1 /* SPDX-License-Identifier: GPL-2.0 */ 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 13 #include <linux/idr.h> /* inotify uses this */ 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> 19 #include <linux/atomic.h> 20 #include <linux/user_namespace.h> 21 #include <linux/refcount.h> 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 */ 41 #define FS_OPEN_EXEC 0x00001000 /* File was opened for exec */ 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 47 #define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */ 48 #define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */ 49 #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ 50 #define FS_DIR_MODIFY 0x00080000 /* Directory entry was modified */ 51 52 #define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */ 53 /* This inode cares about things that happen to its children. Always set for 54 * dnotify and inotify. */ 55 #define FS_EVENT_ON_CHILD 0x08000000 56 57 #define FS_DN_RENAME 0x10000000 /* file renamed */ 58 #define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ 59 #define FS_ISDIR 0x40000000 /* event occurred against dir */ 60 #define FS_IN_ONESHOT 0x80000000 /* only send event once */ 61 62 #define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO) 63 64 /* 65 * Directory entry modification events - reported only to directory 66 * where entry is modified and not to a watching parent. 67 * The watching parent may get an FS_ATTRIB|FS_EVENT_ON_CHILD event 68 * when a directory entry inside a child subdir changes. 69 */ 70 #define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE | \ 71 FS_DIR_MODIFY) 72 73 #define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ 74 FS_OPEN_EXEC_PERM) 75 76 /* 77 * This is a list of all events that may get sent to a parent based on fs event 78 * happening to inodes inside that directory. 79 */ 80 #define FS_EVENTS_POSS_ON_CHILD (ALL_FSNOTIFY_PERM_EVENTS | \ 81 FS_ACCESS | FS_MODIFY | FS_ATTRIB | \ 82 FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | \ 83 FS_OPEN | FS_OPEN_EXEC) 84 85 /* Events that can be reported to backends */ 86 #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \ 87 FS_EVENTS_POSS_ON_CHILD | \ 88 FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \ 89 FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED) 90 91 /* Extra flags that may be reported with event or control handling of events */ 92 #define ALL_FSNOTIFY_FLAGS (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \ 93 FS_DN_MULTISHOT | FS_EVENT_ON_CHILD) 94 95 #define ALL_FSNOTIFY_BITS (ALL_FSNOTIFY_EVENTS | ALL_FSNOTIFY_FLAGS) 96 97 struct fsnotify_group; 98 struct fsnotify_event; 99 struct fsnotify_mark; 100 struct fsnotify_event_private_data; 101 struct fsnotify_fname; 102 struct fsnotify_iter_info; 103 104 struct mem_cgroup; 105 106 /* 107 * Each group much define these ops. The fsnotify infrastructure will call 108 * these operations for each relevant group. 109 * 110 * handle_event - main call for a group to handle an fs event 111 * free_group_priv - called when a group refcnt hits 0 to clean up the private union 112 * freeing_mark - called when a mark is being destroyed for some reason. The group 113 * MUST be holding a reference on each mark and that reference must be 114 * dropped in this function. inotify uses this function to send 115 * userspace messages that marks have been removed. 116 */ 117 struct fsnotify_ops { 118 int (*handle_event)(struct fsnotify_group *group, 119 struct inode *inode, 120 u32 mask, const void *data, int data_type, 121 const struct qstr *file_name, u32 cookie, 122 struct fsnotify_iter_info *iter_info); 123 void (*free_group_priv)(struct fsnotify_group *group); 124 void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group); 125 void (*free_event)(struct fsnotify_event *event); 126 /* called on final put+free to free memory */ 127 void (*free_mark)(struct fsnotify_mark *mark); 128 }; 129 130 /* 131 * all of the information about the original object we want to now send to 132 * a group. If you want to carry more info from the accessing task to the 133 * listener this structure is where you need to be adding fields. 