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     struct event  *event;
 151     unsigned int   filter;   /* notification filter */
 152     int            notified; /* SIGIO counter */
 153     int            want_data; /* return change data */
 154     long           signaled; /* the file changed */
 155     int            subtree;  /* do we want to watch subdirectories? */
 156     struct list    change_records;   /* data for the change */
 157     struct list    in_entry; /* entry in the inode dirs list */
 158     struct inode  *inode;    /* inode of the associated directory */
 159 };
 160
 161 static struct fd *dir_get_fd( struct object *obj );
 162 static unsigned int dir_map_access( struct object *obj, unsigned int access );
 163 static void dir_dump( struct object *obj, int verbose );
 164 static void dir_destroy( struct object *obj );
 165 static int dir_signaled( struct object *obj, struct thread *thread );
 166
 167 static const struct object_ops dir_ops =
 168 {
 169     sizeof(struct dir),       /* size */
 170     dir_dump,                 /* dump */
 171     add_queue,                /* add_queue */
 172     remove_queue,             /* remove_queue */
 173     dir_signaled,             /* signaled */
 174     no_satisfied,             /* satisfied */
 175     no_signal,                /* signal */
 176     dir_get_fd,               /* get_fd */
 177     dir_map_access,           /* map_access */
 178     no_lookup_name,           /* lookup_name */
 179     no_open_file,             /* open_file */
 180     fd_close_handle,          /* close_handle */
 181     dir_destroy               /* destroy */
 182 };
 183
 184 static int dir_get_poll_events( struct fd *fd );
 185 static enum server_fd_type dir_get_info( struct fd *fd, int *flags );
 186
 187 static const struct fd_ops dir_fd_ops =
 188 {
 189     dir_get_poll_events,      /* get_poll_events */
 190     default_poll_event,       /* poll_event */
 191     no_flush,                 /* flush */
 192     dir_get_info,             /* get_file_info */
 193     default_fd_queue_async,   /* queue_async */
 194     default_fd_cancel_async   /* cancel_async */
 195 };
 196
 197 static struct list change_list = LIST_INIT(change_list);
 198
 199 static void dnotify_adjust_changes( struct dir *dir )
 200 {
 201 #if defined(F_SETSIG) && defined(F_NOTIFY)
 202     int fd = get_unix_fd( dir->fd );
 203     unsigned int filter = dir->filter;
 204     unsigned int val;
 205     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 206         return;
 207
 208     val = DN_MULTISHOT;
 209     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 210         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 211     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 212         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 213     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 214         val |= DN_ATTRIB;
 215     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 216         val |= DN_MODIFY;
 217     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 218         val |= DN_MODIFY;
 219     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 220         val |= DN_ACCESS;
 221     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 222         val |= DN_CREATE;
 223     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 224         val |= DN_ATTRIB;
 225     fcntl( fd, F_NOTIFY, val );
 226 #endif
 227 }
 228
 229 /* insert change in the global list */
 230 static inline void insert_change( struct dir *dir )
 231 {
 232     sigset_t sigset;
 233
 234     sigemptyset( &sigset );
 235     sigaddset( &sigset, SIGIO );
 236     sigprocmask( SIG_BLOCK, &sigset, NULL );
 237     list_add_head( &change_list, &dir->entry );
 238     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 239 }
 240
 241 /* remove change from the global list */
 242 static inline void remove_change( struct dir *dir )
 243 {
 244     sigset_t sigset;
 245
 246     sigemptyset( &sigset );
 247     sigaddset( &sigset, SIGIO );
 248     sigprocmask( SIG_BLOCK, &sigset, NULL );
 249     list_remove( &dir->entry );
 250     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 251 }
 252
 253 static void dir_dump( struct object *obj, int verbose )
 254 {
 255     struct dir *dir = (struct dir *)obj;
 256     assert( obj->ops == &dir_ops );
 257     fprintf( stderr, "Dirfile fd=%p event=%p filter=%08x\n",
 258              dir->fd, dir->event, dir->filter );
 259 }
 260
 261 static int dir_signaled( struct object *obj, struct thread *thread )
 262 {
 263     struct dir *dir = (struct dir *)obj;
 264     assert (obj->ops == &dir_ops);
 265     return (dir->event == NULL) && dir->signaled;
 266 }
 267
 268 /* enter here directly from SIGIO signal handler */
 269 void do_change_notify( int unix_fd )
 270 {
 271     struct dir *dir;
 272
 273     /* FIXME: this is O(n) ... probably can be improved */
 274     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 275     {
 276         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 277         interlocked_xchg_add( &dir->notified, 1 );
 278         break;
 279     }
 280 }
 281
 282 static void dir_signal_changed( struct dir *dir )
 283 {
 284     if (!dir->event) wake_up( &dir->obj, 0 );
 285 }
 286
 287 /* SIGIO callback, called synchronously with the poll loop */
 288 void sigio_callback(void)
 289 {
 290     struct dir *dir;
 291
 292     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 293     {
 294         long count = interlocked_xchg( &dir->notified, 0 );
 295         if (count)
 296         {
 297             dir->signaled += count;
 298             if (dir->signaled == count)  /* was it 0? */
 299                 dir_signal_changed( dir );
 300         }
 301     }
 302 }
 303
 304 static struct fd *dir_get_fd( struct object *obj )
 305 {
 306     struct dir *dir = (struct dir *)obj;
 307     assert( obj->ops == &dir_ops );
 308     return (struct fd *)grab_object( dir->fd );
 309 }
 310
 311 static unsigned int dir_map_access( struct object *obj, unsigned int access )
 312 {
 313     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 314     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 315     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 316     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 317     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 318 }
 319
 320 static struct change_record *get_first_change_record( struct dir *dir )
 321 {
 322     struct list *ptr = list_head( &dir->change_records );
 323     if (!ptr) return NULL;
 324     list_remove( ptr );
 325     return LIST_ENTRY( ptr, struct change_record, entry );
 326 }
 327
 328 static void dir_destroy( struct object *obj )
 329 {
 330     struct change_record *record;
 331     struct dir *dir = (struct dir *)obj;
 332     assert (obj->ops == &dir_ops);
 333
 334     if (dir->filter)
 335         remove_change( dir );
 336
 337     if (dir->inode)
 338     {
 339         list_remove( &dir->in_entry );
 340         free_inode( dir->inode );
 341     }
 342
 343     while ((record = get_first_change_record( dir ))) free( record );
 344
 345     if (dir->event) release_object( dir->event );
 346     release_object( dir->fd );
 347
 348     if (inotify_fd && list_empty( &change_list ))
 349     {
 350         release_object( inotify_fd );
 351         inotify_fd = NULL;
 352     }
 353 }
 354
 355 static struct dir *
 356 get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 357 {
 358     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 359 }
 360
 361 static int dir_get_poll_events( struct fd *fd )
 362 {
 363     return 0;
 364 }
 365
 366 static enum server_fd_type dir_get_info( struct fd *fd, int *flags )
 367 {
 368     *flags = 0;
 369     return FD_TYPE_DIR;
 370 }
 371
 372 #ifdef USE_INOTIFY
 373
 374 #define HASH_SIZE 31
 375
 376 struct inode {
 377     struct list ch_entry;    /* entry in the children list */
 378     struct list children;    /* children of this inode */
 379     struct inode *parent;    /* parent of this inode */
 380     struct list dirs;        /* directory handles watching this inode */
 381     struct list ino_entry;   /* entry in the inode hash */
 382     struct list wd_entry;    /* entry in the watch descriptor hash */
