From: Kevin Wolf Date: Wed, 1 Mar 2017 16:30:41 +0000 (+0100) Subject: block: Factor out should_update_child() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d0ac038025bb6e7886c2324258d24e71215b5d35;p=qemu.git block: Factor out should_update_child() Signed-off-by: Kevin Wolf Reviewed-by: Fam Zheng Reviewed-by: Eric Blake Reviewed-by: Philippe Mathieu-Daudé --- diff --git a/block.c b/block.c index f293ccb5af..6dc02b85aa 100644 --- a/block.c +++ b/block.c @@ -2886,28 +2886,40 @@ void bdrv_close_all(void) assert(QTAILQ_EMPTY(&all_bdrv_states)); } +static bool should_update_child(BdrvChild *c, BlockDriverState *to) +{ + BdrvChild *to_c; + + if (c->role->stay_at_node) { + return false; + } + + if (c->role == &child_backing) { + /* 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; + } + } + if (to_c) { + return false; + } + } + + return true; +} + static void change_parent_backing_link(BlockDriverState *from, BlockDriverState *to) { - BdrvChild *c, *next, *to_c; + BdrvChild *c, *next; QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { - if (c->role->stay_at_node) { + if (!should_update_child(c, to)) { continue; } - if (c->role == &child_backing) { - /* 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; - } - } - if (to_c) { - continue; - } - } bdrv_ref(to); /* FIXME Are we sure that bdrv_replace_child() can't run into