block: call rq_qos_exit() after queue is frozen

[ Upstream commit c57cdf7a9e51d97a43e29b8f4a04157875104000 ]

rq_qos_exit() removes the current q->rq_qos, this action has to be
done after queue is frozen, otherwise the IO queue path may never
be waken up, then IO hang is caused.

So fixes this issue by moving rq_qos_exit() after queue is frozen.

Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ming Lei 2018-10-24 21:18:09 +08:00 committed by Greg Kroah-Hartman
parent a125df22d1
commit 9663d294ae
2 changed files with 3 additions and 2 deletions

View File

@ -784,6 +784,9 @@ void blk_cleanup_queue(struct request_queue *q)
* prevent that q->request_fn() gets invoked after draining finished.
*/
blk_freeze_queue(q);
rq_qos_exit(q);
spin_lock_irq(lock);
queue_flag_set(QUEUE_FLAG_DEAD, q);
spin_unlock_irq(lock);

View File

@ -997,8 +997,6 @@ void blk_unregister_queue(struct gendisk *disk)
kobject_del(&q->kobj);
blk_trace_remove_sysfs(disk_to_dev(disk));
rq_qos_exit(q);
mutex_lock(&q->sysfs_lock);
if (q->request_fn || (q->mq_ops && q->elevator))
elv_unregister_queue(q);