block: more check for replaced node

We use mirror+replace to fix quorum's broken child. bs/s->common.bs
is quorum, and to_replace is the broken child. The new child is target_bs.
Without this patch, the replace node can be any node, and it can be
top BDS with BB, or another quorum's child. We just check if the broken
child is part of the quorum BDS in this patch.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Message-id: 55A86486.1000404@cn.fujitsu.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/block.c b/block.c
index d088ee0..090923c 100644
--- a/block.c
+++ b/block.c
@@ -4077,7 +4077,8 @@
     return false;
 }
 
-BlockDriverState *check_to_replace_node(const char *node_name, Error **errp)
+BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
+                                        const char *node_name, Error **errp)
 {
     BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
     AioContext *aio_context;
@@ -4100,7 +4101,7 @@
      * Another benefit is that this tests exclude backing files which are
      * blocked by the backing blockers.
      */
-    if (!bdrv_is_first_non_filter(to_replace_bs)) {
+    if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
         error_setg(errp, "Only top most non filter can be replaced");
         to_replace_bs = NULL;
         goto out;