These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / include / linux / rbtree.h

diff --git a/kernel/include/linux/rbtree.h b/kernel/include/linux/rbtree.h
index fb31765..24ddffd 100644 (file)
--- a/kernel/include/linux/rbtree.h
+++ b/kernel/include/linux/rbtree.h
@@ -73,11 +73,11 @@ extern struct rb_node *rb_first_postorder(const struct rb_root *);
 extern struct rb_node *rb_next_postorder(const struct rb_node *);
 
 /* Fast replacement of a single node without remove/rebalance/add/rebalance */
-extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 
+extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
                            struct rb_root *root);
 
-static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
-                               struct rb_node ** rb_link)
+static inline void rb_link_node(struct rb_node *node, struct rb_node *parent,
+                               struct rb_node **rb_link)
 {
        node->__rb_parent_color = (unsigned long)parent;
        node->rb_left = node->rb_right = NULL;
@@ -85,19 +85,30 @@ static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
        *rb_link = node;
 }
 
+void rb_link_node_rcu(struct rb_node *node, struct rb_node *parent,
+                     struct rb_node **rb_link);
+
 #define rb_entry_safe(ptr, type, member) \
        ({ typeof(ptr) ____ptr = (ptr); \
           ____ptr ? rb_entry(____ptr, type, member) : NULL; \
        })
 
 /**
- * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
- * given type safe against removal of rb_node entry
+ * rbtree_postorder_for_each_entry_safe - iterate in post-order over rb_root of
+ * given type allowing the backing memory of @pos to be invalidated
  *
  * @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'.
+ *
+ * rbtree_postorder_for_each_entry_safe() provides a similar guarantee as
+ * list_for_each_entry_safe() and allows the iteration to continue independent
+ * of changes to @pos by the body of the loop.
+ *
+ * Note, however, that it cannot handle other modifications that re-order the
+ * rbtree it is iterating over. This includes calling rb_erase() on @pos, as
+ * rb_erase() may rebalance the tree, causing us to miss some nodes.
  */
 #define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
        for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \