diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index be581765edd1..e0187798ccae 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -533,8 +533,20 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, if (blk_queue_dying(q)) { atomic_inc(&m->pg_init_in_progress); activate_or_offline_path(pgpath); + return DM_MAPIO_DELAY_REQUEUE; } - return DM_MAPIO_DELAY_REQUEUE; + + /* + * blk-mq's SCHED_RESTART can cover this requeue, so we + * needn't deal with it by DELAY_REQUEUE. More importantly, + * we have to return DM_MAPIO_REQUEUE so that blk-mq can + * get the queue busy feedback (via BLK_STS_RESOURCE), + * otherwise I/O merging can suffer. + */ + if (q->mq_ops) + return DM_MAPIO_REQUEUE; + else + return DM_MAPIO_DELAY_REQUEUE; } clone->bio = clone->biotail = NULL; clone->rq_disk = bdev->bd_disk;