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 51 #define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */ 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 */ 57 #define FS_EVENT_ON_CHILD 0x08000000 58 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 64 #define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO) 65 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 */ 72 #define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE) 73 74 #define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ 75 FS_OPEN_EXEC_PERM) 76 77 /* 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. 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 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 94 /* Events that can be reported to backends */ 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) 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 | \ 102 FS_DN_MULTISHOT | FS_EVENT_ON_CHILD) 103 104 #define ALL_FSNOTIFY_BITS (ALL_FSNOTIFY_EVENTS | ALL_FSNOTIFY_FLAGS) 105 106 struct fsnotify_group; 107 struct fsnotify_event; 108 struct fsnotify_mark; 109 struct fsnotify_event_private_data; 110 struct fsnotify_fname; 111 struct fsnotify_iter_info; 112 113 struct mem_cgroup; 114 115 /* 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 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 * 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. 139 * @file_name: optional file name associated with event 140 * @cookie: inotify rename cookie 141 * 142 * free_group_priv - called when a group refcnt hits 0 to clean up the private union 143 * freeing_mark - called when a mark is being destroyed for some reason. The group 144 * MUST be holding a reference on each mark and that reference must be 145 * dropped in this function. inotify uses this function to send 146 * userspace messages that marks have been removed. 147 */ 148 struct fsnotify_ops { 149 int (*handle_event)(struct fsnotify_group *group, u32 mask, 150 const void *data, int data_type, struct inode *dir, 151 const struct qstr *file_name, u32 cookie, 152 struct fsnotify_iter_info *iter_info); 153 int (*handle_inode_event)(struct fsnotify_mark *mark, u32 mask, 154 struct inode *inode, struct inode *dir, 155 const struct qstr *file_name, u32 cookie); 156 void (*free_group_priv)(struct fsnotify_group *group); 157 void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group); 158 void (*free_event)(struct fsnotify_event *event); 159 /* called on final put+free to free memory */ 160 void (*free_mark)(struct fsnotify_mark *mark); 161 }; 162 163 /* 164 * all of the information about the original object we want to now send to 165 * a group. If you want to carry more info from the accessing task to the 166 * listener this structure is where you need to be adding fields. 167 */ 168 struct fsnotify_event { 169 struct list_head list; 170 unsigned long objectid; /* identifier for queue merges */ 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 { 180 const struct fsnotify_ops *ops; /* how this group handles things */ 181 182 /* 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 */ 190 refcount_t refcnt; /* things with interest in this group */ 191 192 /* needed to send notification to userspace */ 193 spinlock_t notification_lock; /* protect the notification_list */ 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 */ 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; 206 bool shutdown; /* group is being shut down, don't queue more events */ 207 208 /* stores all fastpath marks assoc with this group so they can be cleaned on unregister */ 209 struct mutex mark_mutex; /* protect marks_list */ 210 atomic_t num_marks; /* 1 for each mark and 1 for not being 211 * past the point of no return when freeing 212 * a group */ 213 atomic_t user_waits; /* Number of tasks waiting for user 214 * response */ 215 struct list_head marks_list; /* all inode marks for this group */ 216 217 struct fasync_struct *fsn_fa; /* async notification */ 218 219 struct fsnotify_event *overflow_event; /* Event we queue when the 220 * notification list is too 221 * full */ 222 223 struct mem_cgroup *memcg; /* memcg to charge allocations */ 224 225 /* groups can define private fields here or use the void *private */ 226 union { 227 void *private; 228 #ifdef CONFIG_INOTIFY_USER 229 struct inotify_group_private_data { 230 spinlock_t idr_lock; 231 struct idr idr; 232 struct ucounts *ucounts; 233 } inotify_data; 234 #endif 235 #ifdef CONFIG_FANOTIFY 236 struct fanotify_group_private_data { 237 /* allows a group to block waiting for a userspace response */ 238 struct list_head access_list; 239 wait_queue_head_t access_waitq; 240 int flags; /* flags from fanotify_init() */ 241 int f_flags; /* event_f_flags from fanotify_init() */ 242 unsigned int max_marks; 243 struct user_struct *user; 244 } fanotify_data; 