linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH io_uring backport to 5.13.y] io_uring: Fix race condition when sqp thread goes to sleep
@ 2021-07-25  5:07 Olivier Langlois
  2021-07-25 19:10 ` Jens Axboe
  0 siblings, 1 reply; 3+ messages in thread
From: Olivier Langlois @ 2021-07-25  5:07 UTC (permalink / raw)
  To: Jens Axboe, Pavel Begunkov, io-uring, linux-kernel, stable, gregkh

[ 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


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH io_uring backport to 5.13.y] io_uring: Fix race condition when sqp thread goes to sleep
  2021-07-25  5:07 [PATCH io_uring backport to 5.13.y] io_uring: Fix race condition when sqp thread goes to sleep Olivier Langlois
@ 2021-07-25 19:10 ` Jens Axboe
  2021-07-26  7:42   ` Greg KH
  0 siblings, 1 reply; 3+ messages in thread
From: Jens Axboe @ 2021-07-25 19:10 UTC (permalink / raw)
  To: Olivier Langlois, Pavel Begunkov, io-uring, linux-kernel, stable, gregkh

On 7/24/21 11:07 PM, Olivier Langlois wrote:
> [ 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.

Looks good to me - Greg, would you mind queueing this one up?

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH io_uring backport to 5.13.y] io_uring: Fix race condition when sqp thread goes to sleep
  2021-07-25 19:10 ` Jens Axboe
@ 2021-07-26  7:42   ` Greg KH
  0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2021-07-26  7:42 UTC (permalink / raw)
  To: Jens Axboe
  Cc: Olivier Langlois, Pavel Begunkov, io-uring, linux-kernel, stable

On Sun, Jul 25, 2021 at 01:10:22PM -0600, Jens Axboe wrote:
> On 7/24/21 11:07 PM, Olivier Langlois wrote:
> > [ 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.
> 
> Looks good to me - Greg, would you mind queueing this one up?
> 

Now queued up, thanks!

greg k-h

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-07-26  7:43 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-25  5:07 [PATCH io_uring backport to 5.13.y] io_uring: Fix race condition when sqp thread goes to sleep Olivier Langlois
2021-07-25 19:10 ` Jens Axboe
2021-07-26  7:42   ` Greg KH

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).