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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
0eeca283 RL |
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 | ||
90586523 | 15 | #include <linux/fsnotify_backend.h> |
73241ccc | 16 | #include <linux/audit.h> |
5a0e3ad6 | 17 | #include <linux/slab.h> |
187f1882 | 18 | #include <linux/bug.h> |
0eeca283 | 19 | |
5f02a877 | 20 | /* |
a1aae057 AG |
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). | |
5f02a877 AG |
24 | * |
25 | * Unlike fsnotify_parent(), the event will be reported regardless of the | |
40a100d3 AG |
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. | |
5f02a877 | 28 | */ |
9baf93d6 AG |
29 | static inline int fsnotify_name(__u32 mask, const void *data, int data_type, |
30 | struct inode *dir, const struct qstr *name, | |
31 | u32 cookie) | |
5f02a877 | 32 | { |
e43de7f0 | 33 | if (atomic_long_read(&dir->i_sb->s_fsnotify_connectors) == 0) |
9baf93d6 | 34 | return 0; |
e43de7f0 | 35 | |
9baf93d6 | 36 | return fsnotify(mask, data, data_type, dir, name, NULL, cookie); |
a1aae057 AG |
37 | } |
38 | ||
39 | static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry, | |
40 | __u32 mask) | |
41 | { | |
fd5a3ff4 | 42 | fsnotify_name(mask, dentry, FSNOTIFY_EVENT_DENTRY, dir, &dentry->d_name, 0); |
5f02a877 AG |
43 | } |
44 | ||
82ace1ef AG |
45 | static inline void fsnotify_inode(struct inode *inode, __u32 mask) |
46 | { | |
e43de7f0 AG |
47 | if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0) |
48 | return; | |
49 | ||
82ace1ef AG |
50 | if (S_ISDIR(inode->i_mode)) |
51 | mask |= FS_ISDIR; | |
52 | ||
40a100d3 | 53 | fsnotify(mask, inode, FSNOTIFY_EVENT_INODE, NULL, NULL, inode, 0); |
82ace1ef AG |
54 | } |
55 | ||
71d73410 MG |
56 | /* Notify this dentry's parent about a child's events. */ |
57 | static inline int fsnotify_parent(struct dentry *dentry, __u32 mask, | |
58 | const void *data, int data_type) | |
59 | { | |
c738fbab AG |
60 | struct inode *inode = d_inode(dentry); |
61 | ||
e43de7f0 AG |
62 | if (atomic_long_read(&inode->i_sb->s_fsnotify_connectors) == 0) |
63 | return 0; | |
64 | ||
9b93f331 | 65 | if (S_ISDIR(inode->i_mode)) { |
c738fbab AG |
66 | mask |= FS_ISDIR; |
67 | ||
9b93f331 AG |
68 | /* sb/mount marks are not interested in name of directory */ |
69 | if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED)) | |
70 | goto notify_child; | |
71 | } | |
72 | ||
73 | /* disconnected dentry cannot notify parent */ | |
74 | if (IS_ROOT(dentry)) | |
c738fbab | 75 | goto notify_child; |
71d73410 MG |
76 | |
77 | return __fsnotify_parent(dentry, mask, data, data_type); | |
c738fbab AG |
78 | |
79 | notify_child: | |
40a100d3 | 80 | return fsnotify(mask, data, data_type, NULL, NULL, inode, 0); |
71d73410 MG |
81 | } |
82 | ||
a704bba5 | 83 | /* |
c738fbab AG |
84 | * Simple wrappers to consolidate calls to fsnotify_parent() when an event |
85 | * is on a file/dentry. | |
a704bba5 | 86 | */ |
eae36a2b | 87 | static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask) |
a704bba5 | 88 | { |
fd5a3ff4 | 89 | fsnotify_parent(dentry, mask, dentry, FSNOTIFY_EVENT_DENTRY); |
eae36a2b AG |
90 | } |
91 | ||
92 | static inline int fsnotify_file(struct file *file, __u32 mask) | |
93 | { | |
bc2473c9 | 94 | const struct path *path; |
eae36a2b AG |
95 | |
96 | if (file->f_mode & FMODE_NONOTIFY) | |
97 | return 0; | |
98 | ||
def3ae83 | 99 | path = &file->f_path; |
c738fbab | 100 | return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); |
a704bba5 MB |
101 | } |
102 | ||
66917a31 | 103 | /* Simple call site for access decisions */ |
