Igor Sarkisov | 18c28a2 | 2020-10-06 17:41:08 -0700 | [diff] [blame] | 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 */ |