projects/linux·blob 61844250 · refs

78 lines · 2.0 KiB

1/*
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 "
25 "prev (%p), but was %p. (next=%p).\n",
26 prev, next->prev, next);
27 BUG();
28 }
29 if (unlikely(prev->next != next)) {
30 printk(KERN_ERR "list_add corruption. prev->next should be "
31 "next (%p), but was %p. (prev=%p).\n",
32 next, prev->next, prev);
33 BUG();
34 }
35 next->prev = new;
36 new->next = next;
37 new->prev = prev;
38 prev->next = new;
39}
40EXPORT_SYMBOL(__list_add);
41
42/**
43 * list_add - add a new entry
44 * @new: new entry to be added
45 * @head: list head to add it after
46 *
47 * Insert a new entry after the specified head.
48 * This is good for implementing stacks.
49 */
50void list_add(struct list_head *new, struct list_head *head)
51{
52 __list_add(new, head, head->next);
53}
54EXPORT_SYMBOL(list_add);
55
56/**
57 * list_del - deletes entry from list.
58 * @entry: the element to delete from the list.
59 * Note: list_empty on entry does not return true after this, the entry is
60 * in an undefined state.
61 */
62void list_del(struct list_head *entry)
63{
64 if (unlikely(entry->prev->next != entry)) {
65 printk(KERN_ERR "list_del corruption. prev->next should be %p, "
66 "but was %p\n", entry, entry->prev->next);
67 BUG();
68 }
69 if (unlikely(entry->next->prev != entry)) {
70 printk(KERN_ERR "list_del corruption. next->prev should be %p, "
71 "but was %p\n", entry, entry->next->prev);
72 BUG();
73 }
74 __list_del(entry->prev, entry->next);
75 entry->next = LIST_POISON1;
76 entry->prev = LIST_POISON2;
77}
78EXPORT_SYMBOL(list_del);