245 #endif /* CONFIG_FANOTIFY */ 246 }; 247 }; 248 249 /* When calling fsnotify tell it if the data is a path or inode */ 250 enum fsnotify_data_type { 251 FSNOTIFY_EVENT_NONE, 252 FSNOTIFY_EVENT_PATH, 253 FSNOTIFY_EVENT_INODE, 254 }; 255 256 static inline struct inode *fsnotify_data_inode(const void *data, int data_type) 257 { 258 switch (data_type) { 259 case FSNOTIFY_EVENT_INODE: 260 return (struct inode *)data; 261 case FSNOTIFY_EVENT_PATH: 262 return d_inode(((const struct path *)data)->dentry); 263 default: 264 return NULL; 265 } 266 } 267 268 static inline const struct path *fsnotify_data_path(const void *data, 269 int data_type) 270 { 271 switch (data_type) { 272 case FSNOTIFY_EVENT_PATH: 273 return data; 274 default: 275 return NULL; 276 } 277 } 278 279 enum fsnotify_obj_type { 280 FSNOTIFY_OBJ_TYPE_INODE, 281 FSNOTIFY_OBJ_TYPE_PARENT, 282 FSNOTIFY_OBJ_TYPE_VFSMOUNT, 283 FSNOTIFY_OBJ_TYPE_SB, 284 FSNOTIFY_OBJ_TYPE_COUNT, 285 FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT 286 }; 287 288 #define FSNOTIFY_OBJ_TYPE_INODE_FL (1U << FSNOTIFY_OBJ_TYPE_INODE) 289 #define FSNOTIFY_OBJ_TYPE_PARENT_FL (1U << FSNOTIFY_OBJ_TYPE_PARENT) 290 #define FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL (1U << FSNOTIFY_OBJ_TYPE_VFSMOUNT) 291 #define FSNOTIFY_OBJ_TYPE_SB_FL (1U << FSNOTIFY_OBJ_TYPE_SB) 292 #define FSNOTIFY_OBJ_ALL_TYPES_MASK ((1U << FSNOTIFY_OBJ_TYPE_COUNT) - 1) 293 294 static inline bool fsnotify_valid_obj_type(unsigned int type) 295 { 296 return (type < FSNOTIFY_OBJ_TYPE_COUNT); 297 } 298 299 struct fsnotify_iter_info { 300 struct fsnotify_mark *marks[FSNOTIFY_OBJ_TYPE_COUNT]; 301 unsigned int report_mask; 302 int srcu_idx; 303 }; 304 305 static inline bool fsnotify_iter_should_report_type( 306 struct fsnotify_iter_info *iter_info, int type) 307 { 308 return (iter_info->report_mask & (1U << type)); 309 } 310 311 static inline void fsnotify_iter_set_report_type( 312 struct fsnotify_iter_info *iter_info, int type) 313 { 314 iter_info->report_mask |= (1U << type); 315 } 316 317 static inline void fsnotify_iter_set_report_type_mark( 318 struct fsnotify_iter_info *iter_info, int type, 319 struct fsnotify_mark *mark) 320 { 321 iter_info->marks[type] = mark; 322 iter_info->report_mask |= (1U << type); 323 } 324 325 #define FSNOTIFY_ITER_FUNCS(name, NAME) \ 326 static inline struct fsnotify_mark *fsnotify_iter_##name##_mark( \ 327 struct fsnotify_iter_info *iter_info) \ 328 { \ 329 return (iter_info->report_mask & FSNOTIFY_OBJ_TYPE_##NAME##_FL) ? \ 330 iter_info->marks[FSNOTIFY_OBJ_TYPE_##NAME] : NULL; \ 331 } 332 333 FSNOTIFY_ITER_FUNCS(inode, INODE) 334 FSNOTIFY_ITER_FUNCS(parent, PARENT) 335 FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT) 336 FSNOTIFY_ITER_FUNCS(sb, SB) 337 338 #define fsnotify_foreach_obj_type(type) \ 339 for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++) 340 341 /* 342 * fsnotify_connp_t is what we embed in objects which connector can be attached 343 * to. fsnotify_connp_t * is how we refer from connector back to object. 344 */ 345 struct fsnotify_mark_connector; 346 typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t; 347 348 /* 349 * Inode/vfsmount/sb point to this structure which tracks all marks attached to 350 * the inode/vfsmount/sb. The reference to inode/vfsmount/sb is held by this 351 * structure. We destroy this structure when there are no more marks attached 352 * to it. The structure is protected by fsnotify_mark_srcu. 353 */ 354 struct fsnotify_mark_connector { 355 spinlock_t lock; 356 unsigned short type; /* Type of object [lock] */ 357 #define FSNOTIFY_CONN_FLAG_HAS_FSID 0x01 358 unsigned short flags; /* flags [lock] */ 359 __kernel_fsid_t fsid; /* fsid of filesystem containing object */ 360 union { 361 /* Object pointer [lock] */ 362 fsnotify_connp_t *obj; 363 /* Used listing heads to free after srcu period expires */ 364 struct fsnotify_mark_connector *destroy_next; 365 }; 366 struct hlist_head list; 367 }; 368 369 /* 370 * A mark is simply an object attached to an in core inode which allows an 371 * fsnotify listener to indicate they are either no longer interested in events 372 * of a type matching mask or only interested in those events. 373 * 374 * These are flushed when an inode is evicted from core and may be flushed 375 * when the inode is modified (as seen by fsnotify_access). Some fsnotify 376 * users (such as dnotify) will flush these when the open fd is closed and not 377 * at inode eviction or modification. 