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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_NAMEI_H
2#define _LINUX_NAMEI_H
3
Al Virob853a162015-05-13 09:12:02 -04004#include <linux/kernel.h>
Jan Blunckc5e725f2008-02-14 19:34:31 -08005#include <linux/path.h>
Al Virob853a162015-05-13 09:12:02 -04006#include <linux/fcntl.h>
7#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008
Al Viro737bebd2006-07-14 00:24:29 -07009enum { MAX_NESTED_LINKS = 8 };
Linus Torvalds1da177e2005-04-16 15:20:36 -070010
Al Viro894bc8c2015-05-02 07:16:16 -040011#define MAXSYMLINKS 40
12
Linus Torvalds1da177e2005-04-16 15:20:36 -070013/*
14 * Type of the last component on LOOKUP_PARENT
15 */
16enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
17
18/*
19 * The bitmask for a lookup event:
20 * - follow links at the end
21 * - require a directory
22 * - ending slashes ok even for nonexistent files
Ori Avtalion47a0dfa2009-06-16 12:17:53 +030023 * - internal "there are more path components" flag
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 * - dentry cache is untrusted; force a real lookup
David Howells6f45b652011-01-14 18:45:31 +000025 * - suppress terminal automount
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 */
Nick Piggin31e6b012011-01-07 17:49:52 +110027#define LOOKUP_FOLLOW 0x0001
28#define LOOKUP_DIRECTORY 0x0002
Linus Torvaldsd94c1772011-09-26 17:44:55 -070029#define LOOKUP_AUTOMOUNT 0x0004
Nick Piggin31e6b012011-01-07 17:49:52 +110030
31#define LOOKUP_PARENT 0x0010
32#define LOOKUP_REVAL 0x0020
33#define LOOKUP_RCU 0x0040
Linus Torvaldsb6c80692011-09-27 08:12:33 -070034
Linus Torvalds1da177e2005-04-16 15:20:36 -070035/*
36 * Intent data
37 */
Al Viro35165862008-08-05 03:00:49 -040038#define LOOKUP_OPEN 0x0100
39#define LOOKUP_CREATE 0x0200
40#define LOOKUP_EXCL 0x0400
OGAWA Hirofumi4e9ed2f2008-10-16 07:50:29 +090041#define LOOKUP_RENAME_TARGET 0x0800
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Al Viro16c2cd72011-02-22 15:50:10 -050043#define LOOKUP_JUMPED 0x1000
Al Viro5b6ca022011-03-09 23:04:47 -050044#define LOOKUP_ROOT 0x2000
Al Virof52e0c12011-03-14 18:56:51 -040045#define LOOKUP_EMPTY 0x4000
Al Viro16c2cd72011-02-22 15:50:10 -050046
Andy Whitcroft1fa1e7f2011-11-02 09:44:39 +010047extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
Al Viro2d8f3032008-07-22 09:59:21 -040048
Al Virob853a162015-05-13 09:12:02 -040049static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
50 struct path *path)
51{
52 return user_path_at_empty(dfd, name, flags, path, NULL);
53}
54
55static inline int user_path(const char __user *name, struct path *path)
56{
57 return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
58}
59
60static inline int user_lpath(const char __user *name, struct path *path)
61{
62 return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
63}
64
65static inline int user_path_dir(const char __user *name, struct path *path)
66{
67 return user_path_at_empty(AT_FDCWD, name,
68 LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
69}
Al Viro2d8f3032008-07-22 09:59:21 -040070
Al Virod1811462008-08-02 00:49:18 -040071extern int kern_path(const char *, unsigned, struct path *);
72
Jeff Layton1ac12b42012-12-11 12:10:06 -050073extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
74extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
Al Viro921a1652012-07-20 01:15:31 +040075extern void done_path_create(struct path *, struct dentry *);
Al Viro79714f72012-06-15 03:01:42 +040076extern struct dentry *kern_path_locked(const char *, struct path *);
Al Viro2d864652013-09-08 20:18:44 -040077extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Christoph Hellwigeead1912007-10-16 23:25:38 -070079extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
NeilBrownbbddca82016-01-07 16:08:20 -050080extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
David Howellscc53ce52011-01-14 18:45:26 +000082extern int follow_down_one(struct path *);
Al Viro7cc90cc2011-03-18 09:04:20 -040083extern int follow_down(struct path *);
Al Virobab77eb2009-04-18 03:26:48 -040084extern int follow_up(struct path *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
86extern struct dentry *lock_rename(struct dentry *, struct dentry *);
87extern void unlock_rename(struct dentry *, struct dentry *);
88
Al Viro6e771372015-05-02 13:37:52 -040089extern void nd_jump_link(struct path *path);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Duane Griffin03514682008-12-19 20:47:11 +000091static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
92{
93 ((char *) name)[min(len, maxlen)] = '\0';
94}
95
Jeff Laytonb9d6ba92012-12-20 14:59:40 -050096/**
97 * retry_estale - determine whether the caller should retry an operation
98 * @error: the error that would currently be returned
99 * @flags: flags being used for next lookup attempt
100 *
101 * Check to see if the error code was -ESTALE, and then determine whether
102 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.
103 *
104 * Returns true if the caller should try the operation again.
105 */
106static inline bool
107retry_estale(const long error, const unsigned int flags)
108{
109 return error == -ESTALE && !(flags & LOOKUP_REVAL);
110}
111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112#endif /* _LINUX_NAMEI_H */