diff mbox series

[10/14] blk-mq: skip non-mq queues in blk_mq_quiesce_queue

Message ID 20221101150050.3510-11-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/14] block: set the disk capacity to 0 in blk_mark_disk_dead | expand

Commit Message

Christoph Hellwig Nov. 1, 2022, 3 p.m. UTC 
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>
---
 block/blk-mq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Chaitanya Kulkarni Nov. 2, 2022, 5:47 a.m. UTC | #1 
On 11/1/22 08:00, Christoph Hellwig wrote:
> 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>

-ck
diff mbox series

Patch

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 623e8a506539c..b8f37cfd3ae22 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -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);