From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45432) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cioWy-0006Ol-Me for qemu-devel@nongnu.org; Tue, 28 Feb 2017 15:37:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cioWx-0007zU-PR for qemu-devel@nongnu.org; Tue, 28 Feb 2017 15:37:56 -0500 From: Kevin Wolf Date: Tue, 28 Feb 2017 21:36:31 +0100 Message-Id: <1488314205-16264-33-git-send-email-kwolf@redhat.com> In-Reply-To: <1488314205-16264-1-git-send-email-kwolf@redhat.com> References: <1488314205-16264-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 32/46] block: Allow backing file links in change_parent_backing_link() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org 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(-) diff --git a/block.c b/block.c index 698a5c7..79d9ad0 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? */ -- 1.8.3.1