block: Request real permissions in bdrv_attach_child()

Now that all block drivers with children tell us what permissions they
need from each of their children, bdrv_attach_child() can use this
information and make the right requirements while trying to attach new
children.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

diff --git a/block.c b/block.c
index 52c1f28..bed2367 100644 (file)
--- a/block.c
+++ b/block.c
@@ -1680,10 +1680,16 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
                              Error **errp)
 {
     BdrvChild *child;
+    uint64_t perm, shared_perm;
+
+    bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
+
+    assert(parent_bs->drv);
+    parent_bs->drv->bdrv_child_perm(parent_bs, NULL, child_role,
+                                    perm, shared_perm, &perm, &shared_perm);
 
-    /* FIXME Use real permissions */
     child = bdrv_root_attach_child(child_bs, child_name, child_role,
-                                   0, BLK_PERM_ALL, parent_bs, errp);
+                                   perm, shared_perm, parent_bs, errp);
     if (child == NULL) {
         return NULL;
     }