blob: 7ba9d823d388665cdef6cb647a13cc0bd41ddb75 [file] [log] [blame]
Dave Jones199a9af2006-09-29 01:59:00 -07001/*
2 * Copyright 2006, Red Hat, Inc., Dave Jones
3 * Released under the General Public License (GPL).
4 *
5 * This file contains the linked list implementations for
6 * DEBUG_LIST.
7 */
8
9#include <linux/module.h>
10#include <linux/list.h>
11
12/*
13 * Insert a new entry between two known consecutive entries.
14 *
15 * This is only for internal list manipulation where we know
16 * the prev/next entries already!
17 */
18
19void __list_add(struct list_head *new,
20 struct list_head *prev,
21 struct list_head *next)
22{
23 if (unlikely(next->prev != prev)) {
24 printk(KERN_ERR "list_add corruption. next->prev should be %p, but was %p\n",
25 prev, next->prev);
26 BUG();
27 }
28 if (unlikely(prev->next != next)) {
29 printk(KERN_ERR "list_add corruption. prev->next should be %p, but was %p\n",
30 next, prev->next);
31 BUG();
32 }
33 next->prev = new;
34 new->next = next;
35 new->prev = prev;
36 prev->next = new;
37}
38EXPORT_SYMBOL(__list_add);
39
40/**
41 * list_add - add a new entry
42 * @new: new entry to be added
43 * @head: list head to add it after
44 *
45 * Insert a new entry after the specified head.
46 * This is good for implementing stacks.
47 */
48void list_add(struct list_head *new, struct list_head *head)
49{
50 __list_add(new, head, head->next);
51}
52EXPORT_SYMBOL(list_add);
53
54/**
55 * list_del - deletes entry from list.
56 * @entry: the element to delete from the list.
57 * Note: list_empty on entry does not return true after this, the entry is
58 * in an undefined state.
59 */
60void list_del(struct list_head *entry)
61{
62 if (unlikely(entry->prev->next != entry)) {
Manfred Sprauldf89a862006-09-29 01:59:01 -070063 printk(KERN_ERR "list_del corruption. prev->next should be %p, "
64 "but was %p\n", entry, entry->prev->next);
Dave Jones199a9af2006-09-29 01:59:00 -070065 BUG();
66 }
67 if (unlikely(entry->next->prev != entry)) {
Manfred Sprauldf89a862006-09-29 01:59:01 -070068 printk(KERN_ERR "list_del corruption. next->prev should be %p, "
69 "but was %p\n", entry, entry->next->prev);
Dave Jones199a9af2006-09-29 01:59:00 -070070 BUG();
71 }
72 __list_del(entry->prev, entry->next);
73 entry->next = LIST_POISON1;
74 entry->prev = LIST_POISON2;
75}
76EXPORT_SYMBOL(list_del);