server/change.c

   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_SYS_ERRNO_H
  36 #include <sys/errno.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 "winternl.h"
  48
  49 /* dnotify support */
  50
  51 #ifdef linux
  52 #ifndef F_NOTIFY
  53 #define F_NOTIFY 1026
  54 #define DN_ACCESS       0x00000001      /* File accessed */
  55 #define DN_MODIFY       0x00000002      /* File modified */
  56 #define DN_CREATE       0x00000004      /* File created */
  57 #define DN_DELETE       0x00000008      /* File removed */
  58 #define DN_RENAME       0x00000010      /* File renamed */
  59 #define DN_ATTRIB       0x00000020      /* File changed attibutes */
  60 #define DN_MULTISHOT    0x80000000      /* Don't remove notifier */
  61 #endif
  62 #endif
  63
  64 /* inotify support */
  65
  66 #if defined(__linux__) && defined(__i386__)
  67
  68 #define SYS_inotify_init        291
  69 #define SYS_inotify_add_watch   292
  70 #define SYS_inotify_rm_watch    293
  71
  72 struct inotify_event {
  73     int           wd;
  74     unsigned int  mask;
  75     unsigned int  cookie;
  76     unsigned int  len;
  77     char          name[1];
  78 };
  79
  80 #define IN_ACCESS        0x00000001
  81 #define IN_MODIFY        0x00000002
  82 #define IN_ATTRIB        0x00000004
  83 #define IN_CLOSE_WRITE   0x00000008
  84 #define IN_CLOSE_NOWRITE 0x00000010
  85 #define IN_OPEN          0x00000020
  86 #define IN_MOVED_FROM    0x00000040
  87 #define IN_MOVED_TO      0x00000080
  88 #define IN_CREATE        0x00000100
  89 #define IN_DELETE        0x00000200
  90 #define IN_DELETE_SELF   0x00000400
  91
  92 static inline int inotify_init( void )
  93 {
  94     int ret;
  95     __asm__ __volatile__( "int $0x80"
  96                           : "=a" (ret)
  97                           : "0" (SYS_inotify_init));
  98     if (ret<0) { errno = -ret; ret = -1; }
  99     return ret;
 100 }
 101
 102 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
 103 {
 104     int ret;
 105     __asm__ __volatile__( "pushl %%ebx;\n\t"
 106                           "movl %2,%%ebx;\n\t"
 107                           "int $0x80;\n\t"
 108                           "popl %%ebx"
 109                           : "=a" (ret) : "0" (SYS_inotify_add_watch),
 110                             "r" (fd), "c" (name), "d" (mask) );
 111     if (ret<0) { errno = -ret; ret = -1; }
 112     return ret;
 113 }
 114
 115 static inline int inotify_remove_watch( int fd, int wd )
 116 {
 117     int ret;
 118     __asm__ __volatile__( "pushl %%ebx;\n\t"
 119                           "movl %2,%%ebx;\n\t"
 120                           "int $0x80;\n\t"
 121                           "popl %%ebx"
 122                           : "=a" (ret) : "0" (SYS_inotify_rm_watch),
 123                             "r" (fd), "c" (wd) );
 124     if (ret<0) { errno = -ret; ret = -1; }
 125     return ret;
 126 }
 127
 128 #define USE_INOTIFY
 129
 130 #endif
 131
 132 struct inode;
 133
 134 static void free_inode( struct inode *inode );
 135
 136 static struct fd *inotify_fd;
 137
 138 struct change_record {
 139     struct list entry;
 140     int action;
 141     int len;
 142     char name[1];
 143 };
 144
 145 struct dir
 146 {
 147     struct object  obj;      /* object header */
 148     struct fd     *fd;       /* file descriptor to the directory */
 149     struct list    entry;    /* entry in global change notifications list */
 150     unsigned int   filter;   /* notification filter */
 151     int            notified; /* SIGIO counter */
 152     int            want_data; /* return change data */
 153     int            subtree;  /* do we want to watch subdirectories? */
 154     struct list    change_records;   /* data for the change */
 155     struct list    in_entry; /* entry in the inode dirs list */
 156     struct inode  *inode;    /* inode of the associated directory */
 157 };
 158
 159 static struct fd *dir_get_fd( struct object *obj );
 160 static unsigned int dir_map_access( struct object *obj, unsigned int access );
 161 static void dir_dump( struct object *obj, int verbose );
 162 static void dir_destroy( struct object *obj );
 163
 164 static const struct object_ops dir_ops =
 165 {
 166     sizeof(struct dir),       /* size */
 167     dir_dump,                 /* dump */
