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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> |
90586523 EP |
22 | |
23 | /* | |
24 | * IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily | |
25 | * convert between them. dnotify only needs conversion at watch creation | |
26 | * so no perf loss there. fanotify isn't defined yet, so it can use the | |
27 | * wholes if it needs more events. | |
28 | */ | |
29 | #define FS_ACCESS 0x00000001 /* File was accessed */ | |
30 | #define FS_MODIFY 0x00000002 /* File was modified */ | |
31 | #define FS_ATTRIB 0x00000004 /* Metadata changed */ | |
32 | #define FS_CLOSE_WRITE 0x00000008 /* Writtable file was closed */ | |
33 | #define FS_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */ | |
34 | #define FS_OPEN 0x00000020 /* File was opened */ | |
35 | #define FS_MOVED_FROM 0x00000040 /* File was moved from X */ | |
36 | #define FS_MOVED_TO 0x00000080 /* File was moved to Y */ | |
37 | #define FS_CREATE 0x00000100 /* Subfile was created */ | |
38 | #define FS_DELETE 0x00000200 /* Subfile was deleted */ | |
39 | #define FS_DELETE_SELF 0x00000400 /* Self was deleted */ | |
40 | #define FS_MOVE_SELF 0x00000800 /* Self was moved */ | |
9b076f1c | 41 | #define FS_OPEN_EXEC 0x00001000 /* File was opened for exec */ |
90586523 EP |
42 | |
43 | #define FS_UNMOUNT 0x00002000 /* inode on umount fs */ | |
44 | #define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ | |
45 | #define FS_IN_IGNORED 0x00008000 /* last inotify event here */ | |
46 | ||
c4ec54b4 EP |
47 | #define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */ |
48 | #define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */ | |
66917a31 | 49 | #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ |
c4ec54b4 | 50 | |
8c1934c8 | 51 | #define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */ |
9b93f331 AG |
52 | /* |
53 | * Set on inode mark that cares about things that happen to its children. | |
54 | * Always set for dnotify and inotify. | |
55 | * Set on inode/sb/mount marks that care about parent/name info. | |
56 | */ | |
c28f7e56 EP |
57 | #define FS_EVENT_ON_CHILD 0x08000000 |
58 | ||
6473ea76 AG |
59 | #define FS_DN_RENAME 0x10000000 /* file renamed */ |
60 | #define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ | |
61 | #define FS_ISDIR 0x40000000 /* event occurred against dir */ | |
62 | #define FS_IN_ONESHOT 0x80000000 /* only send event once */ | |
63 | ||
e9fd702a EP |
64 | #define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO) |
65 | ||
e220140f AG |
66 | /* |
67 | * Directory entry modification events - reported only to directory | |
68 | * where entry is modified and not to a watching parent. | |
69 | * The watching parent may get an FS_ATTRIB|FS_EVENT_ON_CHILD event | |
70 | * when a directory entry inside a child subdir changes. | |
71 | */ | |
08b95c33 | 72 | #define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE) |
e220140f | 73 | |
66917a31 MB |
74 | #define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ |
75 | FS_OPEN_EXEC_PERM) | |
ff8bcbd0 | 76 | |
e220140f | 77 | /* |
9b93f331 AG |
78 | * This is a list of all events that may get sent to a parent that is watching |
79 | * with flag FS_EVENT_ON_CHILD based on fs event on a child of that directory. | |
e220140f AG |
80 | */ |
81 | #define FS_EVENTS_POSS_ON_CHILD (ALL_FSNOTIFY_PERM_EVENTS | \ | |
82 | FS_ACCESS | FS_MODIFY | FS_ATTRIB | \ | |
83 | FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | \ | |
84 | FS_OPEN | FS_OPEN_EXEC) | |
85 | ||
9b93f331 AG |
86 | /* |
87 | * This is a list of all events that may get sent with the parent inode as the | |
88 | * @to_tell argument of fsnotify(). | |
89 | * It may include events that can be sent to an inode/sb/mount mark, but cannot | |
90 | * be sent to a parent watching children. | |
91 | */ | |
92 | #define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD) | |
93 | ||
007d1e83 | 94 | /* Events that can be reported to backends */ |
e220140f AG |
