source/locking/brlock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    byte range locking code
   4    Updated to handle range splits/merges.
   5
   6    Copyright (C) Andrew Tridgell 1992-2000
   7    Copyright (C) Jeremy Allison 1992-2000
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 /* This module implements a tdb based byte range locking service,
  25    replacing the fcntl() based byte range locking previously
  26    used. This allows us to provide the same semantics as NT */
  27
  28 #include "includes.h"
  29
  30 #define ZERO_ZERO 0
  31
  32 /* This contains elements that differentiate locks. The smbpid is a
  33    client supplied pid, and is essentially the locking context for
  34    this client */
  35
  36 struct lock_context {
  37         uint16 smbpid;
  38         uint16 tid;
  39         pid_t pid;
  40 };
  41
  42 /* The data in brlock records is an unsorted linear array of these
  43    records.  It is unnecessary to store the count as tdb provides the
  44    size of the record */
  45
  46 struct lock_struct {
  47         struct lock_context context;
  48         br_off start;
  49         br_off size;
  50         int fnum;
  51         enum brl_type lock_type;
  52 };
  53
  54 /* The key used in the brlock database. */
  55
  56 struct lock_key {
  57         SMB_DEV_T device;
  58         SMB_INO_T inode;
  59 };
  60
  61 /* The open brlock.tdb database. */
  62
  63 static TDB_CONTEXT *tdb;
  64
  65 /****************************************************************************
  66  Create a locking key - ensuring zero filled for pad purposes.
  67 ****************************************************************************/
  68
  69 static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
  70 {
  71         static struct lock_key key;
  72         TDB_DATA kbuf;
  73
  74         memset(&key, '\0', sizeof(key));
  75         key.device = dev;
  76         key.inode = inode;
  77         kbuf.dptr = (char *)&key;
  78         kbuf.dsize = sizeof(key);
  79         return kbuf;
  80 }
  81
  82 /****************************************************************************
  83  See if two locking contexts are equal.
  84 ****************************************************************************/
  85
  86 static BOOL brl_same_context(struct lock_context *ctx1,
  87                              struct lock_context *ctx2)
  88 {
  89         return (ctx1->pid == ctx2->pid) &&
  90                 (ctx1->smbpid == ctx2->smbpid) &&
  91                 (ctx1->tid == ctx2->tid);
  92 }
  93
  94 /****************************************************************************
  95  See if lock2 can be added when lock1 is in place.
  96 ****************************************************************************/
  97
  98 static BOOL brl_conflict(struct lock_struct *lck1,
  99                          struct lock_struct *lck2)
 100 {
 101         if (lck1->lock_type == PENDING_LOCK || lck2->lock_type == PENDING_LOCK )
 102                 return False;
 103
 104         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 105                 return False;
 106         }
 107
 108         if (brl_same_context(&lck1->context, &lck2->context) &&
 109             lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
 110                 return False;
 111         }
 112
 113         if (lck1->start >= (lck2->start + lck2->size) ||
 114             lck2->start >= (lck1->start + lck1->size)) {
 115                 return False;
 116         }
 117
 118         return True;
 119 }
 120
 121 #if ZERO_ZERO
 122 static BOOL brl_conflict1(struct lock_struct *lck1,
 123                          struct lock_struct *lck2)
 124 {
 125         if (lck1->lock_type == PENDING_LOCK || lck2->lock_type == PENDING_LOCK )
 126                 return False;
 127
 128         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 129                 return False;
 130         }
 131
 132         if (brl_same_context(&lck1->context, &lck2->context) &&
 133             lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
 134                 return False;
 135         }
 136
 137         if (lck2->start == 0 && lck2->size == 0 && lck1->size != 0) {
 138                 return True;
 139         }
 140
 141         if (lck1->start >= (lck2->start + lck2->size) ||
 142             lck2->start >= (lck1->start + lck1->size)) {
 143                 return False;
 144         }
 145
 146         return True;
 147 }
 148 #endif
 149
 150 /****************************************************************************
 151  Check to see if this lock conflicts, but ignore our own locks on the
 152  same fnum only.
