diff --git a/block.c b/block.c
index a2a4a0d..e49ff8c 100644
--- a/block.c
+++ b/block.c
@@ -2249,12 +2249,14 @@
 };
 
 /*
- * bdrv_replace_child
+ * bdrv_replace_child_tran
  *
  * Note: real unref of old_bs is done only on commit.
+ *
+ * The function doesn't update permissions, caller is responsible for this.
  */
-static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
-                               Transaction *tran)
+static void bdrv_replace_child_tran(BdrvChild *child, BlockDriverState *new_bs,
+                                    Transaction *tran)
 {
     BdrvReplaceChildState *s = g_new(BdrvReplaceChildState, 1);
     *s = (BdrvReplaceChildState) {
@@ -4766,7 +4768,7 @@
     }
 
     /*
-     * We don't have to restore child->bs here to undo bdrv_replace_child()
+     * We don't have to restore child->bs here to undo bdrv_replace_child_tran()
      * because that function is transactionable and it registered own completion
      * entries in @tran, so .abort() for bdrv_replace_child_safe() will be
      * called automatically.
@@ -4802,7 +4804,7 @@
     }
 
     if (child->bs) {
-        bdrv_replace_child(child, NULL, tran);
+        bdrv_replace_child_tran(child, NULL, tran);
     }
 
     s = g_new(BdrvRemoveFilterOrCowChild, 1);
@@ -4842,7 +4844,7 @@
                        c->name, from->node_name);
             return -EPERM;
         }
-        bdrv_replace_child(c, to, tran);
+        bdrv_replace_child_tran(c, to, tran);
     }
 
     return 0;