 383     dev_t dev;               /* device number */
 384     ino_t ino;               /* device's inode number */
 385     int wd;                  /* inotify's watch descriptor */
 386     char *name;              /* basename name of the inode */
 387 };
 388
 389 struct list inode_hash[ HASH_SIZE ];
 390 struct list wd_hash[ HASH_SIZE ];
 391
 392 static int inotify_add_dir( char *path, unsigned int filter );
 393
 394 static struct inode *inode_from_wd( int wd )
 395 {
 396     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 397     struct inode *inode;
 398
 399     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 400         if (inode->wd == wd)
 401             return inode;
 402
 403     return NULL;
 404 }
 405
 406 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 407 {
 408     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 409 }
 410
 411 static struct inode *find_inode( dev_t dev, ino_t ino )
 412 {
 413     struct list *bucket = get_hash_list( dev, ino );
 414     struct inode *inode;
 415
 416     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 417         if (inode->ino == ino && inode->dev == dev)
 418              return inode;
 419
 420     return NULL;
 421 }
 422
 423 static struct inode *create_inode( dev_t dev, ino_t ino )
 424 {
 425     struct inode *inode;
 426
 427     inode = malloc( sizeof *inode );
 428     if (inode)
 429     {
 430         list_init( &inode->children );
 431         list_init( &inode->dirs );
 432         inode->ino = ino;
 433         inode->dev = dev;
 434         inode->wd = -1;
 435         inode->parent = NULL;
 436         inode->name = NULL;
 437         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 438     }
 439     return inode;
 440 }
 441
 442 static struct inode *get_inode( dev_t dev, ino_t ino )
 443 {
 444     struct inode *inode;
 445
 446     inode = find_inode( dev, ino );
 447     if (inode)
 448         return inode;
 449     return create_inode( dev, ino );
 450 }
 451
 452 static void inode_set_wd( struct inode *inode, int wd )
 453 {
 454     if (inode->wd != -1)
 455         list_remove( &inode->wd_entry );
 456     inode->wd = wd;
 457     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 458 }
 459
 460 static void inode_set_name( struct inode *inode, const char *name )
 461 {
 462     free (inode->name);
 463     inode->name = name ? strdup( name ) : NULL;
 464 }
 465
 466 static void free_inode( struct inode *inode )
 467 {
 468     int subtree = 0, watches = 0;
 469     struct dir *dir;
 470
 471     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 472     {
 473         subtree |= dir->subtree;
 474         watches++;
 475     }
 476
 477     if (!subtree && !inode->parent)
 478     {
 479         struct inode *tmp, *next;
 480         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 481                                   struct inode, ch_entry )
 482         {
 483             assert( tmp != inode );
 484             assert( tmp->parent == inode );
 485             free_inode( tmp );
 486         }
 487     }
 488
 489     if (watches)
 490         return;
 491
 492     if (inode->parent)
 493         list_remove( &inode->ch_entry );
 494
 495     if (inode->wd != -1)
 496     {
 497         inotify_remove_watch( get_unix_fd( inotify_fd ), inode->wd );
 498         list_remove( &inode->wd_entry );
 499     }
 500     list_remove( &inode->ino_entry );
 501
 502     free( inode->name );
 503     free( inode );
 504 }
 505
 506 static struct inode *inode_add( struct inode *parent,
 507                                 dev_t dev, ino_t ino, const char *name )
 508 {
 509     struct inode *inode;
 510
 511     inode = get_inode( dev, ino );
 512     if (!inode)
 513         return NULL;
 514
 515     if (!inode->parent)
 516     {
 517         list_add_tail( &parent->children, &inode->ch_entry );
 518         inode->parent = parent;
 519         assert( inode != parent );
 520     }
 521     inode_set_name( inode, name );
 522
 523     return inode;
 524 }
 525
 526 static struct inode *inode_from_name( struct inode *inode, const char *name )
 527 {
 528     struct inode *i;
