block: Factor out bdrv_replace_child_noperm()

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 25 insertions, 13 deletions

diff --git a/block.c b/block.c
index 6dc02b85aa..d4570c85b3 100644
--- a/block.c
+++ b/block.c
@@ -1713,11 +1713,10 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
     *nshared = shared;
 }
 
-static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
-                               bool check_new_perm)
+static void bdrv_replace_child_noperm(BdrvChild *child,
+                                      BlockDriverState *new_bs)
 {
     BlockDriverState *old_bs = child->bs;
-    uint64_t perm, shared_perm;
 
     if (old_bs) {
         if (old_bs->quiesce_counter && child->role->drained_end) {
@@ -1727,7 +1726,29 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
             child->role->detach(child);
         }
         QLIST_REMOVE(child, next_parent);
+    }
+
+    child->bs = new_bs;
+
+    if (new_bs) {
+        QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
+        if (new_bs->quiesce_counter && child->role->drained_begin) {
+            child->role->drained_begin(child);
+        }
+
+        if (child->role->attach) {
+            child->role->attach(child);
+        }
+    }
+}
 
+static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
+                               bool check_new_perm)
+{
+    BlockDriverState *old_bs = child->bs;
+    uint64_t perm, shared_perm;
+
+    if (old_bs) {
         /* Update permissions for old node. This is guaranteed to succeed
          * because we're just taking a parent away, so we're loosening
          * restrictions. */
@@ -1736,23 +1757,14 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
         bdrv_set_perm(old_bs, perm, shared_perm);
     }
 
-    child->bs = new_bs;
+    bdrv_replace_child_noperm(child, new_bs);
 
     if (new_bs) {
-        QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
-        if (new_bs->quiesce_counter && child->role->drained_begin) {
-            child->role->drained_begin(child);
-        }
-
         bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm);
         if (check_new_perm) {
             bdrv_check_perm(new_bs, perm, shared_perm, &error_abort);
         }
         bdrv_set_perm(new_bs, perm, shared_perm);
-
-        if (child->role->attach) {
-            child->role->attach(child);
-        }
     }
 }