From: Olivier Langlois <olivier@trillion01.com>
To: Jens Axboe <axboe@kernel.dk>,
Pavel Begunkov <asml.silence@gmail.com>,
io-uring@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, gregkh@linuxfoundation.org
Subject: [PATCH io_uring backport to 5.13.y] io_uring: Fix race condition when sqp thread goes to sleep
Date: Sat, 24 Jul 2021 22:07:59 -0700 [thread overview]
Message-ID: <82a82077d8b02166482df754b1abb7c3fbc3c560.1627189961.git.olivier@trillion01.com> (raw)
[ Upstream commit 997135017716 ("io_uring: Fix race condition when sqp thread goes to sleep") ]
If an asynchronous completion happens before the task is preparing
itself to wait and set its state to TASK_INTERRUPTIBLE, the completion
will not wake up the sqp thread.
Signed-off-by: Olivier Langlois <olivier@trillion01.com>
---
fs/io_uring.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index eeea6b8c8bee..a7f1cbd7be9a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6876,7 +6876,8 @@ static int io_sq_thread(void *data)
}
prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE);
- if (!test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state)) {
+ if (!test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) &&
+ !io_run_task_work()) {
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
io_ring_set_wakeup_flag(ctx);
--
2.32.0
next reply other threads:[~2021-07-25 17:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-25 5:07 Olivier Langlois [this message]
2021-07-25 19:10 ` [PATCH io_uring backport to 5.13.y] io_uring: Fix race condition when sqp thread goes to sleep Jens Axboe
2021-07-26 7:42 ` Greg KH
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