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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_NAMEI_H
#define _LINUX_NAMEI_H
#include <linux/fs.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};
/* 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_MOUNTPOINT 0x0080 /* follow mounts in the end */
#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
/* Scoping flags for lookup. */
#define LOOKUP_NO_SYMLINKS 0x010000 /* No symlink crossing. */
#define LOOKUP_NO_MAGICLINKS 0x020000 /* No nd_jump_link() crossing. */
#define LOOKUP_NO_XDEV 0x040000 /* No mountpoint crossing. */
#define LOOKUP_BENEATH 0x080000 /* No escaping from starting point. */
#define LOOKUP_IN_ROOT 0x100000 /* Treat dirfd as fs root. */
#define LOOKUP_CACHED 0x200000 /* Only do cached lookup */
#define LOOKUP_LINKAT_EMPTY 0x400000 /* Linkat request with empty path. */
/* LOOKUP_* flags which do scope-related checks based on the dirfd. */
#define LOOKUP_IS_SCOPED (LOOKUP_BENEATH | LOOKUP_IN_ROOT)
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);
}
struct dentry *lookup_one_qstr_excl(const struct qstr *name,
struct dentry *base,
unsigned int flags);
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 struct dentry *user_path_locked_at(int , const char __user *, struct path *);
int vfs_path_parent_lookup(struct filename *filename, unsigned int flags,
struct path *parent, struct qstr *last, int *type,
const struct path *root);
int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *,
unsigned int, struct path *);
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 struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int);
struct dentry *lookup_one(struct mnt_idmap *, const char *, struct dentry *, int);
struct dentry *lookup_one_unlocked(struct mnt_idmap *idmap,
const char *name, struct dentry *base,
int len);
struct dentry *lookup_one_positive_unlocked(struct mnt_idmap *idmap,
const char *name,
struct dentry *base, int len);
extern int follow_down_one(struct path *);
extern int follow_down(struct path *path, unsigned int flags);
extern int follow_up(struct path *);
extern struct dentry *lock_rename(struct dentry *, struct dentry *);
extern struct dentry *lock_rename_child(struct dentry *, struct dentry *);
extern void unlock_rename(struct dentry *, struct dentry *);
/**
* mode_strip_umask - handle vfs umask stripping
* @dir: parent directory of the new inode
* @mode: mode of the new inode to be created in @dir
*
* In most filesystems, umask stripping depends on whether or not the
* filesystem supports POSIX ACLs. If the filesystem doesn't support it umask
* stripping is done directly in here. If the filesystem does support POSIX
* ACLs umask stripping is deferred until the filesystem calls
* posix_acl_create().
*
* Some filesystems (like NFSv4) also want to avoid umask stripping by the
* VFS, but don't support POSIX ACLs. Those filesystems can set SB_I_NOUMASK
* to get this effect without declaring that they support POSIX ACLs.
*
* Returns: mode
*/
static inline umode_t __must_check mode_strip_umask(const struct inode *dir, umode_t mode)
{
if (!IS_POSIXACL(dir) && !(dir->i_sb->s_iflags & SB_I_NOUMASK))
mode &= ~current_umask();
return mode;
}
extern int __must_check nd_jump_link(const 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 unlikely(error == -ESTALE && !(flags & LOOKUP_REVAL));
}
#endif /* _LINUX_NAMEI_H */
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