diff options
| -rw-r--r-- | include/linux/rbtree.h | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h index aa870a4ddf54..57e75ae9910f 100644 --- a/include/linux/rbtree.h +++ b/include/linux/rbtree.h @@ -85,6 +85,11 @@ static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, *rb_link = node; } +#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 @@ -95,12 +100,9 @@ static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, * @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)) + for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \ + pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \ + typeof(*pos), field); 1; }); \ + pos = n) #endif /* _LINUX_RBTREE_H */ |