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Commit 93be3c2e authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

list: introduce list_last_entry(), use list_{first,last}_entry() 



We already have list_first_entry(), it makes sense to also add
list_last_entry() for consistency.  And we use both helpers in
list_for_each_*().

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8120e2e5

include/linux/list.h

+15 −4
Original line number Diff line number Diff line
@@ -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_last_entry - 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 list is expected to be not empty.

 */

#define list_last_entry(ptr, type, member) \

	list_entry((ptr)->prev, type, member)



/**

 * list_first_entry_or_null - get the first element from a list

 * @ptr:	the list head to take the element from.
@@ -432,7 +443,7 @@ static inline void list_splice_tail_init(struct list_head *list, 
 * @member:	the name of the list_struct within the struct.

 */

#define list_for_each_entry(pos, head, member)				\

	for (pos = list_entry((head)->next, typeof(*pos), member);	\

	for (pos = list_first_entry(head, typeof(*pos), member);	\

	     &pos->member != (head);					\

	     pos = list_next_entry(pos, member))
@@ -443,7 +454,7 @@ static inline void list_splice_tail_init(struct list_head *list, 
 * @member:	the name of the list_struct within the struct.

 */

#define list_for_each_entry_reverse(pos, head, member)			\

	for (pos = list_entry((head)->prev, typeof(*pos), member);	\

	for (pos = list_last_entry(head, typeof(*pos), member);		\

	     &pos->member != (head); 					\

	     pos = list_prev_entry(pos, member))
@@ -506,7 +517,7 @@ static inline void list_splice_tail_init(struct list_head *list, 
 * @member:	the name of the list_struct within the struct.

 */

#define list_for_each_entry_safe(pos, n, head, member)			\

	for (pos = list_entry((head)->next, typeof(*pos), member),	\

	for (pos = list_first_entry(head, typeof(*pos), member),	\

		n = list_next_entry(pos, member);			\

	     &pos->member != (head); 					\

	     pos = n, n = list_next_entry(n, member))
@@ -553,7 +564,7 @@ static inline void list_splice_tail_init(struct list_head *list, 
 * of list entry.

 */

#define list_for_each_entry_safe_reverse(pos, n, head, member)		\

	for (pos = list_entry((head)->prev, typeof(*pos), member),	\

	for (pos = list_last_entry(head, typeof(*pos), member),		\

		n = list_prev_entry(pos, member);			\

	     &pos->member != (head); 					\

	     pos = n, n = list_prev_entry(n, member))