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_fd_type( struct fd *fd );
 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_fd_type,             /* get_fd_type */
 190     default_fd_queue_async,      /* queue_async */
 191     default_fd_reselect_async,   /* reselect_async */
 192     default_fd_cancel_async      /* cancel_async */
 193 };
 194
 195 static struct list change_list = LIST_INIT(change_list);
 196
 197 static void dnotify_adjust_changes( struct dir *dir )
 198 {
 199 #if defined(F_SETSIG) && defined(F_NOTIFY)
 200     int fd = get_unix_fd( dir->fd );
 201     unsigned int filter = dir->filter;
 202     unsigned int val;
 203     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 204         return;
 205
 206     val = DN_MULTISHOT;
 207     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 208         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 209     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 210         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 211     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 212         val |= DN_ATTRIB;
 213     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 214         val |= DN_MODIFY;
 215     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 216         val |= DN_MODIFY;
 217     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 218         val |= DN_ACCESS;
 219     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 220         val |= DN_CREATE;
 221     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 222         val |= DN_ATTRIB;
 223     fcntl( fd, F_NOTIFY, val );
 224 #endif
 225 }
 226
 227 /* insert change in the global list */
 228 static inline void insert_change( struct dir *dir )
 229 {
 230     sigset_t sigset;
 231
 232     sigemptyset( &sigset );
 233     sigaddset( &sigset, SIGIO );
 234     sigprocmask( SIG_BLOCK, &sigset, NULL );
 235     list_add_head( &change_list, &dir->entry );
 236     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 237 }
 238
 239 /* remove change from the global list */
 240 static inline void remove_change( struct dir *dir )
 241 {
 242     sigset_t sigset;
 243
 244     sigemptyset( &sigset );
 245     sigaddset( &sigset, SIGIO );
 246     sigprocmask( SIG_BLOCK, &sigset, NULL );
 247     list_remove( &dir->entry );
 248     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 249 }
 250
 251 static void dir_dump( struct object *obj, int verbose )
 252 {
 253     struct dir *dir = (struct dir *)obj;
 254     assert( obj->ops == &dir_ops );
 255     fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
 256 }
 257
 258 /* enter here directly from SIGIO signal handler */
 259 void do_change_notify( int unix_fd )
 260 {
 261     struct dir *dir;
 262
 263     /* FIXME: this is O(n) ... probably can be improved */
 264     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 265     {
 266         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 267         interlocked_xchg_add( &dir->notified, 1 );
 268         break;
 269     }
 270 }
 271
 272 /* SIGIO callback, called synchronously with the poll loop */
 273 void sigio_callback(void)
 274 {
 275     struct dir *dir;
 276
 277     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 278     {
 279         if (interlocked_xchg( &dir->notified, 0 ))
 280             fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
 281     }
 282 }
 283
 284 static struct fd *dir_get_fd( struct object *obj )
 285 {
 286     struct dir *dir = (struct dir *)obj;
 287     assert( obj->ops == &dir_ops );
 288     return (struct fd *)grab_object( dir->fd );
 289 }
 290
 291 static unsigned int dir_map_access( struct object *obj, unsigned int access )
 292 {
 293     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 294     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 295     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 296     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 297     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 298 }
 299
 300 static struct change_record *get_first_change_record( struct dir *dir )
 301 {
 302     struct list *ptr = list_head( &dir->change_records );
 303     if (!ptr) return NULL;
 304     list_remove( ptr );
 305     return LIST_ENTRY( ptr, struct change_record, entry );
 306 }
 307