c4ec54b4 EP |
104 | static inline int fsnotify_perm(struct file *file, int mask) |
105 | { | |
66917a31 | 106 | int ret; |
fb1cfb88 | 107 | __u32 fsnotify_mask = 0; |
c4ec54b4 | 108 | |
c4ec54b4 EP |
109 | if (!(mask & (MAY_READ | MAY_OPEN))) |
110 | return 0; | |
eae36a2b | 111 | |
66917a31 | 112 | if (mask & MAY_OPEN) { |
c4ec54b4 | 113 | fsnotify_mask = FS_OPEN_PERM; |
66917a31 MB |
114 | |
115 | if (file->f_flags & __FMODE_EXEC) { | |
eae36a2b | 116 | ret = fsnotify_file(file, FS_OPEN_EXEC_PERM); |
66917a31 MB |
117 | |
118 | if (ret) | |
119 | return ret; | |
120 | } | |
121 | } else if (mask & MAY_READ) { | |
fb1cfb88 | 122 | fsnotify_mask = FS_ACCESS_PERM; |
66917a31 | 123 | } |
c4ec54b4 | 124 | |
eae36a2b | 125 | return fsnotify_file(file, fsnotify_mask); |
c4ec54b4 EP |
126 | } |
127 | ||
90586523 EP |
128 | /* |
129 | * fsnotify_link_count - inode's link count changed | |
130 | */ | |
131 | static inline void fsnotify_link_count(struct inode *inode) | |
132 | { | |
82ace1ef | 133 | fsnotify_inode(inode, FS_ATTRIB); |
90586523 EP |
134 | } |
135 | ||
0eeca283 RL |
136 | /* |
137 | * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir | |
138 | */ | |
139 | static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, | |
f4ec3a3d | 140 | const struct qstr *old_name, |
0a20df7e AG |
141 | int isdir, struct inode *target, |
142 | struct dentry *moved) | |
0eeca283 | 143 | { |
5a190ae6 | 144 | struct inode *source = moved->d_inode; |
47882c6f | 145 | u32 fs_cookie = fsnotify_get_cookie(); |
5f02a877 AG |
146 | __u32 old_dir_mask = FS_MOVED_FROM; |
147 | __u32 new_dir_mask = FS_MOVED_TO; | |
e54183fa | 148 | __u32 rename_mask = FS_RENAME; |
25b229df | 149 | const struct qstr *new_name = &moved->d_name; |
0eeca283 | 150 | |
90586523 | 151 | if (isdir) { |
b29866aa EP |
152 | old_dir_mask |= FS_ISDIR; |
153 | new_dir_mask |= FS_ISDIR; | |
e54183fa | 154 | rename_mask |= FS_ISDIR; |
90586523 EP |
155 | } |
156 | ||
e54183fa AG |
157 | /* Event with information about both old and new parent+name */ |
158 | fsnotify_name(rename_mask, moved, FSNOTIFY_EVENT_DENTRY, | |
159 | old_dir, old_name, 0); | |
160 | ||
9baf93d6 AG |
161 | fsnotify_name(old_dir_mask, source, FSNOTIFY_EVENT_INODE, |
162 | old_dir, old_name, fs_cookie); | |
163 | fsnotify_name(new_dir_mask, source, FSNOTIFY_EVENT_INODE, | |
164 | new_dir, new_name, fs_cookie); | |
90586523 | 165 | |
2dfc1cae | 166 | if (target) |
90586523 | 167 | fsnotify_link_count(target); |
79cb299c | 168 | fsnotify_inode(source, FS_MOVE_SELF); |
4fa6b5ec | 169 | audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); |
0eeca283 RL |
170 | } |
171 | ||
3be25f49 EP |
172 | /* |
173 | * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed | |
174 | */ | |
175 | static inline void fsnotify_inode_delete(struct inode *inode) | |
176 | { | |
177 | __fsnotify_inode_delete(inode); | |
178 | } | |
179 | ||
ca9c726e AG |
180 | /* |
181 | * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed | |
182 | */ | |
183 | static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt) | |
184 | { | |
185 | __fsnotify_vfsmount_delete(mnt); | |
186 | } | |
187 | ||
7a91bf7f JM |
188 | /* |
189 | * fsnotify_inoderemove - an inode is going away | |
190 | */ | |
191 | static inline void fsnotify_inoderemove(struct inode *inode) | |
192 | { | |
82ace1ef | 193 | fsnotify_inode(inode, FS_DELETE_SELF); |
3be25f49 | 194 | __fsnotify_inode_delete(inode); |
ece95912 JK |
195 | } |
196 | ||
0eeca283 RL |
197 | /* |
198 | * fsnotify_create - 'name' was linked in | |
dabe729d AG |
