Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /*
3 : * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
4 : */
5 :
6 : #include <linux/dcache.h>
7 : #include <linux/fs.h>
8 : #include <linux/gfp.h>
9 : #include <linux/init.h>
10 : #include <linux/module.h>
11 : #include <linux/mount.h>
12 : #include <linux/srcu.h>
13 :
14 : #include <linux/fsnotify_backend.h>
15 : #include "fsnotify.h"
16 :
17 : /*
18 : * Clear all of the marks on an inode when it is being evicted from core
19 : */
20 10 : void __fsnotify_inode_delete(struct inode *inode)
21 : {
22 10 : fsnotify_clear_marks_by_inode(inode);
23 10 : }
24 : EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);
25 :
26 5 : void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
27 : {
28 5 : fsnotify_clear_marks_by_mount(mnt);
29 5 : }
30 :
31 : /**
32 : * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
33 : * @sb: superblock being unmounted.
34 : *
35 : * Called during unmount with no locks held, so needs to be safe against
36 : * concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block.
37 : */
38 5 : static void fsnotify_unmount_inodes(struct super_block *sb)
39 : {
40 5 : struct inode *inode, *iput_inode = NULL;
41 :
42 10 : spin_lock(&sb->s_inode_list_lock);
43 5 : list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
44 : /*
45 : * We cannot __iget() an inode in state I_FREEING,
46 : * I_WILL_FREE, or I_NEW which is fine because by that point
47 : * the inode cannot have any associated watches.
48 : */
49 0 : spin_lock(&inode->i_lock);
50 0 : if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
51 0 : spin_unlock(&inode->i_lock);
52 0 : continue;
53 : }
54 :
55 : /*
56 : * If i_count is zero, the inode cannot have any watches and
57 : * doing an __iget/iput with SB_ACTIVE clear would actually
58 : * evict all inodes with zero i_count from icache which is
59 : * unnecessarily violent and may in fact be illegal to do.
60 : * However, we should have been called /after/ evict_inodes
61 : * removed all zero refcount inodes, in any case. Test to
62 : * be sure.
63 : */
64 0 : if (!atomic_read(&inode->i_count)) {
65 0 : spin_unlock(&inode->i_lock);
66 0 : continue;
67 : }
68 :
69 0 : __iget(inode);
70 0 : spin_unlock(&inode->i_lock);
71 0 : spin_unlock(&sb->s_inode_list_lock);
72 :
73 0 : iput(iput_inode);
74 :
75 : /* for each watch, send FS_UNMOUNT and then remove it */
76 0 : fsnotify_inode(inode, FS_UNMOUNT);
77 :
78 0 : fsnotify_inode_delete(inode);
79 :
80 0 : iput_inode = inode;
81 :
82 0 : cond_resched();
83 0 : spin_lock(&sb->s_inode_list_lock);
84 : }
85 10 : spin_unlock(&sb->s_inode_list_lock);
86 :
87 5 : iput(iput_inode);
88 5 : }
89 :
90 5 : void fsnotify_sb_delete(struct super_block *sb)
91 : {
92 5 : fsnotify_unmount_inodes(sb);
93 5 : fsnotify_clear_marks_by_sb(sb);
94 : /* Wait for outstanding object references from connectors */
95 10 : wait_var_event(&sb->s_fsnotify_connectors,
96 : !atomic_long_read(&sb->s_fsnotify_connectors));
97 5 : }
98 :
99 : /*
100 : * Given an inode, first check if we care what happens to our children. Inotify
101 : * and dnotify both tell their parents about events. If we care about any event
102 : * on a child we run all of our children and set a dentry flag saying that the
103 : * parent cares. Thus when an event happens on a child it can quickly tell
104 : * if there is a need to find a parent and send the event to the parent.
