summaryrefslogtreecommitdiff
path: root/include/linux/fsnotify_backend.h
blob: a9f9dcc1e5151353a9664fa99fb9eb7b1c3ed46d (plain)
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
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Filesystem access notification for Linux
 *
 *  Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
 */

#ifndef __LINUX_FSNOTIFY_BACKEND_H
#define __LINUX_FSNOTIFY_BACKEND_H

#ifdef __KERNEL__

#include <linux/idr.h> /* inotify uses this */
#include <linux/fs.h> /* struct inode */
#include <linux/list.h>
#include <linux/path.h> /* struct path */
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/atomic.h>
#include <linux/user_namespace.h>
#include <linux/refcount.h>

/*
 * IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily
 * convert between them.  dnotify only needs conversion at watch creation
 * so no perf loss there.  fanotify isn't defined yet, so it can use the
 * wholes if it needs more events.
 */
#define FS_ACCESS		0x00000001	/* File was accessed */
#define FS_MODIFY		0x00000002	/* File was modified */
#define FS_ATTRIB		0x00000004	/* Metadata changed */
#define FS_CLOSE_WRITE		0x00000008	/* Writtable file was closed */
#define FS_CLOSE_NOWRITE	0x00000010	/* Unwrittable file closed */
#define FS_OPEN			0x00000020	/* File was opened */
#define FS_MOVED_FROM		0x00000040	/* File was moved from X */
#define FS_MOVED_TO		0x00000080	/* File was moved to Y */
#define FS_CREATE		0x00000100	/* Subfile was created */
#define FS_DELETE		0x00000200	/* Subfile was deleted */
#define FS_DELETE_SELF		0x00000400	/* Self was deleted */
#define FS_MOVE_SELF		0x00000800	/* Self was moved */
#define FS_OPEN_EXEC		0x00001000	/* File was opened for exec */

#define FS_UNMOUNT		0x00002000	/* inode on umount fs */
#define FS_Q_OVERFLOW		0x00004000	/* Event queued overflowed */
#define FS_IN_IGNORED		0x00008000	/* last inotify event here */

#define FS_OPEN_PERM		0x00010000	/* open event in an permission hook */
#define FS_ACCESS_PERM		0x00020000	/* access event in a permissions hook */
#define FS_OPEN_EXEC_PERM	0x00040000	/* open/exec event in a permission hook */

#define FS_EXCL_UNLINK		0x04000000	/* do not send events if object is unlinked */
#define FS_ISDIR		0x40000000	/* event occurred against dir */
#define FS_IN_ONESHOT		0x80000000	/* only send event once */

#define FS_DN_RENAME		0x10000000	/* file renamed */
#define FS_DN_MULTISHOT		0x20000000	/* dnotify multishot */

/* This inode cares about things that happen to its children.  Always set for
 * dnotify and inotify. */
#define FS_EVENT_ON_CHILD	0x08000000

#define FS_MOVE			(FS_MOVED_FROM | FS_MOVED_TO)

/*
 * Directory entry modification events - reported only to directory
 * where entry is modified and not to a watching parent.
 * The watching parent may get an FS_ATTRIB|FS_EVENT_ON_CHILD event
 * when a directory entry inside a child subdir changes.
 */
#define ALL_FSNOTIFY_DIRENT_EVENTS	(FS_CREATE | FS_DELETE | FS_MOVE)

#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \
				  FS_OPEN_EXEC_PERM)

/*
 * This is a list of all events that may get sent to a parent based on fs event
 * happening to inodes inside that directory.
 */
#define FS_EVENTS_POSS_ON_CHILD   (ALL_FSNOTIFY_PERM_EVENTS | \
				   FS_ACCESS | FS_MODIFY | FS_ATTRIB | \
				   FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | \
				   FS_OPEN | FS_OPEN_EXEC)

/* Events that can be reported to backends */
#define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \
			     FS_EVENTS_POSS_ON_CHILD | \
			     FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \
			     FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED)

/* Extra flags that may be reported with event or control handling of events */
#define ALL_FSNOTIFY_FLAGS  (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \
			     FS_DN_MULTISHOT | FS_EVENT_ON_CHILD)

