1 #ifndef _LINUX_NAMEI_H 2 #define _LINUX_NAMEI_H 3 4 #include <linux/dcache.h> 5 #include <linux/errno.h> 6 #include <linux/linkage.h> 7 #include <linux/path.h> 8 9 struct vfsmount; 10 struct nameidata; 11 12 enum { MAX_NESTED_LINKS = 8 }; 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 /* 20 * The bitmask for a lookup event: 21 * - follow links at the end 22 * - require a directory 23 * - ending slashes ok even for nonexistent files 24 * - internal "there are more path components" flag 25 * - dentry cache is untrusted; force a real lookup 26 * - suppress terminal automount 27 */ 28 #define LOOKUP_FOLLOW 0x0001 29 #define LOOKUP_DIRECTORY 0x0002 30 #define LOOKUP_AUTOMOUNT 0x0004 31 32 #define LOOKUP_PARENT 0x0010 33 #define LOOKUP_REVAL 0x0020 34 #define LOOKUP_RCU 0x0040 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(int, const char __user *, unsigned, struct path *); 49 extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty); 50 51 #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path) 52 #define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path) 53 #define user_path_dir(name, path) \ 54 user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path) 55 56 extern int kern_path(const char *, unsigned, struct path *); 57 58 extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int); 59 extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int); 60 extern void done_path_create(struct path *, struct dentry *); 61 extern struct dentry *kern_path_locked(const char *, struct path *); 62 extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int); 63 64 extern struct dentry *lookup_one_len(const char *, struct dentry *, int); 65 66 extern int follow_down_one(struct path *); 67 extern int follow_down(struct path *); 68 extern int follow_up(struct path *); 69 70 extern struct dentry *lock_rename(struct dentry *, struct dentry *); 71 extern void unlock_rename(struct dentry *, struct dentry *); 72 73 extern void nd_jump_link(struct nameidata *nd, struct path *path); 74 extern void nd_set_link(struct nameidata *nd, char *path); 75 extern char *nd_get_link(struct nameidata *nd); 76 77 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) 78 { 79 ((char *) name)[min(len, maxlen)] = '\0'; 80 } 81 82 /** 83 * retry_estale - determine whether the caller should retry an operation 84 * @error: the error that would currently be returned 85 * @flags: flags being used for next lookup attempt 86 * 87 * Check to see if the error code was -ESTALE, and then determine whether 88 * to retry the call based on whether "flags" already has LOOKUP_REVAL set. 89 * 90 * Returns true if the caller should try the operation again. 91 */ 92 static inline bool 93 retry_estale(const long error, const unsigned int flags) 94 { 95 return error == -ESTALE && !(flags & LOOKUP_REVAL); 96 } 97 98 #endif /* _LINUX_NAMEI_H */ 99