[PATCH] Remember to check ioops version in loaded module
[fio.git] / list.h
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1#ifndef _LINUX_LIST_H
2#define _LINUX_LIST_H
3
4#undef offsetof
5#ifdef __compiler_offsetof
6#define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
7#else
8#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
9#endif
10
11#define container_of(ptr, type, member) ({ \
12 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
13 (type *)( (char *)__mptr - offsetof(type,member) );})
14
15/*
16 * Simple doubly linked list implementation.
17 *
18 * Some of the internal functions ("__xxx") are useful when
19 * manipulating whole lists rather than single entries, as
20 * sometimes we already know the next/prev entries and we can
21 * generate better code by using them directly rather than
22 * using the generic single-entry routines.
23 */
24
25struct list_head {
26 struct list_head *next, *prev;
27};
28
29#define LIST_HEAD_INIT(name) { &(name), &(name) }
30
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31#define INIT_LIST_HEAD(ptr) do { \
32 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
33} while (0)
34
35/*
36 * Insert a new entry between two known consecutive entries.
37 *
38 * This is only for internal list manipulation where we know
39 * the prev/next entries already!
40 */
41static inline void __list_add(struct list_head *new,
42 struct list_head *prev,
43 struct list_head *next)
44{
45 next->prev = new;
46 new->next = next;
47 new->prev = prev;
48 prev->next = new;
49}
50
51/**
52 * list_add - add a new entry
53 * @new: new entry to be added
54 * @head: list head to add it after
55 *
56 * Insert a new entry after the specified head.
57 * This is good for implementing stacks.
58 */
59static inline void list_add(struct list_head *new, struct list_head *head)
60{
61 __list_add(new, head, head->next);
62}
63
64static inline void list_add_tail(struct list_head *new, struct list_head *head)
65{
66 __list_add(new, head->prev, head);
67}
68
69/*
70 * Delete a list entry by making the prev/next entries
71 * point to each other.
72 *
73 * This is only for internal list manipulation where we know
74 * the prev/next entries already!
75 */
76static inline void __list_del(struct list_head * prev, struct list_head * next)
77{
78 next->prev = prev;
79 prev->next = next;
80}
81
82/**
83 * list_del - deletes entry from list.
84 * @entry: the element to delete from the list.
85 * Note: list_empty on entry does not return true after this, the entry is
86 * in an undefined state.
87 */
88static inline void list_del(struct list_head *entry)
89{
90 __list_del(entry->prev, entry->next);
91 entry->next = NULL;
92 entry->prev = NULL;
93}
94
95/**
96 * list_empty - tests whether a list is empty
97 * @head: the list to test.
98 */
99static inline int list_empty(const struct list_head *head)
100{
101 return head->next == head;
102}
103
104/**
105 * list_entry - get the struct for this entry
106 * @ptr: the &struct list_head pointer.
107 * @type: the type of the struct this is embedded in.
108 * @member: the name of the list_struct within the struct.
109 */
110#define list_entry(ptr, type, member) \
111 container_of(ptr, type, member)
112
113/**
114 * list_for_each - iterate over a list
115 * @pos: the &struct list_head to use as a loop counter.
116 * @head: the head for your list.
117 */
118#define list_for_each(pos, head) \
119 for (pos = (head)->next; pos != (head); pos = pos->next)
120
121/**
122 * list_for_each_safe - iterate over a list safe against removal of list entry
123 * @pos: the &struct list_head to use as a loop counter.
124 * @n: another &struct list_head to use as temporary storage
125 * @head: the head for your list.
126 */
127#define list_for_each_safe(pos, n, head) \
128 for (pos = (head)->next, n = pos->next; pos != (head); \
129 pos = n, n = pos->next)
130
131#endif