 153 ****************************************************************************/
 154
 155 static BOOL brl_conflict_other(struct lock_struct *lck1, struct lock_struct *lck2)
 156 {
 157         if (lck1->lock_type == PENDING_LOCK || lck2->lock_type == PENDING_LOCK )
 158                 return False;
 159
 160         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
 161                 return False;
 162
 163         /*
 164          * Incoming WRITE locks conflict with existing READ locks even
 165          * if the context is the same. JRA. See LOCKTEST7 in smbtorture.
 166          */
 167
 168         if (!(lck2->lock_type == WRITE_LOCK && lck1->lock_type == READ_LOCK)) {
 169                 if (brl_same_context(&lck1->context, &lck2->context) &&
 170                                         lck1->fnum == lck2->fnum)
 171                         return False;
 172         }
 173
 174         if (lck1->start >= (lck2->start + lck2->size) ||
 175             lck2->start >= (lck1->start + lck1->size))
 176                 return False;
 177
 178         return True;
 179 }
 180
 181
 182 #if DONT_DO_THIS
 183         /* doing this traversal could kill solaris machines under high load (tridge) */
 184         /* delete any dead locks */
 185
 186 /****************************************************************************
 187  Delete a record if it is for a dead process, if check_self is true, then
 188  delete any records belonging to this pid also (there shouldn't be any).
 189 ****************************************************************************/
 190
 191 static int delete_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
 192 {
 193         struct lock_struct *locks;
 194         int count, i;
 195         BOOL check_self = *(BOOL *)state;
 196         pid_t mypid = sys_getpid();
 197
 198         tdb_chainlock(tdb, kbuf);
 199
 200         locks = (struct lock_struct *)dbuf.dptr;
 201
 202         count = dbuf.dsize / sizeof(*locks);
 203         for (i=0; i<count; i++) {
 204                 struct lock_struct *lock = &locks[i];
 205
 206                 /* If check_self is true we want to remove our own records. */
 207                 if (check_self && (mypid == lock->context.pid)) {
 208
 209                         DEBUG(0,("brlock : delete_fn. LOGIC ERROR ! Shutting down and a record for my pid (%u) exists !\n",
 210                                         (unsigned int)lock->context.pid ));
 211
 212                 } else if (process_exists(lock->context.pid)) {
 213
 214                         DEBUG(10,("brlock : delete_fn. pid %u exists.\n", (unsigned int)lock->context.pid ));
 215                         continue;
 216                 }
 217
 218                 DEBUG(10,("brlock : delete_fn. Deleting record for process %u\n",
 219                                 (unsigned int)lock->context.pid ));
 220
 221                 if (count > 1 && i < count-1) {
 222                         memmove(&locks[i], &locks[i+1],
 223                                 sizeof(*locks)*((count-1) - i));
 224                 }
 225                 count--;
 226                 i--;
 227         }
 228
 229         if (count == 0) {
 230                 tdb_delete(tdb, kbuf);
 231         } else if (count < (dbuf.dsize / sizeof(*locks))) {
 232                 dbuf.dsize = count * sizeof(*locks);
 233                 tdb_store(tdb, kbuf, dbuf, TDB_REPLACE);
 234         }
 235
 236         tdb_chainunlock(tdb, kbuf);
 237         return 0;
 238 }
 239 #endif
 240
 241 /****************************************************************************
 242  Open up the brlock.tdb database.
 243 ****************************************************************************/
 244
 245 void brl_init(int read_only)
 246 {
 247         if (tdb)
 248                 return;
 249         tdb = tdb_open_log(lock_path("brlock.tdb"), 0,  TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST),
 250                        read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644);
 251         if (!tdb) {
 252                 DEBUG(0,("Failed to open byte range locking database\n"));
 253                 return;
 254         }
 255
 256 #if DONT_DO_THIS
 257         /* doing this traversal could kill solaris machines under high load (tridge) */
 258         /* delete any dead locks */
 259         if (!read_only) {
 260                 BOOL check_self = False;
 261                 tdb_traverse(tdb, delete_fn, &check_self);
 262         }
 263 #endif
 264 }
 265
 266 /****************************************************************************
