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 11 enum { MAX_NESTED_LINKS = 8 }; 12 13 struct nameidata { 14 struct path path; 15 struct qstr last; 16 struct path root; 17 struct inode *inode; /* path.dentry.d_inode */ 18 unsigned int flags; 19 unsigned seq; 20 int last_type; 21 unsigned depth; 22 char *saved_names[MAX_NESTED_LINKS + 1]; 23 }; 24 25 /* 26 * Type of the last component on LOOKUP_PARENT 27 */ 28 enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; 29 30 /* 31 * The bitmask for a lookup event: 32 * - follow links at the end 33 * - require a directory 34 * - ending slashes ok even for nonexistent files 35 * - internal "there are more path components" flag 36 * - dentry cache is untrusted; force a real lookup 37 * - suppress terminal automount 38 */ 39 #define LOOKUP_FOLLOW 0x0001 40 #define LOOKUP_DIRECTORY 0x0002 41 #define LOOKUP_AUTOMOUNT 0x0004 42 43 #define LOOKUP_PARENT 0x0010 44 #define LOOKUP_REVAL 0x0020 45 #define LOOKUP_RCU 0x0040 46 47 /* 48 * Intent data 49 */ 50 #define LOOKUP_OPEN 0x0100 51 #define LOOKUP_CREATE 0x0200 52 #define LOOKUP_EXCL 0x0400 53 #define LOOKUP_RENAME_TARGET 0x0800 54 55 #define LOOKUP_JUMPED 0x1000 56 #define LOOKUP_ROOT 0x2000 57 #define LOOKUP_EMPTY 0x4000 58 59 extern int user_path_at(int, const char __user *, unsigned, struct path *); 60 extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty); 61 62 #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path) 63 #define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path) 64 #define user_path_dir(name, path) \ 65 user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path) 66 67 extern int kern_path(const char *, unsigned, struct path *); 68 69 extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int); 70 extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int); 71 extern void done_path_create(struct path *, struct dentry *); 72 extern struct dentry *kern_path_locked(const char *, struct path *); 73 extern int vfs_path_lookup(struct dentry *, struct vfsmount *, 74 const char *, unsigned int, struct path *); 75 76 extern struct dentry *lookup_one_len(const char *, struct dentry *, int); 77 78 extern int follow_down_one(struct path *); 79 extern int follow_down(struct path *); 80 extern int follow_up(struct path *); 81 82 extern struct dentry *lock_rename(struct dentry *, struct dentry *); 83 extern void unlock_rename(struct dentry *, struct dentry *); 84 85 extern void nd_jump_link(struct nameidata *nd, struct path *path); 86 87 static inline void nd_set_link(struct nameidata *nd, char *path) 88 { 89 nd->saved_names[nd->depth] = path; 90 } 91 92 static inline char *nd_get_link(struct nameidata *nd) 93 { 94 return nd->saved_names[nd->depth]; 95 } 96 97 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) 98 { 99 ((char *) name)[min(len, maxlen)] = '\0'; 100 } 101 102 /** 103 * retry_estale - determine whether the caller should retry an operation 104 * @error: the error that would currently be returned 105 * @flags: flags being used for next lookup attempt 106 * 107 * Check to see if the error code was -ESTALE, and then determine whether 108 * to retry the call based on whether "flags" already has LOOKUP_REVAL set. 109 * 110 * Returns true if the caller should try the operation again. 111 */ 112 static inline bool 113 retry_estale(const long error, const unsigned int flags) 114 { 115 return error == -ESTALE && !(flags & LOOKUP_REVAL); 116 } 117 118 #endif /* _LINUX_NAMEI_H */ 119