1 /* 2 * Inode based directory notification for Linux 3 * 4 * Copyright (C) 2005 John McCutchan 5 */ 6 7 #ifndef _LINUX_INOTIFY_H 8 #define _LINUX_INOTIFY_H 9 10 /* For O_CLOEXEC and O_NONBLOCK */ 11 #include <linux/fcntl.h> 12 #include <linux/types.h> 13 14 /* 15 * struct inotify_event - structure read from the inotify device for each event 16 * 17 * When you are watching a directory, you will receive the filename for events 18 * such as IN_CREATE, IN_DELETE, IN_OPEN, IN_CLOSE, ..., relative to the wd. 19 */ 20 struct inotify_event { 21 __s32 wd; /* watch descriptor */ 22 __u32 mask; /* watch mask */ 23 __u32 cookie; /* cookie to synchronize two events */ 24 __u32 len; /* length (including nulls) of name */ 25 char name[0]; /* stub for possible name */ 26 }; 27 28 /* the following are legal, implemented events that user-space can watch for */ 29 #define IN_ACCESS 0x00000001 /* File was accessed */ 30 #define IN_MODIFY 0x00000002 /* File was modified */ 31 #define IN_ATTRIB 0x00000004 /* Metadata changed */ 32 #define IN_CLOSE_WRITE 0x00000008 /* Writtable file was closed */ 33 #define IN_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */ 34 #define IN_OPEN 0x00000020 /* File was opened */ 35 #define IN_MOVED_FROM 0x00000040 /* File was moved from X */ 36 #define IN_MOVED_TO 0x00000080 /* File was moved to Y */ 37 #define IN_CREATE 0x00000100 /* Subfile was created */ 38 #define IN_DELETE 0x00000200 /* Subfile was deleted */ 39 #define IN_DELETE_SELF 0x00000400 /* Self was deleted */ 40 #define IN_MOVE_SELF 0x00000800 /* Self was moved */ 41 42 /* the following are legal events. they are sent as needed to any watch */ 43 #define IN_UNMOUNT 0x00002000 /* Backing fs was unmounted */ 44 #define IN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ 45 #define IN_IGNORED 0x00008000 /* File was ignored */ 46 47 /* helper events */ 48 #define IN_CLOSE (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE) /* close */ 49 #define IN_MOVE (IN_MOVED_FROM | IN_MOVED_TO) /* moves */ 50 51 /* special flags */ 52 #define IN_ONLYDIR 0x01000000 /* only watch the path if it is a directory */ 53 #define IN_DONT_FOLLOW 0x02000000 /* don't follow a sym link */ 54 #define IN_MASK_ADD 0x20000000 /* add to the mask of an already existing watch */ 55 #define IN_ISDIR 0x40000000 /* event occurred against dir */ 56 #define IN_ONESHOT 0x80000000 /* only send event once */ 57 58 /* 59 * All of the events - we build the list by hand so that we can add flags in 60 * the future and not break backward compatibility. Apps will get only the 61 * events that they originally wanted. Be sure to add new events here! 62 */ 63 #define IN_ALL_EVENTS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \ 64 IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \ 65 IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF | \ 66 IN_MOVE_SELF) 67 68 /* Flags for sys_inotify_init1. */ 69 #define IN_CLOEXEC O_CLOEXEC 70 #define IN_NONBLOCK O_NONBLOCK 71 72 #ifdef __KERNEL__ 73 74 #include <linux/dcache.h> 75 #include <linux/fs.h> 76 77 /* 78 * struct inotify_watch - represents a watch request on a specific inode 79 * 80 * h_list is protected by ih->mutex of the associated inotify_handle. 81 * i_list, mask are protected by inode->inotify_mutex of the associated inode. 82 * ih, inode, and wd are never written to once the watch is created. 83 * 84 * Callers must use the established inotify interfaces to access inotify_watch 85 * contents. The content of this structure is private to the inotify 86 * implementation. 