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