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/dcache.h>
5#include <linux/errno.h>
6#include <linux/linkage.h>
7#include <linux/path.h>
8
9struct vfsmount;
10
11enum { MAX_NESTED_LINKS = 8 };
12
13struct nameidata {
14 struct path path;
15 struct qstr last;
16 struct path root;
17 struct inode *inode; /* path.dentry.d_inode */
18 unsigned int flags;
19 unsigned seq, m_seq;
20 int last_type;
21 unsigned depth;
22 char *saved_names[MAX_NESTED_LINKS + 1];
23};
24
25/*
26 * Type of the last component on LOOKUP_PARENT
27 */
28enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
29
30/*
31 * The bitmask for a lookup event:
32 * - follow links at the end
33 * - require a directory
34 * - ending slashes ok even for nonexistent files
35 * - internal "there are more path components" flag
36 * - dentry cache is untrusted; force a real lookup
37 * - suppress terminal automount
38 */
39#define LOOKUP_FOLLOW 0x0001
40#define LOOKUP_DIRECTORY 0x0002
41#define LOOKUP_AUTOMOUNT 0x0004
42
43#define LOOKUP_PARENT 0x0010
44#define LOOKUP_REVAL 0x0020
45#define LOOKUP_RCU 0x0040
46
47/*
48 * Intent data
49 */
50#define LOOKUP_OPEN 0x0100
51#define LOOKUP_CREATE 0x0200
52#define LOOKUP_EXCL 0x0400
53#define LOOKUP_RENAME_TARGET 0x0800
54
55#define LOOKUP_JUMPED 0x1000
56#define LOOKUP_ROOT 0x2000
57#define LOOKUP_EMPTY 0x4000
58
59extern int user_path_at(int, const char __user *, unsigned, struct path *);
60extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
61
62#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
63#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
64#define user_path_dir(name, path) \
65 user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
66
67extern int kern_path(const char *, unsigned, struct path *);
68
69extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
70extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
71extern void done_path_create(struct path *, struct dentry *);
72extern struct dentry *kern_path_locked(const char *, struct path *);
73extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
74
75extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
76
77extern int follow_down_one(struct path *);
78extern int follow_down(struct path *);
79extern int follow_up(struct path *);
80
81extern struct dentry *lock_rename(struct dentry *, struct dentry *);
82extern void unlock_rename(struct dentry *, struct dentry *);
83
84extern void nd_jump_link(struct nameidata *nd, struct path *path);
85
86static inline void nd_set_link(struct nameidata *nd, char *path)
87{
88 nd->saved_names[nd->depth] = path;
89}
90
91static inline char *nd_get_link(struct nameidata *nd)
92{
93 return nd->saved_names[nd->depth];
94}
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 */