87 */ 88 struct inotify_watch { 89 struct list_head h_list; /* entry in inotify_handle's list */ 90 struct list_head i_list; /* entry in inode's list */ 91 atomic_t count; /* reference count */ 92 struct inotify_handle *ih; /* associated inotify handle */ 93 struct inode *inode; /* associated inode */ 94 __s32 wd; /* watch descriptor */ 95 __u32 mask; /* event mask for this watch */ 96 }; 97 98 struct inotify_operations { 99 void (*handle_event)(struct inotify_watch *, u32, u32, u32, 100 const char *, struct inode *); 101 void (*destroy_watch)(struct inotify_watch *); 102 }; 103 104 #ifdef CONFIG_INOTIFY 105 106 /* Kernel API for producing events */ 107 108 extern void inotify_d_instantiate(struct dentry *, struct inode *); 109 extern void inotify_d_move(struct dentry *); 110 extern void inotify_inode_queue_event(struct inode *, __u32, __u32, 111 const char *, struct inode *); 112 extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32, 113 const char *); 114 extern void inotify_unmount_inodes(struct list_head *); 115 extern void inotify_inode_is_dead(struct inode *); 116 extern u32 inotify_get_cookie(void); 117 118 /* Kernel Consumer API */ 119 120 extern struct inotify_handle *inotify_init(const struct inotify_operations *); 121 extern void inotify_init_watch(struct inotify_watch *); 122 extern void inotify_destroy(struct inotify_handle *); 123 extern __s32 inotify_find_watch(struct inotify_handle *, struct inode *, 124 struct inotify_watch **); 125 extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *, 126 u32); 127 extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *, 128 struct inode *, __u32); 129 extern __s32 inotify_clone_watch(struct inotify_watch *, struct inotify_watch *); 130 extern void inotify_evict_watch(struct inotify_watch *); 131 extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *); 132 extern int inotify_rm_wd(struct inotify_handle *, __u32); 133 extern void inotify_remove_watch_locked(struct inotify_handle *, 134 struct inotify_watch *); 135 extern void get_inotify_watch(struct inotify_watch *); 136 extern void put_inotify_watch(struct inotify_watch *); 137 extern int pin_inotify_watch(struct inotify_watch *); 138 extern void unpin_inotify_watch(struct inotify_watch *); 139 140 #else 141 142 static inline void inotify_d_instantiate(struct dentry *dentry, 143 struct inode *inode) 144 { 145 } 146 147 static inline void inotify_d_move(struct dentry *dentry) 148 { 149 } 150 151 static inline void inotify_inode_queue_event(struct inode *inode, 152 __u32 mask, __u32 cookie, 153 const char *filename, 154 struct inode *n_inode) 155 { 156 } 157 158 static inline void inotify_dentry_parent_queue_event(struct dentry *dentry, 159 __u32 mask, __u32 cookie, 160 const char *filename) 161 { 162 } 163 164 static inline void inotify_unmount_inodes(struct list_head *list) 165 { 166 } 167 168 static inline void inotify_inode_is_dead(struct inode *inode) 169 { 170 } 171 172 static inline u32 inotify_get_cookie(void) 173 { 174 return 0; 175 } 176 177 static inline struct inotify_handle *inotify_init(const struct inotify_operations *ops) 178 { 179 return ERR_PTR(-EOPNOTSUPP); 180 } 181 182 static inline void inotify_init_watch(struct inotify_watch *watch) 183 { 184 } 185 186 static inline void inotify_destroy(struct inotify_handle *ih) 187 { 188 } 189 190 static inline __s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode, 191 struct inotify_watch **watchp) 192 { 193 return -EOPNOTSUPP; 194 } 195 196 static inline __s32 inotify_find_update_watch(struct inotify_handle *ih, 197 struct inode *inode, u32 mask) 198 { 199 return -EOPNOTSUPP; 200 } 201 202 static inline __s32 inotify_add_watch(struct inotify_handle *ih, 203 struct inotify_watch *watch, 204 struct inode *inode, __u32 mask) 205 { 206 return -EOPNOTSUPP; 207 } 208 209 static inline int inotify_rm_watch(struct inotify_handle *ih, 210 struct inotify_watch *watch) 211 { 212 return -EOPNOTSUPP; 213 } 214 215 static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd) 216 { 217 return -EOPNOTSUPP; 218 } 219 220 static inline void inotify_remove_watch_locked(struct inotify_handle *ih, 221 struct inotify_watch *watch) 222 { 223 } 224 225 static inline void get_inotify_watch(struct inotify_watch *watch) 226 { 227 } 228 229 static inline void put_inotify_watch(struct inotify_watch *watch) 230 { 231 } 232 233 extern inline int pin_inotify_watch(struct inotify_watch *watch) 234 { 235 return 0; 236 } 237 238 extern inline void unpin_inotify_watch(struct inotify_watch *watch) 239 { 240 } 241 242 #endif /* CONFIG_INOTIFY */ 243 244 #endif /* __KERNEL __ */ 245 246 #endif /* _LINUX_INOTIFY_H */ 247