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server: Add support for maintaining a client-side directory cache.
[wine.git] / server / change.c
blob7c0ca990bfac9b54d4587811542c1add8a5a62be
1 /*
2 * Server-side change notification management
3 *
4 * Copyright (C) 1998 Alexandre Julliard
5 * Copyright (C) 2006 Mike McCormack
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
20 */
21
22 #include "config.h"
23 #include "wine/port.h"
24
25 #include <assert.h>
26 #include <fcntl.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <signal.h>
30 #include <sys/stat.h>
31 #include <sys/types.h>
32 #include <limits.h>
33 #include <dirent.h>
34 #include <errno.h>
35 #ifdef HAVE_POLL_H
36 # include <poll.h>
37 #endif
38
39 #include "ntstatus.h"
40 #define WIN32_NO_STATUS
41 #include "windef.h"
42
43 #include "file.h"
44 #include "handle.h"
45 #include "thread.h"
46 #include "request.h"
47 #include "process.h"
48 #include "security.h"
49 #include "winternl.h"
50
51 /* dnotify support */
52
53 #ifdef linux
54 #ifndef F_NOTIFY
55 #define F_NOTIFY 1026
56 #define DN_ACCESS 0x00000001 /* File accessed */
57 #define DN_MODIFY 0x00000002 /* File modified */
58 #define DN_CREATE 0x00000004 /* File created */
59 #define DN_DELETE 0x00000008 /* File removed */
60 #define DN_RENAME 0x00000010 /* File renamed */
61 #define DN_ATTRIB 0x00000020 /* File changed attributes */
62 #define DN_MULTISHOT 0x80000000 /* Don't remove notifier */
63 #endif
64 #endif
65
66 /* inotify support */
67
68 #ifdef HAVE_SYS_INOTIFY_H
69 #include <sys/inotify.h>
70 #define USE_INOTIFY
71 #elif defined(__linux__) && defined(__i386__)
72
73 #define SYS_inotify_init 291
74 #define SYS_inotify_add_watch 292
75 #define SYS_inotify_rm_watch 293
76
77 struct inotify_event {
78 int wd;
79 unsigned int mask;
80 unsigned int cookie;
81 unsigned int len;
82 char name[1];
83 };
84
85 #define IN_ACCESS 0x00000001
86 #define IN_MODIFY 0x00000002
87 #define IN_ATTRIB 0x00000004
88 #define IN_CLOSE_WRITE 0x00000008
89 #define IN_CLOSE_NOWRITE 0x00000010
90 #define IN_OPEN 0x00000020
91 #define IN_MOVED_FROM 0x00000040
92 #define IN_MOVED_TO 0x00000080
93 #define IN_CREATE 0x00000100
94 #define IN_DELETE 0x00000200
95 #define IN_DELETE_SELF 0x00000400
96
97 #define IN_ISDIR 0x40000000
98
99 static inline int inotify_init( void )
100 {
101 return syscall( SYS_inotify_init );
102 }
103
104 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
105 {
106 return syscall( SYS_inotify_add_watch, fd, name, mask );
107 }
108
109 static inline int inotify_rm_watch( int fd, int wd )
110 {
111 return syscall( SYS_inotify_rm_watch, fd, wd );
112 }
113
114 #define USE_INOTIFY
115
116 #endif
117
118 struct inode;
119
120 static void free_inode( struct inode *inode );
121
122 static struct fd *inotify_fd;
123
124 struct change_record {
125 struct list entry;
126 unsigned int cookie;
127 struct filesystem_event event;
128 };
129
130 struct dir
131 {
132 struct object obj; /* object header */
133 struct fd *fd; /* file descriptor to the directory */
134 mode_t mode; /* file stat.st_mode */
135 uid_t uid; /* file stat.st_uid */
136 struct list entry; /* entry in global change notifications list */
137 unsigned int filter; /* notification filter */
138 int notified; /* SIGIO counter */
139 int want_data; /* return change data */
140 int subtree; /* do we want to watch subdirectories? */
141 struct list change_records; /* data for the change */
142 struct list in_entry; /* entry in the inode dirs list */
143 struct inode *inode; /* inode of the associated directory */
144 struct process *client_process; /* client process that has a cache for this directory */
145 int client_entry; /* entry in client process cache */
146 };
147
148 static struct fd *dir_get_fd( struct object *obj );
149 static struct security_descriptor *dir_get_sd( struct object *obj );
150 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
151 unsigned int set_info );
152 static void dir_dump( struct object *obj, int verbose );
153 static struct object_type *dir_get_type( struct object *obj );
154 static int dir_close_handle( struct object *obj, struct process *process, obj_handle_t handle );
155 static void dir_destroy( struct object *obj );
156
157 static const struct object_ops dir_ops =
158 {
159 sizeof(struct dir), /* size */
160 dir_dump, /* dump */