 529
 530     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 531         if (i->name && !strcmp( i->name, name ))
 532             return i;
 533     return NULL;
 534 }
 535
 536 static int inotify_get_poll_events( struct fd *fd );
 537 static void inotify_poll_event( struct fd *fd, int event );
 538
 539 static const struct fd_ops inotify_fd_ops =
 540 {
 541     inotify_get_poll_events,  /* get_poll_events */
 542     inotify_poll_event,       /* poll_event */
 543     no_flush,                 /* flush */
 544     no_get_file_info,         /* get_file_info */
 545     default_fd_queue_async,   /* queue_async */
 546     default_fd_cancel_async,  /* cancel_async */
 547 };
 548
 549 static int inotify_get_poll_events( struct fd *fd )
 550 {
 551     return POLLIN;
 552 }
 553
 554 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 555                                       const char *relpath )
 556 {
 557     struct change_record *record;
 558
 559     assert( dir->obj.ops == &dir_ops );
 560
 561     if (dir->want_data)
 562     {
 563         size_t len = strlen(relpath);
 564         record = malloc( offsetof(struct change_record, name[len]) );
 565         if (!record)
 566             return;
 567
 568         record->action = action;
 569         memcpy( record->name, relpath, len );
 570         record->len = len;
 571
 572         list_add_tail( &dir->change_records, &record->entry );
 573     }
 574
 575     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 576 }
 577
 578 static unsigned int filter_from_event( struct inotify_event *ie )
 579 {
 580     unsigned int filter = 0;
 581
 582     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 583         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 584     if (ie->mask & IN_MODIFY)
 585         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 586     if (ie->mask & IN_ATTRIB)
 587         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 588     if (ie->mask & IN_ACCESS)
 589         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 590     if (ie->mask & IN_CREATE)
 591         filter |= FILE_NOTIFY_CHANGE_CREATION;
 592
 593     return filter;
 594 }
 595
 596 /* scan up the parent directories for watches */
 597 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 598 {
 599     unsigned int filter = 0;
 600     struct dir *dir;
 601
 602     /* combine filters from parents watching subtrees */
 603     while (inode)
 604     {
 605         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 606             if (dir->subtree || !is_parent)
 607                 filter |= dir->filter;
 608         is_parent = 1;
 609         inode = inode->parent;
 610     }
 611
 612     return filter;
 613 }
 614
 615 static char *inode_get_path( struct inode *inode, int sz )
 616 {
 617     struct list *head;
 618     char *path;
 619     int len;
 620
 621     if (!inode)
 622         return NULL;
 623
 624     head = list_head( &inode->dirs );
 625     if (head)
 626     {
 627         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 628         path = malloc ( 32 + sz );
 629         if (path)
 630             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 631         return path;
 632     }
 633
 634     if (!inode->name)
 635         return NULL;
 636
 637     len = strlen( inode->name );
 638     path = inode_get_path( inode->parent, sz + len + 1 );
 639     if (!path)
 640         return NULL;
 641
 642     strcat( path, inode->name );
 643     strcat( path, "/" );
 644
 645     return path;
 646 }
 647
 648 static int inode_check_dir( struct inode *parent, const char *name )
 649 {
 650     char *path;
 651     unsigned int filter;
 652     struct inode *inode;
 653     struct stat st;
 654     int wd = -1, r = -1;
 655
 656     path = inode_get_path( parent, strlen(name) );
 657     if (!path)
 658         return r;
 659
 660     strcat( path, name );
 661
 662     r = stat( path, &st );
 663     if (r < 0) goto end;
 664
 665     if (!S_ISDIR(st.st_mode))
 666     {
 667         r = 0;
 668         goto end;
 669     }
 670
 671     r = 1;
 672
 673     filter = filter_from_inode( parent, 1 );
