From 2b529089257705499207ce7da9d0e3ae26a844ba Mon Sep 17 00:00:00 2001 From: Cody P Schafer Date: Wed, 11 Sep 2013 14:25:11 -0700 Subject: rbtree: add rbtree_postorder_for_each_entry_safe() helper Because deletion (of the entire tree) is a relatively common use of the rbtree_postorder iteration, and because doing it safely means fiddling with temporary storage, provide a helper to simplify postorder rbtree iteration. Signed-off-by: Cody P Schafer Reviewed-by: Seth Jennings Cc: David Woodhouse Cc: Rik van Riel Cc: Michel Lespinasse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/rbtree.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/rbtree.h') diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h index c467151e9950..aa870a4ddf54 100644 --- 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 */ -- cgit v1.2.3-59-g8ed1b