161 dir_get_type, /* get_type */
162 add_queue, /* add_queue */
163 remove_queue, /* remove_queue */
164 default_fd_signaled, /* signaled */
165 no_satisfied, /* satisfied */
166 no_signal, /* signal */
167 dir_get_fd, /* get_fd */
168 default_fd_map_access, /* map_access */
169 dir_get_sd, /* get_sd */
170 dir_set_sd, /* set_sd */
171 no_lookup_name, /* lookup_name */
172 no_link_name, /* link_name */
173 NULL, /* unlink_name */
174 no_open_file, /* open_file */
175 dir_close_handle, /* close_handle */
176 dir_destroy /* destroy */
177 };
178
179 static int dir_get_poll_events( struct fd *fd );
180 static enum server_fd_type dir_get_fd_type( struct fd *fd );
181
182 static const struct fd_ops dir_fd_ops =
183 {
184 dir_get_poll_events, /* get_poll_events */
185 default_poll_event, /* poll_event */
186 dir_get_fd_type, /* get_fd_type */
187 no_fd_read, /* read */
188 no_fd_write, /* write */
189 no_fd_flush, /* flush */
190 default_fd_ioctl, /* ioctl */
191 default_fd_queue_async, /* queue_async */
192 default_fd_reselect_async, /* reselect_async */
193 default_fd_cancel_async /* cancel_async */
194 };
195
196 static struct list change_list = LIST_INIT(change_list);
197
198 /* per-process structure to keep track of cache entries on the client size */
199 struct dir_cache
200 {
201 unsigned int size;
202 unsigned int count;
203 unsigned char state[1];
204 };
205
206 enum dir_cache_state
207 {
208 DIR_CACHE_STATE_FREE,
209 DIR_CACHE_STATE_INUSE,
210 DIR_CACHE_STATE_RELEASED
211 };
212
213 /* return an array of cache entries that can be freed on the client side */
214 static int *get_free_dir_cache_entries( struct process *process, data_size_t *size )
215 {
216 int *ret;
217 struct dir_cache *cache = process->dir_cache;
218 unsigned int i, j, count;
219
220 if (!cache) return NULL;
221 for (i = count = 0; i < cache->count && count < *size / sizeof(*ret); i++)
222 if (cache->state[i] == DIR_CACHE_STATE_RELEASED) count++;
223 if (!count) return NULL;
224
225 if ((ret = malloc( count * sizeof(*ret) )))
226 {
227 for (i = j = 0; j < count; i++)
228 {
229 if (cache->state[i] != DIR_CACHE_STATE_RELEASED) continue;
230 cache->state[i] = DIR_CACHE_STATE_FREE;
231 ret[j++] = i;
232 }
233 *size = count * sizeof(*ret);
234 }
235 return ret;
236 }
237
238 /* allocate a new client-side directory cache entry */
239 static int alloc_dir_cache_entry( struct dir *dir, struct process *process )
240 {
241 unsigned int i = 0;
242 struct dir_cache *cache = process->dir_cache;
243
244 if (cache)
245 for (i = 0; i < cache->count; i++)
246 if (cache->state[i] == DIR_CACHE_STATE_FREE) goto found;
247
248 if (!cache || cache->count == cache->size)
249 {
250 unsigned int size = cache ? cache->size * 2 : 256;
251 if (!(cache = realloc( cache, offsetof( struct dir_cache, state[size] ))))
252 {
253 set_error( STATUS_NO_MEMORY );
254 return -1;
255 }
256 process->dir_cache = cache;
257 cache->size = size;
258 }
259 cache->count = i + 1;
260
261 found:
262 cache->state[i] = DIR_CACHE_STATE_INUSE;
263 return i;
264 }
265
266 /* release a directory cache entry; it will be freed on the client side on the next cache request */
267 static void release_dir_cache_entry( struct dir *dir )
268 {
269 struct dir_cache *cache;
270
271 if (!dir->client_process) return;
272 cache = dir->client_process->dir_cache;
273 cache->state[dir->client_entry] = DIR_CACHE_STATE_RELEASED;
274 release_object( dir->client_process );
275 dir->client_process = NULL;
276 }
277
278 static void dnotify_adjust_changes( struct dir *dir )
279 {
280 #if defined(F_SETSIG) && defined(F_NOTIFY)
281 int fd = get_unix_fd( dir->fd );
282 unsigned int filter = dir->filter;
283 unsigned int val;
284 if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
285 return;
286
287 val = DN_MULTISHOT;
288 if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
289 val |= DN_RENAME | DN_DELETE | DN_CREATE;
290 if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
291 val |= DN_RENAME | DN_DELETE | DN_CREATE;
292 if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
293 val |= DN_ATTRIB;
294 if (filter & FILE_NOTIFY_CHANGE_SIZE)
295 val |= DN_MODIFY;
296 if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
297 val |= DN_MODIFY;
298 if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
299 val |= DN_ACCESS;
300 if (filter & FILE_NOTIFY_CHANGE_CREATION)
