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