134 */ 135 struct fsnotify_event { 136 struct list_head list; 137 unsigned long objectid; /* identifier for queue merges */ 138 }; 139 140 /* 141 * A group is a "thing" that wants to receive notification about filesystem 142 * events. The mask holds the subset of event types this group cares about. 143 * refcnt on a group is up to the implementor and at any moment if it goes 0 144 * everything will be cleaned up. 145 */ 146 struct fsnotify_group { 147 const struct fsnotify_ops *ops; /* how this group handles things */ 148 149 /* 150 * How the refcnt is used is up to each group. When the refcnt hits 0 151 * fsnotify will clean up all of the resources associated with this group. 152 * As an example, the dnotify group will always have a refcnt=1 and that 153 * will never change. Inotify, on the other hand, has a group per 154 * inotify_init() and the refcnt will hit 0 only when that fd has been 155 * closed. 156 */ 157 refcount_t refcnt; /* things with interest in this group */ 158 159 /* needed to send notification to userspace */ 160 spinlock_t notification_lock; /* protect the notification_list */ 161 struct list_head notification_list; /* list of event_holder this group needs to send to userspace */ 162 wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */ 163 unsigned int q_len; /* events on the queue */ 164 unsigned int max_events; /* maximum events allowed on the list */ 165 /* 166 * Valid fsnotify group priorities. Events are send in order from highest 167 * priority to lowest priority. We default to the lowest priority. 168 */ 169 #define FS_PRIO_0 0 /* normal notifiers, no permissions */ 170 #define FS_PRIO_1 1 /* fanotify content based access control */ 171 #define FS_PRIO_2 2 /* fanotify pre-content access */ 172 unsigned int priority; 173 bool shutdown; /* group is being shut down, don't queue more events */ 174 175 /* stores all fastpath marks assoc with this group so they can be cleaned on unregister */ 176 struct mutex mark_mutex; /* protect marks_list */ 177 atomic_t num_marks; /* 1 for each mark and 1 for not being 178 * past the point of no return when freeing 179 * a group */ 180 atomic_t user_waits; /* Number of tasks waiting for user 181 * response */ 182 struct list_head marks_list; /* all inode marks for this group */ 183 184 struct fasync_struct *fsn_fa; /* async notification */ 185 186 struct fsnotify_event *overflow_event; /* Event we queue when the 187 * notification list is too 188 * full */ 189 190 struct mem_cgroup *memcg; /* memcg to charge allocations */ 191 192 /* groups can define private fields here or use the void *private */ 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 /* allows a group to block waiting for a userspace response */ 205 struct list_head access_list; 206 wait_queue_head_t access_waitq; 207 int flags; /* flags from fanotify_init() */ 208 int f_flags; /* event_f_flags from fanotify_init() */ 209 unsigned int max_marks; 210 struct user_struct *user; 211 } fanotify_data; 212 #endif /* CONFIG_FANOTIFY */ 213 }; 214 }; 215 216 /* When calling fsnotify tell it if the data is a path or inode */ 217 enum fsnotify_data_type { 218 FSNOTIFY_EVENT_NONE, 219 FSNOTIFY_EVENT_PATH, 220 FSNOTIFY_EVENT_INODE, 221 }; 222 223 static inline const struct inode *fsnotify_data_inode(const void *data, 224 int data_type) 225 { 226 switch (data_type) { 227 case FSNOTIFY_EVENT_INODE: 228 return data; 229 case FSNOTIFY_EVENT_PATH: 230 return d_inode(((const struct path *)data)->dentry); 231 default: 232 return NULL; 233 } 234 } 235 236 static inline const struct path *fsnotify_data_path(const void *data, 237 int data_type) 238 { 239 switch (data_type) { 240 case FSNOTIFY_EVENT_PATH: 241 return data; 242 default: 243 return NULL; 244 } 245 } 246 247 enum fsnotify_obj_type { 248 FSNOTIFY_OBJ_TYPE_INODE, 249 FSNOTIFY_OBJ_TYPE_VFSMOUNT, 250 FSNOTIFY_OBJ_TYPE_SB, 251 FSNOTIFY_OBJ_TYPE_COUNT, 252 FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT 253 }; 254 255 #define FSNOTIFY_OBJ_TYPE_INODE_FL (1U << FSNOTIFY_OBJ_TYPE_INODE) 256 #define FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL (1U << FSNOTIFY_OBJ_TYPE_VFSMOUNT) 257 #define FSNOTIFY_OBJ_TYPE_SB_FL (1U << FSNOTIFY_OBJ_TYPE_SB) 258 #define