[PATCH 2/8] blk-mq: skip non-mq queues in blk_mq_quiesce_queue

[Christoph Hellwig]

On Fri, Oct 21, 2022 at 09:13:29AM +0800, Ming Lei wrote:
> > -	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:

Another one is the wb_lat_usec sysfs attribute.  But maybe it is better
do just do this in the callers and WARN?