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/* pathwalk mode */
20#define LOOKUP_FOLLOW 0x0001 /* follow links at the end */
21#define LOOKUP_DIRECTORY 0x0002 /* require a directory */
22#define LOOKUP_AUTOMOUNT 0x0004 /* force terminal automount */
23#define LOOKUP_EMPTY 0x4000 /* accept empty path [user_... only] */
24#define LOOKUP_DOWN 0x8000 /* follow mounts in the starting point */
25
26#define LOOKUP_REVAL 0x0020 /* tell ->d_revalidate() to trust no cache */
27#define LOOKUP_RCU 0x0040 /* RCU pathwalk mode; semi-internal */
28
29/* These tell filesystem methods that we are dealing with the final component... */
30#define LOOKUP_OPEN 0x0100 /* ... in open */
31#define LOOKUP_CREATE 0x0200 /* ... in object creation */
32#define LOOKUP_EXCL 0x0400 /* ... in exclusive creation */
33#define LOOKUP_RENAME_TARGET 0x0800 /* ... in destination of rename() */
34
35/* internal use only */
36#define LOOKUP_PARENT 0x0010
37#define LOOKUP_JUMPED 0x1000
38#define LOOKUP_ROOT 0x2000
39#define LOOKUP_ROOT_GRABBED 0x0008
40
41extern int path_pts(struct path *path);
42
43extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
44
45static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
46 struct path *path)
47{
48 return user_path_at_empty(dfd, name, flags, path, NULL);
49}
50
51extern int kern_path(const char *, unsigned, struct path *);
52
53extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
54extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
55extern void done_path_create(struct path *, struct dentry *);
56extern struct dentry *kern_path_locked(const char *, struct path *);
57extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
58
59extern struct dentry *try_lookup_one_len(const char *, struct dentry *, int);
60extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
61extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int);
62extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int);
63
64extern int follow_down_one(struct path *);
65extern int follow_down(struct path *);
66extern int follow_up(struct path *);
67
68extern struct dentry *lock_rename(struct dentry *, struct dentry *);
69extern void unlock_rename(struct dentry *, struct dentry *);
70
71extern void nd_jump_link(struct path *path);
72
73static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
74{
75 ((char *) name)[min(len, maxlen)] = '\0';
76}
77
78/**
79 * retry_estale - determine whether the caller should retry an operation
80 * @error: the error that would currently be returned
81 * @flags: flags being used for next lookup attempt
82 *
83 * Check to see if the error code was -ESTALE, and then determine whether
84 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.
85 *
86 * Returns true if the caller should try the operation again.
87 */
88static inline bool
89retry_estale(const long error, const unsigned int flags)
90{
91 return error == -ESTALE && !(flags & LOOKUP_REVAL);
92}
93
94#endif /* _LINUX_NAMEI_H */