source3/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 #undef DBGC_CLASS
  31 #define DBGC_CLASS DBGC_LOCKING
  32
  33 #define ZERO_ZERO 0
  34
  35 /* The open brlock.tdb database. */
  36
  37 static TDB_CONTEXT *tdb;
  38
  39 /****************************************************************************
  40  Debug info at level 10 for lock struct.
  41 ****************************************************************************/
  42
  43 static void print_lock_struct(unsigned int i, struct lock_struct *pls)
  44 {
  45         DEBUG(10,("[%u]: smbpid = %u, tid = %u, pid = %u, ",
  46                         i,
  47                         (unsigned int)pls->context.smbpid,
  48                         (unsigned int)pls->context.tid,
  49                         (unsigned int)procid_to_pid(&pls->context.pid) ));
  50
  51         DEBUG(10,("start = %.0f, size = %.0f, fnum = %d, %s %s\n",
  52                 (double)pls->start,
  53                 (double)pls->size,
  54                 pls->fnum,
  55                 lock_type_name(pls->lock_type),
  56                 lock_flav_name(pls->lock_flav) ));
  57 }
  58
  59 /****************************************************************************
  60  See if two locking contexts are equal.
  61 ****************************************************************************/
  62
  63 BOOL brl_same_context(const struct lock_context *ctx1,
  64                              const struct lock_context *ctx2)
  65 {
  66         return (procid_equal(&ctx1->pid, &ctx2->pid) &&
  67                 (ctx1->smbpid == ctx2->smbpid) &&
  68                 (ctx1->tid == ctx2->tid));
  69 }
  70
  71 /****************************************************************************
  72  See if lck1 and lck2 overlap.
  73 ****************************************************************************/
  74
  75 static BOOL brl_overlap(const struct lock_struct *lck1,
  76                         const struct lock_struct *lck2)
  77 {
  78         /* this extra check is not redundent - it copes with locks
  79            that go beyond the end of 64 bit file space */
  80         if (lck1->size != 0 &&
  81             lck1->start == lck2->start &&
  82             lck1->size == lck2->size) {
  83                 return True;
  84         }
  85
  86         if (lck1->start >= (lck2->start+lck2->size) ||
  87             lck2->start >= (lck1->start+lck1->size)) {
  88                 return False;
  89         }
  90         return True;
  91 }
  92
  93 /****************************************************************************
  94  See if lock2 can be added when lock1 is in place.
  95 ****************************************************************************/
  96
  97 static BOOL brl_conflict(const struct lock_struct *lck1,
  98                          const struct lock_struct *lck2)
  99 {
 100         /* Ignore PENDING locks. */
 101         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 102                 return False;
 103
 104         /* Read locks never conflict. */
 105         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 106                 return False;
 107         }
 108
 109         if (brl_same_context(&lck1->context, &lck2->context) &&
 110             lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
 111                 return False;
 112         }
 113
 114         return brl_overlap(lck1, lck2);
 115 }
 116
 117 /****************************************************************************
 118  See if lock2 can be added when lock1 is in place - when both locks are POSIX
 119  flavour. POSIX locks ignore fnum - they only care about dev/ino which we
 120  know already match.
 121 ****************************************************************************/
 122
 123 static BOOL brl_conflict_posix(const struct lock_struct *lck1,
 124                                 const struct lock_struct *lck2)
 125 {
 126 #if defined(DEVELOPER)
 127         SMB_ASSERT(lck1->lock_flav == POSIX_LOCK);
 128         SMB_ASSERT(lck2->lock_flav == POSIX_LOCK);
 129 #endif
 130
 131         /* Ignore PENDING locks. */
 132         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 133                 return False;
 134
 135         /* Read locks never conflict. */
 136         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 137                 return False;
 138         }
 139
 140         /* Locks on the same context con't conflict. Ignore fnum. */
 141         if (brl_same_context(&lck1->context, &lck2->context)) {
 142                 return False;
 143         }
 144
 145         /* One is read, the other write, or the context is different,
 146            do they overlap ? */
 147         return brl_overlap(lck1, lck2);
 148 }
 149
 150 #if ZERO_ZERO
 151 static BOOL brl_conflict1(const struct lock_struct *lck1,
 152                          const struct lock_struct *lck2)
 153 {
 154         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 155                 return False;
 156
 157         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 158                 return False;
 159         }
 160
 161         if (brl_same_context(&lck1->context, &lck2->context) &&
 162             lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
 163                 return False;
 164         }
 165
 166         if (lck2->start == 0 && lck2->size == 0 && lck1->size != 0) {
 167                 return True;
 168         }
 169
 170         if (lck1->start >= (lck2->start + lck2->size) ||
 171             lck2->start >= (lck1->start + lck1->size)) {
 172                 return False;
 173         }
 174
 175         return True;
 176 }
 177 #endif
 178
 179 /****************************************************************************
 180  Check to see if this lock conflicts, but ignore our own locks on the
 181  same fnum only. This is the read/write lock check code path.
