This is a note to let you know that I've just added the patch titled
dm-delay: fix hung task introduced by kthread mode
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-delay-fix-hung-task-introduced-by-kthread-mode.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7c5226d5c8620a4b1838cbae958ea483f65b19ed
Author: Joel Colledge <joel.colledge@xxxxxxxxxx>
Date: Mon May 6 09:25:23 2024 +0200
dm-delay: fix hung task introduced by kthread mode
[ Upstream commit d14646f23300a5fc85be867bafdc0702c2002789 ]
If the worker thread is not woken due to a bio, then it is not woken at
all. This causes the hung task check to trigger. This occurs, for
instance, when no bios are submitted. Also when a delay of 0 is
configured, delay_bio() returns without waking the worker.
Prevent the hung task check from triggering by creating the thread with
kthread_run() instead of using kthread_create() directly.
Fixes: 70bbeb29fab0 ("dm delay: for short delays, use kthread instead of timers and wq")
Signed-off-by: Joel Colledge <joel.colledge@xxxxxxxxxx>
Reviewed-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index eec0daa4b227a..4ba12d5369949 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -269,8 +269,7 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
* In case of small requested delays, use kthread instead of
* timers and workqueue to achieve better latency.
*/
- dc->worker = kthread_create(&flush_worker_fn, dc,
- "dm-delay-flush-worker");
+ dc->worker = kthread_run(&flush_worker_fn, dc, "dm-delay-flush-worker");
if (IS_ERR(dc->worker)) {
ret = PTR_ERR(dc->worker);
dc->worker = NULL;