105 : */
106 0 : void __fsnotify_update_child_dentry_flags(struct inode *inode)
107 : {
108 : struct dentry *alias;
109 : int watched;
110 :
111 0 : if (!S_ISDIR(inode->i_mode))
112 : return;
113 :
114 : /* determine if the children should tell inode about their events */
115 0 : watched = fsnotify_inode_watches_children(inode);
116 :
117 0 : spin_lock(&inode->i_lock);
118 : /* run all of the dentries associated with this inode. Since this is a
119 : * directory, there damn well better only be one item on this list */
120 0 : hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
121 : struct dentry *child;
122 :
123 : /* run all of the children of the original inode and fix their
124 : * d_flags to indicate parental interest (their parent is the
125 : * original inode) */
126 0 : spin_lock(&alias->d_lock);
127 0 : list_for_each_entry(child, &alias->d_subdirs, d_child) {
128 0 : if (!child->d_inode)
129 0 : continue;
130 :
131 0 : spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
132 0 : if (watched)
133 0 : child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
134 : else
135 0 : child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
136 0 : spin_unlock(&child->d_lock);
137 : }
138 0 : spin_unlock(&alias->d_lock);
139 : }
140 0 : spin_unlock(&inode->i_lock);
141 : }
142 :
143 : /* Are inode/sb/mount interested in parent and name info with this event? */
144 0 : static bool fsnotify_event_needs_parent(struct inode *inode, struct mount *mnt,
145 : __u32 mask)
146 : {
147 0 : __u32 marks_mask = 0;
148 :
149 : /* We only send parent/name to inode/sb/mount for events on non-dir */
150 0 : if (mask & FS_ISDIR)
151 : return false;
152 :
153 : /*
154 : * All events that are possible on child can also may be reported with
155 : * parent/name info to inode/sb/mount. Otherwise, a watching parent
156 : * could result in events reported with unexpected name info to sb/mount.
157 : */
158 : BUILD_BUG_ON(FS_EVENTS_POSS_ON_CHILD & ~FS_EVENTS_POSS_TO_PARENT);
159 :
160 : /* Did either inode/sb/mount subscribe for events with parent/name? */
161 0 : marks_mask |= fsnotify_parent_needed_mask(inode->i_fsnotify_mask);
162 0 : marks_mask |= fsnotify_parent_needed_mask(inode->i_sb->s_fsnotify_mask);
163 0 : if (mnt)
164 0 : marks_mask |= fsnotify_parent_needed_mask(mnt->mnt_fsnotify_mask);
165 :
166 : /* Did they subscribe for this event with parent/name info? */
167 0 : return mask & marks_mask;
168 : }
169 :
170 : /*
171 : * Notify this dentry's parent about a child's events with child name info
172 : * if parent is watching or if inode/sb/mount are interested in events with
173 : * parent and name info.
174 : *
175 : * Notify only the child without name info if parent is not watching and
176 : * inode/sb/mount are not interested in events with parent and name info.
177 : */
178 0 : int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,
179 : int data_type)
180 : {
181 0 : const struct path *path = fsnotify_data_path(data, data_type);
182 0 : struct mount *mnt = path ? real_mount(path->mnt) : NULL;
183 0 : struct inode *inode = d_inode(dentry);
184 : struct dentry *parent;
185 0 : bool parent_watched = dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED;
186 : bool parent_needed, parent_interested;
187 : __u32 p_mask;
188 0 : struct inode *p_inode = NULL;
189 : struct name_snapshot name;
190 0 : struct qstr *file_name = NULL;
191 0 : int ret = 0;
192 :
193 : /*
194 : * Do inode/sb/mount care about parent and name info on non-dir?
195 : * Do they care about any event at all?
196 : */
197 0 : if (!inode->i_fsnotify_marks && !inode->i_sb->s_fsnotify_marks &&
198 0 : (!mnt || !mnt->mnt_fsnotify_marks) && !parent_watched)
199 : return 0;
200 :
201 0 : parent = NULL;
202 0 : parent_needed = fsnotify_event_needs_parent(inode, mnt, mask);
203 0 : if (!parent_watched && !parent_needed)
204 : goto notify;
205 :
206 : /* Does parent inode care about events on children? */
207 0 : parent = dget_parent(dentry);
208 0 : p_inode = parent->d_inode;
209 0 : p_mask = fsnotify_inode_watches_children(p_inode);
210 0 : if (unlikely(parent_watched && !p_mask))
211 0 : __fsnotify_update_child_dentry_flags(p_inode);
212 :
213 : /*
214 : * Include parent/name in notification either if some notification
215 : * groups require parent info or the parent is interested in this event.