95 | #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \ |
96 | FS_EVENTS_POSS_ON_CHILD | \ | |
97 | FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \ | |
98 | FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED) | |
007d1e83 AG |
99 | |
100 | /* Extra flags that may be reported with event or control handling of events */ | |
101 | #define ALL_FSNOTIFY_FLAGS (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \ | |
20dee624 EP |
102 | FS_DN_MULTISHOT | FS_EVENT_ON_CHILD) |
103 | ||
007d1e83 AG |
104 | #define ALL_FSNOTIFY_BITS (ALL_FSNOTIFY_EVENTS | ALL_FSNOTIFY_FLAGS) |
105 | ||
90586523 EP |
106 | struct fsnotify_group; |
107 | struct fsnotify_event; | |
e61ce867 | 108 | struct fsnotify_mark; |
e4aff117 | 109 | struct fsnotify_event_private_data; |
7053aee2 | 110 | struct fsnotify_fname; |
abc77577 | 111 | struct fsnotify_iter_info; |
90586523 | 112 | |
d46eb14b SB |
113 | struct mem_cgroup; |
114 | ||
90586523 EP |
115 | /* |
116 | * Each group much define these ops. The fsnotify infrastructure will call | |
117 | * these operations for each relevant group. | |
118 | * | |
119 | * handle_event - main call for a group to handle an fs event | |
b54cecf5 AG |
120 | * @group: group to notify |
121 | * @mask: event type and flags | |
122 | * @data: object that event happened on | |
123 | * @data_type: type of object for fanotify_data_XXX() accessors | |
124 | * @dir: optional directory associated with event - | |
125 | * if @file_name is not NULL, this is the directory that | |
126 | * @file_name is relative to | |
127 | * @file_name: optional file name associated with event | |
128 | * @cookie: inotify rename cookie | |
129 | * @iter_info: array of marks from this group that are interested in the event | |
130 | * | |
b9a1b977 AG |
131 | * handle_inode_event - simple variant of handle_event() for groups that only |
132 | * have inode marks and don't have ignore mask | |
133 | * @mark: mark to notify | |
134 | * @mask: event type and flags | |
135 | * @inode: inode that event happened on | |
136 | * @dir: optional directory associated with event - | |
137 | * if @file_name is not NULL, this is the directory that | |
138 | * @file_name is relative to. | |
24dca905 | 139 | * Either @inode or @dir must be non-NULL. |
b9a1b977 | 140 | * @file_name: optional file name associated with event |
950cc0d2 | 141 | * @cookie: inotify rename cookie |
b9a1b977 | 142 | * |
90586523 | 143 | * free_group_priv - called when a group refcnt hits 0 to clean up the private union |
6960b0d9 | 144 | * freeing_mark - called when a mark is being destroyed for some reason. The group |
b9a1b977 AG |
145 | * MUST be holding a reference on each mark and that reference must be |
146 | * dropped in this function. inotify uses this function to send | |
147 | * userspace messages that marks have been removed. | |
90586523 EP |
148 | */ |
149 | struct fsnotify_ops { | |
b54cecf5 AG |
150 | int (*handle_event)(struct fsnotify_group *group, u32 mask, |
151 | const void *data, int data_type, struct inode *dir, | |
e43e9c33 | 152 | const struct qstr *file_name, u32 cookie, |
9385a84d | 153 | struct fsnotify_iter_info *iter_info); |
b9a1b977 AG |
154 | int (*handle_inode_event)(struct fsnotify_mark *mark, u32 mask, |
155 | struct inode *inode, struct inode *dir, | |
950cc0d2 | 156 | const struct qstr *file_name, u32 cookie); |
90586523 | 157 | void (*free_group_priv)(struct fsnotify_group *group); |
841bdc10 | 158 | void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group); |
330ae77d | 159 | void (*free_event)(struct fsnotify_group *group, struct fsnotify_event *event); |
054c636e JK |
160 | /* called on final put+free to free memory */ |
161 | void (*free_mark)(struct fsnotify_mark *mark); | |
7053aee2 JK |
162 | }; |
163 | ||
164 | /* | |
165 | * all of the information about the original object we want to now send to | |
166 | * a group. If you want to carry more info from the accessing task to the | |
167 | * listener this structure is where you need to be adding fields. | |
