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 extern int user_path_umountat(int, const char __user *, unsigned int, struct path *); 62 63 #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path) 64 #define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path) 65 #define user_path_dir(name, path) \ 66 user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path) 67 68 extern int kern_path(const char *, unsigned, struct path *); 69 70 extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int); 71 extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int); 72 extern void done_path_create(struct path *, struct dentry *); 73 extern struct dentry *kern_path_locked(const char *, struct path *); 74 extern int vfs_path_lookup(struct dentry *, struct vfsmount *, 75 const char *, unsigned int, struct path *); 76 77 extern struct dentry *lookup_one_len(const char *, struct dentry *, int); 78 79 extern int follow_down_one(struct path *); 80 extern int follow_down(struct path *); 81 extern int follow_up(struct path *); 82 83 extern struct dentry *lock_rename(struct dentry *, struct dentry *); 84 extern void unlock_rename(struct dentry *, struct dentry *); 85 86 extern void nd_jump_link(struct nameidata *nd, struct path *path); 87 88 static inline void nd_set_link(struct nameidata *nd, char *path) 89 { 90 nd->saved_names[nd->depth] = path; 91 } 92 93 static inline char *nd_get_link(struct nameidata *nd) 94 { 95 return nd->saved_names[nd->depth]; 96 } 97 98 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) 99 { 100 ((char *) name)[min(len, maxlen)] = '\0'; 101 } 102 103 /** 104 * retry_estale - determine whether the caller should retry an operation 105 * @error: the error that would currently be returned 106 * @flags: flags being used for next lookup attempt 107 * 108 * Check to see if the error code was -ESTALE, and then determine whether 109 * to retry the call based on whether "flags" already has LOOKUP_REVAL set. 110 * 111 * Returns true if the caller should try the operation again. 112 */ 113 static inline bool 114 retry_estale(const long error, const unsigned int flags) 115 { 116 return error == -ESTALE && !(flags & LOOKUP_REVAL); 117 } 118 119 #endif /* _LINUX_NAMEI_H */ 120