216 : */
217 0 : parent_interested = mask & p_mask & ALL_FSNOTIFY_EVENTS;
218 0 : if (parent_needed || parent_interested) {
219 : /* When notifying parent, child should be passed as data */
220 0 : WARN_ON_ONCE(inode != fsnotify_data_inode(data, data_type));
221 :
222 : /* Notify both parent and child with child name info */
223 0 : take_dentry_name_snapshot(&name, dentry);
224 0 : file_name = &name.name;
225 0 : if (parent_interested)
226 0 : mask |= FS_EVENT_ON_CHILD;
227 : }
228 :
229 : notify:
230 0 : ret = fsnotify(mask, data, data_type, p_inode, file_name, inode, 0);
231 :
232 0 : if (file_name)
233 0 : release_dentry_name_snapshot(&name);
234 0 : dput(parent);
235 :
236 0 : return ret;
237 : }
238 : EXPORT_SYMBOL_GPL(__fsnotify_parent);
239 :
240 0 : static int fsnotify_handle_inode_event(struct fsnotify_group *group,
241 : struct fsnotify_mark *inode_mark,
242 : u32 mask, const void *data, int data_type,
243 : struct inode *dir, const struct qstr *name,
244 : u32 cookie)
245 : {
246 0 : const struct path *path = fsnotify_data_path(data, data_type);
247 0 : struct inode *inode = fsnotify_data_inode(data, data_type);
248 0 : const struct fsnotify_ops *ops = group->ops;
249 :
250 0 : if (WARN_ON_ONCE(!ops->handle_inode_event))
251 : return 0;
252 :
253 0 : if (WARN_ON_ONCE(!inode && !dir))
254 : return 0;
255 :
256 0 : if ((inode_mark->flags & FSNOTIFY_MARK_FLAG_EXCL_UNLINK) &&
257 0 : path && d_unlinked(path->dentry))
258 : return 0;
259 :
260 : /* Check interest of this mark in case event was sent with two marks */
261 0 : if (!(mask & inode_mark->mask & ALL_FSNOTIFY_EVENTS))
262 : return 0;
263 :
264 0 : return ops->handle_inode_event(inode_mark, mask, inode, dir, name, cookie);
265 : }
266 :
267 0 : static int fsnotify_handle_event(struct fsnotify_group *group, __u32 mask,
268 : const void *data, int data_type,
269 : struct inode *dir, const struct qstr *name,
270 : u32 cookie, struct fsnotify_iter_info *iter_info)
271 : {
272 0 : struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);
273 0 : struct fsnotify_mark *parent_mark = fsnotify_iter_parent_mark(iter_info);
274 : int ret;
275 :
276 0 : if (WARN_ON_ONCE(fsnotify_iter_sb_mark(iter_info)) ||
277 0 : WARN_ON_ONCE(fsnotify_iter_vfsmount_mark(iter_info)))
278 : return 0;
279 :
280 : /*
281 : * For FS_RENAME, 'dir' is old dir and 'data' is new dentry.
282 : * The only ->handle_inode_event() backend that supports FS_RENAME is
283 : * dnotify, where it means file was renamed within same parent.
284 : */
285 0 : if (mask & FS_RENAME) {
286 0 : struct dentry *moved = fsnotify_data_dentry(data, data_type);
287 :
288 0 : if (dir != moved->d_parent->d_inode)
289 : return 0;
290 : }
291 :
292 0 : if (parent_mark) {
293 0 : ret = fsnotify_handle_inode_event(group, parent_mark, mask,
294 : data, data_type, dir, name, 0);
295 0 : if (ret)
296 : return ret;
297 : }
298 :
299 0 : if (!inode_mark)
300 : return 0;
301 :
302 0 : if (mask & FS_EVENT_ON_CHILD) {
303 : /*
304 : * Some events can be sent on both parent dir and child marks
305 : * (e.g. FS_ATTRIB). If both parent dir and child are
306 : * watching, report the event once to parent dir with name (if
307 : * interested) and once to child without name (if interested).
