dm mpath: return DM_MAPIO_DELAY_REQUEUE if QUEUE_IO or PG_INIT_REQUIRED

Avoid using DM_MAPIO_REQUEUE unless absolutely necessary because it
results in dm-rq.c:dm_mq_queue_rq() returning BLK_STS_RESOURCE to
blk-mq -- doing so should only ever be done if the underlying queue is
out of resources.  So switch to returning DM_MAPIO_DELAY_REQUEUE from
multipath_clone_and_map() if either MPATHF_QUEUE_IO or
MPATHF_PG_INIT_REQUIRED are set.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Ming Lei 2018-01-11 14:01:55 +08:00 committed by Mike Snitzer
parent 050af08ffb
commit 459b54019c

View File

@ -517,9 +517,8 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
return DM_MAPIO_KILL;
} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
if (pg_init_all_paths(m))
return DM_MAPIO_DELAY_REQUEUE;
return DM_MAPIO_REQUEUE;
pg_init_all_paths(m);
return DM_MAPIO_DELAY_REQUEUE;
}
mpio->pgpath = pgpath;