Signed-off-by: David Woodhouse <dwmw2@infradead.org>
                        key->serial = 2;
                key_serial_next = key->serial + 1;
 
-               if (!parent->rb_parent)
+               if (!rb_parent(parent))
                        p = &key_serial_tree.rb_node;
-               else if (parent->rb_parent->rb_left == parent)
-                       p = &parent->rb_parent->rb_left;
+               else if (rb_parent(parent)->rb_left == parent)
+                       p = &(rb_parent(parent)->rb_left);
                else
-                       p = &parent->rb_parent->rb_right;
+                       p = &(rb_parent(parent)->rb_right);
 
                parent = rb_next(parent);
                if (!parent)