199 | * |
200 | * Caller must make sure that dentry->d_name is stable. | |
201 | * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate | |
202 | * ->d_inode later | |
0eeca283 | 203 | */ |
dabe729d | 204 | static inline void fsnotify_create(struct inode *dir, struct dentry *dentry) |
0eeca283 | 205 | { |
dabe729d | 206 | audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE); |
90586523 | 207 | |
dabe729d | 208 | fsnotify_dirent(dir, dentry, FS_CREATE); |
0eeca283 RL |
209 | } |
210 | ||
ece95912 JK |
211 | /* |
212 | * fsnotify_link - new hardlink in 'inode' directory | |
dabe729d AG |
213 | * |
214 | * Caller must make sure that new_dentry->d_name is stable. | |
ece95912 JK |
215 | * Note: We have to pass also the linked inode ptr as some filesystems leave |
216 | * new_dentry->d_inode NULL and instantiate inode pointer later | |
217 | */ | |
a1aae057 AG |
218 | static inline void fsnotify_link(struct inode *dir, struct inode *inode, |
219 | struct dentry *new_dentry) | |
ece95912 | 220 | { |
ece95912 | 221 | fsnotify_link_count(inode); |
4fa6b5ec | 222 | audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE); |
90586523 | 223 | |
9baf93d6 AG |
224 | fsnotify_name(FS_CREATE, inode, FSNOTIFY_EVENT_INODE, |
225 | dir, &new_dentry->d_name, 0); | |
ece95912 JK |
226 | } |
227 | ||
a37d9a17 AG |
228 | /* |
229 | * fsnotify_delete - @dentry was unlinked and unhashed | |
230 | * | |
231 | * Caller must make sure that dentry->d_name is stable. | |
232 | * | |
233 | * Note: unlike fsnotify_unlink(), we have to pass also the unlinked inode | |
234 | * as this may be called after d_delete() and old_dentry may be negative. | |
235 | */ | |
236 | static inline void fsnotify_delete(struct inode *dir, struct inode *inode, | |
237 | struct dentry *dentry) | |
238 | { | |
239 | __u32 mask = FS_DELETE; | |
240 | ||
241 | if (S_ISDIR(inode->i_mode)) | |
242 | mask |= FS_ISDIR; | |
243 | ||
244 | fsnotify_name(mask, inode, FSNOTIFY_EVENT_INODE, dir, &dentry->d_name, | |
245 | 0); | |
246 | } | |
247 | ||
248 | /** | |
249 | * d_delete_notify - delete a dentry and call fsnotify_delete() | |
250 | * @dentry: The dentry to delete | |
251 | * | |
252 | * This helper is used to guaranty that the unlinked inode cannot be found | |
253 | * by lookup of this name after fsnotify_delete() event has been delivered. | |
254 | */ | |
255 | static inline void d_delete_notify(struct inode *dir, struct dentry *dentry) | |
256 | { | |
257 | struct inode *inode = d_inode(dentry); | |
258 | ||
259 | ihold(inode); | |
260 | d_delete(dentry); | |
261 | fsnotify_delete(dir, inode, dentry); | |
262 | iput(inode); | |
263 | } | |
264 | ||
116b9731 AG |
265 | /* |
266 | * fsnotify_unlink - 'name' was unlinked | |
267 | * | |
268 | * Caller must make sure that dentry->d_name is stable. | |
269 | */ | |
270 | static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry) | |
271 | { | |
a37d9a17 AG |
272 | if (WARN_ON_ONCE(d_is_negative(dentry))) |
273 | return; | |
116b9731 | 274 | |
a37d9a17 | 275 | fsnotify_delete(dir, d_inode(dentry), dentry); |
116b9731 AG |
276 | } |
277 | ||
0eeca283 RL |
278 | /* |
279 | * fsnotify_mkdir - directory 'name' was created | |
dabe729d AG |
280 | * |
281 | * Caller must make sure that dentry->d_name is stable. | |
282 | * Note: some filesystems (e.g. kernfs) leave @dentry negative and instantiate | |
283 | * ->d_inode later | |
0eeca283 | 284 | */ |
dabe729d | 285 | static inline void fsnotify_mkdir(struct inode *dir, struct dentry *dentry) |
0eeca283 | 286 | { |
dabe729d | 287 | audit_inode_child(dir, dentry, AUDIT_TYPE_CHILD_CREATE); |