168 | */ | |
169 | struct fsnotify_event { | |
170 | struct list_head list; | |
90586523 EP |
171 | }; |
172 | ||
173 | /* | |
174 | * A group is a "thing" that wants to receive notification about filesystem | |
175 | * events. The mask holds the subset of event types this group cares about. | |
176 | * refcnt on a group is up to the implementor and at any moment if it goes 0 | |
177 | * everything will be cleaned up. | |
178 | */ | |
179 | struct fsnotify_group { | |
d46eb14b SB |
180 | const struct fsnotify_ops *ops; /* how this group handles things */ |
181 | ||
90586523 EP |
182 | /* |
183 | * How the refcnt is used is up to each group. When the refcnt hits 0 | |
184 | * fsnotify will clean up all of the resources associated with this group. | |
185 | * As an example, the dnotify group will always have a refcnt=1 and that | |
186 | * will never change. Inotify, on the other hand, has a group per | |
187 | * inotify_init() and the refcnt will hit 0 only when that fd has been | |
188 | * closed. | |
189 | */ | |
7761daa6 | 190 | refcount_t refcnt; /* things with interest in this group */ |
90586523 | 191 | |
a2d8bc6c | 192 | /* needed to send notification to userspace */ |
c21dbe20 | 193 | spinlock_t notification_lock; /* protect the notification_list */ |
a2d8bc6c EP |
194 | struct list_head notification_list; /* list of event_holder this group needs to send to userspace */ |
195 | wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */ | |
196 | unsigned int q_len; /* events on the queue */ | |
197 | unsigned int max_events; /* maximum events allowed on the list */ | |
6ad2d4e3 EP |
198 | /* |
199 | * Valid fsnotify group priorities. Events are send in order from highest | |
200 | * priority to lowest priority. We default to the lowest priority. | |
201 | */ | |
202 | #define FS_PRIO_0 0 /* normal notifiers, no permissions */ | |
203 | #define FS_PRIO_1 1 /* fanotify content based access control */ | |
204 | #define FS_PRIO_2 2 /* fanotify pre-content access */ | |
205 | unsigned int priority; | |
12703dbf | 206 | bool shutdown; /* group is being shut down, don't queue more events */ |
a2d8bc6c | 207 | |
e61ce867 | 208 | /* stores all fastpath marks assoc with this group so they can be cleaned on unregister */ |
986ab098 | 209 | struct mutex mark_mutex; /* protect marks_list */ |
d46eb14b SB |
210 | atomic_t user_waits; /* Number of tasks waiting for user |
211 | * response */ | |
e61ce867 | 212 | struct list_head marks_list; /* all inode marks for this group */ |
3be25f49 | 213 | |
7053aee2 JK |
214 | struct fasync_struct *fsn_fa; /* async notification */ |
215 | ||
ff57cd58 | 216 | struct fsnotify_event *overflow_event; /* Event we queue when the |
7053aee2 JK |
217 | * notification list is too |
218 | * full */ | |
d46eb14b SB |
219 | |
220 | struct mem_cgroup *memcg; /* memcg to charge allocations */ | |
0a6b6bd5 | 221 | |
90586523 EP |
222 | /* groups can define private fields here or use the void *private */ |
223 | union { | |
224 | void *private; | |
63c882a0 EP |
225 | #ifdef CONFIG_INOTIFY_USER |
226 | struct inotify_group_private_data { | |
227 | spinlock_t idr_lock; | |
228 | struct idr idr; | |
1cce1eea | 229 | struct ucounts *ucounts; |
63c882a0 | 230 | } inotify_data; |
9e66e423 | 231 | #endif |
80af2588 | 232 | #ifdef CONFIG_FANOTIFY |
9e66e423 | 233 | struct fanotify_group_private_data { |
94e00d28 AG |
234 | /* Hash table of events for merge */ |
235 | struct hlist_head *merge_hash; | |
9e66e423 | 236 | /* allows a group to block waiting for a userspace response */ |
9e66e423 EP |
237 | struct list_head access_list; |
238 | wait_queue_head_t access_waitq; | |
96a71f21 AG |
239 | int flags; /* flags from fanotify_init() */ |
240 | int f_flags; /* event_f_flags from fanotify_init() */ | |
5b8fea65 | 241 | struct ucounts *ucounts; |
9e66e423 | 242 | } fanotify_data; |
80af2588 | 243 | #endif /* CONFIG_FANOTIFY */ |
90586523 EP |
244 | }; |
245 | }; | |
246 | ||
aa93bdc5 AG |
