1
2
3
4
5
6
7
8#ifndef __LINUX_FSNOTIFY_BACKEND_H
9#define __LINUX_FSNOTIFY_BACKEND_H
10
11#ifdef __KERNEL__
12
13#include <linux/idr.h>
14#include <linux/fs.h>
15#include <linux/list.h>
16#include <linux/path.h>
17#include <linux/spinlock.h>
18#include <linux/types.h>
19#include <linux/atomic.h>
20#include <linux/user_namespace.h>
21#include <linux/refcount.h>
22
23
24
25
26
27
28
29#define FS_ACCESS 0x00000001
30#define FS_MODIFY 0x00000002
31#define FS_ATTRIB 0x00000004
32#define FS_CLOSE_WRITE 0x00000008
33#define FS_CLOSE_NOWRITE 0x00000010
34#define FS_OPEN 0x00000020
35#define FS_MOVED_FROM 0x00000040
36#define FS_MOVED_TO 0x00000080
37#define FS_CREATE 0x00000100
38#define FS_DELETE 0x00000200
39#define FS_DELETE_SELF 0x00000400
40#define FS_MOVE_SELF 0x00000800
41#define FS_OPEN_EXEC 0x00001000
42
43#define FS_UNMOUNT 0x00002000
44#define FS_Q_OVERFLOW 0x00004000
45#define FS_IN_IGNORED 0x00008000
46
47#define FS_OPEN_PERM 0x00010000
48#define FS_ACCESS_PERM 0x00020000
49#define FS_OPEN_EXEC_PERM 0x00040000
50
51#define FS_EXCL_UNLINK 0x04000000
52#define FS_ISDIR 0x40000000
53#define FS_IN_ONESHOT 0x80000000
54
55#define FS_DN_RENAME 0x10000000
56#define FS_DN_MULTISHOT 0x20000000
57
58
59
60#define FS_EVENT_ON_CHILD 0x08000000
61
62#define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO)
63
64
65
66
67
68
69
70#define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE)
71
72#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \
73 FS_OPEN_EXEC_PERM)
74
75
76
77
78
79#define FS_EVENTS_POSS_ON_CHILD (ALL_FSNOTIFY_PERM_EVENTS | \
80 FS_ACCESS | FS_MODIFY | FS_ATTRIB | \
81 FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | \
82 FS_OPEN | FS_OPEN_EXEC)
83
84
85#define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \
86 FS_EVENTS_POSS_ON_CHILD | \
87 FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \
88 FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED)
89
90
91#define ALL_FSNOTIFY_FLAGS (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \
92 FS_DN_MULTISHOT | FS_EVENT_ON_CHILD)
93
94#define ALL_FSNOTIFY_BITS (ALL_FSNOTIFY_EVENTS | ALL_FSNOTIFY_FLAGS)
95
96struct fsnotify_group;
97struct fsnotify_event;
98struct fsnotify_mark;
99struct fsnotify_event_private_data;
100struct fsnotify_fname;
101struct fsnotify_iter_info;
102
103struct mem_cgroup;
104
105
106
107
108
109
110
111
112
113
114
115
116struct fsnotify_ops {
117 int (*handle_event)(struct fsnotify_group *group,
118 struct inode *inode,
119 u32 mask, const void *data, int data_type,
120 const struct qstr *file_name, u32 cookie,
121 struct fsnotify_iter_info *iter_info);
122 void (*free_group_priv)(struct fsnotify_group *group);
123 void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group);
124 void (*free_event)(struct fsnotify_event *event);
125
126 void (*free_mark)(struct fsnotify_mark *mark);
127};
128
129
130
131
132
133
134struct fsnotify_event {
135 struct list_head list;
136
137 struct inode *inode;
138};
139
140
141
142
143
144
145
146struct fsnotify_group {
147 const struct fsnotify_ops *ops;
148
149
150
151
152
153
154
155
156
157 refcount_t refcnt;
158
159
160 spinlock_t notification_lock;
161 struct list_head notification_list;
162 wait_queue_head_t notification_waitq;
163 unsigned int q_len;
164 unsigned int max_events;
165
166
167
168
169 #define FS_PRIO_0 0
170 #define FS_PRIO_1 1
171 #define FS_PRIO_2 2
172 unsigned int priority;
173 bool shutdown;
174
175
176 struct mutex mark_mutex;
177 atomic_t num_marks;
178
179
180 atomic_t user_waits;
181
182 struct list_head marks_list;
183
184 struct fasync_struct *fsn_fa;
185
186 struct fsnotify_event *overflow_event;
187
188
189
190 struct mem_cgroup *memcg;
191
192
193 union {
194 void *private;
195#ifdef CONFIG_INOTIFY_USER
196 struct inotify_group_private_data {
197 spinlock_t idr_lock;
198 struct idr idr;
199 struct ucounts *ucounts;
200 } inotify_data;
201#endif
202#ifdef CONFIG_FANOTIFY
203 struct fanotify_group_private_data {
204
205 struct list_head access_list;
206 wait_queue_head_t access_waitq;
207 int flags;
208 int f_flags;
209 unsigned int max_marks;
210 struct user_struct *user;
211 } fanotify_data;
212#endif
213 };
214};
215
216
217#define FSNOTIFY_EVENT_NONE 0
218#define FSNOTIFY_EVENT_PATH 1
