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_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 static void dnotify_adjust_changes( struct dir *dir )
 199 {
 200 #if defined(F_SETSIG) && defined(F_NOTIFY)
 201     int fd = get_unix_fd( dir->fd );
 202     unsigned int filter = dir->filter;
 203     unsigned int val;
 204     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 205         return;
 206
 207     val = DN_MULTISHOT;
 208     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 209         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 210     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 211         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 212     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 213         val |= DN_ATTRIB;
 214     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 215         val |= DN_MODIFY;
 216     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 217         val |= DN_MODIFY;
 218     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 219         val |= DN_ACCESS;
 220     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 221         val |= DN_CREATE;
 222     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 223         val |= DN_ATTRIB;
 224     fcntl( fd, F_NOTIFY, val );
 225 #endif
 226 }
 227
 228 /* insert change in the global list */
 229 static inline void insert_change( struct dir *dir )
 230 {
 231     sigset_t sigset;
 232
 233     sigemptyset( &sigset );
 234     sigaddset( &sigset, SIGIO );
 235     sigprocmask( SIG_BLOCK, &sigset, NULL );
 236     list_add_head( &change_list, &dir->entry );
 237     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 238 }
 239
 240 /* remove change from the global list */
 241 static inline void remove_change( struct dir *dir )
 242 {
 243     sigset_t sigset;
 244
 245     sigemptyset( &sigset );
 246     sigaddset( &sigset, SIGIO );
 247     sigprocmask( SIG_BLOCK, &sigset, NULL );
 248     list_remove( &dir->entry );
 249     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 250 }
 251
 252 static void dir_dump( struct object *obj, int verbose )
 253 {
 254     struct dir *dir = (struct dir *)obj;
 255     assert( obj->ops == &dir_ops );
 256     fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
 257 }
 258
 259 /* enter here directly from SIGIO signal handler */
 260 void do_change_notify( int unix_fd )
 261 {
 262     struct dir *dir;
 263
 264     /* FIXME: this is O(n) ... probably can be improved */
 265     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 266     {
 267         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 268         interlocked_xchg_add( &dir->notified, 1 );
 269         break;
 270     }
 271 }
 272
 273 /* SIGIO callback, called synchronously with the poll loop */
 274 void sigio_callback(void)
 275 {
 276     struct dir *dir;
 277
 278     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 279     {
 280         if (interlocked_xchg( &dir->notified, 0 ))
 281             fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
 282     }
 283 }
 284
 285 static struct fd *dir_get_fd( struct object *obj )
 286 {
 287     struct dir *dir = (struct dir *)obj;
 288     assert( obj->ops == &dir_ops );
 289     return (struct fd *)grab_object( dir->fd );
 290 }
 291
 292 static unsigned int dir_map_access( struct object *obj, unsigned int access )
 293 {
 294     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 295     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 296     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 297     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 298     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 299 }
 300
 301 static struct change_record *get_first_change_record( struct dir *dir )
 302 {
 303     struct list *ptr = list_head( &dir->change_records );
 304     if (!ptr) return NULL;
 305     list_remove( ptr );
 306     return LIST_ENTRY( ptr, struct change_record, entry );
 307 }
 308
 309 static void dir_destroy( struct object *obj )
 310 {
 311     struct change_record *record;
 312     struct dir *dir = (struct dir *)obj;
 313     assert (obj->ops == &dir_ops);
 314
 315     if (dir->filter)
 316         remove_change( dir );
 317
 318     if (dir->inode)
 319     {
 320         list_remove( &dir->in_entry );
 321         free_inode( dir->inode );
 322     }
 323
 324     while ((record = get_first_change_record( dir ))) free( record );