 308 static void dir_destroy( struct object *obj )
 309 {
 310     struct change_record *record;
 311     struct dir *dir = (struct dir *)obj;
 312     assert (obj->ops == &dir_ops);
 313
 314     if (dir->filter)
 315         remove_change( dir );
 316
 317     if (dir->inode)
 318     {
 319         list_remove( &dir->in_entry );
 320         free_inode( dir->inode );
 321     }
 322
 323     while ((record = get_first_change_record( dir ))) free( record );
 324
 325     release_object( dir->fd );
 326
 327     if (inotify_fd && list_empty( &change_list ))
 328     {
 329         release_object( inotify_fd );
 330         inotify_fd = NULL;
 331     }
 332 }
 333
 334 static struct dir *
 335 get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 336 {
 337     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 338 }
 339
 340 static int dir_get_poll_events( struct fd *fd )
 341 {
 342     return 0;
 343 }
 344
 345 static enum server_fd_type dir_get_fd_type( struct fd *fd )
 346 {
 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     NULL,                        /* flush */
 522     NULL,                        /* get_fd_type */
 523     NULL,                        /* queue_async */
 524     NULL,                        /* reselect_async */
 525     NULL,                        /* cancel_async */
 526 };
 527
 528 static int inotify_get_poll_events( struct fd *fd )
 529 {
 530     return POLLIN;
 531 }
 532
 533 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 534                                       const char *relpath )
 535 {
 536     struct change_record *record;
 537
 538     assert( dir->obj.ops == &dir_ops );
 539
 540     if (dir->want_data)
 541     {
 542         size_t len = strlen(relpath);
 543         record = malloc( offsetof(struct change_record, name[len]) );
 544         if (!record)
 545             return;
 546
 547         record->action = action;
 548         memcpy( record->name, relpath, len );
 549         record->len = len;
 550
 551         list_add_tail( &dir->change_records, &record->entry );
 552     }
 553
 554     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 555 }
 556
 557 static unsigned int filter_from_event( struct inotify_event *ie )
 558 {
 559     unsigned int filter = 0;
 560
 561     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 562         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 563     if (ie->mask & IN_MODIFY)
 564         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 565     if (ie->mask & IN_ATTRIB)
 566         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 567     if (ie->mask & IN_ACCESS)
 568         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 569     if (ie->mask & IN_CREATE)
 570         filter |= FILE_NOTIFY_CHANGE_CREATION;
 571
 572     return filter;
 573 }
 574
 575 /* scan up the parent directories for watches */
 576 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 577 {
 578     unsigned int filter = 0;
 579     struct dir *dir;
 580
 581     /* combine filters from parents watching subtrees */
 582     while (inode)
 583     {
 584         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 585             if (dir->subtree || !is_parent)
 586                 filter |= dir->filter;
 587         is_parent = 1;
 588         inode = inode->parent;
 589     }
 590
 591     return filter;
 592 }
 593
 594 static char *inode_get_path( struct inode *inode, int sz )
 595 {
 596     struct list *head;
 597     char *path;
 598     int len;
 599
 600     if (!inode)
 601         return NULL;
 602
 603     head = list_head( &inode->dirs );
 604     if (head)
 605     {
 606         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 607         path = malloc ( 32 + sz );
 608         if (path)
 609             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 610         return path;
 611     }
 612
 613     if (!inode->name)
 614         return NULL;
 615
 616     len = strlen( inode->name );
 617     path = inode_get_path( inode->parent, sz + len + 1 );
 618     if (!path)
 619         return NULL;
 620
 621     strcat( path, inode->name );
 622     strcat( path, "/" );
 623
 624     return path;
 625 }
 626
 627 static int inode_check_dir( struct inode *parent, const char *name )
 628 {
 629     char *path;
 630     unsigned int filter;
 631     struct inode *inode;