90586523 | 288 | |
dabe729d | 289 | fsnotify_dirent(dir, dentry, FS_CREATE | FS_ISDIR); |
0eeca283 RL |
290 | } |
291 | ||
116b9731 AG |
292 | /* |
293 | * fsnotify_rmdir - directory 'name' was removed | |
294 | * | |
295 | * Caller must make sure that dentry->d_name is stable. | |
296 | */ | |
297 | static inline void fsnotify_rmdir(struct inode *dir, struct dentry *dentry) | |
298 | { | |
a37d9a17 AG |
299 | if (WARN_ON_ONCE(d_is_negative(dentry))) |
300 | return; | |
116b9731 | 301 | |
a37d9a17 | 302 | fsnotify_delete(dir, d_inode(dentry), dentry); |
116b9731 AG |
303 | } |
304 | ||
0eeca283 RL |
305 | /* |
306 | * fsnotify_access - file was read | |
307 | */ | |
2a12a9d7 | 308 | static inline void fsnotify_access(struct file *file) |
0eeca283 | 309 | { |
eae36a2b | 310 | fsnotify_file(file, FS_ACCESS); |
0eeca283 RL |
311 | } |
312 | ||
313 | /* | |
314 | * fsnotify_modify - file was modified | |
315 | */ | |
2a12a9d7 | 316 | static inline void fsnotify_modify(struct file *file) |
0eeca283 | 317 | { |
eae36a2b | 318 | fsnotify_file(file, FS_MODIFY); |
0eeca283 RL |
319 | } |
320 | ||
321 | /* | |
322 | * fsnotify_open - file was opened | |
323 | */ | |
2a12a9d7 | 324 | static inline void fsnotify_open(struct file *file) |
0eeca283 | 325 | { |
90586523 | 326 | __u32 mask = FS_OPEN; |
0eeca283 | 327 | |
9b076f1c MB |
328 | if (file->f_flags & __FMODE_EXEC) |
329 | mask |= FS_OPEN_EXEC; | |
0eeca283 | 330 | |
eae36a2b | 331 | fsnotify_file(file, mask); |
0eeca283 RL |
332 | } |
333 | ||
334 | /* | |
335 | * fsnotify_close - file was closed | |
336 | */ | |
337 | static inline void fsnotify_close(struct file *file) | |
338 | { | |
eae36a2b AG |
339 | __u32 mask = (file->f_mode & FMODE_WRITE) ? FS_CLOSE_WRITE : |
340 | FS_CLOSE_NOWRITE; | |
0eeca283 | 341 | |
eae36a2b | 342 | fsnotify_file(file, mask); |
0eeca283 RL |
343 | } |
344 | ||
345 | /* | |
346 | * fsnotify_xattr - extended attributes were changed | |
347 | */ | |
348 | static inline void fsnotify_xattr(struct dentry *dentry) | |
349 | { | |
eae36a2b | 350 | fsnotify_dentry(dentry, FS_ATTRIB); |
0eeca283 RL |
351 | } |
352 | ||
353 | /* | |
354 | * fsnotify_change - notify_change event. file was modified and/or metadata | |
355 | * was changed. | |
356 | */ | |
357 | static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) | |
358 | { | |
3c5119c0 EP |
359 | __u32 mask = 0; |
360 | ||
361 | if (ia_valid & ATTR_UID) | |
362 | mask |= FS_ATTRIB; | |
363 | if (ia_valid & ATTR_GID) | |
364 | mask |= FS_ATTRIB; | |
365 | if (ia_valid & ATTR_SIZE) | |
366 | mask |= FS_MODIFY; | |
0eeca283 | 367 | |
0eeca283 RL |
368 | /* both times implies a utime(s) call */ |
369 | if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) | |
3c5119c0 EP |
370 | mask |= FS_ATTRIB; |
371 | else if (ia_valid & ATTR_ATIME) | |
372 | mask |= FS_ACCESS; | |
373 | else if (ia_valid & ATTR_MTIME) | |
374 | mask |= FS_MODIFY; | |
375 | ||
376 | if (ia_valid & ATTR_MODE) | |
377 | mask |= FS_ATTRIB; | |
0eeca283 | 378 | |
eae36a2b AG |
379 | if (mask) |
380 | fsnotify_dentry(dentry, mask); | |
0eeca283 RL |
381 | } |
382 | ||
9daa8110 GKB |
383 | static inline int fsnotify_sb_error(struct super_block *sb, struct inode *inode, |
384 | int error) | |
385 | { | |
386 | struct fs_error_report report = { | |
387 | .error = error, | |
388 | .inode = inode, | |
389 | .sb = sb, | |
390 | }; | |
391 | ||
392 | return fsnotify(FS_ERROR, &report, FSNOTIFY_EVENT_ERROR, | |
393 | NULL, NULL, NULL, 0); | |
394 | } | |
395 | ||
0eeca283 | 396 | #endif /* _LINUX_FS_NOTIFY_H */ |