247 | /* When calling fsnotify tell it if the data is a path or inode */ |
248 | enum fsnotify_data_type { | |
249 | FSNOTIFY_EVENT_NONE, | |
250 | FSNOTIFY_EVENT_PATH, | |
251 | FSNOTIFY_EVENT_INODE, | |
fd5a3ff4 | 252 | FSNOTIFY_EVENT_DENTRY, |
aa93bdc5 AG |
253 | }; |
254 | ||
cbcf47ad | 255 | static inline struct inode *fsnotify_data_inode(const void *data, int data_type) |
aa93bdc5 AG |
256 | { |
257 | switch (data_type) { | |
258 | case FSNOTIFY_EVENT_INODE: | |
cbcf47ad | 259 | return (struct inode *)data; |
fd5a3ff4 AG |
260 | case FSNOTIFY_EVENT_DENTRY: |
261 | return d_inode(data); | |
aa93bdc5 AG |
262 | case FSNOTIFY_EVENT_PATH: |
263 | return d_inode(((const struct path *)data)->dentry); | |
264 | default: | |
265 | return NULL; | |
266 | } | |
fd5a3ff4 AG |
267 | } |
268 | ||
269 | static inline struct dentry *fsnotify_data_dentry(const void *data, int data_type) | |
270 | { | |
271 | switch (data_type) { | |
272 | case FSNOTIFY_EVENT_DENTRY: | |
273 | /* Non const is needed for dget() */ | |
274 | return (struct dentry *)data; | |
275 | case FSNOTIFY_EVENT_PATH: | |
276 | return ((const struct path *)data)->dentry; | |
277 | default: | |
278 | return NULL; | |
279 | } | |
aa93bdc5 AG |
280 | } |
281 | ||
282 | static inline const struct path *fsnotify_data_path(const void *data, | |
283 | int data_type) | |
284 | { | |
285 | switch (data_type) { | |
286 | case FSNOTIFY_EVENT_PATH: | |
287 | return data; | |
288 | default: | |
289 | return NULL; | |
290 | } | |
291 | } | |
90586523 | 292 | |
29335033 GKB |
293 | static inline struct super_block *fsnotify_data_sb(const void *data, |
294 | int data_type) | |
295 | { | |
296 | switch (data_type) { | |
297 | case FSNOTIFY_EVENT_INODE: | |
298 | return ((struct inode *)data)->i_sb; | |
299 | case FSNOTIFY_EVENT_DENTRY: | |
300 | return ((struct dentry *)data)->d_sb; | |
301 | case FSNOTIFY_EVENT_PATH: | |
302 | return ((const struct path *)data)->dentry->d_sb; | |
303 | default: | |
304 | return NULL; | |
305 | } | |
306 | } | |
307 | ||
d6f7b98b AG |
308 | enum fsnotify_obj_type { |
309 | FSNOTIFY_OBJ_TYPE_INODE, | |
fecc4559 | 310 | FSNOTIFY_OBJ_TYPE_PARENT, |
d6f7b98b | 311 | FSNOTIFY_OBJ_TYPE_VFSMOUNT, |
1e6cb723 | 312 | FSNOTIFY_OBJ_TYPE_SB, |
d6f7b98b AG |
313 | FSNOTIFY_OBJ_TYPE_COUNT, |
314 | FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT | |
315 | }; | |
316 | ||
317 | #define FSNOTIFY_OBJ_TYPE_INODE_FL (1U << FSNOTIFY_OBJ_TYPE_INODE) | |
fecc4559 | 318 | #define FSNOTIFY_OBJ_TYPE_PARENT_FL (1U << FSNOTIFY_OBJ_TYPE_PARENT) |
d6f7b98b | 319 | #define FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL (1U << FSNOTIFY_OBJ_TYPE_VFSMOUNT) |
1e6cb723 | 320 | #define FSNOTIFY_OBJ_TYPE_SB_FL (1U << FSNOTIFY_OBJ_TYPE_SB) |
d6f7b98b AG |
321 | #define FSNOTIFY_OBJ_ALL_TYPES_MASK ((1U << FSNOTIFY_OBJ_TYPE_COUNT) - 1) |
322 | ||
b812a9f5 AG |
323 | static inline bool fsnotify_valid_obj_type(unsigned int type) |
324 | { | |
325 | return (type < FSNOTIFY_OBJ_TYPE_COUNT); | |
326 | } | |
327 | ||
5b0457ad | 328 | struct fsnotify_iter_info { |
47d9c7cc | 329 | struct fsnotify_mark *marks[FSNOTIFY_OBJ_TYPE_COUNT]; |
5b0457ad AG |
330 | unsigned int report_mask; |
331 | int srcu_idx; | |
332 | }; | |
333 | ||
47d9c7cc AG |
334 | static inline bool fsnotify_iter_should_report_type( |
335 | struct fsnotify_iter_info *iter_info, int type) | |
336 | { | |
337 | return (iter_info->report_mask & (1U << type)); | |
338 | } | |
339 | ||
340 | static inline void fsnotify_iter_set_report_type( | |
341 | struct fsnotify_iter_info *iter_info, int type) | |
342 | { | |
343 | iter_info->report_mask |= (1U << type); | |
344 | } | |
345 | ||
346 | static inline void fsnotify_iter_set_report_type_mark( | |
347 | struct fsnotify_iter_info *iter_info, int type, | |
348 | struct fsnotify_mark *mark) | |
349 | { | |
350 | iter_info->marks[type] = mark; | |
351 | iter_info->report_mask |= (1U << type); | |
352 | } | |
353 | ||
5b0457ad AG |
354 | #define FSNOTIFY_ITER_FUNCS(name, NAME) \ |