 674     if (!filter)
 675         goto end;
 676
 677     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 678     if (!inode || inode->wd != -1)
 679         goto end;
 680
 681     wd = inotify_add_dir( path, filter );
 682     if (wd != -1)
 683         inode_set_wd( inode, wd );
 684     else
 685         free_inode( inode );
 686
 687 end:
 688     free( path );
 689     return r;
 690 }
 691
 692 static int prepend( char **path, const char *segment )
 693 {
 694     int extra;
 695     char *p;
 696
 697     extra = strlen( segment ) + 1;
 698     if (*path)
 699     {
 700         int len = strlen( *path ) + 1;
 701         p = realloc( *path, len + extra );
 702         if (!p) return 0;
 703         memmove( &p[ extra ], p, len );
 704         p[ extra - 1 ] = '/';
 705         memcpy( p, segment, extra - 1 );
 706     }
 707     else
 708     {
 709         p = malloc( extra );
 710         if (!p) return 0;
 711         memcpy( p, segment, extra );
 712     }
 713
 714     *path = p;
 715
 716     return 1;
 717 }
 718
 719 static void inotify_notify_all( struct inotify_event *ie )
 720 {
 721     unsigned int filter, action;
 722     struct inode *inode, *i;
 723     char *path = NULL;
 724     struct dir *dir;
 725
 726     inode = inode_from_wd( ie->wd );
 727     if (!inode)
 728     {
 729         fprintf( stderr, "no inode matches %d\n", ie->wd);
 730         return;
 731     }
 732
 733     filter = filter_from_event( ie );
 734
 735     if (ie->mask & IN_CREATE)
 736     {
 737         switch (inode_check_dir( inode, ie->name ))
 738         {
 739         case 1:
 740             filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 741             break;
 742         case 0:
 743             filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 744             break;
 745         default:
 746             break;
 747             /* Maybe the file disappeared before we could check it? */
 748         }
 749         action = FILE_ACTION_ADDED;
 750     }
 751     else if (ie->mask & IN_DELETE)
 752         action = FILE_ACTION_REMOVED;
 753     else
 754         action = FILE_ACTION_MODIFIED;
 755
 756     /*
 757      * Work our way up the inode hierarchy
 758      *  extending the relative path as we go
 759      *  and notifying all recursive watches.
 760      */
 761     if (!prepend( &path, ie->name ))
 762         return;
 763
 764     for (i = inode; i; i = i->parent)
 765     {
 766         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 767             if ((filter & dir->filter) && (i==inode || dir->subtree))
 768                 inotify_do_change_notify( dir, action, path );
 769
 770         if (!i->name || !prepend( &path, i->name ))
 771             break;
 772     }
 773
 774     free( path );
 775
 776     if (ie->mask & IN_DELETE)
 777     {
 778         i = inode_from_name( inode, ie->name );
 779         if (i)
 780             free_inode( i );
 781     }
 782 }
 783
 784 static void inotify_poll_event( struct fd *fd, int event )
 785 {
 786     int r, ofs, unix_fd;
 787     char buffer[0x1000];
 788     struct inotify_event *ie;
 789
 790     unix_fd = get_unix_fd( fd );
 791     r = read( unix_fd, buffer, sizeof buffer );
 792     if (r < 0)
 793     {
 794         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 795         return;
 796     }
 797
 798     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 799     {
 800         ie = (struct inotify_event*) &buffer[ofs];
 801         if (!ie->len)
 802             break;
 803         ofs += offsetof( struct inotify_event, name[ie->len] );
 804         if (ofs > r) break;
 805         inotify_notify_all( ie );
 806     }
 807 }
 808
 809 static inline struct fd *create_inotify_fd( void )
 810 {
 811     int unix_fd;
 812
 813     unix_fd = inotify_init();
 814     if (unix_fd<0)
 815         return NULL;
 816     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL );
 817 }
 818
 819 static int map_flags( unsigned int filter )
 820 {
 821     unsigned int mask;
 822
 823     /* always watch these so we can track subdirectories in recursive watches */
