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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
90586523 EP |
2 | /* |
3 | * Filesystem access notification for Linux | |
4 | * | |
5 | * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com> | |
6 | */ | |
7 | ||
8 | #ifndef __LINUX_FSNOTIFY_BACKEND_H | |
9 | #define __LINUX_FSNOTIFY_BACKEND_H | |
10 | ||
11 | #ifdef __KERNEL__ | |
12 | ||
63c882a0 | 13 | #include <linux/idr.h> /* inotify uses this */ |
90586523 EP |
14 | #include <linux/fs.h> /* struct inode */ |
15 | #include <linux/list.h> | |
16 | #include <linux/path.h> /* struct path */ | |
17 | #include <linux/spinlock.h> | |
18 | #include <linux/types.h> | |
60063497 | 19 | #include <linux/atomic.h> |
1cce1eea | 20 | #include <linux/user_namespace.h> |
7761daa6 | 21 | #include <linux/refcount.h> |
734a1a5e | 22 | #include <linux/mempool.h> |
90586523 EP |
23 | |
24 | /* | |
25 | * IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily | |
26 | * convert between them. dnotify only needs conversion at watch creation | |
27 | * so no perf loss there. fanotify isn't defined yet, so it can use the | |
28 | * wholes if it needs more events. | |
29 | */ | |
30 | #define FS_ACCESS 0x00000001 /* File was accessed */ | |
31 | #define FS_MODIFY 0x00000002 /* File was modified */ | |
32 | #define FS_ATTRIB 0x00000004 /* Metadata changed */ | |
33 | #define FS_CLOSE_WRITE 0x00000008 /* Writtable file was closed */ | |
34 | #define FS_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */ | |
35 | #define FS_OPEN 0x00000020 /* File was opened */ | |
36 | #define FS_MOVED_FROM 0x00000040 /* File was moved from X */ | |
37 | #define FS_MOVED_TO 0x00000080 /* File was moved to Y */ | |
38 | #define FS_CREATE 0x00000100 /* Subfile was created */ | |
39 | #define FS_DELETE 0x00000200 /* Subfile was deleted */ | |
40 | #define FS_DELETE_SELF 0x00000400 /* Self was deleted */ | |
41 | #define FS_MOVE_SELF 0x00000800 /* Self was moved */ | |
9b076f1c | 42 | #define FS_OPEN_EXEC 0x00001000 /* File was opened for exec */ |
90586523 EP |
43 | |
44 | #define FS_UNMOUNT 0x00002000 /* inode on umount fs */ | |
45 | #define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ | |
9daa8110 GKB |
46 | #define FS_ERROR 0x00008000 /* Filesystem Error (fanotify) */ |
47 | ||
48 | /* | |
49 | * FS_IN_IGNORED overloads FS_ERROR. It is only used internally by inotify | |
50 | * which does not support FS_ERROR. | |
51 | */ | |
90586523 EP |
52 | #define FS_IN_IGNORED 0x00008000 /* last inotify event here */ |
53 | ||
c4ec54b4 EP |
54 | #define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */ |
55 | #define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */ | |
66917a31 | 56 | #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ |
c4ec54b4 | 57 | |
8c1934c8 | 58 | #define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */ |
9b93f331 AG |
59 | /* |
60 | * Set on inode mark that cares about things that happen to its children. | |
61 | * Always set for dnotify and inotify. | |
62 | * Set on inode/sb/mount marks that care about parent/name info. | |
63 | */ | |
c28f7e56 EP |
64 | #define FS_EVENT_ON_CHILD 0x08000000 |
65 | ||
e54183fa | 66 | #define FS_RENAME 0x10000000 /* File was renamed */ |
6473ea76 AG |
67 | #define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ |
68 | #define FS_ISDIR 0x40000000 /* event occurred against dir */ | |
69 | #define FS_IN_ONESHOT 0x80000000 /* only send event once */ | |
70 | ||
e9fd702a EP |
71 | #define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO) |
72 | ||
e220140f AG |
73 | /* |
74 | * Directory entry modification events - reported only to directory | |
75 | * where entry is modified and not to a watching parent. | |
76 | * The watching parent may get an FS_ATTRIB|FS_EVENT_ON_CHILD event | |
77 | * when a directory entry inside a child subdir changes. | |
78 | */ | |
e54183fa | 79 | #define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE | FS_RENAME) |
e220140f | 80 | |
66917a31 MB |
81 | #define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ |
82 | FS_OPEN_EXEC_PERM) | |
ff8bcbd0 | 83 | |
e220140f | 84 | /* |
9b93f331 AG |
85 | * This is a list of all events that may get sent to a parent that is watching |
86 | * with flag FS_EVENT_ON_CHILD based on fs event on a child of that directory. | |
e220140f AG |
87 | */ |
88 | #define FS_EVENTS_POSS_ON_CHILD (ALL_FSNOTIFY_PERM_EVENTS | \ | |