301 val |= DN_CREATE;
302 if (filter & FILE_NOTIFY_CHANGE_SECURITY)
303 val |= DN_ATTRIB;
304 fcntl( fd, F_NOTIFY, val );
305 #endif
306 }
307
308 /* insert change in the global list */
309 static inline void insert_change( struct dir *dir )
310 {
311 sigset_t sigset;
312
313 sigemptyset( &sigset );
314 sigaddset( &sigset, SIGIO );
315 sigprocmask( SIG_BLOCK, &sigset, NULL );
316 list_add_head( &change_list, &dir->entry );
317 sigprocmask( SIG_UNBLOCK, &sigset, NULL );
318 }
319
320 /* remove change from the global list */
321 static inline void remove_change( struct dir *dir )
322 {
323 sigset_t sigset;
324
325 sigemptyset( &sigset );
326 sigaddset( &sigset, SIGIO );
327 sigprocmask( SIG_BLOCK, &sigset, NULL );
328 list_remove( &dir->entry );
329 sigprocmask( SIG_UNBLOCK, &sigset, NULL );
330 }
331
332 static void dir_dump( struct object *obj, int verbose )
333 {
334 struct dir *dir = (struct dir *)obj;
335 assert( obj->ops == &dir_ops );
336 fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
337 }
338
339 static struct object_type *dir_get_type( struct object *obj )
340 {
341 static const WCHAR name[] = {'F','i','l','e'};
342 static const struct unicode_str str = { name, sizeof(name) };
343 return get_object_type( &str );
344 }
345
346 /* enter here directly from SIGIO signal handler */
347 void do_change_notify( int unix_fd )
348 {
349 struct dir *dir;
350
351 /* FIXME: this is O(n) ... probably can be improved */
352 LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
353 {
354 if (get_unix_fd( dir->fd ) != unix_fd) continue;
355 interlocked_xchg_add( &dir->notified, 1 );
356 break;
357 }
358 }
359
360 /* SIGIO callback, called synchronously with the poll loop */
361 void sigio_callback(void)
362 {
363 struct dir *dir;
364
365 LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
366 {
367 if (interlocked_xchg( &dir->notified, 0 ))
368 fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
369 }
370 }
371
372 static struct fd *dir_get_fd( struct object *obj )
373 {
374 struct dir *dir = (struct dir *)obj;
375 assert( obj->ops == &dir_ops );
376 return (struct fd *)grab_object( dir->fd );
377 }
378
379 static int get_dir_unix_fd( struct dir *dir )
380 {
381 return get_unix_fd( dir->fd );
382 }
383
384 static struct security_descriptor *dir_get_sd( struct object *obj )
385 {
386 struct dir *dir = (struct dir *)obj;
387 int unix_fd;
388 struct stat st;
389 struct security_descriptor *sd;
390 assert( obj->ops == &dir_ops );
391
392 unix_fd = get_dir_unix_fd( dir );
393
394 if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
395 return obj->sd;
396
397 /* mode and uid the same? if so, no need to re-generate security descriptor */
398 if (obj->sd &&
399 (st.st_mode & (S_IRWXU|S_IRWXO)) == (dir->mode & (S_IRWXU|S_IRWXO)) &&
400 (st.st_uid == dir->uid))
401 return obj->sd;
402
403 sd = mode_to_sd( st.st_mode,
404 security_unix_uid_to_sid( st.st_uid ),
405 token_get_primary_group( current->process->token ));
406 if (!sd) return obj->sd;
407
408 dir->mode = st.st_mode;
409 dir->uid = st.st_uid;
410 free( obj->sd );
411 obj->sd = sd;
412 return sd;
413 }
414
415 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
416 unsigned int set_info )
417 {
418 struct dir *dir = (struct dir *)obj;
419 const SID *owner;
420 struct stat st;
421 mode_t mode;
422 int unix_fd;
423
424 assert( obj->ops == &dir_ops );
425
426 unix_fd = get_dir_unix_fd( dir );
427
428 if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
429
430 if (set_info & OWNER_SECURITY_INFORMATION)
431 {
432 owner = sd_get_owner( sd );
433 if (!owner)
434 {
435 set_error( STATUS_INVALID_SECURITY_DESCR );
436 return 0;
437 }
438 if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
439 {
440 /* FIXME: get Unix uid and call fchown */
441 }
442 }
443 else if (obj->sd)
444 owner = sd_get_owner( obj->sd );
445 else
446 owner = token_get_user( current->process->token );
447
448 if (set_info & DACL_SECURITY_INFORMATION)
449 {
450 /* keep the bits that we don't map to access rights in the ACL */
451 mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX);
452 mode |= sd_to_mode( sd, owner );
453
454 if (((st.st_mode ^ mode) & (S_IRWXU|S_IRWXG|S_IRWXO)) && fchmod( unix_fd, mode ) == -1)
455 {
456 file_set_error();
457 return 0;
458 }
459 }
460 return 1;
461 }
462
