[linux-2.6-block.git] / include / linux / namei.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_NAMEI_H
#define _LINUX_NAMEI_H

#include <linux/kernel.h>
#include <linux/path.h>
#include <linux/fcntl.h>
#include <linux/errno.h>

enum { MAX_NESTED_LINKS = 8 };

#define MAXSYMLINKS 40

/*
 * 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
 *  - skip revalidation
 *  - don't fetch xattrs on audit_inode
 */
#define LOOKUP_FOLLOW		0x0001
#define LOOKUP_DIRECTORY	0x0002
#define LOOKUP_AUTOMOUNT	0x0004

#define LOOKUP_PARENT		0x0010
#define LOOKUP_REVAL		0x0020
#define LOOKUP_RCU		0x0040
#define LOOKUP_NO_REVAL		0x0080
#define LOOKUP_NO_EVAL		0x0100

/*
 * 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
#define LOOKUP_DOWN		0x8000

extern int path_pts(struct path *path);

extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);

static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
		 struct path *path)
{
	return user_path_at_empty(dfd, name, flags, path, NULL);
}

static inline int user_path(const char __user *name, struct path *path)
{
	return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
}

static inline int user_lpath(const char __user *name, struct path *path)
{
	return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
}

static inline int user_path_dir(const char __user *name, struct path *path)
{
	return user_path_at_empty(AT_FDCWD, name,
				  LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
}

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 *try_lookup_one_len(const char *, struct dentry *, int);
extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
extern struct dentry *lookup_one_len_unlocked(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 path *path);

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 */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef _LINUX_NAMEI_H
	3	#define _LINUX_NAMEI_H
	4
b853a161	5	#include <linux/kernel.h>
c5e725f3	6	#include <linux/path.h>
b853a161 AV	7	#include <linux/fcntl.h>
b853a161 AV	8	#include <linux/errno.h>
1da177e4	9
737bebd1	10	enum { MAX_NESTED_LINKS = 8 };
1da177e4	11
894bc8c4 AV	12	#define MAXSYMLINKS 40
894bc8c4 AV	13
1da177e4 LT	14	/*
	15	* Type of the last component on LOOKUP_PARENT
	16	*/
	17	enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
	18
	19	/*
	20	* The bitmask for a lookup event:
	21	* - follow links at the end
	22	* - require a directory
	23	* - ending slashes ok even for nonexistent files
47a0dfaa	24	* - internal "there are more path components" flag
1da177e4	25	* - dentry cache is untrusted; force a real lookup
6f45b656	26	* - suppress terminal automount
57d46577 RGB	27	* - skip revalidation
57d46577 RGB	28	* - don't fetch xattrs on audit_inode
1da177e4	29	*/
31e6b01f NP	30	#define LOOKUP_FOLLOW 0x0001
31e6b01f NP	31	#define LOOKUP_DIRECTORY 0x0002
d94c177b	32	#define LOOKUP_AUTOMOUNT 0x0004
31e6b01f NP	33
	34	#define LOOKUP_PARENT 0x0010
	35	#define LOOKUP_REVAL 0x0020
	36	#define LOOKUP_RCU 0x0040
949a852e	37	#define LOOKUP_NO_REVAL 0x0080
57d46577	38	#define LOOKUP_NO_EVAL 0x0100
b6c8069d	39
1da177e4 LT	40	/*
	41	* Intent data
	42	*/
3516586a AV	43	#define LOOKUP_OPEN 0x0100
	44	#define LOOKUP_CREATE 0x0200
	45	#define LOOKUP_EXCL 0x0400
4e9ed2f8	46	#define LOOKUP_RENAME_TARGET 0x0800
1da177e4	47
16c2cd71	48	#define LOOKUP_JUMPED 0x1000
5b6ca027	49	#define LOOKUP_ROOT 0x2000
f52e0c11	50	#define LOOKUP_EMPTY 0x4000
4f757f3c	51	#define LOOKUP_DOWN 0x8000
16c2cd71	52
eedf265a EB	53	extern int path_pts(struct path *path);
eedf265a EB	54
1fa1e7f6	55	extern int user_path_at_empty(int, const char __user , unsigned, struct path , int *empty);
2d8f3038	56
b853a161 AV	57	static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
	58	struct path *path)
	59	{
	60	return user_path_at_empty(dfd, name, flags, path, NULL);
	61	}
	62
	63	static inline int user_path(const char __user name, struct path path)
	64	{
	65	return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
	66	}
	67
	68	static inline int user_lpath(const char __user name, struct path path)
	69	{
	70	return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
	71	}
	72
	73	static inline int user_path_dir(const char __user name, struct path path)
	74	{
	75	return user_path_at_empty(AT_FDCWD, name,
	76	LOOKUP_FOLLOW \| LOOKUP_DIRECTORY, path, NULL);
	77	}
2d8f3038	78
d1811465 AV	79	extern int kern_path(const char , unsigned, struct path );
d1811465 AV	80
1ac12b4b JL	81	extern struct dentry kern_path_create(int, const char , struct path *, unsigned int);
1ac12b4b JL	82	extern struct dentry user_path_create(int, const char __user , struct path *, unsigned int);
921a1650	83	extern void done_path_create(struct path , struct dentry );
79714f72	84	extern struct dentry kern_path_locked(const char , struct path *);
2d864651	85	extern int kern_path_mountpoint(int, const char , struct path , unsigned int);
1da177e4	86
0da0b7fd	87	extern struct dentry try_lookup_one_len(const char , struct dentry *, int);
eead1911	88	extern struct dentry lookup_one_len(const char , struct dentry *, int);
bbddca8e	89	extern struct dentry lookup_one_len_unlocked(const char , struct dentry *, int);
1da177e4	90
cc53ce53	91	extern int follow_down_one(struct path *);
7cc90cc3	92	extern int follow_down(struct path *);
bab77ebf	93	extern int follow_up(struct path *);
1da177e4 LT	94
	95	extern struct dentry lock_rename(struct dentry , struct dentry *);
	96	extern void unlock_rename(struct dentry , struct dentry );
	97
6e77137b	98	extern void nd_jump_link(struct path *path);
1da177e4	99
03514685 DG	100	static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
	101	{
	102	((char *) name)[min(len, maxlen)] = '\0';
	103	}
	104
b9d6ba94 JL	105	/**
	106	* retry_estale - determine whether the caller should retry an operation
	107	* @error: the error that would currently be returned
	108	* @flags: flags being used for next lookup attempt
	109	*
	110	* Check to see if the error code was -ESTALE, and then determine whether
	111	* to retry the call based on whether "flags" already has LOOKUP_REVAL set.
	112	*
	113	* Returns true if the caller should try the operation again.
	114	*/
	115	static inline bool
	116	retry_estale(const long error, const unsigned int flags)
	117	{
	118	return error == -ESTALE && !(flags & LOOKUP_REVAL);
	119	}
	120
1da177e4	121	#endif /* _LINUX_NAMEI_H */