 168     add_queue,                /* add_queue */
 169     remove_queue,             /* remove_queue */
 170     default_fd_signaled,      /* signaled */
 171     no_satisfied,             /* satisfied */
 172     no_signal,                /* signal */
 173     dir_get_fd,               /* get_fd */
 174     dir_map_access,           /* map_access */
 175     no_lookup_name,           /* lookup_name */
 176     no_open_file,             /* open_file */
 177     fd_close_handle,          /* close_handle */
 178     dir_destroy               /* destroy */
 179 };
 180
 181 static int dir_get_poll_events( struct fd *fd );
 182 static enum server_fd_type dir_get_info( struct fd *fd, int *flags );
 183
 184 static const struct fd_ops dir_fd_ops =
 185 {
 186     dir_get_poll_events,      /* get_poll_events */
 187     default_poll_event,       /* poll_event */
 188     no_flush,                 /* flush */
 189     dir_get_info,             /* get_file_info */
 190     default_fd_queue_async,   /* queue_async */
 191     default_fd_cancel_async   /* cancel_async */
 192 };
 193
 194 static struct list change_list = LIST_INIT(change_list);
 195
 196 static void dnotify_adjust_changes( struct dir *dir )
 197 {
 198 #if defined(F_SETSIG) && defined(F_NOTIFY)
 199     int fd = get_unix_fd( dir->fd );
 200     unsigned int filter = dir->filter;
 201     unsigned int val;
 202     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 203         return;
 204
 205     val = DN_MULTISHOT;
 206     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 207         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 208     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 209         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 210     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 211         val |= DN_ATTRIB;
 212     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 213         val |= DN_MODIFY;
 214     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 215         val |= DN_MODIFY;
 216     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 217         val |= DN_ACCESS;
 218     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 219         val |= DN_CREATE;
 220     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 221         val |= DN_ATTRIB;
 222     fcntl( fd, F_NOTIFY, val );
 223 #endif
 224 }
 225
 226 /* insert change in the global list */
 227 static inline void insert_change( struct dir *dir )
 228 {
 229     sigset_t sigset;
 230
 231     sigemptyset( &sigset );
 232     sigaddset( &sigset, SIGIO );
 233     sigprocmask( SIG_BLOCK, &sigset, NULL );
 234     list_add_head( &change_list, &dir->entry );
 235     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 236 }
 237
 238 /* remove change from the global list */
 239 static inline void remove_change( struct dir *dir )
 240 {
 241     sigset_t sigset;
 242
 243     sigemptyset( &sigset );
 244     sigaddset( &sigset, SIGIO );
 245     sigprocmask( SIG_BLOCK, &sigset, NULL );
 246     list_remove( &dir->entry );
 247     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 248 }
 249
 250 static void dir_dump( struct object *obj, int verbose )
 251 {
 252     struct dir *dir = (struct dir *)obj;
 253     assert( obj->ops == &dir_ops );
 254     fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
 255 }
 256
 257 /* enter here directly from SIGIO signal handler */
 258 void do_change_notify( int unix_fd )
 259 {
 260     struct dir *dir;
 261
 262     /* FIXME: this is O(n) ... probably can be improved */
 263     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 264     {
 265         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 266         interlocked_xchg_add( &dir->notified, 1 );
 267         break;
 268     }
 269 }
 270
 271 /* SIGIO callback, called synchronously with the poll loop */
 272 void sigio_callback(void)
 273 {
 274     struct dir *dir;
 275
 276     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 277     {
 278         if (interlocked_xchg( &dir->notified, 0 ))
 279             fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
 280     }
 281 }
 282
 283 static struct fd *dir_get_fd( struct object *obj )
 284 {
 285     struct dir *dir = (struct dir *)obj;
 286     assert( obj->ops == &dir_ops );