463 static struct change_record *get_first_change_record( struct dir *dir )
464 {
465 struct list *ptr = list_head( &dir->change_records );
466 if (!ptr) return NULL;
467 list_remove( ptr );
468 return LIST_ENTRY( ptr, struct change_record, entry );
469 }
470
471 static int dir_close_handle( struct object *obj, struct process *process, obj_handle_t handle )
472 {
473 struct dir *dir = (struct dir *)obj;
474
475 if (!fd_close_handle( obj, process, handle )) return 0;
476 if (obj->handle_count == 1) release_dir_cache_entry( dir ); /* closing last handle, release cache */
477 return 1; /* ok to close */
478 }
479
480 static void dir_destroy( struct object *obj )
481 {
482 struct change_record *record;
483 struct dir *dir = (struct dir *)obj;
484 assert (obj->ops == &dir_ops);
485
486 if (dir->filter)
487 remove_change( dir );
488
489 if (dir->inode)
490 {
491 list_remove( &dir->in_entry );
492 free_inode( dir->inode );
493 }
494
495 while ((record = get_first_change_record( dir ))) free( record );
496
497 release_dir_cache_entry( dir );
498 release_object( dir->fd );
499
500 if (inotify_fd && list_empty( &change_list ))
501 {
502 release_object( inotify_fd );
503 inotify_fd = NULL;
504 }
505 }
506
507 struct dir *get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
508 {
509 return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
510 }
511
512 static int dir_get_poll_events( struct fd *fd )
513 {
514 return 0;
515 }
516
517 static enum server_fd_type dir_get_fd_type( struct fd *fd )
518 {
519 return FD_TYPE_DIR;
520 }
521
522 #ifdef USE_INOTIFY
523
524 #define HASH_SIZE 31
525
526 struct inode {
527 struct list ch_entry; /* entry in the children list */
528 struct list children; /* children of this inode */
529 struct inode *parent; /* parent of this inode */
530 struct list dirs; /* directory handles watching this inode */
531 struct list ino_entry; /* entry in the inode hash */
532 struct list wd_entry; /* entry in the watch descriptor hash */
533 dev_t dev; /* device number */
534 ino_t ino; /* device's inode number */
535 int wd; /* inotify's watch descriptor */
536 char *name; /* basename name of the inode */
537 };
538
539 static struct list inode_hash[ HASH_SIZE ];
540 static struct list wd_hash[ HASH_SIZE ];
541
542 static int inotify_add_dir( char *path, unsigned int filter );
543
544 static struct inode *inode_from_wd( int wd )
545 {
546 struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
547 struct inode *inode;
548
549 LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
550 if (inode->wd == wd)
551 return inode;
552
553 return NULL;
554 }
555
556 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
557 {
558 return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
559 }
560
561 static struct inode *find_inode( dev_t dev, ino_t ino )
562 {
563 struct list *bucket = get_hash_list( dev, ino );
564 struct inode *inode;
565
566 LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
567 if (inode->ino == ino && inode->dev == dev)
568 return inode;
569
570 return NULL;
571 }
572
573 static struct inode *create_inode( dev_t dev, ino_t ino )
574 {
575 struct inode *inode;
576
577 inode = malloc( sizeof *inode );
578 if (inode)
579 {
580 list_init( &inode->children );
581 list_init( &inode->dirs );
582 inode->ino = ino;
583 inode->dev = dev;
584 inode->wd = -1;
585 inode->parent = NULL;
586 inode->name = NULL;
587 list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
588 }
589 return inode;
590 }
591
592 static struct inode *get_inode( dev_t dev, ino_t ino )
593 {
594 struct inode *inode;
595
596 inode = find_inode( dev, ino );
597 if (inode)
598 return inode;
599 return create_inode( dev, ino );
600 }
601
602 static void inode_set_wd( struct inode *inode, int wd )
603 {
604 if (inode->wd != -1)
605 list_remove( &inode->wd_entry );
606 inode->wd = wd;
607 list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
608 }
609
610 static void inode_set_name( struct inode *inode, const char *name )
611 {
612 free (inode->name);
613 inode->name = name ? strdup( name ) : NULL;
614 }
615
616 static void free_inode( struct inode *inode )
617 {
618 int subtree = 0, watches = 0;
619 struct inode *tmp, *next;
620 struct dir *dir;
621
622 LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
623 {
624 subtree |= dir->subtree;
625 watches++;
626 }
627