355 | static inline struct fsnotify_mark *fsnotify_iter_##name##_mark( \ | |
356 | struct fsnotify_iter_info *iter_info) \ | |
357 | { \ | |
358 | return (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_##NAME##_FL) ? \ | |
47d9c7cc | 359 | iter_info->marks[FSNOTIFY_OBJ_TYPE_##NAME] : NULL; \ |
5b0457ad AG |
360 | } |
361 | ||
362 | FSNOTIFY_ITER_FUNCS(inode, INODE) | |
fecc4559 | 363 | FSNOTIFY_ITER_FUNCS(parent, PARENT) |
5b0457ad | 364 | FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT) |
1e6cb723 | 365 | FSNOTIFY_ITER_FUNCS(sb, SB) |
5b0457ad | 366 | |
47d9c7cc AG |
367 | #define fsnotify_foreach_obj_type(type) \ |
368 | for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++) | |
369 | ||
36f10f55 AG |
370 | /* |
371 | * fsnotify_connp_t is what we embed in objects which connector can be attached | |
372 | * to. fsnotify_connp_t * is how we refer from connector back to object. | |
373 | */ | |
374 | struct fsnotify_mark_connector; | |
375 | typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t; | |
376 | ||
9dd813c1 | 377 | /* |
1e6cb723 AG |
378 | * Inode/vfsmount/sb point to this structure which tracks all marks attached to |
379 | * the inode/vfsmount/sb. The reference to inode/vfsmount/sb is held by this | |
08991e83 JK |
380 | * structure. We destroy this structure when there are no more marks attached |
381 | * to it. The structure is protected by fsnotify_mark_srcu. | |
9dd813c1 JK |
382 | */ |
383 | struct fsnotify_mark_connector { | |
04662cab | 384 | spinlock_t lock; |
c285a2f0 AG |
385 | unsigned short type; /* Type of object [lock] */ |
386 | #define FSNOTIFY_CONN_FLAG_HAS_FSID 0x01 | |
387 | unsigned short flags; /* flags [lock] */ | |
77115225 | 388 | __kernel_fsid_t fsid; /* fsid of filesystem containing object */ |
36f10f55 AG |
389 | union { |
390 | /* Object pointer [lock] */ | |
391 | fsnotify_connp_t *obj; | |
08991e83 JK |
392 | /* Used listing heads to free after srcu period expires */ |
393 | struct fsnotify_mark_connector *destroy_next; | |
394 | }; | |
d90a10e2 | 395 | struct hlist_head list; |
9dd813c1 JK |
396 | }; |
397 | ||
3be25f49 | 398 | /* |
1e39fc01 | 399 | * A mark is simply an object attached to an in core inode which allows an |
3be25f49 EP |
400 | * fsnotify listener to indicate they are either no longer interested in events |
401 | * of a type matching mask or only interested in those events. | |
402 | * | |
1e39fc01 JK |
403 | * These are flushed when an inode is evicted from core and may be flushed |
404 | * when the inode is modified (as seen by fsnotify_access). Some fsnotify | |
405 | * users (such as dnotify) will flush these when the open fd is closed and not | |
406 | * at inode eviction or modification. | |
407 | * | |
408 | * Text in brackets is showing the lock(s) protecting modifications of a | |
409 | * particular entry. obj_lock means either inode->i_lock or | |
410 | * mnt->mnt_root->d_lock depending on the mark type. | |
3be25f49 | 411 | */ |
e61ce867 | 412 | struct fsnotify_mark { |
1e39fc01 JK |
413 | /* Mask this mark is for [mark->lock, group->mark_mutex] */ |
414 | __u32 mask; | |
415 | /* We hold one for presence in g_list. Also one ref for each 'thing' | |
3be25f49 | 416 | * in kernel that found and may be using this mark. */ |
ab97f873 | 417 | refcount_t refcnt; |
1e39fc01 JK |
418 | /* Group this mark is for. Set on mark creation, stable until last ref |
419 | * is dropped */ | |
420 | struct fsnotify_group *group; | |
8e984f86 | 421 | /* List of marks by group->marks_list. Also reused for queueing |
1e39fc01 JK |
422 | * mark into destroy_list when it's waiting for the end of SRCU period |
423 | * before it can be freed. [group->mark_mutex] */ | |
13d34ac6 | 424 | struct list_head g_list; |
1e39fc01 JK |
425 | /* Protects inode / mnt pointers, flags, masks */ |
426 | spinlock_t lock; | |
6b3f05d2 | 427 | /* List of marks for inode / vfsmount [connector->lock, mark ref] */ |
1e39fc01 | 428 | struct hlist_node obj_list; |
6b3f05d2 | 429 | /* Head of list of marks for an object [mark ref] */ |