219#define FSNOTIFY_EVENT_INODE 2
220
221enum fsnotify_obj_type {
222 FSNOTIFY_OBJ_TYPE_INODE,
223 FSNOTIFY_OBJ_TYPE_VFSMOUNT,
224 FSNOTIFY_OBJ_TYPE_SB,
225 FSNOTIFY_OBJ_TYPE_COUNT,
226 FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT
227};
228
229#define FSNOTIFY_OBJ_TYPE_INODE_FL (1U << FSNOTIFY_OBJ_TYPE_INODE)
230#define FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL (1U << FSNOTIFY_OBJ_TYPE_VFSMOUNT)
231#define FSNOTIFY_OBJ_TYPE_SB_FL (1U << FSNOTIFY_OBJ_TYPE_SB)
232#define FSNOTIFY_OBJ_ALL_TYPES_MASK ((1U << FSNOTIFY_OBJ_TYPE_COUNT) - 1)
233
234static inline bool fsnotify_valid_obj_type(unsigned int type)
235{
236 return (type < FSNOTIFY_OBJ_TYPE_COUNT);
237}
238
239struct fsnotify_iter_info {
240 struct fsnotify_mark *marks[FSNOTIFY_OBJ_TYPE_COUNT];
241 unsigned int report_mask;
242 int srcu_idx;
243};
244
245static inline bool fsnotify_iter_should_report_type(
246 struct fsnotify_iter_info *iter_info, int type)
247{
248 return (iter_info->report_mask & (1U << type));
249}
250
251static inline void fsnotify_iter_set_report_type(
252 struct fsnotify_iter_info *iter_info, int type)
253{
254 iter_info->report_mask |= (1U << type);
255}
256
257static inline void fsnotify_iter_set_report_type_mark(
258 struct fsnotify_iter_info *iter_info, int type,
259 struct fsnotify_mark *mark)
260{
261 iter_info->marks[type] = mark;
262 iter_info->report_mask |= (1U << type);
263}
264
265#define FSNOTIFY_ITER_FUNCS(name, NAME) \
266static inline struct fsnotify_mark *fsnotify_iter_##name##_mark( \
267 struct fsnotify_iter_info *iter_info) \
268{ \
269 return (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_##NAME##_FL) ? \
270 iter_info->marks[FSNOTIFY_OBJ_TYPE_##NAME] : NULL; \
271}
272
273FSNOTIFY_ITER_FUNCS(inode, INODE)
274FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT)
275FSNOTIFY_ITER_FUNCS(sb, SB)
276
277#define fsnotify_foreach_obj_type(type) \
278 for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++)
279
280
281
282
283
284struct fsnotify_mark_connector;
285typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t;
286
287
288
289
290
291
292
293struct fsnotify_mark_connector {
294 spinlock_t lock;
295 unsigned short type;
296#define FSNOTIFY_CONN_FLAG_HAS_FSID 0x01
297 unsigned short flags;
298 __kernel_fsid_t fsid;
299 union {
300
301 fsnotify_connp_t *obj;
302
303 struct fsnotify_mark_connector *destroy_next;
304 };
305 struct hlist_head list;
306};
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322struct fsnotify_mark {
323
324 __u32 mask;
325
326
327 refcount_t refcnt;
328
329
330 struct fsnotify_group *group;
331
332
333
334 struct list_head g_list;
335
336 spinlock_t lock;
337
338 struct hlist_node obj_list;
339
340 struct fsnotify_mark_connector *connector;
341
342 __u32 ignored_mask;
343#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x01
344#define FSNOTIFY_MARK_FLAG_ALIVE 0x02
345#define FSNOTIFY_MARK_FLAG_ATTACHED 0x04
346 unsigned int flags;
347};
348
349#ifdef CONFIG_FSNOTIFY
350
351
352
353
354extern int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
355 const struct qstr *name, u32 cookie);
356extern int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask);
357extern void __fsnotify_inode_delete(struct inode *inode);
358extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt);
359extern void fsnotify_sb_delete(struct super_block *sb);
360extern void fsnotify_nameremove(struct dentry *dentry, int isdir);
361extern u32 fsnotify_get_cookie(void);
362
363static inline int fsnotify_inode_watches_children(struct inode *inode)
364{
365
366 if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD))
367 return 0;
368
369
370 return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD;
371}
372
373
374
375
376
377static inline void fsnotify_update_flags(struct dentry *dentry)
378{
379 assert_spin_locked(&dentry->d_lock);
380
381
382
383
384
385
386
387
388 if (fsnotify_inode_watches_children(dentry->d_parent->d_inode))
389 dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
390 else
391 dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
392}
393
394
395
396
397extern struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops);
398
399extern void fsnotify_get_group(struct fsnotify_group *group);
400