628 if (!subtree && !inode->parent)
629 {
630 LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
631 struct inode, ch_entry )
632 {
633 assert( tmp != inode );
634 assert( tmp->parent == inode );
635 free_inode( tmp );
636 }
637 }
638
639 if (watches)
640 return;
641
642 if (inode->parent)
643 list_remove( &inode->ch_entry );
644
645 /* disconnect remaining children from the parent */
646 LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
647 {
648 list_remove( &tmp->ch_entry );
649 tmp->parent = NULL;
650 }
651
652 if (inode->wd != -1)
653 {
654 inotify_rm_watch( get_unix_fd( inotify_fd ), inode->wd );
655 list_remove( &inode->wd_entry );
656 }
657 list_remove( &inode->ino_entry );
658
659 free( inode->name );
660 free( inode );
661 }
662
663 static struct inode *inode_add( struct inode *parent,
664 dev_t dev, ino_t ino, const char *name )
665 {
666 struct inode *inode;
667
668 inode = get_inode( dev, ino );
669 if (!inode)
670 return NULL;
671
672 if (!inode->parent)
673 {
674 list_add_tail( &parent->children, &inode->ch_entry );
675 inode->parent = parent;
676 assert( inode != parent );
677 }
678 inode_set_name( inode, name );
679
680 return inode;
681 }
682
683 static struct inode *inode_from_name( struct inode *inode, const char *name )
684 {
685 struct inode *i;
686
687 LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
688 if (i->name && !strcmp( i->name, name ))
689 return i;
690 return NULL;
691 }
692
693 static int inotify_get_poll_events( struct fd *fd );
694 static void inotify_poll_event( struct fd *fd, int event );
695
696 static const struct fd_ops inotify_fd_ops =
697 {
698 inotify_get_poll_events, /* get_poll_events */
699 inotify_poll_event, /* poll_event */
700 NULL, /* flush */
701 NULL, /* get_fd_type */
702 NULL, /* ioctl */
703 NULL, /* queue_async */
704 NULL, /* reselect_async */
705 NULL, /* cancel_async */
706 };
707
708 static int inotify_get_poll_events( struct fd *fd )
709 {
710 return POLLIN;
711 }
712
713 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
714 unsigned int cookie, const char *relpath )
715 {
716 struct change_record *record;
717
718 assert( dir->obj.ops == &dir_ops );
719
720 if (dir->want_data)
721 {
722 size_t len = strlen(relpath);
723 record = malloc( offsetof(struct change_record, event.name[len]) );
724 if (!record)
725 return;
726
727 record->cookie = cookie;
728 record->event.action = action;
729 memcpy( record->event.name, relpath, len );
730 record->event.len = len;
731
732 list_add_tail( &dir->change_records, &record->entry );
733 }
734
735 fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
736 }
737
738 static unsigned int filter_from_event( struct inotify_event *ie )
739 {
740 unsigned int filter = 0;
741
742 if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
743 filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
744 if (ie->mask & IN_MODIFY)
745 filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
746 if (ie->mask & IN_ATTRIB)
747 filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
748 if (ie->mask & IN_ACCESS)
749 filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
750 if (ie->mask & IN_CREATE)
751 filter |= FILE_NOTIFY_CHANGE_CREATION;
752
753 if (ie->mask & IN_ISDIR)
754 filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
755 else
756 filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
757
758 return filter;
759 }
760
761 /* scan up the parent directories for watches */
762 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
763 {
764 unsigned int filter = 0;
765 struct dir *dir;
766
767 /* combine filters from parents watching subtrees */
768 while (inode)
769 {
770 LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
771 if (dir->subtree || !is_parent)
772 filter |= dir->filter;
773 is_parent = 1;
774 inode = inode->parent;
775 }
776
777 return filter;
778 }
779
780 static char *inode_get_path( struct inode *inode, int sz )
781 {
782 struct list *head;
783 char *path;
784 int len;
785
786 if (!inode)
787 return NULL;
788
789 head = list_head( &inode->dirs );
790 if (head)
791 {
792 int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
793 path = malloc ( 32 + sz );
794 if (path)
795 sprintf( path, "/proc/self/fd/%u/", unix_fd );
796 return path;
797 }
798
799 if (!inode->name)
800 return NULL;
801
802 len = strlen( inode->name );