86ffe245 | 430 | struct fsnotify_mark_connector *connector; |
1e39fc01 JK |
431 | /* Events types to ignore [mark->lock, group->mark_mutex] */ |
432 | __u32 ignored_mask; | |
e911d8af JK |
433 | #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x01 |
434 | #define FSNOTIFY_MARK_FLAG_ALIVE 0x02 | |
435 | #define FSNOTIFY_MARK_FLAG_ATTACHED 0x04 | |
1e39fc01 | 436 | unsigned int flags; /* flags [mark->lock] */ |
3be25f49 EP |
437 | }; |
438 | ||
90586523 EP |
439 | #ifdef CONFIG_FSNOTIFY |
440 | ||
441 | /* called from the vfs helpers */ | |
442 | ||
443 | /* main fsnotify call to send events */ | |
40a100d3 AG |
444 | extern int fsnotify(__u32 mask, const void *data, int data_type, |
445 | struct inode *dir, const struct qstr *name, | |
446 | struct inode *inode, u32 cookie); | |
71d73410 | 447 | extern int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, |
017de65f | 448 | int data_type); |
3be25f49 | 449 | extern void __fsnotify_inode_delete(struct inode *inode); |
ca9c726e | 450 | extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt); |
1e6cb723 | 451 | extern void fsnotify_sb_delete(struct super_block *sb); |
47882c6f | 452 | extern u32 fsnotify_get_cookie(void); |
90586523 | 453 | |
9b93f331 AG |
454 | static inline __u32 fsnotify_parent_needed_mask(__u32 mask) |
455 | { | |
456 | /* FS_EVENT_ON_CHILD is set on marks that want parent/name info */ | |
457 | if (!(mask & FS_EVENT_ON_CHILD)) | |
458 | return 0; | |
459 | /* | |
460 | * This object might be watched by a mark that cares about parent/name | |
461 | * info, does it care about the specific set of events that can be | |
462 | * reported with parent/name info? | |
463 | */ | |
464 | return mask & FS_EVENTS_POSS_TO_PARENT; | |
465 | } | |
466 | ||
c28f7e56 EP |
467 | static inline int fsnotify_inode_watches_children(struct inode *inode) |
468 | { | |
469 | /* FS_EVENT_ON_CHILD is set if the inode may care */ | |
470 | if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD)) | |
471 | return 0; | |
472 | /* this inode might care about child events, does it care about the | |
473 | * specific set of events that can happen on a child? */ | |
474 | return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD; | |
475 | } | |
476 | ||
477 | /* | |
478 | * Update the dentry with a flag indicating the interest of its parent to receive | |
479 | * filesystem events when those events happens to this dentry->d_inode. | |
480 | */ | |
affda484 | 481 | static inline void fsnotify_update_flags(struct dentry *dentry) |
c28f7e56 | 482 | { |
c28f7e56 EP |
483 | assert_spin_locked(&dentry->d_lock); |
484 | ||
b5c84bf6 NP |
485 | /* |
486 | * Serialisation of setting PARENT_WATCHED on the dentries is provided | |
487 | * by d_lock. If inotify_inode_watched changes after we have taken | |
488 | * d_lock, the following __fsnotify_update_child_dentry_flags call will | |
489 | * find our entry, so it will spin until we complete here, and update | |
490 | * us with the new state. | |
491 | */ | |
affda484 | 492 | if (fsnotify_inode_watches_children(dentry->d_parent->d_inode)) |
c28f7e56 EP |
493 | dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; |
494 | else | |
495 | dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; | |
496 | } | |
497 | ||
90586523 EP |
498 | /* called from fsnotify listeners, such as fanotify or dnotify */ |
499 | ||
98612952 | 500 | /* create a new group */ |
0d2e2a1d | 501 | extern struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops); |
ac7b79fd | 502 | extern struct fsnotify_group *fsnotify_alloc_user_group(const struct fsnotify_ops *ops); |
98612952 LS |
503 | /* get reference to a group */ |
504 | extern void fsnotify_get_group(struct fsnotify_group *group); | |
ffab8340 | 505 | /* drop reference on a group from fsnotify_alloc_group */ |
90586523 | 506 | extern void fsnotify_put_group(struct fsnotify_group *group); |
12703dbf JK |
507 | /* group destruction begins, stop queuing new events */ |