 632     struct stat st;
 633     int wd = -1, r = -1;
 634
 635     path = inode_get_path( parent, strlen(name) );
 636     if (!path)
 637         return r;
 638
 639     strcat( path, name );
 640
 641     r = stat( path, &st );
 642     if (r < 0) goto end;
 643
 644     if (!S_ISDIR(st.st_mode))
 645     {
 646         r = 0;
 647         goto end;
 648     }
 649
 650     r = 1;
 651
 652     filter = filter_from_inode( parent, 1 );
 653     if (!filter)
 654         goto end;
 655
 656     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 657     if (!inode || inode->wd != -1)
 658         goto end;
 659
 660     wd = inotify_add_dir( path, filter );
 661     if (wd != -1)
 662         inode_set_wd( inode, wd );
 663     else
 664         free_inode( inode );
 665
 666 end:
 667     free( path );
 668     return r;
 669 }
 670
 671 static int prepend( char **path, const char *segment )
 672 {
 673     int extra;
 674     char *p;
 675
 676     extra = strlen( segment ) + 1;
 677     if (*path)
 678     {
 679         int len = strlen( *path ) + 1;
 680         p = realloc( *path, len + extra );
 681         if (!p) return 0;
 682         memmove( &p[ extra ], p, len );
 683         p[ extra - 1 ] = '/';
 684         memcpy( p, segment, extra - 1 );
 685     }
 686     else
 687     {
 688         p = malloc( extra );
 689         if (!p) return 0;
 690         memcpy( p, segment, extra );
 691     }
 692
 693     *path = p;
 694
 695     return 1;
 696 }
 697
 698 static void inotify_notify_all( struct inotify_event *ie )
 699 {
 700     unsigned int filter, action;
 701     struct inode *inode, *i;
 702     char *path = NULL;
 703     struct dir *dir;
 704
 705     inode = inode_from_wd( ie->wd );
 706     if (!inode)
 707     {
 708         fprintf( stderr, "no inode matches %d\n", ie->wd);
 709         return;
 710     }
 711
 712     filter = filter_from_event( ie );
 713
 714     if (ie->mask & IN_CREATE)
 715     {
 716         switch (inode_check_dir( inode, ie->name ))
 717         {
 718         case 1:
 719             filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 720             break;
 721         case 0:
 722             filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 723             break;
 724         default:
 725             break;
 726             /* Maybe the file disappeared before we could check it? */
 727         }
 728         action = FILE_ACTION_ADDED;
 729     }
 730     else if (ie->mask & IN_DELETE)
 731         action = FILE_ACTION_REMOVED;
 732     else
 733         action = FILE_ACTION_MODIFIED;
 734
 735     /*
 736      * Work our way up the inode hierarchy
 737      *  extending the relative path as we go
 738      *  and notifying all recursive watches.
 739      */
 740     if (!prepend( &path, ie->name ))
 741         return;
 742
 743     for (i = inode; i; i = i->parent)
 744     {
 745         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 746             if ((filter & dir->filter) && (i==inode || dir->subtree))
 747                 inotify_do_change_notify( dir, action, path );
 748
 749         if (!i->name || !prepend( &path, i->name ))
 750             break;
 751     }
 752
 753     free( path );
 754
 755     if (ie->mask & IN_DELETE)
 756     {
 757         i = inode_from_name( inode, ie->name );
 758         if (i)
 759             free_inode( i );
 760     }
 761 }
 762
 763 static void inotify_poll_event( struct fd *fd, int event )
 764 {
 765     int r, ofs, unix_fd;
 766     char buffer[0x1000];
 767     struct inotify_event *ie;
 768
 769     unix_fd = get_unix_fd( fd );
 770     r = read( unix_fd, buffer, sizeof buffer );
 771     if (r < 0)
 772     {
 773         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 774         return;
 775     }
 776
 777     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 778     {
 779         ie = (struct inotify_event*) &buffer[ofs];
 780         if (!ie->len)
 781             break;
 782         ofs += offsetof( struct inotify_event, name[ie->len] );
 783         if (ofs > r) break;
 784         inotify_notify_all( ie );
 785     }
 786 }
 787
 788 static inline struct fd *create_inotify_fd( void )
 789 {
 790     int unix_fd;
 791
 792     unix_fd = inotify_init();
 793     if (unix_fd<0)
 794         return NULL;
