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author | Ming Lei <ming.lei@redhat.com> | 2020-06-19 11:42:14 +0300 |
---|---|---|
committer | Mike Snitzer <snitzer@redhat.com> | 2020-07-20 18:17:42 +0300 |
commit | e766668c6cd49d741cfb49eaeb38998ba34d27bc (patch) | |
tree | 32cbb6b928ae61335409d593db19655696bcaab6 /drivers/md/dm-rq.c | |
parent | 0c248ea27fc88cf8a3035ba0ed75b210be9abf80 (diff) | |
download | linux-e766668c6cd49d741cfb49eaeb38998ba34d27bc.tar.xz |
dm rq: don't call blk_mq_queue_stopped() in dm_stop_queue()
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@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-rq.c')
-rw-r--r-- | drivers/md/dm-rq.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index 85e0daabad49..20745e2e34b9 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); } |