From 3e44c8e08a4b84ec1f4f1eb249d33005bb9cf572 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 9 Feb 2017 12:51:18 +0100 Subject: block: Allow backing file links in change_parent_backing_link() Now that the backing file child role implements .attach/.detach callbacks, nothing prevents us from modifying the graph even if that involves changing backing file links. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Acked-by: Fam Zheng --- block.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'block.c') diff --git a/block.c b/block.c index 698a5c7e0b..79d9ad0ad6 100644 --- a/block.c +++ b/block.c @@ -2882,9 +2882,9 @@ static void change_parent_backing_link(BlockDriverState *from, continue; } if (c->role == &child_backing) { - /* @from is generally not allowed to be a backing file, except for - * when @to is the overlay. In that case, @from may not be replaced - * by @to as @to's backing node. */ + /* If @from is a backing file of @to, ignore the child to avoid + * creating a loop. We only want to change the pointer of other + * parents. */ QLIST_FOREACH(to_c, &to->children, next) { if (to_c == c) { break; @@ -2895,7 +2895,6 @@ static void change_parent_backing_link(BlockDriverState *from, } } - assert(c->role != &child_backing); bdrv_ref(to); /* FIXME Are we sure that bdrv_replace_child() can't run into * &error_abort because of permissions? */ -- cgit v1.2.1