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/* 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};
/* pathwalk mode */
#define LOOKUP_FOLLOW 0x0001 /* follow links at the end */
#define LOOKUP_DIRECTORY 0x0002 /* require a directory */
#define LOOKUP_AUTOMOUNT 0x0004 /* force terminal automount */
#define LOOKUP_EMPTY 0x4000 /* accept empty path [user_... only] */
#define LOOKUP_DOWN 0x8000 /* follow mounts in the starting point */
#define LOOKUP_REVAL 0x0020 /* tell ->d_revalidate() to trust no cache */
#define LOOKUP_RCU 0x0040 /* RCU pathwalk mode; semi-internal */
/* These tell filesystem methods that we are dealing with the final component... */
#define LOOKUP_OPEN 0x0100 /* ... in open */
#define LOOKUP_CREATE 0x0200 /* ... in object creation */
#define LOOKUP_EXCL 0x0400 /* ... in exclusive creation */
#define LOOKUP_RENAME_TARGET 0x0800 /* ... in destination of rename() */
/* internal use only */
#define LOOKUP_PARENT 0x0010
#define LOOKUP_NO_REVAL 0x0080
#define LOOKUP_JUMPED 0x1000
#define LOOKUP_ROOT 0x2000
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 */
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