308 : * The child watcher is expecting an event without a file name
309 : * and without the FS_EVENT_ON_CHILD flag.
310 : */
311 0 : mask &= ~FS_EVENT_ON_CHILD;
312 0 : dir = NULL;
313 0 : name = NULL;
314 : }
315 :
316 0 : return fsnotify_handle_inode_event(group, inode_mark, mask, data, data_type,
317 : dir, name, cookie);
318 : }
319 :
320 0 : static int send_to_group(__u32 mask, const void *data, int data_type,
321 : struct inode *dir, const struct qstr *file_name,
322 : u32 cookie, struct fsnotify_iter_info *iter_info)
323 : {
324 0 : struct fsnotify_group *group = NULL;
325 0 : __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS);
326 0 : __u32 marks_mask = 0;
327 0 : __u32 marks_ignore_mask = 0;
328 0 : bool is_dir = mask & FS_ISDIR;
329 : struct fsnotify_mark *mark;
330 : int type;
331 :
332 0 : if (!iter_info->report_mask)
333 : return 0;
334 :
335 : /* clear ignored on inode modification */
336 0 : if (mask & FS_MODIFY) {
337 0 : fsnotify_foreach_iter_mark_type(iter_info, mark, type) {
338 0 : if (!(mark->flags &
339 : FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
340 0 : mark->ignore_mask = 0;
341 : }
342 : }
343 :
344 : /* Are any of the group marks interested in this event? */
345 0 : fsnotify_foreach_iter_mark_type(iter_info, mark, type) {
346 0 : group = mark->group;
347 0 : marks_mask |= mark->mask;
348 0 : marks_ignore_mask |=
349 0 : fsnotify_effective_ignore_mask(mark, is_dir, type);
350 : }
351 :
352 : pr_debug("%s: group=%p mask=%x marks_mask=%x marks_ignore_mask=%x data=%p data_type=%d dir=%p cookie=%d\n",
353 : __func__, group, mask, marks_mask, marks_ignore_mask,
354 : data, data_type, dir, cookie);
355 :
356 0 : if (!(test_mask & marks_mask & ~marks_ignore_mask))
357 : return 0;
358 :
359 0 : if (group->ops->handle_event) {
360 0 : return group->ops->handle_event(group, mask, data, data_type, dir,
361 : file_name, cookie, iter_info);
362 : }
363 :
364 0 : return fsnotify_handle_event(group, mask, data, data_type, dir,
365 : file_name, cookie, iter_info);
366 : }
367 :
368 : static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)
369 : {
370 : struct fsnotify_mark_connector *conn;
371 0 : struct hlist_node *node = NULL;
372 :
373 0 : conn = srcu_dereference(*connp, &fsnotify_mark_srcu);
374 0 : if (conn)
375 0 : node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu);
376 :
377 0 : return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
378 : }
379 :
380 : static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
381 : {
382 0 : struct hlist_node *node = NULL;
383 :
384 : if (mark)
385 0 : node = srcu_dereference(mark->obj_list.next,
386 : &fsnotify_mark_srcu);
387 :
388 0 : return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
389 : }
390 :
391 : /*
392 : * iter_info is a multi head priority queue of marks.
393 : * Pick a subset of marks from queue heads, all with the same group
394 : * and set the report_mask to a subset of the selected marks.
395 : * Returns false if there are no more groups to iterate.