#define ALL_FSNOTIFY_BITS   (ALL_FSNOTIFY_EVENTS | ALL_FSNOTIFY_FLAGS)

struct fsnotify_group;
struct fsnotify_event;
struct fsnotify_mark;
struct fsnotify_event_private_data;
struct fsnotify_fname;
struct fsnotify_iter_info;

struct mem_cgroup;

/*
 * Each group much define these ops.  The fsnotify infrastructure will call
 * these operations for each relevant group.
 *
 * handle_event - main call for a group to handle an fs event
 * free_group_priv - called when a group refcnt hits 0 to clean up the private union
 * freeing_mark - called when a mark is being destroyed for some reason.  The group
 * 		MUST be holding a reference on each mark and that reference must be
 * 		dropped in this function.  inotify uses this function to send
 * 		userspace messages that marks have been removed.
 */
struct fsnotify_ops {
	int (*handle_event)(struct fsnotify_group *group,
			    struct inode *inode,
			    u32 mask, const void *data, int data_type,
			    const struct qstr *file_name, u32 cookie,
			    struct fsnotify_iter_info *iter_info);
	void (*free_group_priv)(struct fsnotify_group *group);
	void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group);
	void (*free_event)(struct fsnotify_event *event);
	/* called on final put+free to free memory */
	void (*free_mark)(struct fsnotify_mark *mark);
};

/*
 * all of the information about the original object we want to now send to
 * a group.  If you want to carry more info from the accessing task to the
 * listener this structure is where you need to be adding fields.
 */
struct fsnotify_event {
	struct list_head list;
	/* inode may ONLY be dereferenced during handle_event(). */
	struct inode *inode;	/* either the inode the event happened to or its parent */
};

/*
 * A group is a "thing" that wants to receive notification about filesystem
 * events.  The mask holds the subset of event types this group cares about.
 * refcnt on a group is up to the implementor and at any moment if it goes 0
 * everything will be cleaned up.
 */
struct fsnotify_group {
	const struct fsnotify_ops *ops;	/* how this group handles things */

	/*
	 * How the refcnt is used is up to each group.  When the refcnt hits 0
	 * fsnotify will clean up all of the resources associated with this group.
	 * As an example, the dnotify group will always have a refcnt=1 and that
	 * will never change.  Inotify, on the other hand, has a group per
	 * inotify_init() and the refcnt will hit 0 only when that fd has been
	 * closed.
	 */
	refcount_t refcnt;		/* things with interest in this group */

	/* needed to send notification to userspace */
	spinlock_t notification_lock;		/* protect the notification_list */
	struct list_head notification_list;	/* list of event_holder this group needs to send to userspace */
	wait_queue_head_t notification_waitq;	/* read() on the notification file blocks on this waitq */
	unsigned int q_len;			/* events on the queue */
	unsigned int max_events;		/* maximum events allowed on the list */
	/*
	 * Valid fsnotify group priorities.  Events are send in order from highest
	 * priority to lowest priority.  We default to the lowest priority.
	 */
	#define FS_PRIO_0	0 /* normal notifiers, no permissions */
	#define FS_PRIO_1	1 /* fanotify content based access control */
	#define FS_PRIO_2	2 /* fanotify pre-content access */
	unsigned int priority;
	bool shutdown;		/* group is being shut down, don't queue more events */

	/* stores all fastpath marks assoc with this group so they can be cleaned on unregister */
	struct mutex mark_mutex;	/* protect marks_list */
	atomic_t num_marks;		/* 1 for each mark and 1 for not being
					 * past the point of no return when freeing
					 * a group */
	atomic_t user_waits;		/* Number of tasks waiting for user
					 * response */
	struct list_head marks_list;	/* all inode marks for this group */

	struct fasync_struct *fsn_fa;    /* async notification */

	struct fsnotify_event *overflow_event;	/* Event we queue when the
						 * notification list is too
						 * full */

