From 6d7581e62f8be462440d7b22c6361f7c9fa4902b Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Wed, 29 May 2013 05:02:56 +0000 Subject: [PATCH 1/1] list: introduce list_first_entry_or_null non-rcu variant of list_first_or_null_rcu Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- include/linux/list.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/list.h b/include/linux/list.h index 6a1f8df9144b..b83e5657365a 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -361,6 +361,17 @@ static inline void list_splice_tail_init(struct list_head *list, #define list_first_entry(ptr, type, member) \ list_entry((ptr)->next, type, member) +/** + * list_first_entry_or_null - get the first element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + * + * Note that if the list is empty, it returns NULL. + */ +#define list_first_entry_or_null(ptr, type, member) \ + (!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL) + /** * list_for_each - iterate over a list * @pos: the &struct list_head to use as a loop cursor. -- 2.39.2