From: John Snow <jsnow@redhat.com>

In cases where we abort the block/mirror job, there's no point in
installing the new backing chain before we finish aborting.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180906130225.5118-6-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/mirror.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/mirror.c b/block/mirror.c
index cba555b4ef..bd3e908710 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -642,7 +642,7 @@ static void mirror_exit(Job *job)
      * required before it could become a backing file of target_bs. */
     bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL,
                             &error_abort);
-    if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
+    if (ret == 0 && s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
         BlockDriverState *backing = s->is_none_mode ? src : s->base;
         if (backing_bs(target_bs) != backing) {
             bdrv_set_backing_hd(target_bs, backing, &local_err);
-- 
2.17.1