configfs: Add permission and ownership to configfs objects.

configfs always made item and attribute ownership root.root and
permissions based on a umask of 022.  Add ->setattr() to allow
chown(2)/chmod(2), and persist the changes for the lifetime of the
items and attributes.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/Documentation/filesystems/configfs/configfs_example.c b/Documentation/filesystems/configfs/configfs_example.c
index f3c6e49..3d4713a 100644
--- a/Documentation/filesystems/configfs/configfs_example.c
+++ b/Documentation/filesystems/configfs/configfs_example.c
@@ -320,6 +320,7 @@
 	.ct_item_ops	= &simple_children_item_ops,
 	.ct_group_ops	= &simple_children_group_ops,
 	.ct_attrs	= simple_children_attrs,
+	.ct_owner	= THIS_MODULE,
 };
 
 static struct configfs_subsystem simple_children_subsys = {
@@ -403,6 +404,7 @@
 	.ct_item_ops	= &group_children_item_ops,
 	.ct_group_ops	= &group_children_group_ops,
 	.ct_attrs	= group_children_attrs,
+	.ct_owner	= THIS_MODULE,
 };
 
 static struct configfs_subsystem group_children_subsys = {