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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_NAMEI_H
2#define _LINUX_NAMEI_H
3
Alexey Dobriyan82b05472006-09-30 23:27:22 -07004#include <linux/dcache.h>
Stephen Warren08b60f82012-12-24 11:14:58 -07005#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006#include <linux/linkage.h>
Jan Blunckc5e725f2008-02-14 19:34:31 -08007#include <linux/path.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008
9struct vfsmount;
10
Al Viro737bebd2006-07-14 00:24:29 -070011enum { MAX_NESTED_LINKS = 8 };
Linus Torvalds1da177e2005-04-16 15:20:36 -070012
13struct nameidata {
Jan Blunck4ac91372008-02-14 19:34:32 -080014 struct path path;
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 struct qstr last;
Al Viro2a737872009-04-07 11:49:53 -040016 struct path root;
Nick Piggin31e6b012011-01-07 17:49:52 +110017 struct inode *inode; /* path.dentry.d_inode */
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 unsigned int flags;
Nick Piggin31e6b012011-01-07 17:49:52 +110019 unsigned seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070020 int last_type;
21 unsigned depth;
22 char *saved_names[MAX_NESTED_LINKS + 1];
Linus Torvalds1da177e2005-04-16 15:20:36 -070023};
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
Ori Avtalion47a0dfa2009-06-16 12:17:53 +030035 * - internal "there are more path components" flag
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 * - dentry cache is untrusted; force a real lookup
David Howells6f45b652011-01-14 18:45:31 +000037 * - suppress terminal automount
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 */
Nick Piggin31e6b012011-01-07 17:49:52 +110039#define LOOKUP_FOLLOW 0x0001
40#define LOOKUP_DIRECTORY 0x0002
Linus Torvaldsd94c1772011-09-26 17:44:55 -070041#define LOOKUP_AUTOMOUNT 0x0004
Nick Piggin31e6b012011-01-07 17:49:52 +110042
43#define LOOKUP_PARENT 0x0010
44#define LOOKUP_REVAL 0x0020
45#define LOOKUP_RCU 0x0040
Linus Torvaldsb6c80692011-09-27 08:12:33 -070046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047/*
48 * Intent data
49 */
Al Viro35165862008-08-05 03:00:49 -040050#define LOOKUP_OPEN 0x0100
51#define LOOKUP_CREATE 0x0200
52#define LOOKUP_EXCL 0x0400
OGAWA Hirofumi4e9ed2f2008-10-16 07:50:29 +090053#define LOOKUP_RENAME_TARGET 0x0800
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Al Viro16c2cd72011-02-22 15:50:10 -050055#define LOOKUP_JUMPED 0x1000
Al Viro5b6ca022011-03-09 23:04:47 -050056#define LOOKUP_ROOT 0x2000
Al Virof52e0c12011-03-14 18:56:51 -040057#define LOOKUP_EMPTY 0x4000
Al Viro16c2cd72011-02-22 15:50:10 -050058
Al Viro2d8f3032008-07-22 09:59:21 -040059extern int user_path_at(int, const char __user *, unsigned, struct path *);
Andy Whitcroft1fa1e7f2011-11-02 09:44:39 +010060extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
Al Viro2d8f3032008-07-22 09:59:21 -040061
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
Al Virod1811462008-08-02 00:49:18 -040067extern int kern_path(const char *, unsigned, struct path *);
68
Jeff Layton1ac12b42012-12-11 12:10:06 -050069extern 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);
Al Viro921a1652012-07-20 01:15:31 +040071extern void done_path_create(struct path *, struct dentry *);
Al Viro79714f72012-06-15 03:01:42 +040072extern struct dentry *kern_path_locked(const char *, struct path *);
Josef 'Jeff' Sipek16f18202007-07-19 01:48:18 -070073extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
Al Viroe0a01242011-06-27 17:00:37 -040074 const char *, unsigned int, struct path *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
Christoph Hellwigeead1912007-10-16 23:25:38 -070076extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
David Howellscc53ce52011-01-14 18:45:26 +000078extern int follow_down_one(struct path *);
Al Viro7cc90cc2011-03-18 09:04:20 -040079extern int follow_down(struct path *);
Al Virobab77eb2009-04-18 03:26:48 -040080extern int follow_up(struct path *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82extern struct dentry *lock_rename(struct dentry *, struct dentry *);
83extern void unlock_rename(struct dentry *, struct dentry *);
84
Christoph Hellwigb5fb63c12012-06-18 10:47:04 -040085extern void nd_jump_link(struct nameidata *nd, struct path *path);
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087static inline void nd_set_link(struct nameidata *nd, char *path)
88{
89 nd->saved_names[nd->depth] = path;
90}
91
92static inline char *nd_get_link(struct nameidata *nd)
93{
94 return nd->saved_names[nd->depth];
95}
96
Duane Griffin03514682008-12-19 20:47:11 +000097static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
98{
99 ((char *) name)[min(len, maxlen)] = '\0';
100}
101
Jeff Laytonb9d6ba92012-12-20 14:59:40 -0500102/**
103 * retry_estale - determine whether the caller should retry an operation
104 * @error: the error that would currently be returned
105 * @flags: flags being used for next lookup attempt
106 *
107 * Check to see if the error code was -ESTALE, and then determine whether
108 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.
109 *
110 * Returns true if the caller should try the operation again.
111 */
112static inline bool
113retry_estale(const long error, const unsigned int flags)
114{
115 return error == -ESTALE && !(flags & LOOKUP_REVAL);
116}
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118#endif /* _LINUX_NAMEI_H */