block/copy-before-write: drop extra bdrv_unref on failure path

bdrv_attach_child() do bdrv_unref() on failure, so we shouldn't do it
by hand here.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210824083856.17408-12-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 2a51cc64e4a9cb0d39ac5e120543ee66a2b2f5fc..945d9340f458f01978bb15c45b18b1250d255df2 100644 (file)
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -201,7 +201,6 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
     state->target = bdrv_attach_child(top, target, "target", &child_of_bds,
                                       BDRV_CHILD_DATA, errp);
     if (!state->target) {
-        bdrv_unref(target);
         bdrv_unref(top);
         return NULL;
     }