On Tue, 2017-04-11 at 13:47 -0400, Mike Snitzer wrote: > Other drivers will very likely be caught about by > this blk-mq quirk in the future. Hello Mike, Are you aware that the requirement that blk-mq drivers rerun the queue after having returned BLK_MQ_RQ_QUEUE_BUSY is a requirement that is shared with traditional block drivers? From dm_old_request_fn(): if (... || (ti->type->busy && ti->type->busy(ti))) { blk_delay_queue(q, 10); return; } Bart.