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