 325
 326     release_object( dir->fd );
 327
 328     if (inotify_fd && list_empty( &change_list ))
 329     {
 330         release_object( inotify_fd );
 331         inotify_fd = NULL;
 332     }
 333 }
 334
 335 static struct dir *
 336 get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 337 {
 338     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 339 }
 340
 341 static int dir_get_poll_events( struct fd *fd )
 342 {
 343     return 0;
 344 }
 345
 346 static enum server_fd_type dir_get_fd_type( struct fd *fd )
 347 {
 348     return FD_TYPE_DIR;
 349 }
 350
 351 #ifdef USE_INOTIFY
 352
 353 #define HASH_SIZE 31
 354
 355 struct inode {
 356     struct list ch_entry;    /* entry in the children list */
 357     struct list children;    /* children of this inode */
 358     struct inode *parent;    /* parent of this inode */
 359     struct list dirs;        /* directory handles watching this inode */
 360     struct list ino_entry;   /* entry in the inode hash */
 361     struct list wd_entry;    /* entry in the watch descriptor hash */
 362     dev_t dev;               /* device number */
 363     ino_t ino;               /* device's inode number */
 364     int wd;                  /* inotify's watch descriptor */
 365     char *name;              /* basename name of the inode */
 366 };
 367
 368 struct list inode_hash[ HASH_SIZE ];
 369 struct list wd_hash[ HASH_SIZE ];
 370
 371 static int inotify_add_dir( char *path, unsigned int filter );
 372
 373 static struct inode *inode_from_wd( int wd )
 374 {
 375     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 376     struct inode *inode;
 377
 378     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 379         if (inode->wd == wd)
 380             return inode;
 381
 382     return NULL;
 383 }
 384
 385 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 386 {
 387     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 388 }
 389
 390 static struct inode *find_inode( dev_t dev, ino_t ino )
 391 {
 392     struct list *bucket = get_hash_list( dev, ino );
 393     struct inode *inode;
 394
 395     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 396         if (inode->ino == ino && inode->dev == dev)
 397              return inode;
 398
 399     return NULL;
 400 }
 401
 402 static struct inode *create_inode( dev_t dev, ino_t ino )
 403 {
 404     struct inode *inode;
 405
 406     inode = malloc( sizeof *inode );
 407     if (inode)
 408     {
 409         list_init( &inode->children );
 410         list_init( &inode->dirs );
 411         inode->ino = ino;
 412         inode->dev = dev;
 413         inode->wd = -1;
 414         inode->parent = NULL;
 415         inode->name = NULL;
 416         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 417     }
 418     return inode;
 419 }
 420
 421 static struct inode *get_inode( dev_t dev, ino_t ino )
 422 {
 423     struct inode *inode;
 424
 425     inode = find_inode( dev, ino );
 426     if (inode)
 427         return inode;
 428     return create_inode( dev, ino );
 429 }
 430
 431 static void inode_set_wd( struct inode *inode, int wd )
 432 {
 433     if (inode->wd != -1)
 434         list_remove( &inode->wd_entry );
 435     inode->wd = wd;
 436     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 437 }
 438
 439 static void inode_set_name( struct inode *inode, const char *name )
 440 {
 441     free (inode->name);
 442     inode->name = name ? strdup( name ) : NULL;
 443 }
 444
 445 static void free_inode( struct inode *inode )
 446 {
 447     int subtree = 0, watches = 0;
 448     struct dir *dir;
 449
 450     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 451     {
 452         subtree |= dir->subtree;
 453         watches++;
 454     }
 455
 456     if (!subtree && !inode->parent)
 457     {
 458         struct inode *tmp, *next;
 459         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 460                                   struct inode, ch_entry )
 461         {
 462             assert( tmp != inode );
 463             assert( tmp->parent == inode );
 464             free_inode( tmp );
 465         }
 466     }
 467
 468     if (watches)
 469         return;
 470
 471     if (inode->parent)
 472         list_remove( &inode->ch_entry );
 473
 474     if (inode->wd != -1)
 475     {
 476         inotify_remove_watch( get_unix_fd( inotify_fd ), inode->wd );
 477         list_remove( &inode->wd_entry );
