blk-mq: skip non-mq queues in blk_mq_quiesce_queue

For submit_bio based queues there is no (S)RCU critical section during
I/O submission and thus nothing to wait for in blk_mq_wait_quiesce_done,
so skip doing any synchronization.  No non-mq driver should be calling
this, but for now we have core callers that unconditionally call into it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221101150050.3510-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2022-11-01 16:00:46 +01:00 committed by Jens Axboe
parent 2b4c2355c5
commit 8537380bb9
1 changed files with 3 additions and 1 deletions

View File

@ -280,7 +280,9 @@ EXPORT_SYMBOL_GPL(blk_mq_wait_quiesce_done);
void blk_mq_quiesce_queue(struct request_queue *q)
{
blk_mq_quiesce_queue_nowait(q);
blk_mq_wait_quiesce_done(q);
/* nothing to wait for non-mq queues */
if (queue_is_mq(q))
blk_mq_wait_quiesce_done(q);
}
EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);