| /* 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 */ |
| /* 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); |
| } |
| |
| 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 *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 user_namespace *, 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 int __must_check 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 */ |