block: bdrv_insert_node(): fix and improve error handling

 - use ERRP_GUARD(): function calls error_prepend(), so it must use
   ERRP_GUARD(), otherwise error_prepend() would not be called when
   passed errp is error_fatal

 - drop error propagation, handle return code instead

 - for symmetry, do error_prepend() for the second failure

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210920115538.264372-3-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/block.c b/block.c
index 917fb7faca..5d49188073 100644
--- a/block.c
+++ b/block.c
@@ -5122,8 +5122,9 @@ static void bdrv_delete(BlockDriverState *bs)
 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
                                    int flags, Error **errp)
 {
+    ERRP_GUARD();
+    int ret;
     BlockDriverState *new_node_bs;
-    Error *local_err = NULL;
 
     new_node_bs = bdrv_open(NULL, NULL, node_options, flags, errp);
     if (new_node_bs == NULL) {
@@ -5132,12 +5133,12 @@ BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
     }
 
     bdrv_drained_begin(bs);
-    bdrv_replace_node(bs, new_node_bs, &local_err);
+    ret = bdrv_replace_node(bs, new_node_bs, errp);
     bdrv_drained_end(bs);
 
-    if (local_err) {
+    if (ret < 0) {
+        error_prepend(errp, "Could not replace node: ");
         bdrv_unref(new_node_bs);
-        error_propagate(errp, local_err);
         return NULL;
     }