	struct mem_cgroup *memcg;	/* memcg to charge allocations */

	/* groups can define private fields here or use the void *private */
	union {
		void *private;
#ifdef CONFIG_INOTIFY_USER
		struct inotify_group_private_data {
			spinlock_t	idr_lock;
			struct idr      idr;
			struct ucounts *ucounts;
		} inotify_data;
#endif
#ifdef CONFIG_FANOTIFY
		struct fanotify_group_private_data {
			/* allows a group to block waiting for a userspace response */
			struct list_head access_list;
			wait_queue_head_t access_waitq;
			int flags;           /* flags from fanotify_init() */
			int f_flags; /* event_f_flags from fanotify_init() */
			unsigned int max_marks;
			struct user_struct *user;
		} fanotify_data;
#endif /* CONFIG_FANOTIFY */
	};
};

/* when calling fsnotify tell it if the data is a path or inode */
#define FSNOTIFY_EVENT_NONE	0
#define FSNOTIFY_EVENT_PATH	1
#define FSNOTIFY_EVENT_INODE	2

enum fsnotify_obj_type {
	FSNOTIFY_OBJ_TYPE_INODE,
	FSNOTIFY_OBJ_TYPE_VFSMOUNT,
	FSNOTIFY_OBJ_TYPE_SB,
	FSNOTIFY_OBJ_TYPE_COUNT,
	FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT
};

#define FSNOTIFY_OBJ_TYPE_INODE_FL	(1U << FSNOTIFY_OBJ_TYPE_INODE)
#define FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL	(1U << FSNOTIFY_OBJ_TYPE_VFSMOUNT)
#define FSNOTIFY_OBJ_TYPE_SB_FL		(1U << FSNOTIFY_OBJ_TYPE_SB)
#define FSNOTIFY_OBJ_ALL_TYPES_MASK	((1U << FSNOTIFY_OBJ_TYPE_COUNT) - 1)

static inline bool fsnotify_valid_obj_type(unsigned int type)
{
	return (type < FSNOTIFY_OBJ_TYPE_COUNT);
}

struct fsnotify_iter_info {
	struct fsnotify_mark *marks[FSNOTIFY_OBJ_TYPE_COUNT];
	unsigned int report_mask;
	int srcu_idx;
};

static inline bool fsnotify_iter_should_report_type(
		struct fsnotify_iter_info *iter_info, int type)
{
	return (iter_info->report_mask & (1U << type));
}

static inline void fsnotify_iter_set_report_type(
		struct fsnotify_iter_info *iter_info, int type)
{
	iter_info->report_mask |= (1U << type);
}

static inline void fsnotify_iter_set_report_type_mark(
		struct fsnotify_iter_info *iter_info, int type,
		struct fsnotify_mark *mark)
{
	iter_info->marks[type] = mark;
	iter_info->report_mask |= (1U << type);
}

#define FSNOTIFY_ITER_FUNCS(name, NAME) \
static inline struct fsnotify_mark *fsnotify_iter_##name##_mark( \
		struct fsnotify_iter_info *iter_info) \
{ \
	return (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_##NAME##_FL) ? \
		iter_info->marks[FSNOTIFY_OBJ_TYPE_##NAME] : NULL; \
}

FSNOTIFY_ITER_FUNCS(inode, INODE)
FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT)
FSNOTIFY_ITER_FUNCS(sb, SB)

#define fsnotify_foreach_obj_type(type) \
	for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++)

/*
 * fsnotify_connp_t is what we embed in objects which connector can be attached
 * to. fsnotify_connp_t * is how we refer from connector back to object.
 */
struct fsnotify_mark_connector;
typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t;

/*
 * Inode/vfsmount/sb point to this structure which tracks all marks attached to
 * the inode/vfsmount/sb. The reference to inode/vfsmount/sb is held by this
 * structure. We destroy this structure when there are no more marks attached
 * to it. The structure is protected by fsnotify_mark_srcu.
 */
struct fsnotify_mark_connector {
	spinlock_t lock;
	unsigned int type;	/* Type of object [lock] */
	__kernel_fsid_t fsid;	/* fsid of filesystem containing object */
	union {
		/* Object pointer [lock] */
		fsnotify_connp_t *obj;
		/* Used listing heads to free after srcu period expires */
		struct fsnotify_mark_connector *destroy_next;
	};
	struct hlist_head list;
};

