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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * dcookies.h
3 *
4 * Persistent cookie-path mappings
5 *
6 * Copyright 2002 John Levon <levon@movementarian.org>
7 */
8
9#ifndef DCOOKIES_H
10#define DCOOKIES_H
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012
13#ifdef CONFIG_PROFILING
14
Bob Nelson14748552007-07-20 21:39:53 +020015#include <linux/dcache.h>
Jan Blunck448678a2008-02-14 19:38:36 -080016#include <linux/path.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/types.h>
18
19struct dcookie_user;
20
21/**
22 * dcookie_register - register a user of dcookies
23 *
24 * Register as a dcookie user. Returns %NULL on failure.
25 */
26struct dcookie_user * dcookie_register(void);
27
28/**
29 * dcookie_unregister - unregister a user of dcookies
30 *
31 * Unregister as a dcookie user. This may invalidate
32 * any dcookie values returned from get_dcookie().
33 */
34void dcookie_unregister(struct dcookie_user * user);
35
36/**
37 * get_dcookie - acquire a dcookie
38 *
39 * Convert the given dentry/vfsmount pair into
40 * a cookie value.
41 *
42 * Returns -EINVAL if no living task has registered as a
43 * dcookie user.
44 *
45 * Returns 0 on success, with *cookie filled in
46 */
Jan Blunck448678a2008-02-14 19:38:36 -080047int get_dcookie(struct path *path, unsigned long *cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
49#else
50
Adrian Bunk0072b132005-08-01 21:11:39 -070051static inline struct dcookie_user * dcookie_register(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
53 return NULL;
54}
55
Adrian Bunk0072b132005-08-01 21:11:39 -070056static inline void dcookie_unregister(struct dcookie_user * user)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
58 return;
59}
Jan Blunck448678a2008-02-14 19:38:36 -080060
61static inline int get_dcookie(struct path *path, unsigned long *cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -070062{
63 return -ENOSYS;
Jan Blunck448678a2008-02-14 19:38:36 -080064}
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066#endif /* CONFIG_PROFILING */
Jan Blunck448678a2008-02-14 19:38:36 -080067
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#endif /* DCOOKIES_H */