1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_FS_NOTIFY_H
#define _LINUX_FS_NOTIFY_H
/*
* include/linux/fsnotify.h - generic hooks for filesystem notification, to
* reduce in-source duplication from both dnotify and inotify.
*
* We don't compile any of this away in some complicated menagerie of ifdefs.
* Instead, we rely on the code inside to optimize away as needed.
*
* (C) Copyright 2005 Robert Love
*/
#include <linux/fsnotify_backend.h>
#include <linux/audit.h>
#include <linux/slab.h>
#include <linux/bug.h>
/*
* Notify this @dir inode about a change in a child directory entry.
* The directory entry may have turned positive or negative or its inode may
* have changed (i.e. renamed over).
*
* Unlike fsnotify_parent(), the event will be reported regardless of the
* FS_EVENT_ON_CHILD mask on the parent inode and will not be reported if only
* the child is interested and not the parent.
*/
static inline void fsnotify_name(struct inode *dir, __u32 mask,
struct inode *child,
const struct qstr *name, u32 cookie)
{
fsnotify(mask, child, FSNOTIFY_EVENT_INODE, dir, name, NULL, cookie);
}
static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry,
__u32 mask)
{
fsnotify_name(dir, mask, d_inode(dentry), &dentry->d_name, 0);
}
static inline void fsnotify_inode(struct inode *inode, __u32 mask)
{
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
fsnotify(mask, inode, FSNOTIFY_EVENT_INODE, NULL, NULL, inode, 0);
}
/* Notify this dentry's parent about a child's events. */
static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,
const void *data, int data_type)
{
struct inode *inode = d_inode(dentry);
if (S_ISDIR(inode->i_mode)) {
mask |= FS_ISDIR;
/* sb/mount marks are not interested in name of directory */
if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
goto notify_child;
}
/* disconnected dentry cannot notify parent */
if (IS_ROOT(dentry))
goto notify_child;
return __fsnotify_parent(dentry, mask, data, data_type);
notify_child:
return fsnotify(mask, data, data_type, NULL, NULL, inode, 0);
}
/*
* Simple wrappers to consolidate calls to fsnotify_parent() when an event
* is on a file/dentry.
*/
static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask)
{
fsnotify_parent(dentry, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE);
}
static inline int fsnotify_file(struct file *file, __u32 mask)
{
const struct path *path = &file->f_path;
if (file->f_mode & FMODE_NONOTIFY)
return 0;
return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH);
}
/* Simple call site for access decisions */
static inline int fsnotify_perm(struct file *file, int mask)
{
int ret;
__u32 fsnotify_mask = 0;
if (!(mask & (MAY_READ | MAY_OPEN)))
return 0;
if (mask & MAY_OPEN) {
fsnotify_mask = FS_OPEN_PERM;
if (file->f_flags & __FMODE_EXEC) {
ret = fsnotify_file(file, FS_OPEN_EXEC_PERM);
if (ret)
return ret;
}
} else if (mask & MAY_READ) {
fsnotify_mask = FS_ACCESS_PERM;
}
return fsnotify_file(file, fsnotify_mask);
}
/*
* fsnotify_link_count - inode's link count changed
*/
static inline void fsnotify_link_count(struct inode *inode)
{
fsnotify_inode(inode, FS_ATTRIB);
}
/*
* fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
*/
static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
const struct qstr *old_name,
int isdir, struct inode *target,
struct dentry *moved)
{
struct inode *source = moved->d_inode;
u32 fs_cookie = fsnotify_get_cookie();
__u32 old_dir_mask = FS_MOVED_FROM;
__u32 new_dir_mask = FS_MOVED_TO;
const struct qstr *new_name = &moved->d_name;
if (old_dir == new_dir)
old_dir_mask |= FS_DN_RENAME;
if (isdir) {
old_dir_mask |= FS_ISDIR;
new_dir_mask |= FS_ISDIR;
}
fsnotify_name(old_dir, old_dir_mask, source, old_name, fs_cookie);
fsnotify_name(new_dir, new_dir_mask, source, new_name, fs_cookie);
if (target)
fsnotify_link_count(target);
fsnotify_inode(source, FS_MOVE_SELF);
audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
}
/*
* fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
*/
static inline void fsnotify_inode_delete(struct inode *inode)
{
__fsnotify_inode_delete(inode);
}
/*
* fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
*/
static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
{
__fsnotify_vfsmount_delete(mnt);
}
/*
* fsnotify_inoderemove - an inode is going away
*/
static inline void fsnotify_inoderemove(struct inode *inode)
{
fsnotify_inode(inode, FS_DELETE_SELF);
__fsnotify_inode_delete(inode);
}
/*
* fsnotify_create - 'name' was linked in
*/
static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
{
audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify_dirent(inode, dentry, FS_CREATE);
}
/*
* fsnotify_link - new hardlink in 'inode' directory
* Note: We have to pass also the linked inode ptr as some filesystems leave
* new_dentry->d_inode NULL and instantiate inode pointer later
*/
static inline void fsnotify_link(struct inode *dir, struct inode *inode,
struct dentry *new_dentry)
{
fsnotify_link_count(inode);
audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify_name(dir, FS_CREATE, inode, &new_dentry->d_name, 0);
}
/*
* fsnotify_delete - @dentry was unlinked and unhashed
*
* Caller must make sure that dentry->d_name is stable.
