Messages in this thread Patch in this message | | | Date | Fri, 15 Nov 2013 12:31:15 +0800 | From | Jeff Liu <> | Subject | [PATCH 1/6] list: introduce list_last_entry_or_null() |
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From: Jie Liu <jeff.liu@oracle.com>
Introduce a trivial helper list_last_entry_or_null() to fetch the last entry from a list, return NULL if the list is empty.
Signed-off-by: Jie Liu <jeff.liu@oracle.com> --- include/linux/list.h | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/include/linux/list.h b/include/linux/list.h index ef95941..3337249 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -384,6 +384,17 @@ static inline void list_splice_tail_init(struct list_head *list, (!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL) /** + * list_last_entry_or_null - get the last 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_last_entry_or_null(ptr, type, member) \ + (!list_empty(ptr) ? list_last_entry(ptr, type, member) : NULL) + +/** * list_next_entry - get the next element in list * @pos: the type * to cursor * @member: the name of the list_struct within the struct. -- 1.8.3.2
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