Commit 3e44c8e0 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

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: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
Acked-by: default avatarFam Zheng <famz@redhat.com>
parent db95dbba

block.c

+3 −4
Original line number Diff line number Diff line
@@ -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? */