 267  Close down the brlock.tdb database.
 268 ****************************************************************************/
 269
 270 void brl_shutdown(int read_only)
 271 {
 272         if (!tdb)
 273                 return;
 274
 275 #if DONT_DO_THIS
 276         /* doing this traversal could kill solaris machines under high load (tridge) */
 277         /* delete any dead locks */
 278         if (!read_only) {
 279                 BOOL check_self = True;
 280                 tdb_traverse(tdb, delete_fn, &check_self);
 281         }
 282 #endif
 283
 284         tdb_close(tdb);
 285 }
 286
 287 #if ZERO_ZERO
 288 /****************************************************************************
 289 compare two locks for sorting
 290 ****************************************************************************/
 291 static int lock_compare(struct lock_struct *lck1,
 292                          struct lock_struct *lck2)
 293 {
 294         if (lck1->start != lck2->start) return (lck1->start - lck2->start);
 295         if (lck2->size != lck1->size) {
 296                 return ((int)lck1->size - (int)lck2->size);
 297         }
 298         return 0;
 299 }
 300 #endif
 301
 302 /****************************************************************************
 303  Lock a range of bytes.
 304 ****************************************************************************/
 305
 306 NTSTATUS brl_lock(SMB_DEV_T dev, SMB_INO_T ino, int fnum,
 307                   uint16 smbpid, pid_t pid, uint16 tid,
 308                   br_off start, br_off size,
 309                   enum brl_type lock_type, BOOL *my_lock_ctx)
 310 {
 311         TDB_DATA kbuf, dbuf;
 312         int count, i;
 313         struct lock_struct lock, *locks;
 314         char *tp;
 315         NTSTATUS status = NT_STATUS_OK;
 316         static int last_failed = -1;
 317         static br_off last_failed_start;
 318
 319         *my_lock_ctx = False;
 320         kbuf = locking_key(dev,ino);
 321
 322         dbuf.dptr = NULL;
 323
 324 #if !ZERO_ZERO
 325         if (start == 0 && size == 0) {
 326                 DEBUG(0,("client sent 0/0 lock - please report this\n"));
 327         }
 328 #endif
 329
 330         tdb_chainlock(tdb, kbuf);
 331         dbuf = tdb_fetch(tdb, kbuf);
 332
 333         lock.context.smbpid = smbpid;
 334         lock.context.pid = pid;
 335         lock.context.tid = tid;
 336         lock.start = start;
 337         lock.size = size;
 338         lock.fnum = fnum;
 339         lock.lock_type = lock_type;
 340
 341         if (dbuf.dptr) {
 342                 /* there are existing locks - make sure they don't conflict */
 343                 locks = (struct lock_struct *)dbuf.dptr;
 344                 count = dbuf.dsize / sizeof(*locks);
 345                 for (i=0; i<count; i++) {
 346                         if (brl_conflict(&locks[i], &lock)) {
 347                                 status = NT_STATUS_LOCK_NOT_GRANTED;
 348                                 /* Did we block ourselves ? */
 349                                 if (brl_same_context(&locks[i].context, &lock.context))
 350                                         *my_lock_ctx = True;
 351                                 goto fail;
 352                         }
 353 #if ZERO_ZERO
 354                         if (lock.start == 0 && lock.size == 0 &&
 355                             locks[i].size == 0) {
 356                                 break;
 357                         }
 358 #endif
 359                 }
 360         }
 361
 362         /* no conflicts - add it to the list of locks */
 363         tp = Realloc(dbuf.dptr, dbuf.dsize + sizeof(*locks));
 364         if (!tp) {
 365                 status = NT_STATUS_NO_MEMORY;
 366                 goto fail;
 367         } else {
 368                 dbuf.dptr = tp;
 369         }
 370         memcpy(dbuf.dptr + dbuf.dsize, &lock, sizeof(lock));
 371         dbuf.dsize += sizeof(lock);
 372
 373 #if ZERO_ZERO
 374         /* sort the lock list */
 375         qsort(dbuf.dptr, dbuf.dsize/sizeof(lock), sizeof(lock), lock_compare);
 376 #endif
 377
 378         tdb_store(tdb, kbuf, dbuf, TDB_REPLACE);
 379
 380         SAFE_FREE(dbuf.dptr);
 381         tdb_chainunlock(tdb, kbuf);
 382         return NT_STATUS_OK;
 383
 384  fail:
 385         /* this is a nasty hack to try to simulate the lock result cache code in w2k.