 287     return (struct fd *)grab_object( dir->fd );
 288 }
 289
 290 static unsigned int dir_map_access( struct object *obj, unsigned int access )
 291 {
 292     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 293     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 294     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 295     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 296     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 297 }
 298
 299 static struct change_record *get_first_change_record( struct dir *dir )
 300 {
 301     struct list *ptr = list_head( &dir->change_records );
 302     if (!ptr) return NULL;
 303     list_remove( ptr );
 304     return LIST_ENTRY( ptr, struct change_record, entry );
 305 }
 306
 307 static void dir_destroy( struct object *obj )
 308 {
 309     struct change_record *record;
 310     struct dir *dir = (struct dir *)obj;
 311     assert (obj->ops == &dir_ops);
 312
 313     if (dir->filter)
 314         remove_change( dir );
 315
 316     if (dir->inode)
 317     {
 318         list_remove( &dir->in_entry );
 319         free_inode( dir->inode );
 320     }
 321
 322     while ((record = get_first_change_record( dir ))) free( record );
 323
 324     release_object( dir->fd );
 325
 326     if (inotify_fd && list_empty( &change_list ))
 327     {
 328         release_object( inotify_fd );
 329         inotify_fd = NULL;
 330     }
 331 }
 332
 333 static struct dir *
 334 get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 335 {
 336     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 337 }
 338
 339 static int dir_get_poll_events( struct fd *fd )
 340 {
 341     return 0;
 342 }
 343
 344 static enum server_fd_type dir_get_info( struct fd *fd, int *flags )
 345 {
 346     *flags = 0;
 347     return FD_TYPE_DIR;
 348 }
 349
 350 #ifdef USE_INOTIFY
 351
 352 #define HASH_SIZE 31
 353
 354 struct inode {
 355     struct list ch_entry;    /* entry in the children list */
 356     struct list children;    /* children of this inode */
 357     struct inode *parent;    /* parent of this inode */
 358     struct list dirs;        /* directory handles watching this inode */
 359     struct list ino_entry;   /* entry in the inode hash */
 360     struct list wd_entry;    /* entry in the watch descriptor hash */
 361     dev_t dev;               /* device number */
 362     ino_t ino;               /* device's inode number */
 363     int wd;                  /* inotify's watch descriptor */
 364     char *name;              /* basename name of the inode */
 365 };
 366
 367 struct list inode_hash[ HASH_SIZE ];
 368 struct list wd_hash[ HASH_SIZE ];
 369
 370 static int inotify_add_dir( char *path, unsigned int filter );
 371
 372 static struct inode *inode_from_wd( int wd )
 373 {
 374     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 375     struct inode *inode;
 376
 377     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 378         if (inode->wd == wd)
 379             return inode;
 380
 381     return NULL;
 382 }
 383
 384 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 385 {
 386     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 387 }
 388
 389 static struct inode *find_inode( dev_t dev, ino_t ino )
 390 {
 391     struct list *bucket = get_hash_list( dev, ino );
 392     struct inode *inode;
 393
 394     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 395         if (inode->ino == ino && inode->dev == dev)
 396              return inode;
 397
 398     return NULL;
 399 }
 400
 401 static struct inode *create_inode( dev_t dev, ino_t ino )
 402 {
 403     struct inode *inode;
 404
 405     inode = malloc( sizeof *inode );
 406     if (inode)
 407     {
 408         list_init( &inode->children );
 409         list_init( &inode->dirs );
 410         inode->ino = ino;
 411         inode->dev = dev;
 412         inode->wd = -1;
 413         inode->parent = NULL;
 414         inode->name = NULL;
 415         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 416     }
 417     return inode;
 418 }
 419
 420 static struct inode *get_inode( dev_t dev, ino_t ino )
 421 {
 422     struct inode *inode;
 423
 424     inode = find_inode( dev, ino );
 425     if (inode)
 426         return inode;
 427     return create_inode( dev, ino );
 428 }
 429
