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authorLinus Torvalds <torvalds@linux-foundation.org>2021-01-30 00:47:47 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-01-30 00:47:47 +0300
commitc0ec4ffc40939e9a5a5844ce455f2b5b66a005fd (patch)
treede598f07b026cf965790e8888fef9d56ab6496a1
parent8ef24c2011b77bd6344d16630d3cd95d63de63f8 (diff)
parent3a7efd1ad269ccaf9c1423364d97c9661ba6dafa (diff)
downloadlinux-c0ec4ffc40939e9a5a5844ce455f2b5b66a005fd.tar.xz
Merge tag 'io_uring-5.11-2021-01-29' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe: "We got the cancelation story sorted now, so for all intents and purposes, this should be it for 5.11 outside of any potential little fixes that may come in. This contains: - task_work task state fixes (Hao, Pavel) - Cancelation fixes (me, Pavel) - Fix for an inflight req patch in this release (Pavel) - Fix for a lock deadlock issue (Pavel)" * tag 'io_uring-5.11-2021-01-29' of git://git.kernel.dk/linux-block: io_uring: reinforce cancel on flush during exit io_uring: fix sqo ownership false positive warning io_uring: fix list corruption for splice file_get io_uring: fix flush cqring overflow list while TASK_INTERRUPTIBLE io_uring: fix wqe->lock/completion_lock deadlock io_uring: fix cancellation taking mutex while TASK_UNINTERRUPTIBLE io_uring: fix __io_uring_files_cancel() with TASK_UNINTERRUPTIBLE io_uring: only call io_cqring_ev_posted() if events were posted io_uring: if we see flush on exit, cancel related tasks
-rw-r--r--fs/io_uring.c95
1 files changed, 53 insertions, 42 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index c07913ec0cca..38c6cbe1ab38 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1026,6 +1026,7 @@ 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;
@@ -1069,8 +1070,12 @@ static bool io_match_task(struct io_kiocb *head,
{
struct io_kiocb *req;
- if (task && head->task != task)
+ 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;
@@ -1630,18 +1635,11 @@ 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);
- struct io_kiocb *link;
if (req_need_defer(de->req, de->seq))
break;
list_del_init(&de->list);
- /* punt-init is done before queueing for defer */
- link = __io_queue_async_work(de->req);
- if (link) {
- __io_queue_linked_timeout(link);
- /* drop submission reference */
- io_put_req_deferred(link, 1);
- }
+ io_req_task_queue(de->req);
kfree(de);
} while (!list_empty(&ctx->defer_list));
}
@@ -1775,12 +1773,13 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
struct io_kiocb *req, *tmp;
struct io_uring_cqe *cqe;
unsigned long flags;
- bool all_flushed;
+ bool all_flushed, posted;
LIST_HEAD(list);
if (!force && __io_cqring_events(ctx) == rings->cq_ring_entries)
return false;
+ posted = false;
spin_lock_irqsave(&ctx->completion_lock, flags);
list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) {
if (!io_match_task(req, tsk, files))
@@ -1800,6 +1799,7 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
WRITE_ONCE(ctx->rings->cq_overflow,
ctx->cached_cq_overflow);
}
+ posted = true;
}
all_flushed = list_empty(&ctx->cq_overflow_list);
@@ -1809,9 +1809,11 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
}
- io_commit_cqring(ctx);
+ if (posted)
+ io_commit_cqring(ctx);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
- io_cqring_ev_posted(ctx);
+ if (posted)
+ io_cqring_ev_posted(ctx);
while (!list_empty(&list)) {
req = list_first_entry(&list, struct io_kiocb, compl.list);
@@ -6458,7 +6460,8 @@ static struct file *io_file_get(struct io_submit_state *state,
file = __io_file_get(state, fd);
}
- if (file && file->f_op == &io_uring_fops) {
+ if (file && file->f_op == &io_uring_fops &&
+ !(req->flags & REQ_F_INFLIGHT)) {
io_req_init_async(req);
req->flags |= REQ_F_INFLIGHT;
@@ -7266,14 +7269,18 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
TASK_INTERRUPTIBLE);
/* make sure we run task_work before checking for signals */
ret = io_run_task_work_sig();
- if (ret > 0)
+ 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))
+ if (test_bit(0, &ctx->cq_check_overflow)) {
+ finish_wait(&ctx->wait, &iowq.wq);
continue;
+ }
if (uts) {
timeout = schedule_timeout(timeout);
if (timeout == 0) {
@@ -8865,30 +8872,31 @@ static void io_cancel_defer_files(struct io_ring_ctx *ctx,
}
}
+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 };
- struct io_kiocb *req;
DEFINE_WAIT(wait);
- bool found = false;
-
- spin_lock_irq(&ctx->inflight_lock);
- list_for_each_entry(req, &ctx->inflight_list, inflight_entry) {
- if (!io_match_task(req, task, files))
- continue;
- found = true;
- break;
- }
- if (found)
- prepare_to_wait(&task->io_uring->wait, &wait,
- TASK_UNINTERRUPTIBLE);
- spin_unlock_irq(&ctx->inflight_lock);
+ int inflight;
- /* We need to keep going until we don't find a matching req */
- if (!found)
+ inflight = io_uring_count_inflight(ctx, task, files);
+ if (!inflight)
break;
io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true);
@@ -8897,7 +8905,11 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
io_cqring_overflow_flush(ctx, true, task, files);
/* cancellations _may_ trigger task work */
io_run_task_work();
- schedule();
+
+ 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);
}
}
@@ -8955,8 +8967,6 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
struct task_struct *task = current;
if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
- /* for SQPOLL only sqo_task has task notes */
- WARN_ON_ONCE(ctx->sqo_task != current);
io_disable_sqo_submit(ctx);
task = ctx->sq_data->thread;
atomic_inc(&task->io_uring->in_idle);
@@ -8966,10 +8976,9 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
io_cancel_defer_files(ctx, task, files);
io_cqring_overflow_flush(ctx, true, task, files);
+ io_uring_cancel_files(ctx, 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);
@@ -9116,16 +9125,15 @@ void __io_uring_task_cancel(void)
prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
/*
- * If we've seen completions, retry. This avoids a race where
- * a completion comes in before we did prepare_to_wait().
+ * 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))
- continue;
- schedule();
+ if (inflight == tctx_inflight(tctx))
+ schedule();
finish_wait(&tctx->wait, &wait);
} while (1);
- finish_wait(&tctx->wait, &wait);
atomic_dec(&tctx->in_idle);
io_uring_remove_task_files(tctx);
@@ -9136,6 +9144,9 @@ 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;