 182  This is never used in the POSIX lock case.
 183 ****************************************************************************/
 184
 185 static BOOL brl_conflict_other(const struct lock_struct *lck1, const struct lock_struct *lck2)
 186 {
 187         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 188                 return False;
 189
 190         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
 191                 return False;
 192
 193         /* POSIX flavour locks never conflict here - this is only called
 194            in the read/write path. */
 195
 196         if (lck1->lock_flav == POSIX_LOCK && lck2->lock_flav == POSIX_LOCK)
 197                 return False;
 198
 199         /*
 200          * Incoming WRITE locks conflict with existing READ locks even
 201          * if the context is the same. JRA. See LOCKTEST7 in smbtorture.
 202          */
 203
 204         if (!(lck2->lock_type == WRITE_LOCK && lck1->lock_type == READ_LOCK)) {
 205                 if (brl_same_context(&lck1->context, &lck2->context) &&
 206                                         lck1->fnum == lck2->fnum)
 207                         return False;
 208         }
 209
 210         return brl_overlap(lck1, lck2);
 211 }
 212
 213 /****************************************************************************
 214  Check if an unlock overlaps a pending lock.
 215 ****************************************************************************/
 216
 217 static BOOL brl_pending_overlap(const struct lock_struct *lock, const struct lock_struct *pend_lock)
 218 {
 219         if ((lock->start <= pend_lock->start) && (lock->start + lock->size > pend_lock->start))
 220                 return True;
 221         if ((lock->start >= pend_lock->start) && (lock->start <= pend_lock->start + pend_lock->size))
 222                 return True;
 223         return False;
 224 }
 225
 226 /****************************************************************************
 227  Amazingly enough, w2k3 "remembers" whether the last lock failure on a fnum
 228  is the same as this one and changes its error code. I wonder if any
 229  app depends on this ?
 230 ****************************************************************************/
 231
 232 static NTSTATUS brl_lock_failed(files_struct *fsp, const struct lock_struct *lock, BOOL blocking_lock)
 233 {
 234         if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) {
 235                 /* amazing the little things you learn with a test
 236                    suite. Locks beyond this offset (as a 64 bit
 237                    number!) always generate the conflict error code,
 238                    unless the top bit is set */
 239                 if (!blocking_lock) {
 240                         fsp->last_lock_failure = *lock;
 241                 }
 242                 return NT_STATUS_FILE_LOCK_CONFLICT;
 243         }
 244
 245         if (procid_equal(&lock->context.pid, &fsp->last_lock_failure.context.pid) &&
 246                         lock->context.tid == fsp->last_lock_failure.context.tid &&
 247                         lock->fnum == fsp->last_lock_failure.fnum &&
 248                         lock->start == fsp->last_lock_failure.start) {
 249                 return NT_STATUS_FILE_LOCK_CONFLICT;
 250         }
 251
 252         if (!blocking_lock) {
 253                 fsp->last_lock_failure = *lock;
 254         }
 255         return NT_STATUS_LOCK_NOT_GRANTED;
 256 }
 257
 258 /****************************************************************************
 259  Open up the brlock.tdb database.
 260 ****************************************************************************/
 261
 262 void brl_init(int read_only)
 263 {
 264         if (tdb) {
 265                 return;
 266         }
 267         tdb = tdb_open_log(lock_path("brlock.tdb"),
 268                         lp_open_files_db_hash_size(),
 269                         TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST),
 270                         read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644 );
 271         if (!tdb) {
 272                 DEBUG(0,("Failed to open byte range locking database %s\n",
 273                         lock_path("brlock.tdb")));
 274                 return;
 275         }
 276
 277         /* Activate the per-hashchain freelist */
 278         tdb_set_max_dead(tdb, 5);
 279 }
 280
 281 /****************************************************************************
 282  Close down the brlock.tdb database.
 283 ****************************************************************************/
 284
 285 void brl_shutdown(int read_only)
 286 {
 287         if (!tdb) {
 288                 return;
 289         }
 290         tdb_close(tdb);
 291 }
 292
 293 #if ZERO_ZERO
 294 /****************************************************************************
