx_inflight(tctx, !cancel_all))
schedule();
finish_wait(&tctx->wait, &wait);
} while (1);
atomic_dec(&tctx->in_idle);

io_uring_clean_tctx(tctx);
- if (!files) {
+ if (cancel_all) {
/* for exec all current's requests should be gone, kill tctx */
__io_uring_free(current);
}
--
2.30.2