core: Add list_append_init

To append to end of list, as compared to list_splice_init which prepends.

Signed-off-by: Shehjar Tikoo <shehjart@gluster.com>
Signed-off-by: Vijay Bellur <vijay@dev.gluster.com>

BUG: 2491 ()
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2491

1 files changed, 33 insertions, 0 deletions

diff --git a/libglusterfs/src/list.h b/libglusterfs/src/list.h
index 886c4f273a..52d98fc518 100644
--- a/libglusterfs/src/list.h
+++ b/libglusterfs/src/list.h
@@ -120,6 +120,7 @@ list_splice (struct list_head *list, struct list_head *head)
 }
 
 
+/* Splice moves @list to the head of the list at @head. */
 static inline void
 list_splice_init (struct list_head *list, struct list_head *head)
 {
@@ -131,6 +132,38 @@ list_splice_init (struct list_head *list, struct list_head *head)
 }
 
 
+static inline void
+__list_append (struct list_head *list, struct list_head *head)
+{
+	(head->prev)->next = (list->next);
+        (list->next)->prev = (head->prev);
+        (head->prev) = (list->prev);
+        (list->prev)->next = head;
+}
+
+
+static inline void
+list_append (struct list_head *list, struct list_head *head)
+{
+	if (list_empty (list))
+		return;
+
+	__list_append (list, head);
+}
+
+
+/* Append moves @list to the end of @head */
+static inline void
+list_append_init (struct list_head *list, struct list_head *head)
+{
+	if (list_empty (list))
+		return;
+
+	__list_append (list, head);
+	INIT_LIST_HEAD (list);
+}
+
+
 #define list_entry(ptr, type, member)					\
 	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))