From: Ming Lei <ming.lei@xxxxxxxxxx>
[ Upstream commit e766668c6cd49d741cfb49eaeb38998ba34d27bc ]
dm_stop_queue() only uses blk_mq_quiesce_queue() so it doesn't
formally stop the blk-mq queue; therefore there is no point making the
blk_mq_queue_stopped() check -- it will never be stopped.
In addition, even though dm_stop_queue() actually tries to quiesce hw
queues via blk_mq_quiesce_queue(), checking with blk_queue_quiesced()
to avoid unnecessary queue quiesce isn't reliable because: the
QUEUE_FLAG_QUIESCED flag is set before synchronize_rcu() and
dm_stop_queue() may be called when synchronize_rcu() from another
blk_mq_quiesce_queue() is in-progress.
Fixes: 7b17c2f7292ba ("dm: Fix a race condition related to stopping and starting queues")
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/md/dm-rq.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 85e0daabad49c..20745e2e34b94 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -70,9 +70,6 @@ void dm_start_queue(struct request_queue *q)
void dm_stop_queue(struct request_queue *q)
{
- if (blk_mq_queue_stopped(q))
- return;
-
blk_mq_quiesce_queue(q);
}
--
2.25.1
