brd: support barriers

brd is always ordered (not that it matters, as it is defined not to
survive when the system goes down). So tell the block layer it is
ordered, which might be of help with testing filesystems.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index bdd4f5f..ee8ed68 100644 (file)
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -436,6 +436,7 @@ static struct brd_device *brd_alloc(int i)
        if (!brd->brd_queue)
                goto out_free_dev;
        blk_queue_make_request(brd->brd_queue, brd_make_request);
+       blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG, NULL);
        blk_queue_max_sectors(brd->brd_queue, 1024);
        blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);