 478     }
 479     list_remove( &inode->ino_entry );
 480
 481     free( inode->name );
 482     free( inode );
 483 }
 484
 485 static struct inode *inode_add( struct inode *parent,
 486                                 dev_t dev, ino_t ino, const char *name )
 487 {
 488     struct inode *inode;
 489
 490     inode = get_inode( dev, ino );
 491     if (!inode)
 492         return NULL;
 493
 494     if (!inode->parent)
 495     {
 496         list_add_tail( &parent->children, &inode->ch_entry );
 497         inode->parent = parent;
 498         assert( inode != parent );
 499     }
 500     inode_set_name( inode, name );
 501
 502     return inode;
 503 }
 504
 505 static struct inode *inode_from_name( struct inode *inode, const char *name )
 506 {
 507     struct inode *i;
 508
 509     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 510         if (i->name && !strcmp( i->name, name ))
 511             return i;
 512     return NULL;
 513 }
 514
 515 static int inotify_get_poll_events( struct fd *fd );
 516 static void inotify_poll_event( struct fd *fd, int event );
 517
 518 static const struct fd_ops inotify_fd_ops =
 519 {
 520     inotify_get_poll_events,     /* get_poll_events */
 521     inotify_poll_event,          /* poll_event */
 522     NULL,                        /* flush */
 523     NULL,                        /* get_fd_type */
 524     NULL,                        /* ioctl */
 525     NULL,                        /* queue_async */
 526     NULL,                        /* reselect_async */
 527     NULL,                        /* cancel_async */
 528 };
 529
 530 static int inotify_get_poll_events( struct fd *fd )
 531 {
 532     return POLLIN;
 533 }
 534
 535 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 536                                       const char *relpath )
 537 {
 538     struct change_record *record;
 539
 540     assert( dir->obj.ops == &dir_ops );
 541
 542     if (dir->want_data)
 543     {
 544         size_t len = strlen(relpath);
 545         record = malloc( offsetof(struct change_record, name[len]) );
 546         if (!record)
 547             return;
 548
 549         record->action = action;
 550         memcpy( record->name, relpath, len );
 551         record->len = len;
 552
 553         list_add_tail( &dir->change_records, &record->entry );
 554     }
 555
 556     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 557 }
 558
 559 static unsigned int filter_from_event( struct inotify_event *ie )
 560 {
 561     unsigned int filter = 0;
 562
 563     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 564         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 565     if (ie->mask & IN_MODIFY)
 566         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 567     if (ie->mask & IN_ATTRIB)
 568         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 569     if (ie->mask & IN_ACCESS)
 570         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 571     if (ie->mask & IN_CREATE)
 572         filter |= FILE_NOTIFY_CHANGE_CREATION;
 573
 574     return filter;
 575 }
 576
 577 /* scan up the parent directories for watches */
 578 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 579 {
 580     unsigned int filter = 0;
 581     struct dir *dir;
 582
 583     /* combine filters from parents watching subtrees */
 584     while (inode)
 585     {
 586         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 587             if (dir->subtree || !is_parent)
 588                 filter |= dir->filter;
 589         is_parent = 1;
 590         inode = inode->parent;
 591     }
 592
 593     return filter;
 594 }
 595
 596 static char *inode_get_path( struct inode *inode, int sz )
 597 {
 598     struct list *head;
 599     char *path;
 600     int len;
 601
 602     if (!inode)
 603         return NULL;
 604
 605     head = list_head( &inode->dirs );
 606     if (head)
 607     {
 608         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 609         path = malloc ( 32 + sz );
 610         if (path)
 611             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 612         return path;
 613     }
 614
 615     if (!inode->name)
 616         return NULL;
 617
 618     len = strlen( inode->name );
 619     path = inode_get_path( inode->parent, sz + len + 1 );
 620     if (!path)
 621         return NULL;
 622
 623     strcat( path, inode->name );
 624     strcat( path, "/" );