378 * 379 * Text in brackets is showing the lock(s) protecting modifications of a 380 * particular entry. obj_lock means either inode->i_lock or 381 * mnt->mnt_root->d_lock depending on the mark type. 382 */ 383 struct fsnotify_mark { 384 /* Mask this mark is for [mark->lock, group->mark_mutex] */ 385 __u32 mask; 386 /* We hold one for presence in g_list. Also one ref for each 'thing' 387 * in kernel that found and may be using this mark. */ 388 refcount_t refcnt; 389 /* Group this mark is for. Set on mark creation, stable until last ref 390 * is dropped */ 391 struct fsnotify_group *group; 392 /* List of marks by group->marks_list. Also reused for queueing 393 * mark into destroy_list when it's waiting for the end of SRCU period 394 * before it can be freed. [group->mark_mutex] */ 395 struct list_head g_list; 396 /* Protects inode / mnt pointers, flags, masks */ 397 spinlock_t lock; 398 /* List of marks for inode / vfsmount [connector->lock, mark ref] */ 399 struct hlist_node obj_list; 400 /* Head of list of marks for an object [mark ref] */ 401 struct fsnotify_mark_connector *connector; 402 /* Events types to ignore [mark->lock, group->mark_mutex] */ 403 __u32 ignored_mask; 404 #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x01 405 #define FSNOTIFY_MARK_FLAG_ALIVE 0x02 406 #define FSNOTIFY_MARK_FLAG_ATTACHED 0x04 407 unsigned int flags; /* flags [mark->lock] */ 408 }; 409 410 #ifdef CONFIG_FSNOTIFY 411 412 /* called from the vfs helpers */ 413 414 /* main fsnotify call to send events */ 415 extern int fsnotify(__u32 mask, const void *data, int data_type, 416 struct inode *dir, const struct qstr *name, 417 struct inode *inode, u32 cookie); 418 extern int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data, 419 int data_type); 420 extern void __fsnotify_inode_delete(struct inode *inode); 421 extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt); 422 extern void fsnotify_sb_delete(struct super_block *sb); 423 extern u32 fsnotify_get_cookie(void); 424 425 static inline __u32 fsnotify_parent_needed_mask(__u32 mask) 426 { 427 /* FS_EVENT_ON_CHILD is set on marks that want parent/name info */ 428 if (!(mask & FS_EVENT_ON_CHILD)) 429 return 0; 430 /* 431 * This object might be watched by a mark that cares about parent/name 432 * info, does it care about the specific set of events that can be 433 * reported with parent/name info? 434 */ 435 return mask & FS_EVENTS_POSS_TO_PARENT; 436 } 437 438 static inline int fsnotify_inode_watches_children(struct inode *inode) 439 { 440 /* FS_EVENT_ON_CHILD is set if the inode may care */ 441 if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD)) 442 return 0; 443 /* this inode might care about child events, does it care about the 444 * specific set of events that can happen on a child? */ 445 return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD; 446 } 447 448 /* 449 * Update the dentry with a flag indicating the interest of its parent to receive 450 * filesystem events when those events happens to this dentry->d_inode. 451 */ 452 static inline void fsnotify_update_flags(struct dentry *dentry) 453 { 454 assert_spin_locked(&dentry->d_lock); 455 456 /* 457 * Serialisation of setting PARENT_WATCHED on the dentries is provided 458 * by d_lock. If inotify_inode_watched changes after we have taken 459 * d_lock, the following __fsnotify_update_child_dentry_flags call will 460 * find our entry, so it will spin until we complete here, and update 461 * us with the new state. 462 */ 463 if (fsnotify_inode_watches_children(dentry->d_parent->d_inode)) 464 dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; 465 else 466 dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; 467 } 468 469 /* called from fsnotify listeners, such as fanotify or dnotify */ 470 471 /* create a new group */ 472 extern struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops); 473 extern struct fsnotify_group *fsnotify_alloc_user_group(const struct fsnotify_ops *ops); 474 /* get reference to a group */ 475 extern void fsnotify_get_group(struct fsnotify_group *group); 476 /* drop reference on a group from fsnotify_alloc_group */ 477 extern void fsnotify_put_group(struct fsnotify_group *group); 478 /* group destruction begins, stop queuing new events */ 479 extern void fsnotify_group_stop_queueing(struct fsnotify_group *group); 480 /* destroy group */ 481 extern void fsnotify_destroy_group(struct fsnotify_group *group); 482 /* fasync handler function */ 483 extern int fsnotify_fasync(int fd, struct file *file, int on); 484 /* Free event from memory */ 485 extern void fsnotify_destroy_event(struct fsnotify_group *group, 486 struct fsnotify_event *event); 487 /* attach the event to the group notification queue */ 488 extern int fsnotify_add_event(struct fsnotify_group *group, 489 struct fsnotify_event *event, 490 int (*merge)(struct list_head *, 491 struct fsnotify_event *)); 492 /* Queue overflow event to a notification group */ 493 static inline void fsnotify_queue_overflow(struct fsnotify_group *group) 494 { 495 fsnotify_add_event(group, group->overflow_event, NULL); 496 } 497 498 /* true if the group notification queue is empty */ 499 extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); 