Commits
Sasha Levin committed 655fe78746d
dm rq: fix the starting and stopping of blk-mq queues [ Upstream commit 7d9595d848cdff5c7939f68eec39e0c5d36a1d67 ] Improve dm_stop_queue() to cancel any requeue_work. Also, have dm_start_queue() and dm_stop_queue() clear/set the QUEUE_FLAG_STOPPED for the blk-mq request_queue. On suspend dm_stop_queue() handles stopping the blk-mq request_queue BUT: even though the hw_queues are marked BLK_MQ_S_STOPPED at that point there is still a race that is allowing block/blk-mq.c to call ->queue_rq against a hctx that it really shouldn't. Add a check to dm_mq_queue_rq() that guards against this rarity (albeit _not_ race-free). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # must patch dm.c on < 4.8 kernels Signed-off-by: Sasha Levin <alexander.levin@verizon.com>