block-vbd: Fix vbd_aio_flush() no-op case

Call the completion function if flush features are not supported in blkfront.

Signed-off-by: Yosuke Iwamatsu <y-iwamatsu@ab.jp.nec.com>

diff --git a/block-vbd.c b/block-vbd.c
index 4341259b12ae8e92728b1b950230c3282ee8946d..129a1f55c60f16401f1026b6069dab08f4e32ec1 100644 (file)
--- a/block-vbd.c
+++ b/block-vbd.c
@@ -261,7 +261,8 @@ static BlockDriverAIOCB *vbd_aio_flush(BlockDriverState *bs,
     BDRVVbdState *s = bs->opaque;
     VbdAIOCB *acb = NULL;
 
-    if (s->info.mode == O_RDONLY) {
+    if (s->info.mode == O_RDONLY ||
+        s->info.barrier != 1 || s->info.flush != 1) {
         cb(opaque, 0);
         return NULL;
     }