From f42e6ed8b8c71b3cdc1f0ed7c3f8d2f0c0ec6427 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@zip.com.au>
Date: Thu, 4 Jul 2002 08:30:49 -0700
Subject: [PATCH] add new list_splice_init()

A little cleanup: Most callers of list_splice() immediately
reinitialise the source list_head after calling list_splice().

So create a new list_splice_init() which does all that.
---
 include/linux/list.h | 36 ++++++++++++++++++++++++++++--------
 1 file changed, 28 insertions(+), 8 deletions(-)

(limited to 'include/linux')

diff --git a/include/linux/list.h b/include/linux/list.h
index ac65cc310ab6..3e70aa03ac11 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -136,6 +136,19 @@ static inline int list_empty(list_t *head)
 	return head->next == head;
 }
 
+static inline void __list_splice(list_t *list, list_t *head)
+{
+	list_t *first = list->next;
+	list_t *last = list->prev;
+	list_t *at = head->next;
+
+	first->prev = head;
+	head->next = first;
+
+	last->next = at;
+	at->prev = last;
+}
+
 /**
  * list_splice - join two lists
  * @list: the new list to add.
@@ -145,15 +158,22 @@ static inline void list_splice(list_t *list, list_t *head)
 {
 	list_t *first = list->next;
 
-	if (first != list) {
-		list_t *last = list->prev;
-		list_t *at = head->next;
-
-		first->prev = head;
-		head->next = first;
+	if (first != list)
+		__list_splice(list, head);
+}
 
-		last->next = at;
-		at->prev = last;
+/**
+ * list_splice_init - join two lists and reinitialise the emptied list.
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_init(list_t *list, list_t *head)
+{
+	if (!list_empty(list)) {
+		__list_splice(list, head);
+		INIT_LIST_HEAD(list);
 	}
 }
 
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