396 : */
397 0 : static bool fsnotify_iter_select_report_types(
398 : struct fsnotify_iter_info *iter_info)
399 : {
400 0 : struct fsnotify_group *max_prio_group = NULL;
401 : struct fsnotify_mark *mark;
402 : int type;
403 :
404 : /* Choose max prio group among groups of all queue heads */
405 0 : fsnotify_foreach_iter_type(type) {
406 0 : mark = iter_info->marks[type];
407 0 : if (mark &&
408 0 : fsnotify_compare_groups(max_prio_group, mark->group) > 0)
409 0 : max_prio_group = mark->group;
410 : }
411 :
412 0 : if (!max_prio_group)
413 : return false;
414 :
415 : /* Set the report mask for marks from same group as max prio group */
416 0 : iter_info->current_group = max_prio_group;
417 0 : iter_info->report_mask = 0;
418 0 : fsnotify_foreach_iter_type(type) {
419 0 : mark = iter_info->marks[type];
420 0 : if (mark && mark->group == iter_info->current_group) {
421 : /*
422 : * FSNOTIFY_ITER_TYPE_PARENT indicates that this inode
423 : * is watching children and interested in this event,
424 : * which is an event possible on child.
425 : * But is *this mark* watching children?
426 : */
427 0 : if (type == FSNOTIFY_ITER_TYPE_PARENT &&
428 0 : !(mark->mask & FS_EVENT_ON_CHILD) &&
429 0 : !(fsnotify_ignore_mask(mark) & FS_EVENT_ON_CHILD))
430 0 : continue;
431 :
432 0 : fsnotify_iter_set_report_type(iter_info, type);
433 : }
434 : }
435 :
436 : return true;
437 : }
438 :
439 : /*
440 : * Pop from iter_info multi head queue, the marks that belong to the group of
441 : * current iteration step.
442 : */
443 : static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
444 : {
445 : struct fsnotify_mark *mark;
446 : int type;
447 :
448 : /*
449 : * We cannot use fsnotify_foreach_iter_mark_type() here because we
450 : * may need to advance a mark of type X that belongs to current_group
451 : * but was not selected for reporting.
452 : */
453 0 : fsnotify_foreach_iter_type(type) {
454 0 : mark = iter_info->marks[type];
455 0 : if (mark && mark->group == iter_info->current_group)
456 0 : iter_info->marks[type] =
457 0 : fsnotify_next_mark(iter_info->marks[type]);
458 : }
459 : }
460 :
461 : /*
462 : * fsnotify - This is the main call to fsnotify.
463 : *
464 : * The VFS calls into hook specific functions in linux/fsnotify.h.
465 : * Those functions then in turn call here. Here will call out to all of the
466 : * registered fsnotify_group. Those groups can then use the notification event
467 : * in whatever means they feel necessary.
468 : *
469 : * @mask: event type and flags
470 : * @data: object that event happened on
471 : * @data_type: type of object for fanotify_data_XXX() accessors
472 : * @dir: optional directory associated with event -
473 : * if @file_name is not NULL, this is the directory that
474 : * @file_name is relative to
475 : * @file_name: optional file name associated with event
476 : * @inode: optional inode associated with event -
477 : * If @dir and @inode are both non-NULL, event may be
478 : * reported to both.
479 : * @cookie: inotify rename cookie
480 : */
481 0 : int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
482 : const struct qstr *file_name, struct inode *inode, u32 cookie)
483 : {
484 0 : const struct path *path = fsnotify_data_path(data, data_type);
485 0 : struct super_block *sb = fsnotify_data_sb(data, data_type);
486 0 : struct fsnotify_iter_info iter_info = {};
487 0 : struct mount *mnt = NULL;
488 0 : struct inode *inode2 = NULL;
489 : struct dentry *moved;
490 : int inode2_type;
491 0 : int ret = 0;
492 : __u32 test_mask, marks_mask;
493 :
494 0 : if (path)
495 0 : mnt = real_mount(path->mnt);
496 :
497 0 : if (!inode) {
498 : /* Dirent event - report on TYPE_INODE to dir */
499 0 : inode = dir;
500 : /* For FS_RENAME, inode is old_dir and inode2 is new_dir */
501 0 : if (mask & FS_RENAME) {
502 0 : moved = fsnotify_data_dentry(data, data_type);
503 0 : inode2 = moved->d_parent->d_inode;
504 0 : inode2_type = FSNOTIFY_ITER_TYPE_INODE2;
505 : }
506 0 : } else if (mask & FS_EVENT_ON_CHILD) {
507 : /*
508 : * Event on child - report on TYPE_PARENT to dir if it is
509 : * watching children and on TYPE_INODE to child.