89 | FS_ACCESS | FS_MODIFY | FS_ATTRIB | \ | |
90 | FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | \ | |
91 | FS_OPEN | FS_OPEN_EXEC) | |
92 | ||
9b93f331 AG |
93 | /* |
94 | * This is a list of all events that may get sent with the parent inode as the | |
95 | * @to_tell argument of fsnotify(). | |
96 | * It may include events that can be sent to an inode/sb/mount mark, but cannot | |
97 | * be sent to a parent watching children. | |
98 | */ | |
99 | #define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD) | |
100 | ||
007d1e83 | 101 | /* Events that can be reported to backends */ |
e220140f AG |
102 | #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \ |
103 | FS_EVENTS_POSS_ON_CHILD | \ | |
e54183fa | 104 | FS_DELETE_SELF | FS_MOVE_SELF | \ |
9daa8110 GKB |
105 | FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \ |
106 | FS_ERROR) | |
007d1e83 AG |
107 | |
108 | /* Extra flags that may be reported with event or control handling of events */ | |
109 | #define ALL_FSNOTIFY_FLAGS (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \ | |
20dee624 EP |
110 | FS_DN_MULTISHOT | FS_EVENT_ON_CHILD) |
111 | ||
007d1e83 AG |
112 | #define ALL_FSNOTIFY_BITS (ALL_FSNOTIFY_EVENTS | ALL_FSNOTIFY_FLAGS) |
113 | ||
90586523 EP |
114 | struct fsnotify_group; |
115 | struct fsnotify_event; | |
e61ce867 | 116 | struct fsnotify_mark; |
e4aff117 | 117 | struct fsnotify_event_private_data; |
7053aee2 | 118 | struct fsnotify_fname; |
abc77577 | 119 | struct fsnotify_iter_info; |
90586523 | 120 | |
d46eb14b SB |
121 | struct mem_cgroup; |
122 | ||
90586523 EP |
123 | /* |
124 | * Each group much define these ops. The fsnotify infrastructure will call | |
125 | * these operations for each relevant group. | |
126 | * | |
127 | * handle_event - main call for a group to handle an fs event | |
b54cecf5 AG |
128 | * @group: group to notify |
129 | * @mask: event type and flags | |
130 | * @data: object that event happened on | |
131 | * @data_type: type of object for fanotify_data_XXX() accessors | |
132 | * @dir: optional directory associated with event - | |
133 | * if @file_name is not NULL, this is the directory that | |
134 | * @file_name is relative to | |
135 | * @file_name: optional file name associated with event | |
136 | * @cookie: inotify rename cookie | |
137 | * @iter_info: array of marks from this group that are interested in the event | |
138 | * | |
b9a1b977 AG |
139 | * handle_inode_event - simple variant of handle_event() for groups that only |
140 | * have inode marks and don't have ignore mask | |
141 | * @mark: mark to notify | |
142 | * @mask: event type and flags | |
143 | * @inode: inode that event happened on | |
144 | * @dir: optional directory associated with event - | |
145 | * if @file_name is not NULL, this is the directory that | |
146 | * @file_name is relative to. | |
24dca905 | 147 | * Either @inode or @dir must be non-NULL. |
b9a1b977 | 148 | * @file_name: optional file name associated with event |
950cc0d2 | 149 | * @cookie: inotify rename cookie |
b9a1b977 | 150 | * |
90586523 | 151 | * free_group_priv - called when a group refcnt hits 0 to clean up the private union |
6960b0d9 | 152 | * freeing_mark - called when a mark is being destroyed for some reason. The group |
b9a1b977 AG |
153 | * MUST be holding a reference on each mark and that reference must be |
154 | * dropped in this function. inotify uses this function to send | |
155 | * userspace messages that marks have been removed. | |
90586523 EP |
156 | */ |
157 | struct fsnotify_ops { | |
b54cecf5 AG |
158 | int (*handle_event)(struct fsnotify_group *group, u32 mask, |
159 | const void *data, int data_type, struct inode *dir, | |
e43e9c33 | 160 | const struct qstr *file_name, u32 cookie, |
9385a84d | 161 | struct fsnotify_iter_info *iter_info); |
b9a1b977 AG |
162 | int (*handle_inode_event)(struct fsnotify_mark *mark, u32 mask, |
163 | struct inode *inode, struct inode *dir, | |
950cc0d2 | 164 | const struct qstr *file_name, u32 cookie); |
90586523 | 165 | void (*free_group_priv)(struct fsnotify_group *group); |
841bdc10 | 166 | void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group); |
330ae77d | 167 | void (*free_event)(struct fsnotify_group *group, struct fsnotify_event *event); |
054c636e JK |
168 | /* called on final put+free to free memory */ |
169 | void (*free_mark)(struct fsnotify_mark *mark); | |