 386            It isn't completely accurate as I haven't yet worked out the correct
 387            semantics (tridge)
 388         */
 389         if (last_failed == fnum &&
 390             last_failed_start == start &&
 391             NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 392                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 393         }
 394         last_failed = fnum;
 395         last_failed_start = start;
 396
 397         SAFE_FREE(dbuf.dptr);
 398         tdb_chainunlock(tdb, kbuf);
 399         return status;
 400 }
 401
 402 /****************************************************************************
 403  Check if an unlock overlaps a pending lock.
 404 ****************************************************************************/
 405
 406 static BOOL brl_pending_overlap(struct lock_struct *lock, struct lock_struct *pend_lock)
 407 {
 408         if ((lock->start <= pend_lock->start) && (lock->start + lock->size > pend_lock->start))
 409                 return True;
 410         if ((lock->start >= pend_lock->start) && (lock->start <= pend_lock->start + pend_lock->size))
 411                 return True;
 412         return False;
 413 }
 414
 415 /****************************************************************************
 416  Unlock a range of bytes.
 417 ****************************************************************************/
 418
 419 BOOL brl_unlock(SMB_DEV_T dev, SMB_INO_T ino, int fnum,
 420                 uint16 smbpid, pid_t pid, uint16 tid,
 421                 br_off start, br_off size,
 422                 BOOL remove_pending_locks_only,
 423                 void (*pre_unlock_fn)(void *),
 424                 void *pre_unlock_data)
 425 {
 426         TDB_DATA kbuf, dbuf;
 427         int count, i, j;
 428         struct lock_struct *locks;
 429         struct lock_context context;
 430
 431         kbuf = locking_key(dev,ino);
 432
 433         dbuf.dptr = NULL;
 434
 435         tdb_chainlock(tdb, kbuf);
 436         dbuf = tdb_fetch(tdb, kbuf);
 437
 438         if (!dbuf.dptr) {
 439                 DEBUG(10,("brl_unlock: tdb_fetch failed !\n"));
 440                 goto fail;
 441         }
 442
 443         context.smbpid = smbpid;
 444         context.pid = pid;
 445         context.tid = tid;
 446
 447         /* there are existing locks - find a match */
 448         locks = (struct lock_struct *)dbuf.dptr;
 449         count = dbuf.dsize / sizeof(*locks);
 450
 451 #if ZERO_ZERO
 452         for (i=0; i<count; i++) {
 453                 struct lock_struct *lock = &locks[i];
 454
 455                 if (lock->lock_type == WRITE_LOCK &&
 456                     brl_same_context(&lock->context, &context) &&
 457                     lock->fnum == fnum &&
 458                     lock->start == start &&
 459                     lock->size == size) {
 460
 461                         if (pre_unlock_fn)
 462                                 (*pre_unlock_fn)(pre_unlock_data);
 463
 464                         /* found it - delete it */
 465                         if (count == 1) {
 466                                 tdb_delete(tdb, kbuf);
 467                         } else {
 468                                 if (i < count-1) {
 469                                         memmove(&locks[i], &locks[i+1],
 470                                                 sizeof(*locks)*((count-1) - i));
 471                                 }
 472                                 dbuf.dsize -= sizeof(*locks);
 473                                 tdb_store(tdb, kbuf, dbuf, TDB_REPLACE);
 474                         }
 475
 476                         SAFE_FREE(dbuf.dptr);
 477                         tdb_chainunlock(tdb, kbuf);
 478                         return True;
 479                 }
 480         }
 481 #endif
 482
 483         locks = (struct lock_struct *)dbuf.dptr;
 484         count = dbuf.dsize / sizeof(*locks);
 485         for (i=0; i<count; i++) {
 486                 struct lock_struct *lock = &locks[i];
 487
 488                 if (brl_same_context(&lock->context, &context) &&
 489                                 lock->fnum == fnum &&
 490                                 lock->start == start &&
 491                                 lock->size == size) {
 492
