Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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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#define LOOKUP_NO_REVAL 0x0080
35
36/*
37 * Intent data
38 */
39#define LOOKUP_OPEN 0x0100
40#define LOOKUP_CREATE 0x0200
41#define LOOKUP_EXCL 0x0400
42#define LOOKUP_RENAME_TARGET 0x0800
43
44#define LOOKUP_JUMPED 0x1000
45#define LOOKUP_ROOT 0x2000
46#define LOOKUP_EMPTY 0x4000
47#define LOOKUP_DOWN 0x8000
48
49extern int path_pts(struct path *path);
50
51extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
52
53static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
54 struct path *path)
55{
56 return user_path_at_empty(dfd, name, flags, path, NULL);
57}
58
59static inline int user_path(const char __user *name, struct path *path)
60{
61 return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
62}
63
64static inline int user_lpath(const char __user *name, struct path *path)
65{
66 return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
67}
68
69static inline int user_path_dir(const char __user *name, struct path *path)
70{
71 return user_path_at_empty(AT_FDCWD, name,
72 LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
73}
74
75extern int kern_path(const char *, unsigned, struct path *);
76
77extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
78extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
79extern void done_path_create(struct path *, struct dentry *);
80extern struct dentry *kern_path_locked(const char *, struct path *);
81extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
82
83extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
84extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int);
85
86extern int follow_down_one(struct path *);
87extern int follow_down(struct path *);
88extern int follow_up(struct path *);
89
90extern struct dentry *lock_rename(struct dentry *, struct dentry *);
91extern void unlock_rename(struct dentry *, struct dentry *);
92
93extern void nd_jump_link(struct path *path);
94
95static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
96{
97 ((char *) name)[min(len, maxlen)] = '\0';
98}
99
100/**
101 * retry_estale - determine whether the caller should retry an operation
102 * @error: the error that would currently be returned
103 * @flags: flags being used for next lookup attempt
104 *
105 * Check to see if the error code was -ESTALE, and then determine whether
106 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.
107 *
108 * Returns true if the caller should try the operation again.
109 */
110static inline bool
111retry_estale(const long error, const unsigned int flags)
112{
113 return error == -ESTALE && !(flags & LOOKUP_REVAL);
114}
115
116#endif /* _LINUX_NAMEI_H */