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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 */
20struct 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 */
88struct 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
98struct 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
108extern void inotify_d_instantiate(struct dentry *, struct inode *);
109extern void inotify_d_move(struct dentry *);
110extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
111 const char *, struct inode *);
112extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32,
113 const char *);
114extern void inotify_unmount_inodes(struct list_head *);
115extern void inotify_inode_is_dead(struct inode *);
116extern u32 inotify_get_cookie(void);
117
118/* Kernel Consumer API */
119
120extern struct inotify_handle *inotify_init(const struct inotify_operations *);
121extern void inotify_init_watch(struct inotify_watch *);
122extern void inotify_destroy(struct inotify_handle *);
123extern __s32 inotify_find_watch(struct inotify_handle *, struct inode *,
124 struct inotify_watch **);
125extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,
126 u32);
127extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,
128 struct inode *, __u32);
129extern __s32 inotify_clone_watch(struct inotify_watch *, struct inotify_watch *);
130extern void inotify_evict_watch(struct inotify_watch *);
131extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *);
132extern int inotify_rm_wd(struct inotify_handle *, __u32);
133extern void inotify_remove_watch_locked(struct inotify_handle *,
134 struct inotify_watch *);
135extern void get_inotify_watch(struct inotify_watch *);
136extern void put_inotify_watch(struct inotify_watch *);
137extern int pin_inotify_watch(struct inotify_watch *);
138extern void unpin_inotify_watch(struct inotify_watch *);
139
140#else
141
142static inline void inotify_d_instantiate(struct dentry *dentry,
143 struct inode *inode)
144{
145}
146
147static inline void inotify_d_move(struct dentry *dentry)
148{
149}
150
151static 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
158static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
159 __u32 mask, __u32 cookie,
160 const char *filename)
161{
162}
163
164static inline void inotify_unmount_inodes(struct list_head *list)
165{
166}
167
168static inline void inotify_inode_is_dead(struct inode *inode)
169{
170}
171
172static inline u32 inotify_get_cookie(void)
173{
174 return 0;
175}
176
177static inline struct inotify_handle *inotify_init(const struct inotify_operations *ops)
178{
179 return ERR_PTR(-EOPNOTSUPP);
180}
181
182static inline void inotify_init_watch(struct inotify_watch *watch)
183{
184}
185
186static inline void inotify_destroy(struct inotify_handle *ih)
187{
188}
189
190static inline __s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
191 struct inotify_watch **watchp)
192{
193 return -EOPNOTSUPP;
194}
195
196static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,
197 struct inode *inode, u32 mask)
198{
199 return -EOPNOTSUPP;
200}
201
202static 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
209static inline int inotify_rm_watch(struct inotify_handle *ih,
210 struct inotify_watch *watch)
211{
212 return -EOPNOTSUPP;
213}
214
215static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)
216{
217 return -EOPNOTSUPP;
218}
219
220static inline void inotify_remove_watch_locked(struct inotify_handle *ih,
221 struct inotify_watch *watch)
222{
223}
224
225static inline void get_inotify_watch(struct inotify_watch *watch)
226{
227}
228
229static inline void put_inotify_watch(struct inotify_watch *watch)
230{
231}
232
233extern inline int pin_inotify_watch(struct inotify_watch *watch)
234{
235 return 0;
236}
237
238extern 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 */