 493                         if (remove_pending_locks_only && lock->lock_type != PENDING_LOCK)
 494                                 continue;
 495
 496                         if (lock->lock_type != PENDING_LOCK) {
 497
 498                                 /* Do any POSIX unlocks needed. */
 499                                 if (pre_unlock_fn)
 500                                         (*pre_unlock_fn)(pre_unlock_data);
 501
 502                                 /* Send unlock messages to any pending waiters that overlap. */
 503                                 for (j=0; j<count; j++) {
 504                                         struct lock_struct *pend_lock = &locks[j];
 505
 506                                         /* Ignore non-pending locks. */
 507                                         if (pend_lock->lock_type != PENDING_LOCK)
 508                                                 continue;
 509
 510                                         /* We could send specific lock info here... */
 511                                         if (brl_pending_overlap(lock, pend_lock)) {
 512                                                 DEBUG(10,("brl_unlock: sending unlock message to pid %u\n",
 513                                                                         (unsigned int)pend_lock->context.pid ));
 514
 515                                                 message_send_pid(pend_lock->context.pid,
 516                                                                 MSG_SMB_UNLOCK,
 517                                                                 NULL, 0, True);
 518                                         }
 519                                 }
 520                         }
 521
 522                         /* found it - delete it */
 523                         if (count == 1) {
 524                                 tdb_delete(tdb, kbuf);
 525                         } else {
 526                                 if (i < count-1) {
 527                                         memmove(&locks[i], &locks[i+1],
 528                                                 sizeof(*locks)*((count-1) - i));
 529                                 }
 530                                 dbuf.dsize -= sizeof(*locks);
 531                                 tdb_store(tdb, kbuf, dbuf, TDB_REPLACE);
 532                         }
 533
 534                         SAFE_FREE(dbuf.dptr);
 535                         tdb_chainunlock(tdb, kbuf);
 536                         return True;
 537                 }
 538         }
 539
 540         /* we didn't find it */
 541
 542  fail:
 543         SAFE_FREE(dbuf.dptr);
 544         tdb_chainunlock(tdb, kbuf);
 545         return False;
 546 }
 547
 548
 549 /****************************************************************************
 550  Test if we could add a lock if we wanted to.
 551 ****************************************************************************/
 552
 553 BOOL brl_locktest(SMB_DEV_T dev, SMB_INO_T ino, int fnum,
 554                   uint16 smbpid, pid_t pid, uint16 tid,
 555                   br_off start, br_off size,
 556                   enum brl_type lock_type, int check_self)
 557 {
 558         TDB_DATA kbuf, dbuf;
 559         int count, i;
 560         struct lock_struct lock, *locks;
 561
 562         kbuf = locking_key(dev,ino);
 563
 564         dbuf.dptr = NULL;
 565
 566         tdb_chainlock(tdb, kbuf);
 567         dbuf = tdb_fetch(tdb, kbuf);
 568
 569         lock.context.smbpid = smbpid;
 570         lock.context.pid = pid;
 571         lock.context.tid = tid;
 572         lock.start = start;
 573         lock.size = size;
 574         lock.fnum = fnum;
 575         lock.lock_type = lock_type;
 576
 577         if (dbuf.dptr) {
 578                 /* there are existing locks - make sure they don't conflict */
 579                 locks = (struct lock_struct *)dbuf.dptr;
 580                 count = dbuf.dsize / sizeof(*locks);
 581                 for (i=0; i<count; i++) {
 582                         if (check_self) {
 583                                 if (brl_conflict(&locks[i], &lock))
 584                                         goto fail;
 585                         } else {
 586                                 /*
 587                                  * Our own locks don't conflict.