/*
 * A mark is simply an object attached to an in core inode which allows an
 * fsnotify listener to indicate they are either no longer interested in events
 * of a type matching mask or only interested in those events.
 *
 * These are flushed when an inode is evicted from core and may be flushed
 * when the inode is modified (as seen by fsnotify_access).  Some fsnotify
 * users (such as dnotify) will flush these when the open fd is closed and not
 * at inode eviction or modification.
 *
 * Text in brackets is showing the lock(s) protecting modifications of a
 * particular entry. obj_lock means either inode->i_lock or
 * mnt->mnt_root->d_lock depending on the mark type.
 */
struct fsnotify_mark {
	/* Mask this mark is for [mark->lock, group->mark_mutex] */
	__u32 mask;
	/* We hold one for presence in g_list. Also one ref for each 'thing'
	 * in kernel that found and may be using this mark. */
	refcount_t refcnt;
	/* Group this mark is for. Set on mark creation, stable until last ref
	 * is dropped */
	struct fsnotify_group *group;
	/* List of marks by group->marks_list. Also reused for queueing
	 * mark into destroy_list when it's waiting for the end of SRCU period
	 * before it can be freed. [group->mark_mutex] */
	struct list_head g_list;
	/* Protects inode / mnt pointers, flags, masks */
	spinlock_t lock;
	/* List of marks for inode / vfsmount [connector->lock, mark ref] */
	struct hlist_node obj_list;
	/* Head of list of marks for an object [mark ref] */
	struct fsnotify_mark_connector *connector;
	/* Events types to ignore [mark->lock, group->mark_mutex] */
	__u32 ignored_mask;
#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY	0x01
#define FSNOTIFY_MARK_FLAG_ALIVE		0x02
#define FSNOTIFY_MARK_FLAG_ATTACHED		0x04
	unsigned int flags;		/* flags [mark->lock] */
};

#ifdef CONFIG_FSNOTIFY

/* called from the vfs helpers */

/* main fsnotify call to send events */
extern int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
		    const struct qstr *name, u32 cookie);
extern int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask);
extern void __fsnotify_inode_delete(struct inode *inode);
extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt);
extern void fsnotify_sb_delete(struct super_block *sb);
extern void fsnotify_nameremove(struct dentry *dentry, int isdir);
extern u32 fsnotify_get_cookie(void);

static inline int fsnotify_inode_watches_children(struct inode *inode)
{
	/* FS_EVENT_ON_CHILD is set if the inode may care */
	if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD))
		return 0;
	/* this inode might care about child events, does it care about the
	 * specific set of events that can happen on a child? */
	return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD;
}

/*
 * Update the dentry with a flag indicating the interest of its parent to receive
 * filesystem events when those events happens to this dentry->d_inode.
 */
static inline void fsnotify_update_flags(struct dentry *dentry)
{
	assert_spin_locked(&dentry->d_lock);

	/*
	 * Serialisation of setting PARENT_WATCHED on the dentries is provided
	 * by d_lock. If inotify_inode_watched changes after we have taken
	 * d_lock, the following __fsnotify_update_child_dentry_flags call will
	 * find our entry, so it will spin until we complete here, and update
	 * us with the new state.
	 */
	if (fsnotify_inode_watches_children(dentry->d_parent->d_inode))
		dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
	else
		dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
}

/* called from fsnotify listeners, such as fanotify or dnotify */

/* create a new group */
extern struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops);
/* get reference to a group */
extern void fsnotify_get_group(struct fsnotify_group *group);
/* drop reference on a group from fsnotify_alloc_group */
extern void fsnotify_put_group(struct fsnotify_group *group);
/* group destruction begins, stop queuing new events */
extern void fsnotify_group_stop_queueing(struct fsnotify_group *group);
/* destroy group */
extern void fsnotify_destroy_group(struct fsnotify_group *group);
/* fasync handler function */
extern int fsnotify_fasync(int fd, struct file *file, int on);
/* Free event from memory */
extern void fsnotify_destroy_event(struct fsnotify_group *group,
				   struct fsnotify_event *event);
/* attach the event to the group notification queue */
extern int fsnotify_add_event(struct fsnotify_group *group,
			      struct fsnotify_event *event,
			      int (*merge)(struct list_head *,
					   struct fsnotify_event *));
/* Queue overflow event to a notification group */
static inline void fsnotify_queue_overflow(struct fsnotify_group *group)
{
	fsnotify_add_event(group, group->overflow_event, NULL);
}

