6.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joel Colledge <joel.colledge@xxxxxxxxxx>
[ 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>
---
drivers/md/dm-delay.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
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;
--
2.43.0
