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Robert Love0eeca282005-07-12 17:06:03 -04001/*
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 */
18struct 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 */
John McCutchan89204c42005-08-15 12:13:28 -040038#define IN_MOVE_SELF 0x00000800 /* Self was moved */
Robert Love0eeca282005-07-12 17:06:03 -040039
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 */
John McCutchan8140a502005-12-12 00:37:14 -080050#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 */
John McCutchan7ea60402005-09-06 15:18:02 -070052#define IN_MASK_ADD 0x20000000 /* add to the mask of an already existing watch */
Robert Love0eeca282005-07-12 17:06:03 -040053#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 | \
John McCutchan89204c42005-08-15 12:13:28 -040063 IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF | \
64 IN_MOVE_SELF)
Robert Love0eeca282005-07-12 17:06:03 -040065
66#ifdef __KERNEL__
67
68#include <linux/dcache.h>
69#include <linux/fs.h>
Robert Love0eeca282005-07-12 17:06:03 -040070
Amy Griffis2d9048e2006-06-01 13:10:59 -070071/*
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 */
82struct 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
92struct inotify_operations {
93 void (*handle_event)(struct inotify_watch *, u32, u32, u32,
Amy Griffis7c297722006-06-01 13:11:01 -070094 const char *, struct inode *);
Amy Griffis2d9048e2006-06-01 13:10:59 -070095 void (*destroy_watch)(struct inotify_watch *);
96};
97
Robert Love0eeca282005-07-12 17:06:03 -040098#ifdef CONFIG_INOTIFY
99
Amy Griffis2d9048e2006-06-01 13:10:59 -0700100/* Kernel API for producing events */
101
Nick Pigginc32ccd82006-03-25 03:07:09 -0800102extern void inotify_d_instantiate(struct dentry *, struct inode *);
103extern void inotify_d_move(struct dentry *);
Robert Love0eeca282005-07-12 17:06:03 -0400104extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
Amy Griffis7c297722006-06-01 13:11:01 -0700105 const char *, struct inode *);
Robert Love0eeca282005-07-12 17:06:03 -0400106extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32,
107 const char *);
108extern void inotify_unmount_inodes(struct list_head *);
109extern void inotify_inode_is_dead(struct inode *);
110extern u32 inotify_get_cookie(void);
111
Amy Griffis2d9048e2006-06-01 13:10:59 -0700112/* Kernel Consumer API */
113
114extern struct inotify_handle *inotify_init(const struct inotify_operations *);
Amy Griffisa9dc9712006-06-01 13:11:03 -0700115extern void inotify_init_watch(struct inotify_watch *);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700116extern void inotify_destroy(struct inotify_handle *);
Amy Griffisa9dc9712006-06-01 13:11:03 -0700117extern __s32 inotify_find_watch(struct inotify_handle *, struct inode *,
118 struct inotify_watch **);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700119extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,
120 u32);
121extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,
122 struct inode *, __u32);
Amy Griffisa9dc9712006-06-01 13:11:03 -0700123extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700124extern int inotify_rm_wd(struct inotify_handle *, __u32);
Amy Griffis3ca10062006-06-01 13:11:05 -0700125extern void inotify_remove_watch_locked(struct inotify_handle *,
126 struct inotify_watch *);
Amy Griffis2d9048e2006-06-01 13:10:59 -0700127extern void get_inotify_watch(struct inotify_watch *);
128extern void put_inotify_watch(struct inotify_watch *);
129
Robert Love0eeca282005-07-12 17:06:03 -0400130#else
131
Nick Pigginc32ccd82006-03-25 03:07:09 -0800132static inline void inotify_d_instantiate(struct dentry *dentry,
133 struct inode *inode)
134{
135}
136
137static inline void inotify_d_move(struct dentry *dentry)
138{
139}
140
Robert Love0eeca282005-07-12 17:06:03 -0400141static inline void inotify_inode_queue_event(struct inode *inode,
142 __u32 mask, __u32 cookie,
Amy Griffis7c297722006-06-01 13:11:01 -0700143 const char *filename,
144 struct inode *n_inode)
Robert Love0eeca282005-07-12 17:06:03 -0400145{
146}
147
148static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
149 __u32 mask, __u32 cookie,
150 const char *filename)
151{
152}
153
154static inline void inotify_unmount_inodes(struct list_head *list)
155{
156}
157
158static inline void inotify_inode_is_dead(struct inode *inode)
159{
160}
161
162static inline u32 inotify_get_cookie(void)
163{
164 return 0;
165}
166
Amy Griffis2d9048e2006-06-01 13:10:59 -0700167static inline struct inotify_handle *inotify_init(const struct inotify_operations *ops)
168{
169 return ERR_PTR(-EOPNOTSUPP);
170}
171
Amy Griffisa9dc9712006-06-01 13:11:03 -0700172static inline void inotify_init_watch(struct inotify_watch *watch)
173{
174}
175
Amy Griffis2d9048e2006-06-01 13:10:59 -0700176static inline void inotify_destroy(struct inotify_handle *ih)
177{
178}
179
Amy Griffisa9dc9712006-06-01 13:11:03 -0700180static inline __s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
181 struct inotify_watch **watchp)
182{
183 return -EOPNOTSUPP;
184}
185
Amy Griffis2d9048e2006-06-01 13:10:59 -0700186static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,
187 struct inode *inode, u32 mask)
188{
189 return -EOPNOTSUPP;
190}
191
192static 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
Amy Griffisa9dc9712006-06-01 13:11:03 -0700199static inline int inotify_rm_watch(struct inotify_handle *ih,
200 struct inotify_watch *watch)
201{
202 return -EOPNOTSUPP;
203}
204
Amy Griffis2d9048e2006-06-01 13:10:59 -0700205static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)
206{
207 return -EOPNOTSUPP;
208}
209
Amy Griffis3ca10062006-06-01 13:11:05 -0700210static inline void inotify_remove_watch_locked(struct inotify_handle *ih,
211 struct inotify_watch *watch)
212{
213}
214
Amy Griffis2d9048e2006-06-01 13:10:59 -0700215static inline void get_inotify_watch(struct inotify_watch *watch)
216{
217}
218
219static inline void put_inotify_watch(struct inotify_watch *watch)
220{
221}
222
Robert Love0eeca282005-07-12 17:06:03 -0400223#endif /* CONFIG_INOTIFY */
224
225#endif /* __KERNEL __ */
226
227#endif /* _LINUX_INOTIFY_H */