/* true if the group notification queue is empty */
extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group);
/* return, but do not dequeue the first event on the notification queue */
extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group);
/* return AND dequeue the first event on the notification queue */
extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group);
/* Remove event queued in the notification list */
extern void fsnotify_remove_queued_event(struct fsnotify_group *group,
					 struct fsnotify_event *event);

/* functions used to manipulate the marks attached to inodes */

/* Get mask of events for a list of marks */
extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn);
/* Calculate mask of events for a list of marks */
extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn);
extern void fsnotify_init_mark(struct fsnotify_mark *mark,
			       struct fsnotify_group *group);
/* Find mark belonging to given group in the list of marks */
extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp,
						struct fsnotify_group *group);
/* Get cached fsid of filesystem containing object */
extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn,
				  __kernel_fsid_t *fsid);
/* attach the mark to the object */
extern int fsnotify_add_mark(struct fsnotify_mark *mark,
			     fsnotify_connp_t *connp, unsigned int type,
			     int allow_dups, __kernel_fsid_t *fsid);
extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
				    fsnotify_connp_t *connp,
				    unsigned int type, int allow_dups,
				    __kernel_fsid_t *fsid);

/* attach the mark to the inode */
static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
					  struct inode *inode,
					  int allow_dups)
{
	return fsnotify_add_mark(mark, &inode->i_fsnotify_marks,
				 FSNOTIFY_OBJ_TYPE_INODE, allow_dups, NULL);
}
static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark,
						 struct inode *inode,
						 int allow_dups)
{
	return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks,
					FSNOTIFY_OBJ_TYPE_INODE, allow_dups,
					NULL);
}

/* given a group and a mark, flag mark to be freed when all references are dropped */
extern void fsnotify_destroy_mark(struct fsnotify_mark *mark,
				  struct fsnotify_group *group);
/* detach mark from inode / mount list, group list, drop inode reference */
extern void fsnotify_detach_mark(struct fsnotify_mark *mark);
/* free mark */
extern void fsnotify_free_mark(struct fsnotify_mark *mark);
/* run all the marks in a group, and clear all of the marks attached to given object type */
extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group, unsigned int type);
/* run all the marks in a group, and clear all of the vfsmount marks */
static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
{
	fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL);
}
/* run all the marks in a group, and clear all of the inode marks */
static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
{
	fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE_FL);
}
/* run all the marks in a group, and clear all of the sn marks */
static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group)
{
	fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB_FL);
}
extern void fsnotify_get_mark(struct fsnotify_mark *mark);
extern void fsnotify_put_mark(struct fsnotify_mark *mark);
extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info);
extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info);

static inline void fsnotify_init_event(struct fsnotify_event *event,
				       struct inode *inode)
{
	INIT_LIST_HEAD(&event->list);
	event->inode = inode;
}

#else

static inline int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
			   const struct qstr *name, u32 cookie)
{
	return 0;
}

static inline int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask)
{
	return 0;
}

static inline void __fsnotify_inode_delete(struct inode *inode)
{}

static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
{}

static inline void fsnotify_sb_delete(struct super_block *sb)
{}

static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
{}

static inline void fsnotify_update_flags(struct dentry *dentry)
{}

static inline u32 fsnotify_get_cookie(void)
{
	return 0;
}

static inline void fsnotify_unmount_inodes(struct super_block *sb)
{}

#endif	/* CONFIG_FSNOTIFY */

#endif	/* __KERNEL __ */

#endif	/* __LINUX_FSNOTIFY_BACKEND_H */