 824     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 825
 826     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 827         mask |= IN_ATTRIB;
 828     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 829         mask |= IN_MODIFY;
 830     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 831         mask |= IN_MODIFY;
 832     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 833         mask |= IN_ACCESS;
 834     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 835         mask |= IN_ATTRIB;
 836
 837     return mask;
 838 }
 839
 840 static int inotify_add_dir( char *path, unsigned int filter )
 841 {
 842     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 843                                 path, map_flags( filter ) );
 844     if (wd != -1)
 845         set_fd_events( inotify_fd, POLLIN );
 846     return wd;
 847 }
 848
 849 static int init_inotify( void )
 850 {
 851     int i;
 852
 853     if (inotify_fd)
 854         return 1;
 855
 856     inotify_fd = create_inotify_fd();
 857     if (!inotify_fd)
 858         return 0;
 859
 860     for (i=0; i<HASH_SIZE; i++)
 861     {
 862         list_init( &inode_hash[i] );
 863         list_init( &wd_hash[i] );
 864     }
 865
 866     return 1;
 867 }
 868
 869 static int inotify_adjust_changes( struct dir *dir )
 870 {
 871     unsigned int filter;
 872     struct inode *inode;
 873     struct stat st;
 874     char path[32];
 875     int wd, unix_fd;
 876
 877     if (!inotify_fd)
 878         return 0;
 879
 880     unix_fd = get_unix_fd( dir->fd );
 881
 882     inode = dir->inode;
 883     if (!inode)
 884     {
 885         /* check if this fd is already being watched */
 886         if (-1 == fstat( unix_fd, &st ))
 887             return 0;
 888
 889         inode = get_inode( st.st_dev, st.st_ino );
 890         if (!inode)
 891             inode = create_inode( st.st_dev, st.st_ino );
 892         if (!inode)
 893             return 0;
 894         list_add_tail( &inode->dirs, &dir->in_entry );
 895         dir->inode = inode;
 896     }
 897
 898     filter = filter_from_inode( inode, 0 );
 899
 900     sprintf( path, "/proc/self/fd/%u", unix_fd );
 901     wd = inotify_add_dir( path, filter );
 902     if (wd == -1) return 0;
 903
 904     inode_set_wd( inode, wd );
 905
 906     return 1;
 907 }
 908
 909 static char *get_basename( const char *link )
 910 {
 911     char *buffer, *name = NULL;
 912     int r, n = 0x100;
 913
 914     while (1)
 915     {
 916         buffer = malloc( n );
 917         if (!buffer) return NULL;
 918
 919         r = readlink( link, buffer, n );
 920         if (r < 0)
 921             break;
 922
 923         if (r < n)
 924         {
 925             name = buffer;
 926             break;
 927         }
 928         free( buffer );
 929         n *= 2;
 930     }
 931
 932     if (name)
 933     {
 934         while (r > 0 && name[ r - 1 ] == '/' )
 935             r--;
 936         name[ r ] = 0;
 937
 938         name = strrchr( name, '/' );
 939         if (name)
 940             name = strdup( &name[1] );
 941     }
 942
 943     free( buffer );
 944     return name;
 945 }
 946
 947 static int dir_add_to_existing_notify( struct dir *dir )
 948 {
 949     struct inode *inode, *parent;
 950     unsigned int filter = 0;
 951     struct stat st, st_new;
 952     char link[35], *name;
 953     int wd, unix_fd;
 954
 955     if (!inotify_fd)
 956         return 0;
 957
 958     unix_fd = get_unix_fd( dir->fd );
 959
 960     /* check if it's in the list of inodes we want to watch */
 961     if (-1 == fstat( unix_fd, &st_new ))
 962         return 0;
 963     inode = find_inode( st_new.st_dev, st_new.st_ino );
 964     if (inode)
 965         return 0;
 966
 967     /* lookup the parent */
 968     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
 969     if (-1 == stat( link, &st ))
 970         return 0;
 971
 972     /*
 973      * If there's no parent, stop.  We could keep going adding
 974      *  ../ to the path until we hit the root of the tree or
 975      *  find a recursively watched ancestor.
 976      * Assume it's too expensive to search up the tree for now.