803 path = inode_get_path( inode->parent, sz + len + 1 );
804 if (!path)
805 return NULL;
806
807 strcat( path, inode->name );
808 strcat( path, "/" );
809
810 return path;
811 }
812
813 static void inode_check_dir( struct inode *parent, const char *name )
814 {
815 char *path;
816 unsigned int filter;
817 struct inode *inode;
818 struct stat st;
819 int wd = -1;
820
821 path = inode_get_path( parent, strlen(name) );
822 if (!path)
823 return;
824
825 strcat( path, name );
826
827 if (stat( path, &st ) < 0)
828 goto end;
829
830 filter = filter_from_inode( parent, 1 );
831 if (!filter)
832 goto end;
833
834 inode = inode_add( parent, st.st_dev, st.st_ino, name );
835 if (!inode || inode->wd != -1)
836 goto end;
837
838 wd = inotify_add_dir( path, filter );
839 if (wd != -1)
840 inode_set_wd( inode, wd );
841 else
842 free_inode( inode );
843
844 end:
845 free( path );
846 }
847
848 static int prepend( char **path, const char *segment )
849 {
850 int extra;
851 char *p;
852
853 extra = strlen( segment ) + 1;
854 if (*path)
855 {
856 int len = strlen( *path ) + 1;
857 p = realloc( *path, len + extra );
858 if (!p) return 0;
859 memmove( &p[ extra ], p, len );
860 p[ extra - 1 ] = '/';
861 memcpy( p, segment, extra - 1 );
862 }
863 else
864 {
865 p = malloc( extra );
866 if (!p) return 0;
867 memcpy( p, segment, extra );
868 }
869
870 *path = p;
871
872 return 1;
873 }
874
875 static void inotify_notify_all( struct inotify_event *ie )
876 {
877 unsigned int filter, action;
878 struct inode *inode, *i;
879 char *path = NULL;
880 struct dir *dir;
881
882 inode = inode_from_wd( ie->wd );
883 if (!inode)
884 {
885 fprintf( stderr, "no inode matches %d\n", ie->wd);
886 return;
887 }
888
889 filter = filter_from_event( ie );
890
891 if (ie->mask & IN_CREATE)
892 {
893 if (ie->mask & IN_ISDIR)
894 inode_check_dir( inode, ie->name );
895
896 action = FILE_ACTION_ADDED;
897 }
898 else if (ie->mask & IN_DELETE)
899 action = FILE_ACTION_REMOVED;
900 else if (ie->mask & IN_MOVED_FROM)
901 action = FILE_ACTION_RENAMED_OLD_NAME;
902 else if (ie->mask & IN_MOVED_TO)
903 action = FILE_ACTION_RENAMED_NEW_NAME;
904 else
905 action = FILE_ACTION_MODIFIED;
906
907 /*
908 * Work our way up the inode hierarchy
909 * extending the relative path as we go
910 * and notifying all recursive watches.
911 */
912 if (!prepend( &path, ie->name ))
913 return;
914
915 for (i = inode; i; i = i->parent)
916 {
917 LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
918 if ((filter & dir->filter) && (i==inode || dir->subtree))
919 inotify_do_change_notify( dir, action, ie->cookie, path );
920
921 if (!i->name || !prepend( &path, i->name ))
922 break;
923 }
924
925 free( path );
926
927 if (ie->mask & IN_DELETE)
928 {
929 i = inode_from_name( inode, ie->name );
930 if (i)
931 free_inode( i );
932 }
933 }
934
935 static void inotify_poll_event( struct fd *fd, int event )
936 {
937 int r, ofs, unix_fd;
938 char buffer[0x1000];
939 struct inotify_event *ie;
940
941 unix_fd = get_unix_fd( fd );
942 r = read( unix_fd, buffer, sizeof buffer );
943 if (r < 0)
944 {
945 fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
946 return;
947 }
948
949 for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
950 {
951 ie = (struct inotify_event*) &buffer[ofs];
952 if (!ie->len)
953 break;
954 ofs += offsetof( struct inotify_event, name[ie->len] );
955 if (ofs > r) break;
956 inotify_notify_all( ie );
957 }
958 }
959
960 static inline struct fd *create_inotify_fd( void )
961 {
962 int unix_fd;
963
964 unix_fd = inotify_init();
965 if (unix_fd<0)
966 return NULL;
967 return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
968 }
969
970 static int map_flags( unsigned int filter )
971 {
972 unsigned int mask;
973
974 /* always watch these so we can track subdirectories in recursive watches */
975 mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
976
977 if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
978 mask |= IN_ATTRIB;
979 if (filter & FILE_NOTIFY_CHANGE_SIZE)
980 mask |= IN_MODIFY;
981 if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
982 mask |= IN_MODIFY;
983 if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
984 mask |= IN_ACCESS;
985 if (filter & FILE_NOTIFY_CHANGE_SECURITY)
986 mask |= IN_ATTRIB;
987
988 return mask;
989 }
990
991 static int inotify_add_dir( char *path, unsigned int filter )
