rbtree: add rbtree_postorder_for_each_entry_safe() helper

[linux-2.6-microblaze.git] / include / linux / rbtree.h

diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index c467151..aa870a4 100644 (file)
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -85,4 +85,22 @@ static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
        *rb_link = node;
 }
 
+/**
+ * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
+ * given type safe against removal of rb_node entry
+ *
+ * @pos:       the 'type *' to use as a loop cursor.
+ * @n:         another 'type *' to use as temporary storage
+ * @root:      'rb_root *' of the rbtree.
+ * @field:     the name of the rb_node field within 'type'.
+ */
+#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
+       for (pos = rb_entry(rb_first_postorder(root), typeof(*pos), field),\
+               n = rb_entry(rb_next_postorder(&pos->field), \
+                       typeof(*pos), field); \
+            &pos->field; \
+            pos = n, \
+               n = rb_entry(rb_next_postorder(&pos->field), \
+                       typeof(*pos), field))
+
 #endif /* _LINUX_RBTREE_H */