 795     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
 796 }
 797
 798 static int map_flags( unsigned int filter )
 799 {
 800     unsigned int mask;
 801
 802     /* always watch these so we can track subdirectories in recursive watches */
 803     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 804
 805     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 806         mask |= IN_ATTRIB;
 807     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 808         mask |= IN_MODIFY;
 809     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 810         mask |= IN_MODIFY;
 811     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 812         mask |= IN_ACCESS;
 813     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 814         mask |= IN_ATTRIB;
 815
 816     return mask;
 817 }
 818
 819 static int inotify_add_dir( char *path, unsigned int filter )
 820 {
 821     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 822                                 path, map_flags( filter ) );
 823     if (wd != -1)
 824         set_fd_events( inotify_fd, POLLIN );
 825     return wd;
 826 }
 827
 828 static int init_inotify( void )
 829 {
 830     int i;
 831
 832     if (inotify_fd)
 833         return 1;
 834
 835     inotify_fd = create_inotify_fd();
 836     if (!inotify_fd)
 837         return 0;
 838
 839     for (i=0; i<HASH_SIZE; i++)
 840     {
 841         list_init( &inode_hash[i] );
 842         list_init( &wd_hash[i] );
 843     }
 844
 845     return 1;
 846 }
 847
 848 static int inotify_adjust_changes( struct dir *dir )
 849 {
 850     unsigned int filter;
 851     struct inode *inode;
 852     struct stat st;
 853     char path[32];
 854     int wd, unix_fd;
 855
 856     if (!inotify_fd)
 857         return 0;
 858
 859     unix_fd = get_unix_fd( dir->fd );
 860
 861     inode = dir->inode;
 862     if (!inode)
 863     {
 864         /* check if this fd is already being watched */
 865         if (-1 == fstat( unix_fd, &st ))
 866             return 0;
 867
 868         inode = get_inode( st.st_dev, st.st_ino );
 869         if (!inode)
 870             inode = create_inode( st.st_dev, st.st_ino );
 871         if (!inode)
 872             return 0;
 873         list_add_tail( &inode->dirs, &dir->in_entry );
 874         dir->inode = inode;
 875     }
 876
 877     filter = filter_from_inode( inode, 0 );
 878
 879     sprintf( path, "/proc/self/fd/%u", unix_fd );
 880     wd = inotify_add_dir( path, filter );
 881     if (wd == -1) return 0;
 882
 883     inode_set_wd( inode, wd );
 884
 885     return 1;
 886 }
 887
 888 static char *get_basename( const char *link )
 889 {
 890     char *buffer, *name = NULL;
 891     int r, n = 0x100;
 892
 893     while (1)
 894     {
 895         buffer = malloc( n );
 896         if (!buffer) return NULL;
 897
 898         r = readlink( link, buffer, n );
 899         if (r < 0)
 900             break;
 901
 902         if (r < n)
 903         {
 904             name = buffer;
 905             break;
 906         }
 907         free( buffer );
 908         n *= 2;
 909     }
 910
 911     if (name)
 912     {
 913         while (r > 0 && name[ r - 1 ] == '/' )
 914             r--;
 915         name[ r ] = 0;
 916
 917         name = strrchr( name, '/' );
 918         if (name)
 919             name = strdup( &name[1] );
 920     }
 921
 922     free( buffer );
 923     return name;
 924 }
 925
 926 static int dir_add_to_existing_notify( struct dir *dir )
 927 {
 928     struct inode *inode, *parent;
 929     unsigned int filter = 0;
 930     struct stat st, st_new;
 931     char link[35], *name;
 932     int wd, unix_fd;
 933
 934     if (!inotify_fd)
 935         return 0;
 936
 937     unix_fd = get_unix_fd( dir->fd );
 938
 939     /* check if it's in the list of inodes we want to watch */
 940     if (-1 == fstat( unix_fd, &st_new ))
 941         return 0;
 942     inode = find_inode( st_new.st_dev, st_new.st_ino );
 943     if (inode)
 944         return 0;
 945
 946     /* lookup the parent */
 947     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
 948     if (-1 == stat( link, &st ))
 949         return 0;
 950
 951     /*
 952      * If there's no parent, stop.  We could keep going adding
 953      *  ../ to the path until we hit the root of the tree or
 954      *  find a recursively watched ancestor.