7053aee2 JK |
170 | }; |
171 | ||
172 | /* | |
173 | * all of the information about the original object we want to now send to | |
174 | * a group. If you want to carry more info from the accessing task to the | |
175 | * listener this structure is where you need to be adding fields. | |
176 | */ | |
177 | struct fsnotify_event { | |
178 | struct list_head list; | |
90586523 EP |
179 | }; |
180 | ||
181 | /* | |
182 | * A group is a "thing" that wants to receive notification about filesystem | |
183 | * events. The mask holds the subset of event types this group cares about. | |
184 | * refcnt on a group is up to the implementor and at any moment if it goes 0 | |
185 | * everything will be cleaned up. | |
186 | */ | |
187 | struct fsnotify_group { | |
d46eb14b SB |
188 | const struct fsnotify_ops *ops; /* how this group handles things */ |
189 | ||
90586523 EP |
190 | /* |
191 | * How the refcnt is used is up to each group. When the refcnt hits 0 | |
192 | * fsnotify will clean up all of the resources associated with this group. | |
193 | * As an example, the dnotify group will always have a refcnt=1 and that | |
194 | * will never change. Inotify, on the other hand, has a group per | |
195 | * inotify_init() and the refcnt will hit 0 only when that fd has been | |
196 | * closed. | |
197 | */ | |
7761daa6 | 198 | refcount_t refcnt; /* things with interest in this group */ |
90586523 | 199 | |
a2d8bc6c | 200 | /* needed to send notification to userspace */ |
c21dbe20 | 201 | spinlock_t notification_lock; /* protect the notification_list */ |
a2d8bc6c EP |
202 | struct list_head notification_list; /* list of event_holder this group needs to send to userspace */ |
203 | wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */ | |
204 | unsigned int q_len; /* events on the queue */ | |
205 | unsigned int max_events; /* maximum events allowed on the list */ | |
6ad2d4e3 EP |
206 | /* |
207 | * Valid fsnotify group priorities. Events are send in order from highest | |
208 | * priority to lowest priority. We default to the lowest priority. | |
209 | */ | |
210 | #define FS_PRIO_0 0 /* normal notifiers, no permissions */ | |
211 | #define FS_PRIO_1 1 /* fanotify content based access control */ | |
212 | #define FS_PRIO_2 2 /* fanotify pre-content access */ | |
213 | unsigned int priority; | |
12703dbf | 214 | bool shutdown; /* group is being shut down, don't queue more events */ |
a2d8bc6c | 215 | |
e61ce867 | 216 | /* stores all fastpath marks assoc with this group so they can be cleaned on unregister */ |
986ab098 | 217 | struct mutex mark_mutex; /* protect marks_list */ |
d46eb14b SB |
218 | atomic_t user_waits; /* Number of tasks waiting for user |
219 | * response */ | |
e61ce867 | 220 | struct list_head marks_list; /* all inode marks for this group */ |
3be25f49 | 221 | |
7053aee2 JK |
222 | struct fasync_struct *fsn_fa; /* async notification */ |
223 | ||
ff57cd58 | 224 | struct fsnotify_event *overflow_event; /* Event we queue when the |
7053aee2 JK |
225 | * notification list is too |
226 | * full */ | |
d46eb14b SB |
227 | |
228 | struct mem_cgroup *memcg; /* memcg to charge allocations */ | |
0a6b6bd5 | 229 | |
90586523 EP |
230 | /* groups can define private fields here or use the void *private */ |
231 | union { | |
232 | void *private; | |
63c882a0 EP |
233 | #ifdef CONFIG_INOTIFY_USER |
234 | struct inotify_group_private_data { | |
235 | spinlock_t idr_lock; | |
236 | struct idr idr; | |
1cce1eea | 237 | struct ucounts *ucounts; |
63c882a0 | 238 | } inotify_data; |
9e66e423 | 239 | #endif |
80af2588 | 240 | #ifdef CONFIG_FANOTIFY |
9e66e423 | 241 | struct fanotify_group_private_data { |
94e00d28 AG |
242 | /* Hash table of events for merge */ |
243 | struct hlist_head *merge_hash; | |
9e66e423 | 244 | /* allows a group to block waiting for a userspace response */ |
9e66e423 EP |
245 | struct list_head access_list; |
246 | wait_queue_head_t access_waitq; | |
96a71f21 AG |
247 | int flags; /* flags from fanotify_init() */ |
248 | int f_flags; /* event_f_flags from fanotify_init() */ | |
5b8fea65 | 249 | struct ucounts *ucounts; |
734a1a5e | 250 | mempool_t error_events_pool; |
9e66e423 | 251 | } fanotify_data; |
80af2588 | 252 | #endif /* CONFIG_FANOTIFY */ |
90586523 EP |
253 | }; |
254 | }; | |
255 | ||
aa93bdc5 AG |
256 | /* When calling fsnotify tell it if the data is a path or inode */ |
257 | enum fsnotify_data_type { | |
