blocK: Restore barrier support for md and probably other virtual devi…

…ces. The next_ordered flag is only meaningful for devices that use __make_request. So move the test against next_ordered out of generic code and in to __make_request Since this test was added, barriers have not worked on md or any devices that don't use __make_request and so don't bother to set next_ordered. (dm explicitly sets something other than QUEUE_ORDERED_NONE since commit 99360b4 but notes in the comments that it is otherwise meaningless). Cc: Ken Milmore <[email protected]> Cc: [email protected] Signed-off-by: NeilBrown <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
josf · Jul 1, 2009 · db64f68 · db64f68
1 parent 018e044
commit db64f68
Showing 1 changed file with 5 additions and 5 deletions.
diff --git a/block/blk-core.c b/block/blk-core.c
@@ -1170,6 +1170,11 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 	const int unplug = bio_unplug(bio);
 	int rw_flags;
 
+	if (bio_barrier(bio) && bio_has_data(bio) &&
+	    (q->next_ordered == QUEUE_ORDERED_NONE)) {
+		bio_endio(bio, -EOPNOTSUPP);
+		return 0;
+	}
 	/*
 	 * low level driver can indicate that it wants pages above a
 	 * certain limit bounced to low memory (ie for highmem, or even
@@ -1470,11 +1475,6 @@ static inline void __generic_make_request(struct bio *bio)
 			err = -EOPNOTSUPP;
 			goto end_io;
 		}
-		if (bio_barrier(bio) && bio_has_data(bio) &&
-		    (q->next_ordered == QUEUE_ORDERED_NONE)) {
-			err = -EOPNOTSUPP;
-			goto end_io;
-		}
 
 		ret = q->make_request_fn(q, bio);
 	} while (ret);