510 : */
511 0 : inode2 = dir;
512 0 : inode2_type = FSNOTIFY_ITER_TYPE_PARENT;
513 : }
514 :
515 : /*
516 : * Optimization: srcu_read_lock() has a memory barrier which can
517 : * be expensive. It protects walking the *_fsnotify_marks lists.
518 : * However, if we do not walk the lists, we do not have to do
519 : * SRCU because we have no references to any objects and do not
520 : * need SRCU to keep them "alive".
521 : */
522 0 : if (!sb->s_fsnotify_marks &&
523 0 : (!mnt || !mnt->mnt_fsnotify_marks) &&
524 0 : (!inode || !inode->i_fsnotify_marks) &&
525 0 : (!inode2 || !inode2->i_fsnotify_marks))
526 : return 0;
527 :
528 0 : marks_mask = sb->s_fsnotify_mask;
529 0 : if (mnt)
530 0 : marks_mask |= mnt->mnt_fsnotify_mask;
531 0 : if (inode)
532 0 : marks_mask |= inode->i_fsnotify_mask;
533 0 : if (inode2)
534 0 : marks_mask |= inode2->i_fsnotify_mask;
535 :
536 :
537 : /*
538 : * If this is a modify event we may need to clear some ignore masks.
539 : * In that case, the object with ignore masks will have the FS_MODIFY
540 : * event in its mask.
541 : * Otherwise, return if none of the marks care about this type of event.
542 : */
543 0 : test_mask = (mask & ALL_FSNOTIFY_EVENTS);
544 0 : if (!(test_mask & marks_mask))
545 : return 0;
546 :
547 0 : iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
548 :
549 0 : iter_info.marks[FSNOTIFY_ITER_TYPE_SB] =
550 0 : fsnotify_first_mark(&sb->s_fsnotify_marks);
551 0 : if (mnt) {
552 0 : iter_info.marks[FSNOTIFY_ITER_TYPE_VFSMOUNT] =
553 0 : fsnotify_first_mark(&mnt->mnt_fsnotify_marks);
554 : }
555 0 : if (inode) {
556 0 : iter_info.marks[FSNOTIFY_ITER_TYPE_INODE] =
557 0 : fsnotify_first_mark(&inode->i_fsnotify_marks);
558 : }
559 0 : if (inode2) {
560 0 : iter_info.marks[inode2_type] =
561 0 : fsnotify_first_mark(&inode2->i_fsnotify_marks);
562 : }
563 :
564 : /*
565 : * We need to merge inode/vfsmount/sb mark lists so that e.g. inode mark
566 : * ignore masks are properly reflected for mount/sb mark notifications.
567 : * That's why this traversal is so complicated...
568 : */
569 0 : while (fsnotify_iter_select_report_types(&iter_info)) {
570 0 : ret = send_to_group(mask, data, data_type, dir, file_name,
571 : cookie, &iter_info);
572 :
573 0 : if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
574 : goto out;
575 :
576 : fsnotify_iter_next(&iter_info);
577 : }
578 : ret = 0;
579 : out:
580 0 : srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx);
581 :
582 0 : return ret;
583 : }
584 : EXPORT_SYMBOL_GPL(fsnotify);
585 :
586 1 : static __init int fsnotify_init(void)
587 : {
588 : int ret;
589 :
590 : BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 23);
591 :
592 1 : ret = init_srcu_struct(&fsnotify_mark_srcu);
593 1 : if (ret)
594 0 : panic("initializing fsnotify_mark_srcu");
595 :
596 1 : fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector,
597 : SLAB_PANIC);
598 :
599 1 : return 0;
600 : }
601 : core_initcall(fsnotify_init);
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