 430 static void inode_set_wd( struct inode *inode, int wd )
 431 {
 432     if (inode->wd != -1)
 433         list_remove( &inode->wd_entry );
 434     inode->wd = wd;
 435     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 436 }
 437
 438 static void inode_set_name( struct inode *inode, const char *name )
 439 {
 440     free (inode->name);
 441     inode->name = name ? strdup( name ) : NULL;
 442 }
 443
 444 static void free_inode( struct inode *inode )
 445 {
 446     int subtree = 0, watches = 0;
 447     struct dir *dir;
 448
 449     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 450     {
 451         subtree |= dir->subtree;
 452         watches++;
 453     }
 454
 455     if (!subtree && !inode->parent)
 456     {
 457         struct inode *tmp, *next;
 458         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 459                                   struct inode, ch_entry )
 460         {
 461             assert( tmp != inode );
 462             assert( tmp->parent == inode );
 463             free_inode( tmp );
 464         }
 465     }
 466
 467     if (watches)
 468         return;
 469
 470     if (inode->parent)
 471         list_remove( &inode->ch_entry );
 472
 473     if (inode->wd != -1)
 474     {
 475         inotify_remove_watch( get_unix_fd( inotify_fd ), inode->wd );
 476         list_remove( &inode->wd_entry );
 477     }
 478     list_remove( &inode->ino_entry );
 479
 480     free( inode->name );
 481     free( inode );
 482 }
 483
 484 static struct inode *inode_add( struct inode *parent,
 485                                 dev_t dev, ino_t ino, const char *name )
 486 {
 487     struct inode *inode;
 488
 489     inode = get_inode( dev, ino );
 490     if (!inode)
 491         return NULL;
 492
 493     if (!inode->parent)
 494     {
 495         list_add_tail( &parent->children, &inode->ch_entry );
 496         inode->parent = parent;
 497         assert( inode != parent );
 498     }
 499     inode_set_name( inode, name );
 500
 501     return inode;
 502 }
 503
 504 static struct inode *inode_from_name( struct inode *inode, const char *name )
 505 {
 506     struct inode *i;
 507
 508     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 509         if (i->name && !strcmp( i->name, name ))
 510             return i;
 511     return NULL;
 512 }
 513
 514 static int inotify_get_poll_events( struct fd *fd );
 515 static void inotify_poll_event( struct fd *fd, int event );
 516
 517 static const struct fd_ops inotify_fd_ops =
 518 {
 519     inotify_get_poll_events,  /* get_poll_events */
 520     inotify_poll_event,       /* poll_event */
 521     no_flush,                 /* flush */
 522     no_get_file_info,         /* get_file_info */
 523     default_fd_queue_async,   /* queue_async */
 524     default_fd_cancel_async,  /* cancel_async */
 525 };
 526
 527 static int inotify_get_poll_events( struct fd *fd )
 528 {
 529     return POLLIN;
 530 }
 531
 532 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 533                                       const char *relpath )
 534 {
 535     struct change_record *record;
 536
 537     assert( dir->obj.ops == &dir_ops );
 538
 539     if (dir->want_data)
 540     {
 541         size_t len = strlen(relpath);
 542         record = malloc( offsetof(struct change_record, name[len]) );
 543         if (!record)
 544             return;
 545
 546         record->action = action;
 547         memcpy( record->name, relpath, len );
 548         record->len = len;
 549
 550         list_add_tail( &dir->change_records, &record->entry );
 551     }
 552
 553     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 554 }
 555
 556 static unsigned int filter_from_event( struct inotify_event *ie )
 557 {
 558     unsigned int filter = 0;
 559
 560     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 561         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 562     if (ie->mask & IN_MODIFY)
 563         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 564     if (ie->mask & IN_ATTRIB)
 565         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 566     if (ie->mask & IN_ACCESS)
 567         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 568     if (ie->mask & IN_CREATE)
 569         filter |= FILE_NOTIFY_CHANGE_CREATION;
 570
 571     return filter;