*
* Note: unlike fsnotify_unlink(), we have to pass also the unlinked inode
* as this may be called after d_delete() and old_dentry may be negative.
*/
static inline void fsnotify_delete(struct inode *dir, struct inode *inode,
struct dentry *dentry)
{
__u32 mask = FS_DELETE;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
fsnotify_name(dir, mask, inode, &dentry->d_name, 0);
}
/**
* d_delete_notify - delete a dentry and call fsnotify_delete()
* @dentry: The dentry to delete
*
* This helper is used to guaranty that the unlinked inode cannot be found
* by lookup of this name after fsnotify_delete() event has been delivered.
*/
static inline void d_delete_notify(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
ihold(inode);
d_delete(dentry);
fsnotify_delete(dir, inode, dentry);
iput(inode);
}
/*
* fsnotify_unlink - 'name' was unlinked
*
* Caller must make sure that dentry->d_name is stable.
*/
static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry)
{
if (WARN_ON_ONCE(d_is_negative(dentry)))
return;
fsnotify_delete(dir, d_inode(dentry), dentry);
}
/*
* fsnotify_mkdir - directory 'name' was created
*/
static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
{
audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR);
}
/*
* fsnotify_rmdir - directory 'name' was removed
*
* Caller must make sure that dentry->d_name is stable.
*/
static inline void fsnotify_rmdir(struct inode *dir, struct dentry *dentry)
{
if (WARN_ON_ONCE(d_is_negative(dentry)))
return;
fsnotify_delete(dir, d_inode(dentry), dentry);
}
/*
* fsnotify_access - file was read
*/
static inline void fsnotify_access(struct file *file)
{
fsnotify_file(file, FS_ACCESS);
}
/*
* fsnotify_modify - file was modified
*/
static inline void fsnotify_modify(struct file *file)
{
fsnotify_file(file, FS_MODIFY);
}
/*
* fsnotify_open - file was opened
*/
static inline void fsnotify_open(struct file *file)
{
__u32 mask = FS_OPEN;
if (file->f_flags & __FMODE_EXEC)
mask |= FS_OPEN_EXEC;
fsnotify_file(file, mask);
}
/*
* fsnotify_close - file was closed
*/
static inline void fsnotify_close(struct file *file)
{
__u32 mask = (file->f_mode & FMODE_WRITE) ? FS_CLOSE_WRITE :
FS_CLOSE_NOWRITE;
fsnotify_file(file, mask);
}
/*
* fsnotify_xattr - extended attributes were changed
*/
static inline void fsnotify_xattr(struct dentry *dentry)
{
fsnotify_dentry(dentry, FS_ATTRIB);
}
/*
* fsnotify_change - notify_change event. file was modified and/or metadata
* was changed.
*/
static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
{
__u32 mask = 0;
if (ia_valid & ATTR_UID)
mask |= FS_ATTRIB;
if (ia_valid & ATTR_GID)
mask |= FS_ATTRIB;
if (ia_valid & ATTR_SIZE)
mask |= FS_MODIFY;
/* both times implies a utime(s) call */
if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
mask |= FS_ATTRIB;
else if (ia_valid & ATTR_ATIME)
mask |= FS_ACCESS;
else if (ia_valid & ATTR_MTIME)
mask |= FS_MODIFY;
if (ia_valid & ATTR_MODE)
mask |= FS_ATTRIB;
if (mask)
fsnotify_dentry(dentry, mask);
}
#endif /* _LINUX_FS_NOTIFY_H */
|