500 /* return, but do not dequeue the first event on the notification queue */ 501 extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group); 502 /* return AND dequeue the first event on the notification queue */ 503 extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group); 504 /* Remove event queued in the notification list */ 505 extern void fsnotify_remove_queued_event(struct fsnotify_group *group, 506 struct fsnotify_event *event); 507 508 /* functions used to manipulate the marks attached to inodes */ 509 510 /* Get mask of events for a list of marks */ 511 extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn); 512 /* Calculate mask of events for a list of marks */ 513 extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn); 514 extern void fsnotify_init_mark(struct fsnotify_mark *mark, 515 struct fsnotify_group *group); 516 /* Find mark belonging to given group in the list of marks */ 517 extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp, 518 struct fsnotify_group *group); 519 /* Get cached fsid of filesystem containing object */ 520 extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn, 521 __kernel_fsid_t *fsid); 522 /* attach the mark to the object */ 523 extern int fsnotify_add_mark(struct fsnotify_mark *mark, 524 fsnotify_connp_t *connp, unsigned int type, 525 int allow_dups, __kernel_fsid_t *fsid); 526 extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, 527 fsnotify_connp_t *connp, 528 unsigned int type, int allow_dups, 529 __kernel_fsid_t *fsid); 530 531 /* attach the mark to the inode */ 532 static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark, 533 struct inode *inode, 534 int allow_dups) 535 { 536 return fsnotify_add_mark(mark, &inode->i_fsnotify_marks, 537 FSNOTIFY_OBJ_TYPE_INODE, allow_dups, NULL); 538 } 539 static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark, 540 struct inode *inode, 541 int allow_dups) 542 { 543 return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks, 544 FSNOTIFY_OBJ_TYPE_INODE, allow_dups, 545 NULL); 546 } 547 548 /* given a group and a mark, flag mark to be freed when all references are dropped */ 549 extern void fsnotify_destroy_mark(struct fsnotify_mark *mark, 550 struct fsnotify_group *group); 551 /* detach mark from inode / mount list, group list, drop inode reference */ 552 extern void fsnotify_detach_mark(struct fsnotify_mark *mark); 553 /* free mark */ 554 extern void fsnotify_free_mark(struct fsnotify_mark *mark); 555 /* Wait until all marks queued for destruction are destroyed */ 556 extern void fsnotify_wait_marks_destroyed(void); 557 /* run all the marks in a group, and clear all of the marks attached to given object type */ 558 extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group, unsigned int type); 559 /* run all the marks in a group, and clear all of the vfsmount marks */ 560 static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group) 561 { 562 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL); 563 } 564 /* run all the marks in a group, and clear all of the inode marks */ 565 static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group) 566 { 567 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE_FL); 568 } 569 /* run all the marks in a group, and clear all of the sn marks */ 570 static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group) 571 { 572 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB_FL); 573 } 574 extern void fsnotify_get_mark(struct fsnotify_mark *mark); 575 extern void fsnotify_put_mark(struct fsnotify_mark *mark); 576 extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info); 577 extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info); 578 579 static inline void fsnotify_init_event(struct fsnotify_event *event, 580 unsigned long objectid) 581 { 582 INIT_LIST_HEAD(&event->list); 583 event->objectid = objectid; 584 } 585 586 #else 587 588 static inline int fsnotify(__u32 mask, const void *data, int data_type, 589 struct inode *dir, const struct qstr *name, 590 struct inode *inode, u32 cookie) 591 { 592 return 0; 593 } 594 595 static inline int __fsnotify_parent(struct dentry *dentry, __u32 mask, 596 const void *data, int data_type) 597 { 598 return 0; 599 } 600 601 static inline void __fsnotify_inode_delete(struct inode *inode) 602 {} 603 604 static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt) 605 {} 606 607 static inline void fsnotify_sb_delete(struct super_block *sb) 608 {} 609 610 static inline void fsnotify_update_flags(struct dentry *dentry) 611 {} 612 613 static inline u32 fsnotify_get_cookie(void) 614 { 615 return 0; 616 } 617 618 static inline void fsnotify_unmount_inodes(struct super_block *sb) 619 {} 620 621 #endif /* CONFIG_FSNOTIFY */ 622 623 #endif /* __KERNEL __ */ 624 625 #endif /* __LINUX_FSNOTIFY_BACKEND_H */ 626