 977      */
 978     parent = find_inode( st.st_dev, st.st_ino );
 979     if (!parent)
 980         return 0;
 981
 982     if (parent->wd == -1)
 983         return 0;
 984
 985     filter = filter_from_inode( parent, 1 );
 986     if (!filter)
 987         return 0;
 988
 989     sprintf( link, "/proc/self/fd/%u", unix_fd );
 990     name = get_basename( link );
 991     if (!name)
 992         return 0;
 993     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
 994     free( name );
 995     if (!inode)
 996         return 0;
 997
 998     /* Couldn't find this inode at the start of the function, must be new */
 999     assert( inode->wd == -1 );
1000
1001     wd = inotify_add_dir( link, filter );
1002     if (wd != -1)
1003         inode_set_wd( inode, wd );
1004
1005     return 1;
1006 }
1007
1008 #else
1009
1010 static int init_inotify( void )
1011 {
1012     return 0;
1013 }
1014
1015 static int inotify_adjust_changes( struct dir *dir )
1016 {
1017     return 0;
1018 }
1019
1020 static void free_inode( struct inode *inode )
1021 {
1022     assert( 0 );
1023 }
1024
1025 static int dir_add_to_existing_notify( struct dir *dir )
1026 {
1027     return 0;
1028 }
1029
1030 #endif  /* USE_INOTIFY */
1031
1032 struct object *create_dir_obj( struct fd *fd )
1033 {
1034     struct dir *dir;
1035
1036     dir = alloc_object( &dir_ops );
1037     if (!dir)
1038         return NULL;
1039
1040     list_init( &dir->change_records );
1041     dir->event = NULL;
1042     dir->filter = 0;
1043     dir->notified = 0;
1044     dir->signaled = 0;
1045     dir->want_data = 0;
1046     dir->inode = NULL;
1047     grab_object( fd );
1048     dir->fd = fd;
1049     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1050
1051     dir_add_to_existing_notify( dir );
1052
1053     return &dir->obj;
1054 }
1055
1056 /* enable change notifications for a directory */
1057 DECL_HANDLER(read_directory_changes)
1058 {
1059     struct event *event = NULL;
1060     struct dir *dir;
1061
1062     if (!req->filter)
1063     {
1064         set_error(STATUS_INVALID_PARAMETER);
1065         return;
1066     }
1067
1068     dir = get_dir_obj( current->process, req->handle, 0 );
1069     if (!dir)
1070         return;
1071
1072     /* possibly send changes through an event flag */
1073     if (req->async.event &&
1074         !(event = get_event_obj( current->process, req->async.event, EVENT_MODIFY_STATE )))
1075         goto end;
1076
1077     /* discard the current data, and move onto the next event */
1078     if (dir->event) release_object( dir->event );
1079     dir->event = event;
1080
1081     /* requests don't timeout */
1082     if (!fd_queue_async_timeout( dir->fd, &req->async, ASYNC_TYPE_WAIT, 0, NULL )) goto end;
1083
1084     /* assign it once */
1085     if (!dir->filter)
1086     {
1087         init_inotify();
1088         insert_change( dir );
1089         dir->filter = req->filter;
1090         dir->subtree = req->subtree;
1091         dir->want_data = req->want_data;
1092     }
1093
1094     /* remove any notifications */
1095     if (dir->signaled>0)
1096         dir->signaled--;
1097
1098     /* if there's already a change in the queue, send it */
1099     if (!list_empty( &dir->change_records ))
1100         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1101
1102     /* setup the real notification */
1103     if (!inotify_adjust_changes( dir ))
1104         dnotify_adjust_changes( dir );
1105
1106     set_error(STATUS_PENDING);
1107
1108 end:
1109     release_object( dir );
1110 }
1111
1112 DECL_HANDLER(read_change)
1113 {
1114     struct change_record *record;
1115     struct dir *dir;
1116
1117     dir = get_dir_obj( current->process, req->handle, 0 );
1118     if (!dir)
1119         return;
1120
1121     if ((record = get_first_change_record( dir )) != NULL)
1122     {
1123         reply->action = record->action;
1124         set_reply_data( record->name, record->len );
1125         free( record );
1126     }
1127     else
1128         set_error( STATUS_NO_DATA_DETECTED );
1129
1130     /* now signal it */
1131     dir->signaled++;
1132     dir_signal_changed( dir );
1133
1134     release_object( dir );
1135 }