258 | FSNOTIFY_EVENT_NONE, | |
259 | FSNOTIFY_EVENT_PATH, | |
260 | FSNOTIFY_EVENT_INODE, | |
fd5a3ff4 | 261 | FSNOTIFY_EVENT_DENTRY, |
9daa8110 GKB |
262 | FSNOTIFY_EVENT_ERROR, |
263 | }; | |
264 | ||
265 | struct fs_error_report { | |
266 | int error; | |
267 | struct inode *inode; | |
268 | struct super_block *sb; | |
aa93bdc5 AG |
269 | }; |
270 | ||
cbcf47ad | 271 | static inline struct inode *fsnotify_data_inode(const void *data, int data_type) |
aa93bdc5 AG |
272 | { |
273 | switch (data_type) { | |
274 | case FSNOTIFY_EVENT_INODE: | |
cbcf47ad | 275 | return (struct inode *)data; |
fd5a3ff4 AG |
276 | case FSNOTIFY_EVENT_DENTRY: |
277 | return d_inode(data); | |
aa93bdc5 AG |
278 | case FSNOTIFY_EVENT_PATH: |
279 | return d_inode(((const struct path *)data)->dentry); | |
9daa8110 GKB |
280 | case FSNOTIFY_EVENT_ERROR: |
281 | return ((struct fs_error_report *)data)->inode; | |
aa93bdc5 AG |
282 | default: |
283 | return NULL; | |
284 | } | |
fd5a3ff4 AG |
285 | } |
286 | ||
287 | static inline struct dentry *fsnotify_data_dentry(const void *data, int data_type) | |
288 | { | |
289 | switch (data_type) { | |
290 | case FSNOTIFY_EVENT_DENTRY: | |
291 | /* Non const is needed for dget() */ | |
292 | return (struct dentry *)data; | |
293 | case FSNOTIFY_EVENT_PATH: | |
294 | return ((const struct path *)data)->dentry; | |
295 | default: | |
296 | return NULL; | |
297 | } | |
aa93bdc5 AG |
298 | } |
299 | ||
300 | static inline const struct path *fsnotify_data_path(const void *data, | |
301 | int data_type) | |
302 | { | |
303 | switch (data_type) { | |
304 | case FSNOTIFY_EVENT_PATH: | |
305 | return data; | |
306 | default: | |
307 | return NULL; | |
308 | } | |
309 | } | |
90586523 | 310 | |
29335033 GKB |
311 | static inline struct super_block *fsnotify_data_sb(const void *data, |
312 | int data_type) | |
313 | { | |
314 | switch (data_type) { | |
315 | case FSNOTIFY_EVENT_INODE: | |
316 | return ((struct inode *)data)->i_sb; | |
317 | case FSNOTIFY_EVENT_DENTRY: | |
318 | return ((struct dentry *)data)->d_sb; | |
319 | case FSNOTIFY_EVENT_PATH: | |
320 | return ((const struct path *)data)->dentry->d_sb; | |
9daa8110 GKB |
321 | case FSNOTIFY_EVENT_ERROR: |
322 | return ((struct fs_error_report *) data)->sb; | |
323 | default: | |
324 | return NULL; | |
325 | } | |
326 | } | |
327 | ||
328 | static inline struct fs_error_report *fsnotify_data_error_report( | |
329 | const void *data, | |
330 | int data_type) | |
331 | { | |
332 | switch (data_type) { | |
333 | case FSNOTIFY_EVENT_ERROR: | |
334 | return (struct fs_error_report *) data; | |
29335033 GKB |
335 | default: |
336 | return NULL; | |
337 | } | |
338 | } | |
339 | ||
1c9007d6 AG |
340 | /* |
341 | * Index to merged marks iterator array that correlates to a type of watch. | |
342 | * The type of watched object can be deduced from the iterator type, but not | |
343 | * the other way around, because an event can match different watched objects | |
344 | * of the same object type. | |
345 | * For example, both parent and child are watching an object of type inode. | |
346 | */ | |
347 | enum fsnotify_iter_type { | |
348 | FSNOTIFY_ITER_TYPE_INODE, | |
349 | FSNOTIFY_ITER_TYPE_VFSMOUNT, | |
350 | FSNOTIFY_ITER_TYPE_SB, | |
351 | FSNOTIFY_ITER_TYPE_PARENT, | |
e54183fa | 352 | FSNOTIFY_ITER_TYPE_INODE2, |
1c9007d6 AG |
353 | FSNOTIFY_ITER_TYPE_COUNT |
354 | }; | |
355 | ||
356 | /* The type of object that a mark is attached to */ | |
d6f7b98b | 357 | enum fsnotify_obj_type { |
ad69cd99 | 358 | FSNOTIFY_OBJ_TYPE_ANY = -1, |
d6f7b98b AG |
359 | FSNOTIFY_OBJ_TYPE_INODE, |
360 | FSNOTIFY_OBJ_TYPE_VFSMOUNT, | |
1e6cb723 | 361 | FSNOTIFY_OBJ_TYPE_SB, |
d6f7b98b AG |
362 | FSNOTIFY_OBJ_TYPE_COUNT, |
363 | FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT | |
364 | }; | |
365 | ||
ad69cd99 | 366 | static inline bool fsnotify_valid_obj_type(unsigned int obj_type) |
b812a9f5 | 367 | { |
ad69cd99 | 368 | return (obj_type < FSNOTIFY_OBJ_TYPE_COUNT); |
b812a9f5 AG |
369 | } |
370 | ||
5b0457ad | 371 | struct fsnotify_iter_info { |
1c9007d6 | 372 | struct fsnotify_mark *marks[FSNOTIFY_ITER_TYPE_COUNT]; |
5b0457ad AG |
373 | unsigned int report_mask; |
374 | int srcu_idx; | |
375 | }; | |
376 | ||
47d9c7cc | 377 | static inline bool fsnotify_iter_should_report_type( |
1c9007d6 | 378 | struct fsnotify_iter_info *iter_info, int iter_type) |
47d9c7cc | 379 | { |