FSNOTIFY_OBJ_ALL_TYPES_MASK ((1U << FSNOTIFY_OBJ_TYPE_COUNT) - 1) 259 260 static inline bool fsnotify_valid_obj_type(unsigned int type) 261 { 262 return (type < FSNOTIFY_OBJ_TYPE_COUNT); 263 } 264 265 struct fsnotify_iter_info { 266 struct fsnotify_mark *marks[FSNOTIFY_OBJ_TYPE_COUNT]; 267 unsigned int report_mask; 268 int srcu_idx; 269 }; 270 271 static inline bool fsnotify_iter_should_report_type( 272 struct fsnotify_iter_info *iter_info, int type) 273 { 274 return (iter_info->report_mask & (1U << type)); 275 } 276 277 static inline void fsnotify_iter_set_report_type( 278 struct fsnotify_iter_info *iter_info, int type) 279 { 280 iter_info->report_mask |= (1U << type); 281 } 282 283 static inline void fsnotify_iter_set_report_type_mark( 284 struct fsnotify_iter_info *iter_info, int type, 285 struct fsnotify_mark *mark) 286 { 287 iter_info->marks[type] = mark; 288 iter_info->report_mask |= (1U << type); 289 } 290 291 #define FSNOTIFY_ITER_FUNCS(name, NAME) \ 292 static inline struct fsnotify_mark *fsnotify_iter_##name##_mark( \ 293 struct fsnotify_iter_info *iter_info) \ 294 { \ 295 return (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_##NAME##_FL) ? \ 296 iter_info->marks[FSNOTIFY_OBJ_TYPE_##NAME] : NULL; \ 297 } 298 299 FSNOTIFY_ITER_FUNCS(inode, INODE) 300 FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT) 301 FSNOTIFY_ITER_FUNCS(sb, SB) 302 303 #define fsnotify_foreach_obj_type(type) \ 304 for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++) 305 306 /* 307 * fsnotify_connp_t is what we embed in objects which connector can be attached 308 * to. fsnotify_connp_t * is how we refer from connector back to object. 309 */ 310 struct fsnotify_mark_connector; 311 typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t; 312 313 /* 314 * Inode/vfsmount/sb point to this structure which tracks all marks attached to 315 * the inode/vfsmount/sb. The reference to inode/vfsmount/sb is held by this 316 * structure. We destroy this structure when there are no more marks attached 317 * to it. The structure is protected by fsnotify_mark_srcu. 318 */ 319 struct fsnotify_mark_connector { 320 spinlock_t lock; 321 unsigned short type; /* Type of object [lock] */ 322 #define FSNOTIFY_CONN_FLAG_HAS_FSID 0x01 323 unsigned short flags; /* flags [lock] */ 324 __kernel_fsid_t fsid; /* fsid of filesystem containing object */ 325 union { 326 /* Object pointer [lock] */ 327 fsnotify_connp_t *obj; 328 /* Used listing heads to free after srcu period expires */ 329 struct fsnotify_mark_connector *destroy_next; 330 }; 331 struct hlist_head list; 332 }; 333 334 /* 335 * A mark is simply an object attached to an in core inode which allows an 336 * fsnotify listener to indicate they are either no longer interested in events 337 * of a type matching mask or only interested in those events. 338 * 339 * These are flushed when an inode is evicted from core and may be flushed 340 * when the inode is modified (as seen by fsnotify_access). Some fsnotify 341 * users (such as dnotify) will flush these when the open fd is closed and not 342 * at inode eviction or modification. 343 * 344 * Text in brackets is showing the lock(s) protecting modifications of a 345 * particular entry. obj_lock means either inode->i_lock or 346 * mnt->mnt_root->d_lock depending on the mark type. 347 */ 348 struct fsnotify_mark { 349 /* Mask this mark is for [mark->lock, group->mark_mutex] */ 350 __u32 mask; 351 /* We hold one for presence in g_list. Also one ref for each 'thing' 352 * in kernel that found and may be using this mark. */ 353 refcount_t refcnt; 354 /* Group this mark is for. Set on mark creation, stable until last ref 355 * is dropped */ 356 struct fsnotify_group *group; 357 /* List of marks by group->marks_list. Also reused for queueing 358 * mark into destroy_list when it's waiting for the end of SRCU period 359 * before it can be freed. [group->mark_mutex] */ 360 struct list_head g_list; 361 /* Protects inode / mnt pointers, flags, masks */ 362 spinlock_t lock; 363 /* List of marks for inode / vfsmount [connector->lock, mark ref] */ 364 struct hlist_node obj_list; 365 /* Head of list of marks for an object [mark ref] */ 366 struct