 625
 626     return path;
 627 }
 628
 629 static int inode_check_dir( struct inode *parent, const char *name )
 630 {
 631     char *path;
 632     unsigned int filter;
 633     struct inode *inode;
 634     struct stat st;
 635     int wd = -1, r = -1;
 636
 637     path = inode_get_path( parent, strlen(name) );
 638     if (!path)
 639         return r;
 640
 641     strcat( path, name );
 642
 643     r = stat( path, &st );
 644     if (r < 0) goto end;
 645
 646     if (!S_ISDIR(st.st_mode))
 647     {
 648         r = 0;
 649         goto end;
 650     }
 651
 652     r = 1;
 653
 654     filter = filter_from_inode( parent, 1 );
 655     if (!filter)
 656         goto end;
 657
 658     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 659     if (!inode || inode->wd != -1)
 660         goto end;
 661
 662     wd = inotify_add_dir( path, filter );
 663     if (wd != -1)
 664         inode_set_wd( inode, wd );
 665     else
 666         free_inode( inode );
 667
 668 end:
 669     free( path );
 670     return r;
 671 }
 672
 673 static int prepend( char **path, const char *segment )
 674 {
 675     int extra;
 676     char *p;
 677
 678     extra = strlen( segment ) + 1;
 679     if (*path)
 680     {
 681         int len = strlen( *path ) + 1;
 682         p = realloc( *path, len + extra );
 683         if (!p) return 0;
 684         memmove( &p[ extra ], p, len );
 685         p[ extra - 1 ] = '/';
 686         memcpy( p, segment, extra - 1 );
 687     }
 688     else
 689     {
 690         p = malloc( extra );
 691         if (!p) return 0;
 692         memcpy( p, segment, extra );
 693     }
 694
 695     *path = p;
 696
 697     return 1;
 698 }
 699
 700 static void inotify_notify_all( struct inotify_event *ie )
 701 {
 702     unsigned int filter, action;
 703     struct inode *inode, *i;
 704     char *path = NULL;
 705     struct dir *dir;
 706
 707     inode = inode_from_wd( ie->wd );
 708     if (!inode)
 709     {
 710         fprintf( stderr, "no inode matches %d\n", ie->wd);
 711         return;
 712     }
 713
 714     filter = filter_from_event( ie );
 715
 716     if (ie->mask & IN_CREATE)
 717     {
 718         switch (inode_check_dir( inode, ie->name ))
 719         {
 720         case 1:
 721             filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 722             break;
 723         case 0:
 724             filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 725             break;
 726         default:
 727             break;
 728             /* Maybe the file disappeared before we could check it? */
 729         }
 730         action = FILE_ACTION_ADDED;
 731     }
 732     else if (ie->mask & IN_DELETE)
 733         action = FILE_ACTION_REMOVED;
 734     else
 735         action = FILE_ACTION_MODIFIED;
 736
 737     /*
 738      * Work our way up the inode hierarchy
 739      *  extending the relative path as we go
 740      *  and notifying all recursive watches.
 741      */
 742     if (!prepend( &path, ie->name ))
 743         return;
 744
 745     for (i = inode; i; i = i->parent)
 746     {
 747         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 748             if ((filter & dir->filter) && (i==inode || dir->subtree))
 749                 inotify_do_change_notify( dir, action, path );
 750
 751         if (!i->name || !prepend( &path, i->name ))
 752             break;
 753     }
 754
 755     free( path );
 756
 757     if (ie->mask & IN_DELETE)
 758     {
 759         i = inode_from_name( inode, ie->name );
 760         if (i)
 761             free_inode( i );
 762     }
 763 }
 764
 765 static void inotify_poll_event( struct fd *fd, int event )
 766 {
 767     int r, ofs, unix_fd;
 768     char buffer[0x1000];
 769     struct inotify_event *ie;
 770
 771     unix_fd = get_unix_fd( fd );
 772     r = read( unix_fd, buffer, sizeof buffer );
 773     if (r < 0)
 774     {
 775         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 776         return;
 777     }
 778
 779     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 780     {
 781         ie = (struct inotify_event*) &buffer[ofs];
 782         if (!ie->len)
 783             break;
 784         ofs += offsetof( struct inotify_event, name[ie->len] );
 785         if (ofs > r) break;
 786         inotify_notify_all( ie );
 787     }
 788 }
 789
 790 static inline struct fd *create_inotify_fd( void )
 791 {
 792     int unix_fd;
 793