1c9007d6 | 380 | return (iter_info->report_mask & (1U << iter_type)); |
47d9c7cc AG |
381 | } |
382 | ||
383 | static inline void fsnotify_iter_set_report_type( | |
1c9007d6 | 384 | struct fsnotify_iter_info *iter_info, int iter_type) |
47d9c7cc | 385 | { |
1c9007d6 | 386 | iter_info->report_mask |= (1U << iter_type); |
47d9c7cc AG |
387 | } |
388 | ||
389 | static inline void fsnotify_iter_set_report_type_mark( | |
1c9007d6 | 390 | struct fsnotify_iter_info *iter_info, int iter_type, |
47d9c7cc AG |
391 | struct fsnotify_mark *mark) |
392 | { | |
1c9007d6 AG |
393 | iter_info->marks[iter_type] = mark; |
394 | iter_info->report_mask |= (1U << iter_type); | |
47d9c7cc AG |
395 | } |
396 | ||
5b0457ad AG |
397 | #define FSNOTIFY_ITER_FUNCS(name, NAME) \ |
398 | static inline struct fsnotify_mark *fsnotify_iter_##name##_mark( \ | |
399 | struct fsnotify_iter_info *iter_info) \ | |
400 | { \ | |
1c9007d6 AG |
401 | return (iter_info->report_mask & (1U << FSNOTIFY_ITER_TYPE_##NAME)) ? \ |
402 | iter_info->marks[FSNOTIFY_ITER_TYPE_##NAME] : NULL; \ | |
5b0457ad AG |
403 | } |
404 | ||
405 | FSNOTIFY_ITER_FUNCS(inode, INODE) | |
fecc4559 | 406 | FSNOTIFY_ITER_FUNCS(parent, PARENT) |
5b0457ad | 407 | FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT) |
1e6cb723 | 408 | FSNOTIFY_ITER_FUNCS(sb, SB) |
5b0457ad | 409 | |
1c9007d6 AG |
410 | #define fsnotify_foreach_iter_type(type) \ |
411 | for (type = 0; type < FSNOTIFY_ITER_TYPE_COUNT; type++) | |
47d9c7cc | 412 | |
36f10f55 AG |
413 | /* |
414 | * fsnotify_connp_t is what we embed in objects which connector can be attached | |
415 | * to. fsnotify_connp_t * is how we refer from connector back to object. | |
416 | */ | |
417 | struct fsnotify_mark_connector; | |
418 | typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t; | |
419 | ||
9dd813c1 | 420 | /* |
1e6cb723 AG |
421 | * Inode/vfsmount/sb point to this structure which tracks all marks attached to |
422 | * the inode/vfsmount/sb. The reference to inode/vfsmount/sb is held by this | |
08991e83 JK |
423 | * structure. We destroy this structure when there are no more marks attached |
424 | * to it. The structure is protected by fsnotify_mark_srcu. | |
9dd813c1 JK |
425 | */ |
426 | struct fsnotify_mark_connector { | |
04662cab | 427 | spinlock_t lock; |
c285a2f0 AG |
428 | unsigned short type; /* Type of object [lock] */ |
429 | #define FSNOTIFY_CONN_FLAG_HAS_FSID 0x01 | |
430 | unsigned short flags; /* flags [lock] */ | |
77115225 | 431 | __kernel_fsid_t fsid; /* fsid of filesystem containing object */ |
36f10f55 AG |
432 | union { |
433 | /* Object pointer [lock] */ | |
434 | fsnotify_connp_t *obj; | |
08991e83 JK |
435 | /* Used listing heads to free after srcu period expires */ |
436 | struct fsnotify_mark_connector *destroy_next; | |
437 | }; | |
d90a10e2 | 438 | struct hlist_head list; |
9dd813c1 JK |
439 | }; |
440 | ||
3be25f49 | 441 | /* |
1e39fc01 | 442 | * A mark is simply an object attached to an in core inode which allows an |
3be25f49 EP |
443 | * fsnotify listener to indicate they are either no longer interested in events |
444 | * of a type matching mask or only interested in those events. | |
445 | * | |
1e39fc01 JK |
446 | * These are flushed when an inode is evicted from core and may be flushed |
447 | * when the inode is modified (as seen by fsnotify_access). Some fsnotify | |
448 | * users (such as dnotify) will flush these when the open fd is closed and not | |
449 | * at inode eviction or modification. | |
450 | * | |
451 | * Text in brackets is showing the lock(s) protecting modifications of a | |
452 | * particular entry. obj_lock means either inode->i_lock or | |
453 | * mnt->mnt_root->d_lock depending on the mark type. | |
3be25f49 | 454 | */ |
e61ce867 | 455 | struct fsnotify_mark { |
1e39fc01 JK |
456 | /* Mask this mark is for [mark->lock, group->mark_mutex] */ |
457 | __u32 mask; | |
458 | /* We hold one for presence in g_list. Also one ref for each 'thing' | |
3be25f49 | 459 | * in kernel that found and may be using this mark. */ |
ab97f873 | 460 | refcount_t refcnt; |
1e39fc01 JK |
461 | /* Group this mark is for. Set on mark creation, stable until last ref |
462 | * is dropped */ | |
463 | struct fsnotify_group *group; | |
8e984f86 | 464 | /* List of marks by group->marks_list. Also reused for queueing |
1e39fc01 JK |
465 | * mark into destroy_list when it's waiting for the end of SRCU period |