992 {
993 int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
994 path, map_flags( filter ) );
995 if (wd != -1)
996 set_fd_events( inotify_fd, POLLIN );
997 return wd;
998 }
999
1000 static int init_inotify( void )
1001 {
1002 int i;
1003
1004 if (inotify_fd)
1005 return 1;
1006
1007 inotify_fd = create_inotify_fd();
1008 if (!inotify_fd)
1009 return 0;
1010
1011 for (i=0; i<HASH_SIZE; i++)
1012 {
1013 list_init( &inode_hash[i] );
1014 list_init( &wd_hash[i] );
1015 }
1016
1017 return 1;
1018 }
1019
1020 static int inotify_adjust_changes( struct dir *dir )
1021 {
1022 unsigned int filter;
1023 struct inode *inode;
1024 struct stat st;
1025 char path[32];
1026 int wd, unix_fd;
1027
1028 if (!inotify_fd)
1029 return 0;
1030
1031 unix_fd = get_unix_fd( dir->fd );
1032
1033 inode = dir->inode;
1034 if (!inode)
1035 {
1036 /* check if this fd is already being watched */
1037 if (-1 == fstat( unix_fd, &st ))
1038 return 0;
1039
1040 inode = get_inode( st.st_dev, st.st_ino );
1041 if (!inode)
1042 inode = create_inode( st.st_dev, st.st_ino );
1043 if (!inode)
1044 return 0;
1045 list_add_tail( &inode->dirs, &dir->in_entry );
1046 dir->inode = inode;
1047 }
1048
1049 filter = filter_from_inode( inode, 0 );
1050
1051 sprintf( path, "/proc/self/fd/%u", unix_fd );
1052 wd = inotify_add_dir( path, filter );
1053 if (wd == -1) return 0;
1054
1055 inode_set_wd( inode, wd );
1056
1057 return 1;
1058 }
1059
1060 static char *get_basename( const char *link )
1061 {
1062 char *buffer, *name = NULL;
1063 int r, n = 0x100;
1064
1065 while (1)
1066 {
1067 buffer = malloc( n );
1068 if (!buffer) return NULL;
1069
1070 r = readlink( link, buffer, n );
1071 if (r < 0)
1072 break;
1073
1074 if (r < n)
1075 {
1076 name = buffer;
1077 break;
1078 }
1079 free( buffer );
1080 n *= 2;
1081 }
1082
1083 if (name)
1084 {
1085 while (r > 0 && name[ r - 1 ] == '/' )
1086 r--;
1087 name[ r ] = 0;
1088
1089 name = strrchr( name, '/' );
1090 if (name)
1091 name = strdup( &name[1] );
1092 }
1093
1094 free( buffer );
1095 return name;
1096 }
1097
1098 static int dir_add_to_existing_notify( struct dir *dir )
1099 {
1100 struct inode *inode, *parent;
1101 unsigned int filter = 0;
1102 struct stat st, st_new;
1103 char link[35], *name;
1104 int wd, unix_fd;
1105
1106 if (!inotify_fd)
1107 return 0;
1108
1109 unix_fd = get_unix_fd( dir->fd );
1110
1111 /* check if it's in the list of inodes we want to watch */
1112 if (-1 == fstat( unix_fd, &st_new ))
1113 return 0;
1114 inode = find_inode( st_new.st_dev, st_new.st_ino );
1115 if (inode)
1116 return 0;
1117
1118 /* lookup the parent */
1119 sprintf( link, "/proc/self/fd/%u/..", unix_fd );
1120 if (-1 == stat( link, &st ))
1121 return 0;
1122
1123 /*
1124 * If there's no parent, stop. We could keep going adding
1125 * ../ to the path until we hit the root of the tree or
1126 * find a recursively watched ancestor.
1127 * Assume it's too expensive to search up the tree for now.
1128 */
1129 parent = find_inode( st.st_dev, st.st_ino );
1130 if (!parent)
1131 return 0;
1132
1133 if (parent->wd == -1)
1134 return 0;
1135
1136 filter = filter_from_inode( parent, 1 );
1137 if (!filter)
1138 return 0;
1139
1140 sprintf( link, "/proc/self/fd/%u", unix_fd );
1141 name = get_basename( link );
1142 if (!name)
1143 return 0;
1144 inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
1145 free( name );
1146 if (!inode)
1147 return 0;
1148
1149 /* Couldn't find this inode at the start of the function, must be new */
1150 assert( inode->wd == -1 );
1151
1152 wd = inotify_add_dir( link, filter );
1153 if (wd != -1)
1154 inode_set_wd( inode, wd );
1155
1156 return 1;
1157 }
1158
1159 #else
1160
1161 static int init_inotify( void )
1162 {
1163 return 0;
1164 }
1165
1166 static int inotify_adjust_changes( struct dir *dir )
1167 {
1168 return 0;
1169 }
1170
1171 static void free_inode( struct inode *inode )
1172 {
1173 assert( 0 );
1174 }
1175
1176 static int dir_add_to_existing_notify( struct dir *dir )
1177 {
1178 return 0;
1179 }
1180
1181 #endif /* USE_INOTIFY */
1182
1183 struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1184 {
1185 struct dir *dir;
1186
1187 dir = alloc_object( &dir_ops );
1188 if (!dir)
1189 return NULL;
1190
1191 list_init( &dir->change_records );
1192 dir->filter = 0;
1193 dir->notified = 0;