 955      * Assume it's too expensive to search up the tree for now.
 956      */
 957     parent = find_inode( st.st_dev, st.st_ino );
 958     if (!parent)
 959         return 0;
 960
 961     if (parent->wd == -1)
 962         return 0;
 963
 964     filter = filter_from_inode( parent, 1 );
 965     if (!filter)
 966         return 0;
 967
 968     sprintf( link, "/proc/self/fd/%u", unix_fd );
 969     name = get_basename( link );
 970     if (!name)
 971         return 0;
 972     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
 973     free( name );
 974     if (!inode)
 975         return 0;
 976
 977     /* Couldn't find this inode at the start of the function, must be new */
 978     assert( inode->wd == -1 );
 979
 980     wd = inotify_add_dir( link, filter );
 981     if (wd != -1)
 982         inode_set_wd( inode, wd );
 983
 984     return 1;
 985 }
 986
 987 #else
 988
 989 static int init_inotify( void )
 990 {
 991     return 0;
 992 }
 993
 994 static int inotify_adjust_changes( struct dir *dir )
 995 {
 996     return 0;
 997 }
 998
 999 static void free_inode( struct inode *inode )
1000 {
1001     assert( 0 );
1002 }
1003
1004 static int dir_add_to_existing_notify( struct dir *dir )
1005 {
1006     return 0;
1007 }
1008
1009 #endif  /* USE_INOTIFY */
1010
1011 struct object *create_dir_obj( struct fd *fd )
1012 {
1013     struct dir *dir;
1014
1015     dir = alloc_object( &dir_ops );
1016     if (!dir)
1017         return NULL;
1018
1019     list_init( &dir->change_records );
1020     dir->filter = 0;
1021     dir->notified = 0;
1022     dir->want_data = 0;
1023     dir->inode = NULL;
1024     grab_object( fd );
1025     dir->fd = fd;
1026     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1027
1028     dir_add_to_existing_notify( dir );
1029
1030     return &dir->obj;
1031 }
1032
1033 /* enable change notifications for a directory */
1034 DECL_HANDLER(read_directory_changes)
1035 {
1036     struct dir *dir;
1037     struct async *async;
1038
1039     if (!req->filter)
1040     {
1041         set_error(STATUS_INVALID_PARAMETER);
1042         return;
1043     }
1044
1045     dir = get_dir_obj( current->process, req->handle, 0 );
1046     if (!dir)
1047         return;
1048
1049     /* requests don't timeout */
1050     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT, 0 ))) goto end;
1051
1052     /* assign it once */
1053     if (!dir->filter)
1054     {
1055         init_inotify();
1056         insert_change( dir );
1057         dir->filter = req->filter;
1058         dir->subtree = req->subtree;
1059         dir->want_data = req->want_data;
1060     }
1061
1062     /* if there's already a change in the queue, send it */
1063     if (!list_empty( &dir->change_records ))
1064         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1065
1066     /* setup the real notification */
1067     if (!inotify_adjust_changes( dir ))
1068         dnotify_adjust_changes( dir );
1069
1070     release_object( async );
1071     set_error(STATUS_PENDING);
1072
1073 end:
1074     release_object( dir );
1075 }
1076
1077 DECL_HANDLER(read_change)
1078 {
1079     struct change_record *record;
1080     struct dir *dir;
1081
1082     dir = get_dir_obj( current->process, req->handle, 0 );
1083     if (!dir)
1084         return;
1085
1086     if ((record = get_first_change_record( dir )) != NULL)
1087     {
1088         reply->action = record->action;
1089         set_reply_data( record->name, record->len );
1090         free( record );
1091     }
1092     else
1093         set_error( STATUS_NO_DATA_DETECTED );
1094
1095     release_object( dir );
1096 }