 572 }
 573
 574 /* scan up the parent directories for watches */
 575 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 576 {
 577     unsigned int filter = 0;
 578     struct dir *dir;
 579
 580     /* combine filters from parents watching subtrees */
 581     while (inode)
 582     {
 583         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 584             if (dir->subtree || !is_parent)
 585                 filter |= dir->filter;
 586         is_parent = 1;
 587         inode = inode->parent;
 588     }
 589
 590     return filter;
 591 }
 592
 593 static char *inode_get_path( struct inode *inode, int sz )
 594 {
 595     struct list *head;
 596     char *path;
 597     int len;
 598
 599     if (!inode)
 600         return NULL;
 601
 602     head = list_head( &inode->dirs );
 603     if (head)
 604     {
 605         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 606         path = malloc ( 32 + sz );
 607         if (path)
 608             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 609         return path;
 610     }
 611
 612     if (!inode->name)
 613         return NULL;
 614
 615     len = strlen( inode->name );
 616     path = inode_get_path( inode->parent, sz + len + 1 );
 617     if (!path)
 618         return NULL;
 619
 620     strcat( path, inode->name );
 621     strcat( path, "/" );
 622
 623     return path;
 624 }
 625
 626 static int inode_check_dir( struct inode *parent, const char *name )
 627 {
 628     char *path;
 629     unsigned int filter;
 630     struct inode *inode;
 631     struct stat st;
 632     int wd = -1, r = -1;
 633
 634     path = inode_get_path( parent, strlen(name) );
 635     if (!path)
 636         return r;
 637
 638     strcat( path, name );
 639
 640     r = stat( path, &st );
 641     if (r < 0) goto end;
 642
 643     if (!S_ISDIR(st.st_mode))
 644     {
 645         r = 0;
 646         goto end;
 647     }
 648
 649     r = 1;
 650
 651     filter = filter_from_inode( parent, 1 );
 652     if (!filter)
 653         goto end;
 654
 655     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 656     if (!inode || inode->wd != -1)
 657         goto end;
 658
 659     wd = inotify_add_dir( path, filter );
 660     if (wd != -1)
 661         inode_set_wd( inode, wd );
 662     else
 663         free_inode( inode );
 664
 665 end:
 666     free( path );
 667     return r;
 668 }
 669
 670 static int prepend( char **path, const char *segment )
 671 {
 672     int extra;
 673     char *p;
 674
 675     extra = strlen( segment ) + 1;
 676     if (*path)
 677     {
 678         int len = strlen( *path ) + 1;
 679         p = realloc( *path, len + extra );
 680         if (!p) return 0;
 681         memmove( &p[ extra ], p, len );
 682         p[ extra - 1 ] = '/';
 683         memcpy( p, segment, extra - 1 );
 684     }
 685     else
 686     {
 687         p = malloc( extra );
 688         if (!p) return 0;
 689         memcpy( p, segment, extra );
 690     }
 691
 692     *path = p;
 693
 694     return 1;
 695 }
 696
 697 static void inotify_notify_all( struct inotify_event *ie )
 698 {
 699     unsigned int filter, action;
 700     struct inode *inode, *i;
 701     char *path = NULL;
 702     struct dir *dir;
 703
 704     inode = inode_from_wd( ie->wd );
 705     if (!inode)
 706     {
 707         fprintf( stderr, "no inode matches %d\n", ie->wd);
 708         return;
 709     }
 710
 711     filter = filter_from_event( ie );
 712
 713     if (ie->mask & IN_CREATE)
 714     {
 715         switch (inode_check_dir( inode, ie->name ))
 716         {
 717         case 1:
 718             filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 719             break;
 720         case 0:
 721             filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 722             break;
 723         default:
 724             break;
 725             /* Maybe the file disappeared before we could check it? */
 726         }
 727         action = FILE_ACTION_ADDED;
 728     }
 729     else if (ie->mask & IN_DELETE)
 730         action = FILE_ACTION_REMOVED;
 731     else
 732         action = FILE_ACTION_MODIFIED;
 733
 734     /*
 735      * Work our way up the inode hierarchy
 736      *  extending the relative path as we go
 737      *  and notifying all recursive watches.