 794     unix_fd = inotify_init();
 795     if (unix_fd<0)
 796         return NULL;
 797     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
 798 }
 799
 800 static int map_flags( unsigned int filter )
 801 {
 802     unsigned int mask;
 803
 804     /* always watch these so we can track subdirectories in recursive watches */
 805     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 806
 807     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 808         mask |= IN_ATTRIB;
 809     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 810         mask |= IN_MODIFY;
 811     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 812         mask |= IN_MODIFY;
 813     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 814         mask |= IN_ACCESS;
 815     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 816         mask |= IN_ATTRIB;
 817
 818     return mask;
 819 }
 820
 821 static int inotify_add_dir( char *path, unsigned int filter )
 822 {
 823     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 824                                 path, map_flags( filter ) );
 825     if (wd != -1)
 826         set_fd_events( inotify_fd, POLLIN );
 827     return wd;
 828 }
 829
 830 static int init_inotify( void )
 831 {
 832     int i;
 833
 834     if (inotify_fd)
 835         return 1;
 836
 837     inotify_fd = create_inotify_fd();
 838     if (!inotify_fd)
 839         return 0;
 840
 841     for (i=0; i<HASH_SIZE; i++)
 842     {
 843         list_init( &inode_hash[i] );
 844         list_init( &wd_hash[i] );
 845     }
 846
 847     return 1;
 848 }
 849
 850 static int inotify_adjust_changes( struct dir *dir )
 851 {
 852     unsigned int filter;
 853     struct inode *inode;
 854     struct stat st;
 855     char path[32];
 856     int wd, unix_fd;
 857
 858     if (!inotify_fd)
 859         return 0;
 860
 861     unix_fd = get_unix_fd( dir->fd );
 862
 863     inode = dir->inode;
 864     if (!inode)
 865     {
 866         /* check if this fd is already being watched */
 867         if (-1 == fstat( unix_fd, &st ))
 868             return 0;
 869
 870         inode = get_inode( st.st_dev, st.st_ino );
 871         if (!inode)
 872             inode = create_inode( st.st_dev, st.st_ino );
 873         if (!inode)
 874             return 0;
 875         list_add_tail( &inode->dirs, &dir->in_entry );
 876         dir->inode = inode;
 877     }
 878
 879     filter = filter_from_inode( inode, 0 );
 880
 881     sprintf( path, "/proc/self/fd/%u", unix_fd );
 882     wd = inotify_add_dir( path, filter );
 883     if (wd == -1) return 0;
 884
 885     inode_set_wd( inode, wd );
 886
 887     return 1;
 888 }
 889
 890 static char *get_basename( const char *link )
 891 {
 892     char *buffer, *name = NULL;
 893     int r, n = 0x100;
 894
 895     while (1)
 896     {
 897         buffer = malloc( n );
 898         if (!buffer) return NULL;
 899
 900         r = readlink( link, buffer, n );
 901         if (r < 0)
 902             break;
 903
 904         if (r < n)
 905         {
 906             name = buffer;
 907             break;
 908         }
 909         free( buffer );
 910         n *= 2;
 911     }
 912
 913     if (name)
 914     {
 915         while (r > 0 && name[ r - 1 ] == '/' )
 916             r--;
 917         name[ r ] = 0;
 918
 919         name = strrchr( name, '/' );
 920         if (name)
 921             name = strdup( &name[1] );
 922     }
 923
 924     free( buffer );
 925     return name;
 926 }
 927
 928 static int dir_add_to_existing_notify( struct dir *dir )
 929 {
 930     struct inode *inode, *parent;
 931     unsigned int filter = 0;
 932     struct stat st, st_new;
 933     char link[35], *name;
 934     int wd, unix_fd;
 935
 936     if (!inotify_fd)
 937         return 0;
 938
 939     unix_fd = get_unix_fd( dir->fd );
 940
 941     /* check if it's in the list of inodes we want to watch */
 942     if (-1 == fstat( unix_fd, &st_new ))
 943         return 0;
 944     inode = find_inode( st_new.st_dev, st_new.st_ino );
 945     if (inode)
 946         return 0;
 947
 948     /* lookup the parent */
 949     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
 950     if (-1 == stat( link, &st ))
 951         return 0;
 952
 953     /*
 954      * If there's no parent, stop.  We could keep going adding
 955      *  ../ to the path until we hit the root of the tree or
 956      *  find a recursively watched ancestor.