508 | extern void fsnotify_group_stop_queueing(struct fsnotify_group *group); | |
d8153d4d LS |
509 | /* destroy group */ |
510 | extern void fsnotify_destroy_group(struct fsnotify_group *group); | |
0a6b6bd5 EP |
511 | /* fasync handler function */ |
512 | extern int fsnotify_fasync(int fd, struct file *file, int on); | |
7053aee2 JK |
513 | /* Free event from memory */ |
514 | extern void fsnotify_destroy_event(struct fsnotify_group *group, | |
515 | struct fsnotify_event *event); | |
a2d8bc6c | 516 | /* attach the event to the group notification queue */ |
1ad03c3a GKB |
517 | extern int fsnotify_insert_event(struct fsnotify_group *group, |
518 | struct fsnotify_event *event, | |
519 | int (*merge)(struct fsnotify_group *, | |
520 | struct fsnotify_event *), | |
521 | void (*insert)(struct fsnotify_group *, | |
522 | struct fsnotify_event *)); | |
523 | ||
524 | static inline int fsnotify_add_event(struct fsnotify_group *group, | |
525 | struct fsnotify_event *event, | |
526 | int (*merge)(struct fsnotify_group *, | |
527 | struct fsnotify_event *)) | |
528 | { | |
529 | return fsnotify_insert_event(group, event, merge, NULL); | |
530 | } | |
531 | ||
7b1f6417 JK |
532 | /* Queue overflow event to a notification group */ |
533 | static inline void fsnotify_queue_overflow(struct fsnotify_group *group) | |
534 | { | |
1ad03c3a | 535 | fsnotify_add_event(group, group->overflow_event, NULL); |
7b1f6417 JK |
536 | } |
537 | ||
808967a0 GKB |
538 | static inline bool fsnotify_is_overflow_event(u32 mask) |
539 | { | |
540 | return mask & FS_Q_OVERFLOW; | |
541 | } | |
542 | ||
6f73171e AG |
543 | static inline bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group) |
544 | { | |
545 | assert_spin_locked(&group->notification_lock); | |
546 | ||
547 | return list_empty(&group->notification_list); | |
548 | } | |
549 | ||
a2d8bc6c EP |
550 | extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); |
551 | /* return, but do not dequeue the first event on the notification queue */ | |
8ba8fa91 | 552 | extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group); |
e4aff117 | 553 | /* return AND dequeue the first event on the notification queue */ |
8ba8fa91 | 554 | extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group); |
f7db89ac JK |
555 | /* Remove event queued in the notification list */ |
556 | extern void fsnotify_remove_queued_event(struct fsnotify_group *group, | |
557 | struct fsnotify_event *event); | |
a2d8bc6c | 558 | |
3be25f49 EP |
559 | /* functions used to manipulate the marks attached to inodes */ |
560 | ||
3ac70bfc AG |
561 | /* Get mask of events for a list of marks */ |
562 | extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn); | |
a242677b JK |
563 | /* Calculate mask of events for a list of marks */ |
564 | extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn); | |
7b129323 | 565 | extern void fsnotify_init_mark(struct fsnotify_mark *mark, |
054c636e | 566 | struct fsnotify_group *group); |
b1362edf | 567 | /* Find mark belonging to given group in the list of marks */ |
9b6e5434 AG |
568 | extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp, |
569 | struct fsnotify_group *group); | |
77115225 AG |
570 | /* Get cached fsid of filesystem containing object */ |
571 | extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn, | |
572 | __kernel_fsid_t *fsid); | |
b812a9f5 AG |
573 | /* attach the mark to the object */ |
574 | extern int fsnotify_add_mark(struct fsnotify_mark *mark, | |
575 | fsnotify_connp_t *connp, unsigned int type, | |
77115225 | 576 | int allow_dups, __kernel_fsid_t *fsid); |
7b129323 | 577 | extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, |
77115225 AG |
578 | fsnotify_connp_t *connp, |
579 | unsigned int type, int allow_dups, | |
580 | __kernel_fsid_t *fsid); | |
581 | ||
b249f5be AG |
582 | /* attach the mark to the inode */ |
583 | static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark, | |
584 | struct inode *inode, | |
585 | int allow_dups) | |
586 | { | |
