On Thu, Oct 20, 2022 at 12:56:02PM +0200, 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.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> block/blk-mq.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 33292c01875d5..df967c8af9fee 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);
This interface can't work as expected for bio drivers, the only user
should be del_gendisk(), but anyway the patch is fine:
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
thanks,
Ming