1194 dir->want_data = 0;
1195 dir->inode = NULL;
1196 grab_object( fd );
1197 dir->fd = fd;
1198 dir->mode = mode;
1199 dir->uid = ~(uid_t)0;
1200 dir->client_process = NULL;
1201 set_fd_user( fd, &dir_fd_ops, &dir->obj );
1202
1203 dir_add_to_existing_notify( dir );
1204
1205 return &dir->obj;
1206 }
1207
1208 /* retrieve (or allocate) the client-side directory cache entry */
1209 DECL_HANDLER(get_directory_cache_entry)
1210 {
1211 struct dir *dir;
1212 int *free_entries;
1213 data_size_t free_size;
1214
1215 if (!(dir = get_dir_obj( current->process, req->handle, 0 ))) return;
1216
1217 if (!dir->client_process)
1218 {
1219 if ((dir->client_entry = alloc_dir_cache_entry( dir, current->process )) == -1) goto done;
1220 dir->client_process = (struct process *)grab_object( current->process );
1221 }
1222
1223 if (dir->client_process == current->process) reply->entry = dir->client_entry;
1224 else set_error( STATUS_SHARING_VIOLATION );
1225
1226 done: /* allow freeing entries even on failure */
1227 free_size = get_reply_max_size();
1228 free_entries = get_free_dir_cache_entries( current->process, &free_size );
1229 if (free_entries) set_reply_data_ptr( free_entries, free_size );
1230
1231 release_object( dir );
1232 }
1233
1234 /* enable change notifications for a directory */
1235 DECL_HANDLER(read_directory_changes)
1236 {
1237 struct dir *dir;
1238 struct async *async;
1239
1240 if (!req->filter)
1241 {
1242 set_error(STATUS_INVALID_PARAMETER);
1243 return;
1244 }
1245
1246 dir = get_dir_obj( current->process, req->async.handle, 0 );
1247 if (!dir)
1248 return;
1249
1250 /* requests don't timeout */
1251 if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1252
1253 /* assign it once */
1254 if (!dir->filter)
1255 {
1256 init_inotify();
1257 insert_change( dir );
1258 dir->filter = req->filter;
1259 dir->subtree = req->subtree;
1260 dir->want_data = req->want_data;
1261 }
1262
1263 /* if there's already a change in the queue, send it */
1264 if (!list_empty( &dir->change_records ))
1265 fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1266
1267 /* setup the real notification */
1268 if (!inotify_adjust_changes( dir ))
1269 dnotify_adjust_changes( dir );
1270
1271 release_object( async );
1272 set_error(STATUS_PENDING);
1273
1274 end:
1275 release_object( dir );
1276 }
1277
1278 DECL_HANDLER(read_change)
1279 {
1280 struct change_record *record, *next;
1281 struct dir *dir;
1282 struct list events;
1283 char *data, *event;
1284 int size = 0;
1285
1286 dir = get_dir_obj( current->process, req->handle, 0 );
1287 if (!dir)
1288 return;
1289
1290 list_init( &events );
1291 list_move_tail( &events, &dir->change_records );
1292 release_object( dir );
1293
1294 if (list_empty( &events ))
1295 {
1296 set_error( STATUS_NO_DATA_DETECTED );
1297 return;
1298 }
1299
1300 LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
1301 {
1302 size += (offsetof(struct filesystem_event, name[record->event.len])
1303 + sizeof(int)-1) / sizeof(int) * sizeof(int);
1304 }
1305
1306 if (size > get_reply_max_size())
1307 set_error( STATUS_BUFFER_TOO_SMALL );
1308 else if ((data = mem_alloc( size )) != NULL)
1309 {
1310 event = data;
1311 LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
1312 {
1313 data_size_t len = offsetof( struct filesystem_event, name[record->event.len] );
1314
1315 /* FIXME: rename events are sometimes reported as delete/create */
1316 if (record->event.action == FILE_ACTION_RENAMED_OLD_NAME)
1317 {
1318 struct list *elem = list_next( &events, &record->entry );
1319 if (elem)
1320 next = LIST_ENTRY(elem, struct change_record, entry);
1321
1322 if (elem && next->cookie == record->cookie)
1323 next->cookie = 0;
1324 else
1325 record->event.action = FILE_ACTION_REMOVED;
1326 }
1327 else if (record->event.action == FILE_ACTION_RENAMED_NEW_NAME && record->cookie)
1328 record->event.action = FILE_ACTION_ADDED;
1329
1330 memcpy( event, &record->event, len );
1331 event += len;
1332 if (len % sizeof(int))
1333 {
1334 memset( event, 0, sizeof(int) - len % sizeof(int) );
1335 event += sizeof(int) - len % sizeof(int);
1336 }
1337 }
1338 set_reply_data_ptr( data, size );
1339 }
1340
1341 LIST_FOR_EACH_ENTRY_SAFE( record, next, &events, struct change_record, entry )
1342 {
1343 list_remove( &record->entry );
1344 free( record );
1345 }
1346 }
Windows API implementation