466 | * before it can be freed. [group->mark_mutex] */ | |
13d34ac6 | 467 | struct list_head g_list; |
1e39fc01 JK |
468 | /* Protects inode / mnt pointers, flags, masks */ |
469 | spinlock_t lock; | |
6b3f05d2 | 470 | /* List of marks for inode / vfsmount [connector->lock, mark ref] */ |
1e39fc01 | 471 | struct hlist_node obj_list; |
6b3f05d2 | 472 | /* Head of list of marks for an object [mark ref] */ |
86ffe245 | 473 | struct fsnotify_mark_connector *connector; |
1e39fc01 JK |
474 | /* Events types to ignore [mark->lock, group->mark_mutex] */ |
475 | __u32 ignored_mask; | |
e911d8af JK |
476 | #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x01 |
477 | #define FSNOTIFY_MARK_FLAG_ALIVE 0x02 | |
478 | #define FSNOTIFY_MARK_FLAG_ATTACHED 0x04 | |
1e39fc01 | 479 | unsigned int flags; /* flags [mark->lock] */ |
3be25f49 EP |
480 | }; |
481 | ||
90586523 EP |
482 | #ifdef CONFIG_FSNOTIFY |
483 | ||
484 | /* called from the vfs helpers */ | |
485 | ||
486 | /* main fsnotify call to send events */ | |
40a100d3 AG |
487 | extern int fsnotify(__u32 mask, const void *data, int data_type, |
488 | struct inode *dir, const struct qstr *name, | |
489 | struct inode *inode, u32 cookie); | |
71d73410 | 490 | extern int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, |
017de65f | 491 | int data_type); |
3be25f49 | 492 | extern void __fsnotify_inode_delete(struct inode *inode); |
ca9c726e | 493 | extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt); |
1e6cb723 | 494 | extern void fsnotify_sb_delete(struct super_block *sb); |
47882c6f | 495 | extern u32 fsnotify_get_cookie(void); |
90586523 | 496 | |
9b93f331 AG |
497 | static inline __u32 fsnotify_parent_needed_mask(__u32 mask) |
498 | { | |
499 | /* FS_EVENT_ON_CHILD is set on marks that want parent/name info */ | |
500 | if (!(mask & FS_EVENT_ON_CHILD)) | |
501 | return 0; | |
502 | /* | |
503 | * This object might be watched by a mark that cares about parent/name | |
504 | * info, does it care about the specific set of events that can be | |
505 | * reported with parent/name info? | |
506 | */ | |
507 | return mask & FS_EVENTS_POSS_TO_PARENT; | |
508 | } | |
509 | ||
c28f7e56 EP |
510 | static inline int fsnotify_inode_watches_children(struct inode *inode) |
511 | { | |
512 | /* FS_EVENT_ON_CHILD is set if the inode may care */ | |
513 | if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD)) | |
514 | return 0; | |
515 | /* this inode might care about child events, does it care about the | |
516 | * specific set of events that can happen on a child? */ | |
517 | return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD; | |
518 | } | |
519 | ||
520 | /* | |
521 | * Update the dentry with a flag indicating the interest of its parent to receive | |
522 | * filesystem events when those events happens to this dentry->d_inode. | |
523 | */ | |
affda484 | 524 | static inline void fsnotify_update_flags(struct dentry *dentry) |
c28f7e56 | 525 | { |
c28f7e56 EP |
526 | assert_spin_locked(&dentry->d_lock); |
527 | ||
b5c84bf6 NP |
528 | /* |
529 | * Serialisation of setting PARENT_WATCHED on the dentries is provided | |
530 | * by d_lock. If inotify_inode_watched changes after we have taken | |
531 | * d_lock, the following __fsnotify_update_child_dentry_flags call will | |
532 | * find our entry, so it will spin until we complete here, and update | |
533 | * us with the new state. | |
534 | */ | |
affda484 | 535 | if (fsnotify_inode_watches_children(dentry->d_parent->d_inode)) |
c28f7e56 EP |
536 | dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; |
537 | else | |
538 | dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; | |
539 | } | |
540 | ||
90586523 EP |
541 | /* called from fsnotify listeners, such as fanotify or dnotify */ |
542 | ||
98612952 | 543 | /* create a new group */ |
0d2e2a1d | 544 | extern struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops); |
ac7b79fd | 545 | extern struct fsnotify_group *fsnotify_alloc_user_group(const struct fsnotify_ops *ops); |
98612952 LS |
546 | /* get reference to a group */ |
547 | extern void fsnotify_get_group(struct fsnotify_group *group); | |
ffab8340 | 548 | /* drop reference on a group from fsnotify_alloc_group */ |
90586523 | 549 | extern void fsnotify_put_group(struct fsnotify_group *group); |
12703dbf JK |
550 | /* group destruction begins, stop queuing new events */ |
551 | extern void fsnotify_group_stop_queueing(struct fsnotify_group *group); | |