 738      */
 739     if (!prepend( &path, ie->name ))
 740         return;
 741
 742     for (i = inode; i; i = i->parent)
 743     {
 744         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 745             if ((filter & dir->filter) && (i==inode || dir->subtree))
 746                 inotify_do_change_notify( dir, action, path );
 747
 748         if (!i->name || !prepend( &path, i->name ))
 749             break;
 750     }
 751
 752     free( path );
 753
 754     if (ie->mask & IN_DELETE)
 755     {
 756         i = inode_from_name( inode, ie->name );
 757         if (i)
 758             free_inode( i );
 759     }
 760 }
 761
 762 static void inotify_poll_event( struct fd *fd, int event )
 763 {
 764     int r, ofs, unix_fd;
 765     char buffer[0x1000];
 766     struct inotify_event *ie;
 767
 768     unix_fd = get_unix_fd( fd );
 769     r = read( unix_fd, buffer, sizeof buffer );
 770     if (r < 0)
 771     {
 772         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 773         return;
 774     }
 775
 776     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 777     {
 778         ie = (struct inotify_event*) &buffer[ofs];
 779         if (!ie->len)
 780             break;
 781         ofs += offsetof( struct inotify_event, name[ie->len] );
 782         if (ofs > r) break;
 783         inotify_notify_all( ie );
 784     }
 785 }
 786
 787 static inline struct fd *create_inotify_fd( void )
 788 {
 789     int unix_fd;
 790
 791     unix_fd = inotify_init();
 792     if (unix_fd<0)
 793         return NULL;
 794     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL );
 795 }
 796
 797 static int map_flags( unsigned int filter )
 798 {
 799     unsigned int mask;
 800
 801     /* always watch these so we can track subdirectories in recursive watches */
 802     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 803
 804     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 805         mask |= IN_ATTRIB;
 806     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 807         mask |= IN_MODIFY;
 808     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 809         mask |= IN_MODIFY;
 810     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 811         mask |= IN_ACCESS;
 812     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 813         mask |= IN_ATTRIB;
 814
 815     return mask;
 816 }
 817
 818 static int inotify_add_dir( char *path, unsigned int filter )
 819 {
 820     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 821                                 path, map_flags( filter ) );
 822     if (wd != -1)
 823         set_fd_events( inotify_fd, POLLIN );
 824     return wd;
 825 }
 826
 827 static int init_inotify( void )
 828 {
 829     int i;
 830
 831     if (inotify_fd)
 832         return 1;
 833
 834     inotify_fd = create_inotify_fd();
 835     if (!inotify_fd)
 836         return 0;
 837
 838     for (i=0; i<HASH_SIZE; i++)
 839     {
 840         list_init( &inode_hash[i] );
 841         list_init( &wd_hash[i] );
 842     }
 843
 844     return 1;
 845 }
 846
 847 static int inotify_adjust_changes( struct dir *dir )
 848 {
 849     unsigned int filter;
 850     struct inode *inode;
 851     struct stat st;
 852     char path[32];
 853     int wd, unix_fd;
 854
 855     if (!inotify_fd)
 856         return 0;
 857
 858     unix_fd = get_unix_fd( dir->fd );
 859
 860     inode = dir->inode;
 861     if (!inode)
 862     {
 863         /* check if this fd is already being watched */
 864         if (-1 == fstat( unix_fd, &st ))
 865             return 0;
 866
 867         inode = get_inode( st.st_dev, st.st_ino );
 868         if (!inode)
 869             inode = create_inode( st.st_dev, st.st_ino );
 870         if (!inode)
 871             return 0;
 872         list_add_tail( &inode->dirs, &dir->in_entry );
 873         dir->inode = inode;
 874     }
 875
 876     filter = filter_from_inode( inode, 0 );
 877
 878     sprintf( path, "/proc/self/fd/%u", unix_fd );
 879     wd = inotify_add_dir( path, filter );
 880     if (wd == -1) return 0;
 881
 882     inode_set_wd( inode, wd );
 883
 884     return 1;
 885 }
 886
 887 static char *get_basename( const char *link )
 888 {
 889     char *buffer, *name = NULL;
 890     int r, n = 0x100;
 891
 892     while (1)
 893     {
 894         buffer = malloc( n );
 895         if (!buffer) return NULL;
 896
 897         r = readlink( link, buffer, n );
 898         if (r < 0)
 899             break;
 900
 901         if (r < n)
 902         {
 903             name = buffer;
 904             break;
 905         }
 906         free( buffer );
 907         n *= 2;
 908     }
 909
 910     if (name)
 911     {
 912         while (r > 0 && name[ r - 1 ] == '/' )
 913             r--;
 914         name[ r ] = 0;
 915
 916         name = strrchr( name, '/' );
 917         if (name)
 918             name = strdup( &name[1] );
 919     }
 920
 921     free( buffer );
 922     return name;
 923 }
 924
 925 static int dir_add_to_existing_notify( struct dir *dir )
 926 {
 927     struct inode *inode, *parent;
 928     unsigned int filter = 0;
 929     struct stat st, st_new;
 930     char link[35], *name;
 931     int wd, unix_fd;
 932
 933     if (!inotify_fd)
 934         return 0;
 935
 936     unix_fd = get_unix_fd( dir->fd );
 937
 938     /* check if it's in the list of inodes we want to watch */
 939     if (-1 == fstat( unix_fd, &st_new ))
 940         return 0;
 941     inode = find_inode( st_new.st_dev, st_new.st_ino );
 942     if (inode)
 943         return 0;
 944
 945     /* lookup the parent */
 946     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
 947     if (-1 == stat( link, &st ))
 948         return 0;
 949
 950     /*
 951      * If there's no parent, stop.  We could keep going adding
 952      *  ../ to the path until we hit the root of the tree or
 953      *  find a recursively watched ancestor.
