block: fix bdrv_root_attach_child forget to unref child_bs

bdrv_root_attach_child promises to drop child_bs reference on failure.
It does it on first handled failure path, but not on the second. Fix
that.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200324155921.23822-1-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/block.c b/block.c
index af3faf664e..2e3905c99e 100644
--- a/block.c
+++ b/block.c
@@ -2617,6 +2617,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
             error_propagate(errp, local_err);
             g_free(child);
             bdrv_abort_perm_update(child_bs);
+            bdrv_unref(child_bs);
             return NULL;
         }
     }