 957      * Assume it's too expensive to search up the tree for now.
 958      */
 959     parent = find_inode( st.st_dev, st.st_ino );
 960     if (!parent)
 961         return 0;
 962
 963     if (parent->wd == -1)
 964         return 0;
 965
 966     filter = filter_from_inode( parent, 1 );
 967     if (!filter)
 968         return 0;
 969
 970     sprintf( link, "/proc/self/fd/%u", unix_fd );
 971     name = get_basename( link );
 972     if (!name)
 973         return 0;
 974     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
 975     free( name );
 976     if (!inode)
 977         return 0;
 978
 979     /* Couldn't find this inode at the start of the function, must be new */
 980     assert( inode->wd == -1 );
 981
 982     wd = inotify_add_dir( link, filter );
 983     if (wd != -1)
 984         inode_set_wd( inode, wd );
 985
 986     return 1;
 987 }
 988
 989 #else
 990
 991 static int init_inotify( void )
 992 {
 993     return 0;
 994 }
 995
 996 static int inotify_adjust_changes( struct dir *dir )
 997 {
 998     return 0;
 999 }
1000
1001 static void free_inode( struct inode *inode )
1002 {
1003     assert( 0 );
1004 }
1005
1006 static int dir_add_to_existing_notify( struct dir *dir )
1007 {
1008     return 0;
1009 }
1010
1011 #endif  /* USE_INOTIFY */
1012
1013 struct object *create_dir_obj( struct fd *fd )
1014 {
1015     struct dir *dir;
1016
1017     dir = alloc_object( &dir_ops );
1018     if (!dir)
1019         return NULL;
1020
1021     list_init( &dir->change_records );
1022     dir->filter = 0;
1023     dir->notified = 0;
1024     dir->want_data = 0;
1025     dir->inode = NULL;
1026     grab_object( fd );
1027     dir->fd = fd;
1028     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1029
1030     dir_add_to_existing_notify( dir );
1031
1032     return &dir->obj;
1033 }
1034
1035 /* enable change notifications for a directory */
1036 DECL_HANDLER(read_directory_changes)
1037 {
1038     struct dir *dir;
1039     struct async *async;
1040
1041     if (!req->filter)
1042     {
1043         set_error(STATUS_INVALID_PARAMETER);
1044         return;
1045     }
1046
1047     dir = get_dir_obj( current->process, req->handle, 0 );
1048     if (!dir)
1049         return;
1050
1051     /* requests don't timeout */
1052     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT, 0 ))) goto end;
1053
1054     /* assign it once */
1055     if (!dir->filter)
1056     {
1057         init_inotify();
1058         insert_change( dir );
1059         dir->filter = req->filter;
1060         dir->subtree = req->subtree;
1061         dir->want_data = req->want_data;
1062     }
1063
1064     /* if there's already a change in the queue, send it */
1065     if (!list_empty( &dir->change_records ))
1066         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1067
1068     /* setup the real notification */
1069     if (!inotify_adjust_changes( dir ))
1070         dnotify_adjust_changes( dir );
1071
1072     release_object( async );
1073     set_error(STATUS_PENDING);
1074
1075 end:
1076     release_object( dir );
1077 }
1078
1079 DECL_HANDLER(read_change)
1080 {
1081     struct change_record *record;
1082     struct dir *dir;
1083
1084     dir = get_dir_obj( current->process, req->handle, 0 );
1085     if (!dir)
1086         return;
1087
1088     if ((record = get_first_change_record( dir )) != NULL)
1089     {
1090         reply->action = record->action;
1091         set_reply_data( record->name, record->len );
1092         free( record );
1093     }
1094     else
1095         set_error( STATUS_NO_DATA_DETECTED );
1096
1097     release_object( dir );
1098 }