Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

[linux-2.6] / include / linux / list.h

diff --git a/include/linux/list.h b/include/linux/list.h
index a886f27a11817c3303826d1f13ce5cf0255a38e7..db35ef02e74522881a1d5b1e00ce993280e2178b 100644 (file)
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -214,6 +214,46 @@ static inline int list_is_singular(const struct list_head *head)
        return !list_empty(head) && (head->next == head->prev);
 }
 
+static inline void __list_cut_position(struct list_head *list,
+               struct list_head *head, struct list_head *entry)
+{
+       struct list_head *new_first = entry->next;
+       list->next = head->next;
+       list->next->prev = list;
+       list->prev = entry;
+       entry->next = list;
+       head->next = new_first;
+       new_first->prev = head;
+}
+
+/**
+ * list_cut_position - cut a list into two
+ * @list: a new list to add all removed entries
+ * @head: a list with entries
+ * @entry: an entry within head, could be the head itself
+ *     and if so we won't cut the list
+ *
+ * This helper moves the initial part of @head, up to and
+ * including @entry, from @head to @list. You should
+ * pass on @entry an element you know is on @head. @list
+ * should be an empty list or a list you do not care about
+ * losing its data.
+ *
+ */
+static inline void list_cut_position(struct list_head *list,
+               struct list_head *head, struct list_head *entry)
+{
+       if (list_empty(head))
+               return;
+       if (list_is_singular(head) &&
+               (head->next != entry && head != entry))
+               return;
+       if (entry == head)
+               INIT_LIST_HEAD(list);
+       else
+               __list_cut_position(list, head, entry);
+}
+
 static inline void __list_splice(const struct list_head *list,
                                 struct list_head *prev,
                                 struct list_head *next)
@@ -269,11 +309,11 @@ static inline void list_splice_init(struct list_head *list,
 }
 
 /**
- * list_splice_tail_init - join two lists, each list being a queue, and
- *     reinitialise the emptied list.
+ * list_splice_tail_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.
  *
+ * Each of the lists is a queue.
  * The list at @list is reinitialised
  */
 static inline void list_splice_tail_init(struct list_head *list,