1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_NAMEI_H 3 #define _LINUX_NAMEI_H 4 5 #include <linux/kernel.h> 6 #include <linux/path.h> 7 #include <linux/fcntl.h> 8 #include <linux/errno.h> 9 10 enum { MAX_NESTED_LINKS = 8 }; 11 12 #define MAXSYMLINKS 40 13 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 /* pathwalk mode */ 20 #define LOOKUP_FOLLOW 0x0001 /* follow links at the end */ 21 #define LOOKUP_DIRECTORY 0x0002 /* require a directory */ 22 #define LOOKUP_AUTOMOUNT 0x0004 /* force terminal automount */ 23 #define LOOKUP_EMPTY 0x4000 /* accept empty path [user_... only] */ 24 #define LOOKUP_DOWN 0x8000 /* follow mounts in the starting point */ 25 26 #define LOOKUP_REVAL 0x0020 /* tell ->d_revalidate() to trust no cache */ 27 #define LOOKUP_RCU 0x0040 /* RCU pathwalk mode; semi-internal */ 28 29 /* These tell filesystem methods that we are dealing with the final component... */ 30 #define LOOKUP_OPEN 0x0100 /* ... in open */ 31 #define LOOKUP_CREATE 0x0200 /* ... in object creation */ 32 #define LOOKUP_EXCL 0x0400 /* ... in exclusive creation */ 33 #define LOOKUP_RENAME_TARGET 0x0800 /* ... in destination of rename() */ 34 35 /* internal use only */ 36 #define LOOKUP_PARENT 0x0010 37 #define LOOKUP_JUMPED 0x1000 38 #define LOOKUP_ROOT 0x2000 39 #define LOOKUP_ROOT_GRABBED 0x0008 40 41 extern int path_pts(struct path *path); 42 43 extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty); 44 45 static inline int user_path_at(int dfd, const char __user *name, unsigned flags, 46 struct path *path) 47 { 48 return user_path_at_empty(dfd, name, flags, path, NULL); 49 } 50 51 extern int kern_path(const char *, unsigned, struct path *); 52 53 extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int); 54 extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int); 55 extern void done_path_create(struct path *, struct dentry *); 56 extern struct dentry *kern_path_locked(const char *, struct path *); 57 extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int); 58 59 extern struct dentry *try_lookup_one_len(const char *, struct dentry *, int); 60 extern struct dentry *lookup_one_len(const char *, struct dentry *, int); 61 extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int); 62 extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int); 63 64 extern int follow_down_one(struct path *); 65 extern int follow_down(struct path *); 66 extern int follow_up(struct path *); 67 68 extern struct dentry *lock_rename(struct dentry *, struct dentry *); 69 extern void unlock_rename(struct dentry *, struct dentry *); 70 71 extern void nd_jump_link(struct path *path); 72 73 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) 74 { 75 ((char *) name)[min(len, maxlen)] = '\0'; 76 } 77 78 /** 79 * retry_estale - determine whether the caller should retry an operation 80 * @error: the error that would currently be returned 81 * @flags: flags being used for next lookup attempt 82 * 83 * Check to see if the error code was -ESTALE, and then determine whether 84 * to retry the call based on whether "flags" already has LOOKUP_REVAL set. 85 * 86 * Returns true if the caller should try the operation again. 87 */ 88 static inline bool 89 retry_estale(const long error, const unsigned int flags) 90 { 91 return error == -ESTALE && !(flags & LOOKUP_REVAL); 92 } 93 94 #endif /* _LINUX_NAMEI_H */ 95