 954      * Assume it's too expensive to search up the tree for now.
 955      */
 956     parent = find_inode( st.st_dev, st.st_ino );
 957     if (!parent)
 958         return 0;
 959
 960     if (parent->wd == -1)
 961         return 0;
 962
 963     filter = filter_from_inode( parent, 1 );
 964     if (!filter)
 965         return 0;
 966
 967     sprintf( link, "/proc/self/fd/%u", unix_fd );
 968     name = get_basename( link );
 969     if (!name)
 970         return 0;
 971     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
 972     free( name );
 973     if (!inode)
 974         return 0;
 975
 976     /* Couldn't find this inode at the start of the function, must be new */
 977     assert( inode->wd == -1 );
 978
 979     wd = inotify_add_dir( link, filter );
 980     if (wd != -1)
 981         inode_set_wd( inode, wd );
 982
 983     return 1;
 984 }
 985
 986 #else
 987
 988 static int init_inotify( void )
 989 {
 990     return 0;
 991 }
 992
 993 static int inotify_adjust_changes( struct dir *dir )
 994 {
 995     return 0;
 996 }
 997
 998 static void free_inode( struct inode *inode )
 999 {
1000     assert( 0 );
1001 }
1002
1003 static int dir_add_to_existing_notify( struct dir *dir )
1004 {
1005     return 0;
1006 }
1007
1008 #endif  /* USE_INOTIFY */
1009
1010 struct object *create_dir_obj( struct fd *fd )
1011 {
1012     struct dir *dir;
1013
1014     dir = alloc_object( &dir_ops );
1015     if (!dir)
1016         return NULL;
1017
1018     list_init( &dir->change_records );
1019     dir->filter = 0;
1020     dir->notified = 0;
1021     dir->want_data = 0;
1022     dir->inode = NULL;
1023     grab_object( fd );
1024     dir->fd = fd;
1025     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1026
1027     dir_add_to_existing_notify( dir );
1028
1029     return &dir->obj;
1030 }
1031
1032 /* enable change notifications for a directory */
1033 DECL_HANDLER(read_directory_changes)
1034 {
1035     struct dir *dir;
1036     struct async *async;
1037
1038     if (!req->filter)
1039     {
1040         set_error(STATUS_INVALID_PARAMETER);
1041         return;
1042     }
1043
1044     dir = get_dir_obj( current->process, req->handle, 0 );
1045     if (!dir)
1046         return;
1047
1048     /* requests don't timeout */
1049     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT, 0 ))) goto end;
1050
1051     /* assign it once */
1052     if (!dir->filter)
1053     {
1054         init_inotify();
1055         insert_change( dir );
1056         dir->filter = req->filter;
1057         dir->subtree = req->subtree;
1058         dir->want_data = req->want_data;
1059     }
1060
1061     /* if there's already a change in the queue, send it */
1062     if (!list_empty( &dir->change_records ))
1063         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1064
1065     /* setup the real notification */
1066     if (!inotify_adjust_changes( dir ))
1067         dnotify_adjust_changes( dir );
1068
1069     release_object( async );
1070     set_error(STATUS_PENDING);
1071
1072 end:
1073     release_object( dir );
1074 }
1075
1076 DECL_HANDLER(read_change)
1077 {
1078     struct change_record *record;
1079     struct dir *dir;
1080
1081     dir = get_dir_obj( current->process, req->handle, 0 );
1082     if (!dir)
1083         return;
1084
1085     if ((record = get_first_change_record( dir )) != NULL)
1086     {
1087         reply->action = record->action;
1088         set_reply_data( record->name, record->len );
1089         free( record );
1090     }
1091     else
1092         set_error( STATUS_NO_DATA_DETECTED );
1093
1094     release_object( dir );
1095 }