fsnotify_mark_connector *connector; 367 /* Events types to ignore [mark->lock, group->mark_mutex] */ 368 __u32 ignored_mask; 369 #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x01 370 #define FSNOTIFY_MARK_FLAG_ALIVE 0x02 371 #define FSNOTIFY_MARK_FLAG_ATTACHED 0x04 372 unsigned int flags; /* flags [mark->lock] */ 373 }; 374 375 #ifdef CONFIG_FSNOTIFY 376 377 /* called from the vfs helpers */ 378 379 /* main fsnotify call to send events */ 380 extern int fsnotify(struct inode *to_tell, __u32 mask, const void *data, 381 int data_type, const struct qstr *name, u32 cookie); 382 extern int fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, 383 int data_type); 384 extern void __fsnotify_inode_delete(struct inode *inode); 385 extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt); 386 extern void fsnotify_sb_delete(struct super_block *sb); 387 extern u32 fsnotify_get_cookie(void); 388 389 static inline int fsnotify_inode_watches_children(struct inode *inode) 390 { 391 /* FS_EVENT_ON_CHILD is set if the inode may care */ 392 if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD)) 393 return 0; 394 /* this inode might care about child events, does it care about the 395 * specific set of events that can happen on a child? */ 396 return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD; 397 } 398 399 /* 400 * Update the dentry with a flag indicating the interest of its parent to receive 401 * filesystem events when those events happens to this dentry->d_inode. 402 */ 403 static inline void fsnotify_update_flags(struct dentry *dentry) 404 { 405 assert_spin_locked(&dentry->d_lock); 406 407 /* 408 * Serialisation of setting PARENT_WATCHED on the dentries is provided 409 * by d_lock. If inotify_inode_watched changes after we have taken 410 * d_lock, the following __fsnotify_update_child_dentry_flags call will 411 * find our entry, so it will spin until we complete here, and update 412 * us with the new state. 413 */ 414 if (fsnotify_inode_watches_children(dentry->d_parent->d_inode)) 415 dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; 416 else 417 dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; 418 } 419 420 /* called from fsnotify listeners, such as fanotify or dnotify */ 421 422 /* create a new group */ 423 extern struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops); 424 /* get reference to a group */ 425 extern void fsnotify_get_group(struct fsnotify_group *group); 426 /* drop reference on a group from fsnotify_alloc_group */ 427 extern void fsnotify_put_group(struct fsnotify_group *group); 428 /* group destruction begins, stop queuing new events */ 429 extern void fsnotify_group_stop_queueing(struct fsnotify_group *group); 430 /* destroy group */ 431 extern void fsnotify_destroy_group(struct fsnotify_group *group); 432 /* fasync handler function */ 433 extern int fsnotify_fasync(int fd, struct file *file, int on); 434 /* Free event from memory */ 435 extern void fsnotify_destroy_event(struct fsnotify_group *group, 436 struct fsnotify_event *event); 437 /* attach the event to the group notification queue */ 438 extern int fsnotify_add_event(struct fsnotify_group *group, 439 struct fsnotify_event *event, 440 int (*merge)(struct list_head *, 441 struct fsnotify_event *)); 442 /* Queue overflow event to a notification group */ 443 static inline void fsnotify_queue_overflow(struct fsnotify_group *group) 444 { 445 fsnotify_add_event(group, group->overflow_event, NULL); 446 } 447 448 /* true if the group notification queue is empty */ 449 extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); 450 /* return, but do not dequeue the first event on the notification queue */ 451 extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group); 452 /* return AND dequeue the first event on the notification queue */ 453 extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group); 454 /* Remove event queued in the notification list */ 455 extern void fsnotify_remove_queued_event(struct fsnotify_group *group, 456 struct fsnotify_event *event); 457 458 /* functions used to manipulate the marks attached to inodes */ 459 460 /* Get mask of events for a list of marks */ 461 extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn); 462 /* Calculate mask of events for a list of marks */ 463 extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn); 464 extern void fsnotify_init_mark(struct fsnotify_mark *mark, 465 struct fsnotify_group *group); 466 /* Find mark belonging to given group in the list of marks */ 467 extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp, 468 struct fsnotify_group *group); 469 /* Get cached fsid of filesystem containing object */ 470 extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn, 471 __kernel_fsid_t *fsid); 472 /* attach the mark to the object */ 473 extern int fsnotify_add_mark(struct fsnotify_mark *mark, 474 fsnotify_connp_t *connp, unsigned int type, 475 int allow_dups, __kernel_fsid_t *fsid); 476 extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, 477 fsnotify_connp_t *connp, 478 unsigned int type, int allow_dups, 479 __kernel_fsid_t *fsid); 480 481 /* attach the mark to the inode */ 482 static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark, 483 struct inode *inode, 484 int allow_dups) 485 { 486 return fsnotify_add_mark(mark, &inode->i_fsnotify_marks, 487 FSNOTIFY_OBJ_TYPE_INODE, allow_dups, NULL); 488 } 489 static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark, 490 struct inode *inode, 491 int allow_dups) 492 { 493 return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks, 494 FSNOTIFY_OBJ_TYPE_INODE, allow_dups, 495 NULL); 496 } 497 498 /* given a group and a mark, flag mark to be freed when all references are dropped */ 499 extern void fsnotify_destroy_mark(struct fsnotify_mark *mark, 500 struct fsnotify_group *group); 501 /* detach mark from inode / mount list, group list, drop inode reference */ 502 extern void fsnotify_detach_mark(struct fsnotify_mark *mark); 503 /* free mark */ 504 extern void fsnotify_free_mark(struct fsnotify_mark *mark); 505 /* Wait until all marks queued for destruction are destroyed */ 506 extern void fsnotify_wait_marks_destroyed(void); 507 /* run all the marks in a group, and clear all of the marks attached to given object type */ 508 extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group, unsigned int type); 509 /* run all the marks in a group, and clear all of the vfsmount marks */ 510 static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group) 511 { 512 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL); 513 } 514 /* run all the marks in a group, and clear all of the inode marks */ 515 static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group) 516 { 517 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE_FL); 518 } 519 /* run all the marks in a group, and clear all of the sn marks */ 520 static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group) 521 { 522 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB_FL); 523 } 524 extern void fsnotify_get_mark(struct fsnotify_mark *mark); 525 extern void fsnotify_put_mark(struct fsnotify_mark *mark); 526 extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info); 527 extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info); 528 529 static inline void fsnotify_init_event(struct fsnotify_event *event, 530 unsigned long objectid) 531 { 532 INIT_LIST_HEAD(&event->list); 533 event->objectid = objectid; 534 } 535 536 #else 537 538 static inline int fsnotify(struct inode *to_tell, __u32 mask, const void *data, 539 int data_type, const struct qstr *name, u32 cookie) 540 { 541 return 0; 542 } 543 544 static inline int fsnotify_parent(struct dentry *dentry, __u32 mask, 545 const void *data, int data_type) 546 { 547 return 0; 548 } 549 550 static inline void __fsnotify_inode_delete(struct inode *inode) 551 {} 552 553 static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt) 554 {} 555 556 static inline void fsnotify_sb_delete(struct super_block *sb) 557 {} 558 559 static inline void fsnotify_update_flags(struct dentry *dentry) 560 {} 561 562 static inline u32 fsnotify_get_cookie(void) 563 { 564 return 0; 565 } 566 567 static inline void fsnotify_unmount_inodes(struct super_block *sb) 568 {} 569 570 #endif /* CONFIG_FSNOTIFY */ 571 572 #endif /* __KERNEL __ */ 573 574 #endif /* __LINUX_FSNOTIFY_BACKEND_H */ 575