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?