summaryrefslogtreecommitdiff
path: root/drivers/md
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-mpath.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 2704a55f8b6e..8b7328666eaa 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -502,8 +502,20 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
if (queue_dying) {
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;