d8153d4d LS |
552 | /* destroy group */ |
553 | extern void fsnotify_destroy_group(struct fsnotify_group *group); | |
0a6b6bd5 EP |
554 | /* fasync handler function */ |
555 | extern int fsnotify_fasync(int fd, struct file *file, int on); | |
7053aee2 JK |
556 | /* Free event from memory */ |
557 | extern void fsnotify_destroy_event(struct fsnotify_group *group, | |
558 | struct fsnotify_event *event); | |
a2d8bc6c | 559 | /* attach the event to the group notification queue */ |
1ad03c3a GKB |
560 | extern int fsnotify_insert_event(struct fsnotify_group *group, |
561 | struct fsnotify_event *event, | |
562 | int (*merge)(struct fsnotify_group *, | |
563 | struct fsnotify_event *), | |
564 | void (*insert)(struct fsnotify_group *, | |
565 | struct fsnotify_event *)); | |
566 | ||
567 | static inline int fsnotify_add_event(struct fsnotify_group *group, | |
568 | struct fsnotify_event *event, | |
569 | int (*merge)(struct fsnotify_group *, | |
570 | struct fsnotify_event *)) | |
571 | { | |
572 | return fsnotify_insert_event(group, event, merge, NULL); | |
573 | } | |
574 | ||
7b1f6417 JK |
575 | /* Queue overflow event to a notification group */ |
576 | static inline void fsnotify_queue_overflow(struct fsnotify_group *group) | |
577 | { | |
1ad03c3a | 578 | fsnotify_add_event(group, group->overflow_event, NULL); |
7b1f6417 JK |
579 | } |
580 | ||
808967a0 GKB |
581 | static inline bool fsnotify_is_overflow_event(u32 mask) |
582 | { | |
583 | return mask & FS_Q_OVERFLOW; | |
584 | } | |
585 | ||
6f73171e AG |
586 | static inline bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group) |
587 | { | |
588 | assert_spin_locked(&group->notification_lock); | |
589 | ||
590 | return list_empty(&group->notification_list); | |
591 | } | |
592 | ||
a2d8bc6c EP |
593 | extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); |
594 | /* return, but do not dequeue the first event on the notification queue */ | |
8ba8fa91 | 595 | extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group); |
e4aff117 | 596 | /* return AND dequeue the first event on the notification queue */ |
8ba8fa91 | 597 | extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group); |
f7db89ac JK |
598 | /* Remove event queued in the notification list */ |
599 | extern void fsnotify_remove_queued_event(struct fsnotify_group *group, | |
600 | struct fsnotify_event *event); | |
a2d8bc6c | 601 | |
3be25f49 EP |
602 | /* functions used to manipulate the marks attached to inodes */ |
603 | ||
4f0b903d AG |
604 | /* Get mask for calculating object interest taking ignored mask into account */ |
605 | static inline __u32 fsnotify_calc_mask(struct fsnotify_mark *mark) | |
606 | { | |
607 | __u32 mask = mark->mask; | |
608 | ||
609 | if (!mark->ignored_mask) | |
610 | return mask; | |
611 | ||
04e317ba AG |
612 | /* Interest in FS_MODIFY may be needed for clearing ignored mask */ |
613 | if (!(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)) | |
614 | mask |= FS_MODIFY; | |
615 | ||
4f0b903d AG |
616 | /* |
617 | * If mark is interested in ignoring events on children, the object must | |
618 | * show interest in those events for fsnotify_parent() to notice it. | |
619 | */ | |
620 | return mask | (mark->ignored_mask & ALL_FSNOTIFY_EVENTS); | |
621 | } | |
622 | ||
3ac70bfc AG |
623 | /* Get mask of events for a list of marks */ |
624 | extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn); | |
a242677b JK |
625 | /* Calculate mask of events for a list of marks */ |
626 | extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn); | |
7b129323 | 627 | extern void fsnotify_init_mark(struct fsnotify_mark *mark, |
054c636e | 628 | struct fsnotify_group *group); |
b1362edf | 629 | /* Find mark belonging to given group in the list of marks */ |
9b6e5434 AG |
630 | extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp, |
631 | struct fsnotify_group *group); | |
77115225 AG |
632 | /* Get cached fsid of filesystem containing object */ |
633 | extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn, | |
634 | __kernel_fsid_t *fsid); | |
b812a9f5 AG |
635 | /* attach the mark to the object */ |
636 | extern int fsnotify_add_mark(struct fsnotify_mark *mark, | |
ad69cd99 | 637 | fsnotify_connp_t *connp, unsigned int obj_type, |
77115225 | 638 | int allow_dups, __kernel_fsid_t *fsid); |
7b129323 | 639 | extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, |
