dm: do not set QUEUE_ORDERED_DRAIN if request based

Request-based dm doesn't have barrier support yet.
So we need to set QUEUE_ORDERED_DRAIN only for bio-based dm.
Since the device type is decided at the first table loading time,
the flag set is deferred until then.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index aaeb82e..4899ebe 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -830,6 +830,11 @@
 	return t->type;
 }
 
+bool dm_table_bio_based(struct dm_table *t)
+{
+	return dm_table_get_type(t) == DM_TYPE_BIO_BASED;
+}
+
 bool dm_table_request_based(struct dm_table *t)
 {
 	return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;