|
@@ -518,3 +518,43 @@ void rb_replace_node(struct rb_node *victim, struct rb_node *new,
|
|
|
*new = *victim;
|
|
|
}
|
|
|
EXPORT_SYMBOL(rb_replace_node);
|
|
|
+
|
|
|
+static struct rb_node *rb_left_deepest_node(const struct rb_node *node)
|
|
|
+{
|
|
|
+ for (;;) {
|
|
|
+ if (node->rb_left)
|
|
|
+ node = node->rb_left;
|
|
|
+ else if (node->rb_right)
|
|
|
+ node = node->rb_right;
|
|
|
+ else
|
|
|
+ return (struct rb_node *)node;
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+struct rb_node *rb_next_postorder(const struct rb_node *node)
|
|
|
+{
|
|
|
+ const struct rb_node *parent;
|
|
|
+ if (!node)
|
|
|
+ return NULL;
|
|
|
+ parent = rb_parent(node);
|
|
|
+
|
|
|
+ /* If we're sitting on node, we've already seen our children */
|
|
|
+ if (parent && node == parent->rb_left && parent->rb_right) {
|
|
|
+ /* If we are the parent's left node, go to the parent's right
|
|
|
+ * node then all the way down to the left */
|
|
|
+ return rb_left_deepest_node(parent->rb_right);
|
|
|
+ } else
|
|
|
+ /* Otherwise we are the parent's right node, and the parent
|
|
|
+ * should be next */
|
|
|
+ return (struct rb_node *)parent;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(rb_next_postorder);
|
|
|
+
|
|
|
+struct rb_node *rb_first_postorder(const struct rb_root *root)
|
|
|
+{
|
|
|
+ if (!root->rb_node)
|
|
|
+ return NULL;
|
|
|
+
|
|
|
+ return rb_left_deepest_node(root->rb_node);
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(rb_first_postorder);
|