77115225 | 640 | fsnotify_connp_t *connp, |
ad69cd99 | 641 | unsigned int obj_type, int allow_dups, |
77115225 AG |
642 | __kernel_fsid_t *fsid); |
643 | ||
b249f5be AG |
644 | /* attach the mark to the inode */ |
645 | static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark, | |
646 | struct inode *inode, | |
647 | int allow_dups) | |
648 | { | |
b812a9f5 | 649 | return fsnotify_add_mark(mark, &inode->i_fsnotify_marks, |
77115225 | 650 | FSNOTIFY_OBJ_TYPE_INODE, allow_dups, NULL); |
b249f5be AG |
651 | } |
652 | static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark, | |
653 | struct inode *inode, | |
654 | int allow_dups) | |
655 | { | |
b812a9f5 | 656 | return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks, |
77115225 AG |
657 | FSNOTIFY_OBJ_TYPE_INODE, allow_dups, |
658 | NULL); | |
b249f5be | 659 | } |
77115225 | 660 | |
e2a29943 LS |
661 | /* given a group and a mark, flag mark to be freed when all references are dropped */ |
662 | extern void fsnotify_destroy_mark(struct fsnotify_mark *mark, | |
663 | struct fsnotify_group *group); | |
4712e722 JK |
664 | /* detach mark from inode / mount list, group list, drop inode reference */ |
665 | extern void fsnotify_detach_mark(struct fsnotify_mark *mark); | |
666 | /* free mark */ | |
667 | extern void fsnotify_free_mark(struct fsnotify_mark *mark); | |
b72679ee TM |
668 | /* Wait until all marks queued for destruction are destroyed */ |
669 | extern void fsnotify_wait_marks_destroyed(void); | |
ad69cd99 AG |
670 | /* Clear all of the marks of a group attached to a given object type */ |
671 | extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group, | |
672 | unsigned int obj_type); | |
416bcdbc JK |
673 | /* run all the marks in a group, and clear all of the vfsmount marks */ |
674 | static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group) | |
675 | { | |
ad69cd99 | 676 | fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT); |
416bcdbc JK |
677 | } |
678 | /* run all the marks in a group, and clear all of the inode marks */ | |
679 | static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group) | |
680 | { | |
ad69cd99 | 681 | fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE); |
416bcdbc | 682 | } |
1e6cb723 AG |
683 | /* run all the marks in a group, and clear all of the sn marks */ |
684 | static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group) | |
685 | { | |
ad69cd99 | 686 | fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB); |
1e6cb723 | 687 | } |
841bdc10 EP |
688 | extern void fsnotify_get_mark(struct fsnotify_mark *mark); |
689 | extern void fsnotify_put_mark(struct fsnotify_mark *mark); | |
abc77577 JK |
690 | extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info); |
691 | extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info); | |
3be25f49 | 692 | |
8988f11a | 693 | static inline void fsnotify_init_event(struct fsnotify_event *event) |
a0a92d26 AG |
694 | { |
695 | INIT_LIST_HEAD(&event->list); | |
a0a92d26 | 696 | } |
b4e4e140 | 697 | |
90586523 EP |
698 | #else |
699 | ||
40a100d3 AG |
700 | static inline int fsnotify(__u32 mask, const void *data, int data_type, |
701 | struct inode *dir, const struct qstr *name, | |
702 | struct inode *inode, u32 cookie) | |
c4ec54b4 EP |
703 | { |
704 | return 0; | |
705 | } | |
3be25f49 | 706 | |
71d73410 | 707 | static inline int __fsnotify_parent(struct dentry *dentry, __u32 mask, |
017de65f | 708 | const void *data, int data_type) |
52420392 EP |
709 | { |
710 | return 0; | |
711 | } | |
c28f7e56 | 712 | |
3be25f49 EP |
713 | static inline void __fsnotify_inode_delete(struct inode *inode) |
714 | {} | |
715 | ||
ca9c726e AG |
716 | static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt) |
717 | {} | |
718 | ||
1e6cb723 AG |
719 | static inline void fsnotify_sb_delete(struct super_block *sb) |
720 | {} | |
721 | ||
affda484 | 722 | static inline void fsnotify_update_flags(struct dentry *dentry) |
c28f7e56 EP |
723 | {} |
724 | ||
47882c6f EP |
725 | static inline u32 fsnotify_get_cookie(void) |
726 | { | |
727 | return 0; | |
728 | } | |
729 | ||
74278da9 | 730 | static inline void fsnotify_unmount_inodes(struct super_block *sb) |
164bc619 EP |
731 | {} |
732 | ||
90586523 EP |
733 | #endif /* CONFIG_FSNOTIFY */ |
734 | ||
735 | #endif /* __KERNEL __ */ | |
736 | ||
737 | #endif /* __LINUX_FSNOTIFY_BACKEND_H */ |