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 bdd4f5f45575bbf1b0bd69df7f68ed09a52a3776..ee8ed68f197ed9d83b3b22535308d993c31ffba8 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);