b812a9f5 | 587 | return fsnotify_add_mark(mark, &inode->i_fsnotify_marks, |
77115225 | 588 | FSNOTIFY_OBJ_TYPE_INODE, allow_dups, NULL); |
b249f5be AG |
589 | } |
590 | static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark, | |
591 | struct inode *inode, | |
592 | int allow_dups) | |
593 | { | |
b812a9f5 | 594 | return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks, |
77115225 AG |
595 | FSNOTIFY_OBJ_TYPE_INODE, allow_dups, |
596 | NULL); | |
b249f5be | 597 | } |
77115225 | 598 | |
e2a29943 LS |
599 | /* given a group and a mark, flag mark to be freed when all references are dropped */ |
600 | extern void fsnotify_destroy_mark(struct fsnotify_mark *mark, | |
601 | struct fsnotify_group *group); | |
4712e722 JK |
602 | /* detach mark from inode / mount list, group list, drop inode reference */ |
603 | extern void fsnotify_detach_mark(struct fsnotify_mark *mark); | |
604 | /* free mark */ | |
605 | extern void fsnotify_free_mark(struct fsnotify_mark *mark); | |
b72679ee TM |
606 | /* Wait until all marks queued for destruction are destroyed */ |
607 | extern void fsnotify_wait_marks_destroyed(void); | |
86ffe245 | 608 | /* run all the marks in a group, and clear all of the marks attached to given object type */ |
18f2e0d3 | 609 | extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group, unsigned int type); |
416bcdbc JK |
610 | /* run all the marks in a group, and clear all of the vfsmount marks */ |
611 | static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group) | |
612 | { | |
d6f7b98b | 613 | fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL); |
416bcdbc JK |
614 | } |
615 | /* run all the marks in a group, and clear all of the inode marks */ | |
616 | static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group) | |
617 | { | |
d6f7b98b | 618 | fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE_FL); |
416bcdbc | 619 | } |
1e6cb723 AG |
620 | /* run all the marks in a group, and clear all of the sn marks */ |
621 | static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group) | |
622 | { | |
623 | fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB_FL); | |
624 | } | |
841bdc10 EP |
625 | extern void fsnotify_get_mark(struct fsnotify_mark *mark); |
626 | extern void fsnotify_put_mark(struct fsnotify_mark *mark); | |
abc77577 JK |
627 | extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info); |
628 | extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info); | |
3be25f49 | 629 | |
8988f11a | 630 | static inline void fsnotify_init_event(struct fsnotify_event *event) |
a0a92d26 AG |
631 | { |
632 | INIT_LIST_HEAD(&event->list); | |
a0a92d26 | 633 | } |
b4e4e140 | 634 | |
90586523 EP |
635 | #else |
636 | ||
40a100d3 AG |
637 | static inline int fsnotify(__u32 mask, const void *data, int data_type, |
638 | struct inode *dir, const struct qstr *name, | |
639 | struct inode *inode, u32 cookie) | |
c4ec54b4 EP |
640 | { |
641 | return 0; | |
642 | } | |
3be25f49 | 643 | |
71d73410 | 644 | static inline int __fsnotify_parent(struct dentry *dentry, __u32 mask, |
017de65f | 645 | const void *data, int data_type) |
52420392 EP |
646 | { |
647 | return 0; | |
648 | } | |
c28f7e56 | 649 | |
3be25f49 EP |
650 | static inline void __fsnotify_inode_delete(struct inode *inode) |
651 | {} | |
652 | ||
ca9c726e AG |
653 | static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt) |
654 | {} | |
655 | ||
1e6cb723 AG |
656 | static inline void fsnotify_sb_delete(struct super_block *sb) |
657 | {} | |
658 | ||
affda484 | 659 | static inline void fsnotify_update_flags(struct dentry *dentry) |
c28f7e56 EP |
660 | {} |
661 | ||
47882c6f EP |
662 | static inline u32 fsnotify_get_cookie(void) |
663 | { | |
664 | return 0; | |
665 | } | |
666 | ||
74278da9 | 667 | static inline void fsnotify_unmount_inodes(struct super_block *sb) |
164bc619 EP |
668 | {} |
669 | ||
90586523 EP |
670 | #endif /* CONFIG_FSNOTIFY */ |
671 | ||
672 | #endif /* __KERNEL __ */ | |
673 | ||
674 | #endif /* __LINUX_FSNOTIFY_BACKEND_H */ |