 588                                  */
 589                                 if (brl_conflict_other(&locks[i], &lock))
 590                                         goto fail;
 591                         }
 592                 }
 593         }
 594
 595         /* no conflicts - we could have added it */
 596         SAFE_FREE(dbuf.dptr);
 597         tdb_chainunlock(tdb, kbuf);
 598         return True;
 599
 600  fail:
 601         SAFE_FREE(dbuf.dptr);
 602         tdb_chainunlock(tdb, kbuf);
 603         return False;
 604 }
 605
 606 /****************************************************************************
 607  Remove any locks associated with a open file.
 608 ****************************************************************************/
 609
 610 void brl_close(SMB_DEV_T dev, SMB_INO_T ino, pid_t pid, int tid, int fnum)
 611 {
 612         TDB_DATA kbuf, dbuf;
 613         int count, i, j, dcount=0;
 614         struct lock_struct *locks;
 615
 616         kbuf = locking_key(dev,ino);
 617
 618         dbuf.dptr = NULL;
 619
 620         tdb_chainlock(tdb, kbuf);
 621         dbuf = tdb_fetch(tdb, kbuf);
 622
 623         if (!dbuf.dptr) goto fail;
 624
 625         /* there are existing locks - remove any for this fnum */
 626         locks = (struct lock_struct *)dbuf.dptr;
 627         count = dbuf.dsize / sizeof(*locks);
 628
 629         for (i=0; i<count; i++) {
 630                 struct lock_struct *lock = &locks[i];
 631
 632                 if (lock->context.tid == tid &&
 633                     lock->context.pid == pid &&
 634                     lock->fnum == fnum) {
 635
 636                         /* Send unlock messages to any pending waiters that overlap. */
 637                         for (j=0; j<count; j++) {
 638                                 struct lock_struct *pend_lock = &locks[j];
 639
 640                                 /* Ignore our own or non-pending locks. */
 641                                 if (pend_lock->lock_type != PENDING_LOCK)
 642                                         continue;
 643
 644                                 if (pend_lock->context.tid == tid &&
 645                                     pend_lock->context.pid == pid &&
 646                                     pend_lock->fnum == fnum)
 647                                         continue;
 648
 649                                 /* We could send specific lock info here... */
 650                                 if (brl_pending_overlap(lock, pend_lock))
 651                                         message_send_pid(pend_lock->context.pid,
 652                                                         MSG_SMB_UNLOCK,
 653                                                         NULL, 0, True);
 654                         }
 655
 656                         /* found it - delete it */
 657                         if (count > 1 && i < count-1) {
 658                                 memmove(&locks[i], &locks[i+1],
 659                                         sizeof(*locks)*((count-1) - i));
 660                         }
 661                         count--;
 662                         i--;
 663                         dcount++;
 664                 }
 665         }
 666
 667         if (count == 0) {
 668                 tdb_delete(tdb, kbuf);
 669         } else if (count < (dbuf.dsize / sizeof(*locks))) {
 670                 dbuf.dsize -= dcount * sizeof(*locks);
 671                 tdb_store(tdb, kbuf, dbuf, TDB_REPLACE);
 672         }
 673
 674         /* we didn't find it */
 675  fail:
 676         SAFE_FREE(dbuf.dptr);
 677         tdb_chainunlock(tdb, kbuf);
 678 }
 679
 680 /****************************************************************************
 681  Traverse the whole database with this function, calling traverse_callback
 682  on each lock.
 683 ****************************************************************************/
 684
 685 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
 686 {
 687         struct lock_struct *locks;
 688         struct lock_key *key;
 689         int i;
 690
 691         BRLOCK_FN(traverse_callback) = (BRLOCK_FN_CAST())state;
 692
 693         locks = (struct lock_struct *)dbuf.dptr;
 694         key = (struct lock_key *)kbuf.dptr;
 695
 696         for (i=0;i<dbuf.dsize/sizeof(*locks);i++) {
 697                 traverse_callback(key->device, key->inode,
 698                                   locks[i].context.pid,
 699                                   locks[i].lock_type,
 700                                   locks[i].start,
 701                                   locks[i].size);
 702         }
 703         return 0;
 704 }
 705
 706 /*******************************************************************
 707  Call the specified function on each lock in the database.
 708 ********************************************************************/
 709
 710 int brl_forall(BRLOCK_FN(fn))
 711 {
 712         if (!tdb) return 0;
 713         return tdb_traverse(tdb, traverse_fn, (void *)fn);
 714 }