1 #ifndef _LINUX_NAMEI_H 2 #define _LINUX_NAMEI_H 3 4 #include <linux/kernel.h> 5 #include <linux/path.h> 6 #include <linux/fcntl.h> 7 #include <linux/errno.h> 8 9 enum { MAX_NESTED_LINKS = 8 }; 10 11 #define MAXSYMLINKS 40 12 13 /* 14 * Type of the last component on LOOKUP_PARENT 15 */ 16 enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; 17 18 /* 19 * The bitmask for a lookup event: 20 * - follow links at the end 21 * - require a directory 22 * - ending slashes ok even for nonexistent files 23 * - internal "there are more path components" flag 24 * - dentry cache is untrusted; force a real lookup 25 * - suppress terminal automount 26 */ 27 #define LOOKUP_FOLLOW 0x0001 28 #define LOOKUP_DIRECTORY 0x0002 29 #define LOOKUP_AUTOMOUNT 0x0004 30 31 #define LOOKUP_PARENT 0x0010 32 #define LOOKUP_REVAL 0x0020 33 #define LOOKUP_RCU 0x0040 34 #define LOOKUP_NO_REVAL 0x0080 35 36 /* 37 * Intent data 38 */ 39 #define LOOKUP_OPEN 0x0100 40 #define LOOKUP_CREATE 0x0200 41 #define LOOKUP_EXCL 0x0400 42 #define LOOKUP_RENAME_TARGET 0x0800 43 44 #define LOOKUP_JUMPED 0x1000 45 #define LOOKUP_ROOT 0x2000 46 #define LOOKUP_EMPTY 0x4000 47 48 extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty); 49 50 static inline int user_path_at(int dfd, const char __user *name, unsigned flags, 51 struct path *path) 52 { 53 return user_path_at_empty(dfd, name, flags, path, NULL); 54 } 55 56 static inline int user_path(const char __user *name, struct path *path) 57 { 58 return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL); 59 } 60 61 static inline int user_lpath(const char __user *name, struct path *path) 62 { 63 return user_path_at_empty(AT_FDCWD, name, 0, path, NULL); 64 } 65 66 static inline int user_path_dir(const char __user *name, struct path *path) 67 { 68 return user_path_at_empty(AT_FDCWD, name, 69 LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL); 70 } 71 72 extern int kern_path(const char *, unsigned, struct path *); 73 74 extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int); 75 extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int); 76 extern void done_path_create(struct path *, struct dentry *); 77 extern struct dentry *kern_path_locked(const char *, struct path *); 78 extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int); 79 80 extern struct dentry *lookup_one_len(const char *, struct dentry *, int); 81 extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int); 82 struct qstr; 83 extern struct dentry *lookup_hash(const struct qstr *, struct dentry *); 84 85 extern int follow_down_one(struct path *); 86 extern int follow_down(struct path *); 87 extern int follow_up(struct path *); 88 89 extern struct dentry *lock_rename(struct dentry *, struct dentry *); 90 extern void unlock_rename(struct dentry *, struct dentry *); 91 92 extern void nd_jump_link(struct path *path); 93 94 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) 95 { 96 ((char *) name)[min(len, maxlen)] = '\0'; 97 } 98 99 /** 100 * retry_estale - determine whether the caller should retry an operation 101 * @error: the error that would currently be returned 102 * @flags: flags being used for next lookup attempt 103 * 104 * Check to see if the error code was -ESTALE, and then determine whether 105 * to retry the call based on whether "flags" already has LOOKUP_REVAL set. 106 * 107 * Returns true if the caller should try the operation again. 108 */ 109 static inline bool 110 retry_estale(const long error, const unsigned int flags) 111 { 112 return error == -ESTALE && !(flags & LOOKUP_REVAL); 113 } 114 115 #endif /* _LINUX_NAMEI_H */ 116