401extern void fsnotify_put_group(struct fsnotify_group *group);
402
403extern void fsnotify_group_stop_queueing(struct fsnotify_group *group);
404
405extern void fsnotify_destroy_group(struct fsnotify_group *group);
406
407extern int fsnotify_fasync(int fd, struct file *file, int on);
408
409extern void fsnotify_destroy_event(struct fsnotify_group *group,
410 struct fsnotify_event *event);
411
412extern int fsnotify_add_event(struct fsnotify_group *group,
413 struct fsnotify_event *event,
414 int (*merge)(struct list_head *,
415 struct fsnotify_event *));
416
417static inline void fsnotify_queue_overflow(struct fsnotify_group *group)
418{
419 fsnotify_add_event(group, group->overflow_event, NULL);
420}
421
422
423extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group);
424
425extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group);
426
427extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group);
428
429extern void fsnotify_remove_queued_event(struct fsnotify_group *group,
430 struct fsnotify_event *event);
431
432
433
434
435extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn);
436
437extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn);
438extern void fsnotify_init_mark(struct fsnotify_mark *mark,
439 struct fsnotify_group *group);
440
441extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp,
442 struct fsnotify_group *group);
443
444extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn,
445 __kernel_fsid_t *fsid);
446
447extern int fsnotify_add_mark(struct fsnotify_mark *mark,
448 fsnotify_connp_t *connp, unsigned int type,
449 int allow_dups, __kernel_fsid_t *fsid);
450extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
451 fsnotify_connp_t *connp,
452 unsigned int type, int allow_dups,
453 __kernel_fsid_t *fsid);
454
455
456static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
457 struct inode *inode,
458 int allow_dups)
459{
460 return fsnotify_add_mark(mark, &inode->i_fsnotify_marks,
461 FSNOTIFY_OBJ_TYPE_INODE, allow_dups, NULL);
462}
463static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark,
464 struct inode *inode,
465 int allow_dups)
466{
467 return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks,
468 FSNOTIFY_OBJ_TYPE_INODE, allow_dups,
469 NULL);
470}
471
472
473extern void fsnotify_destroy_mark(struct fsnotify_mark *mark,
474 struct fsnotify_group *group);
475
476extern void fsnotify_detach_mark(struct fsnotify_mark *mark);
477
478extern void fsnotify_free_mark(struct fsnotify_mark *mark);
479
480extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group, unsigned int type);
481
482static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
483{
484 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL);
485}
486
487static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
488{
489 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE_FL);
490}
491
492static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group)
493{
494 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB_FL);
495}
496extern void fsnotify_get_mark(struct fsnotify_mark *mark);
497extern void fsnotify_put_mark(struct fsnotify_mark *mark);
498extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info);
499extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info);
500
501static inline void fsnotify_init_event(struct fsnotify_event *event,
502 struct inode *inode)
503{
504 INIT_LIST_HEAD(&event->list);
505 event->inode = inode;
506}
507
508#else
509
510static inline int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
511 const struct qstr *name, u32 cookie)
512{
513 return 0;
514}
515
516static inline int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask)
517{
518 return 0;
519}
520
521static inline void __fsnotify_inode_delete(struct inode *inode)
522{}
523
524static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
525{}
526
527static inline void fsnotify_sb_delete(struct super_block *sb)
528{}
529
530static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
531{}
532
533static inline void fsnotify_update_flags(struct dentry *dentry)
534{}
535
536static inline u32 fsnotify_get_cookie(void)
537{
538 return 0;
539}
540
541static inline void fsnotify_unmount_inodes(struct super_block *sb)
542{}
543
544#endif
545
546#endif
547
548#endif
549