Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#ifndef _LINUX_NAMEI_H
2#define _LINUX_NAMEI_H
3
4#include <linux/kernel.h>
5#include <linux/path.h>
6#include <linux/fcntl.h>
7#include <linux/errno.h>
8
9enum { MAX_NESTED_LINKS = 8 };
10
11#define MAXSYMLINKS 40
12
13/*
14 * Type of the last component on LOOKUP_PARENT
15 */
16enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
17
18/*
19 * The bitmask for a lookup event:
20 * - follow links at the end
21 * - require a directory
22 * - ending slashes ok even for nonexistent files
23 * - internal "there are more path components" flag
24 * - dentry cache is untrusted; force a real lookup
25 * - suppress terminal automount
26 */
27#define LOOKUP_FOLLOW 0x0001
28#define LOOKUP_DIRECTORY 0x0002
29#define LOOKUP_AUTOMOUNT 0x0004
30
31#define LOOKUP_PARENT 0x0010
32#define LOOKUP_REVAL 0x0020
33#define LOOKUP_RCU 0x0040
34
35/*
36 * Intent data
37 */
38#define LOOKUP_OPEN 0x0100
39#define LOOKUP_CREATE 0x0200
40#define LOOKUP_EXCL 0x0400
41#define LOOKUP_RENAME_TARGET 0x0800
42
43#define LOOKUP_JUMPED 0x1000
44#define LOOKUP_ROOT 0x2000
45#define LOOKUP_EMPTY 0x4000
46
47extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
48
49static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
50 struct path *path)
51{
52 return user_path_at_empty(dfd, name, flags, path, NULL);
53}
54
55static inline int user_path(const char __user *name, struct path *path)
56{
57 return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
58}
59
60static inline int user_lpath(const char __user *name, struct path *path)
61{
62 return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
63}
64
65static inline int user_path_dir(const char __user *name, struct path *path)
66{
67 return user_path_at_empty(AT_FDCWD, name,
68 LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
69}
70
71extern int kern_path(const char *, unsigned, struct path *);
72
73extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
74extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
75extern void done_path_create(struct path *, struct dentry *);
76extern struct dentry *kern_path_locked(const char *, struct path *);
77extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
78
79extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
80
81extern int follow_down_one(struct path *);
82extern int follow_down(struct path *);
83extern int follow_up(struct path *);
84
85extern struct dentry *lock_rename(struct dentry *, struct dentry *);
86extern void unlock_rename(struct dentry *, struct dentry *);
87
88extern void nd_jump_link(struct path *path);
89
90static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
91{
92 ((char *) name)[min(len, maxlen)] = '\0';
93}
94
95/**
96 * retry_estale - determine whether the caller should retry an operation
97 * @error: the error that would currently be returned
98 * @flags: flags being used for next lookup attempt
99 *
100 * Check to see if the error code was -ESTALE, and then determine whether
101 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.
102 *
103 * Returns true if the caller should try the operation again.
104 */
105static inline bool
106retry_estale(const long error, const unsigned int flags)
107{
108 return error == -ESTALE && !(flags & LOOKUP_REVAL);
109}
110
111#endif /* _LINUX_NAMEI_H */