Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_NAMEI_H
3#define _LINUX_NAMEI_H
4
5#include <linux/kernel.h>
6#include <linux/path.h>
7#include <linux/fcntl.h>
8#include <linux/errno.h>
9
10enum { MAX_NESTED_LINKS = 8 };
11
12#define MAXSYMLINKS 40
13
14/*
15 * Type of the last component on LOOKUP_PARENT
16 */
17enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
18
19/*
20 * The bitmask for a lookup event:
21 * - follow links at the end
22 * - require a directory
23 * - ending slashes ok even for nonexistent files
24 * - internal "there are more path components" flag
25 * - dentry cache is untrusted; force a real lookup
26 * - suppress terminal automount
27 */
28#define LOOKUP_FOLLOW 0x0001
29#define LOOKUP_DIRECTORY 0x0002
30#define LOOKUP_AUTOMOUNT 0x0004
31
32#define LOOKUP_PARENT 0x0010
33#define LOOKUP_REVAL 0x0020
34#define LOOKUP_RCU 0x0040
35#define LOOKUP_NO_REVAL 0x0080
36
37/*
38 * Intent data
39 */
40#define LOOKUP_OPEN 0x0100
41#define LOOKUP_CREATE 0x0200
42#define LOOKUP_EXCL 0x0400
43#define LOOKUP_RENAME_TARGET 0x0800
44
45#define LOOKUP_JUMPED 0x1000
46#define LOOKUP_ROOT 0x2000
47#define LOOKUP_EMPTY 0x4000
48#define LOOKUP_DOWN 0x8000
49
50extern int path_pts(struct path *path);
51
52extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
53
54static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
55 struct path *path)
56{
57 return user_path_at_empty(dfd, name, flags, path, NULL);
58}
59
60static inline int user_path(const char __user *name, struct path *path)
61{
62 return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
63}
64
65static inline int user_lpath(const char __user *name, struct path *path)
66{
67 return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
68}
69
70static inline int user_path_dir(const char __user *name, struct path *path)
71{
72 return user_path_at_empty(AT_FDCWD, name,
73 LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
74}
75
76extern int kern_path(const char *, unsigned, struct path *);
77
78extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
79extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
80extern void done_path_create(struct path *, struct dentry *);
81extern struct dentry *kern_path_locked(const char *, struct path *);
82extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
83
84extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
85extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int);
86
87extern int follow_down_one(struct path *);
88extern int follow_down(struct path *);
89extern int follow_up(struct path *);
90
91extern struct dentry *lock_rename(struct dentry *, struct dentry *);
92extern void unlock_rename(struct dentry *, struct dentry *);
93
94extern void nd_jump_link(struct path *path);
95
96static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
97{
98 ((char *) name)[min(len, maxlen)] = '\0';
99}
100
101/**
102 * retry_estale - determine whether the caller should retry an operation
103 * @error: the error that would currently be returned
104 * @flags: flags being used for next lookup attempt
105 *
106 * Check to see if the error code was -ESTALE, and then determine whether
107 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.
108 *
109 * Returns true if the caller should try the operation again.
110 */
111static inline bool
112retry_estale(const long error, const unsigned int flags)
113{
114 return error == -ESTALE && !(flags & LOOKUP_REVAL);
115}
116
117#endif /* _LINUX_NAMEI_H */