Signed-off-by: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Fam Zheng <f...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
---
block.c | 42 +++++++++++++++++++++++++++---------------
1 file changed, 27 insertions(+), 15 deletions(-)
diff --git a/block.c b/block.c
index f293ccb..6dc02b8 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
--
1.8.3.1
