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