 295  Compare two locks for sorting.
 296 ****************************************************************************/
 297
 298 static int lock_compare(const struct lock_struct *lck1,
 299                          const struct lock_struct *lck2)
 300 {
 301         if (lck1->start != lck2->start) {
 302                 return (lck1->start - lck2->start);
 303         }
 304         if (lck2->size != lck1->size) {
 305                 return ((int)lck1->size - (int)lck2->size);
 306         }
 307         return 0;
 308 }
 309 #endif
 310
 311 /****************************************************************************
 312  Lock a range of bytes - Windows lock semantics.
 313 ****************************************************************************/
 314
 315 static NTSTATUS brl_lock_windows(struct byte_range_lock *br_lck,
 316                         const struct lock_struct *plock, BOOL blocking_lock)
 317 {
 318         unsigned int i;
 319         files_struct *fsp = br_lck->fsp;
 320         struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
 321
 322         for (i=0; i < br_lck->num_locks; i++) {
 323                 /* Do any Windows or POSIX locks conflict ? */
 324                 if (brl_conflict(&locks[i], plock)) {
 325                         return brl_lock_failed(fsp,plock,blocking_lock);
 326                 }
 327 #if ZERO_ZERO
 328                 if (plock->start == 0 && plock->size == 0 &&
 329                                 locks[i].size == 0) {
 330                         break;
 331                 }
 332 #endif
 333         }
 334
 335         /* We can get the Windows lock, now see if it needs to
 336            be mapped into a lower level POSIX one, and if so can
 337            we get it ? */
 338
 339         if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(fsp->conn->params)) {
 340                 int errno_ret;
 341                 if (!set_posix_lock_windows_flavour(fsp,
 342                                 plock->start,
 343                                 plock->size,
 344                                 plock->lock_type,
 345                                 &plock->context,
 346                                 locks,
 347                                 br_lck->num_locks,
 348                                 &errno_ret)) {
 349                         if (errno_ret == EACCES || errno_ret == EAGAIN) {
 350                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 351                         } else {
 352                                 return map_nt_error_from_unix(errno);
 353                         }
 354                 }
 355         }
 356
 357         /* no conflicts - add it to the list of locks */
 358         locks = (struct lock_struct *)SMB_REALLOC(locks, (br_lck->num_locks + 1) * sizeof(*locks));
 359         if (!locks) {
 360                 return NT_STATUS_NO_MEMORY;
 361         }
 362
 363         memcpy(&locks[br_lck->num_locks], plock, sizeof(struct lock_struct));
 364         br_lck->num_locks += 1;
 365         br_lck->lock_data = (void *)locks;
 366         br_lck->modified = True;
 367
 368         return NT_STATUS_OK;
 369 }
 370
 371 /****************************************************************************
 372  Cope with POSIX range splits and merges.
 373 ****************************************************************************/
 374
 375 static unsigned int brlock_posix_split_merge(struct lock_struct *lck_arr,               /* Output array. */
 376                                                 const struct lock_struct *ex,           /* existing lock. */
 377                                                 const struct lock_struct *plock,        /* proposed lock. */
 378                                                 BOOL *lock_was_added)
 379 {
 380         BOOL lock_types_differ = (ex->lock_type != plock->lock_type);
 381
 382         /* We can't merge non-conflicting locks on different context - ignore fnum. */
 383
 384         if (!brl_same_context(&ex->context, &plock->context)) {
 385                 /* Just copy. */
 386                 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 387                 return 1;
 388         }
 389
 390         /* We now know we have the same context. */
 391
 392         /* Did we overlap ? */
 393
 394 /*********************************************
 395                                              +---------+
 396                                              | ex      |
 397                                              +---------+
 398                               +-------+
 399                               | plock |
 400                               +-------+
 401 OR....
 402              +---------+
 403              |  ex     |
 404              +---------+
 405 **********************************************/
 406
 407         if ( (ex->start > (plock->start + plock->size)) ||
 408                         (plock->start > (ex->start + ex->size))) {
 409                 /* No overlap with this lock - copy existing. */
 410                 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 411                 return 1;
 412         }
 413
 414 /*********************************************
 415         +---------------------------+
 416         |          ex               |
 417         +---------------------------+
 418         +---------------------------+
 419         |       plock               | -> replace with plock.
 420         +---------------------------+
 421 **********************************************/
 422
 423         if ( (ex->start >= plock->start) &&
 424                         (ex->start + ex->size <= plock->start + plock->size) ) {
 425                 memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
 426                 *lock_was_added = True;
 427                 return 1;
 428         }
 429
 430 /*********************************************
 431         +-----------------------+
 432         |          ex           |
 433         +-----------------------+
 434         +---------------+
 435         |   plock       |
 436         +---------------+
 437 OR....
 438                         +-------+
 439                         |  ex   |
 440                         +-------+
 441         +---------------+
 442         |   plock       |
 443         +---------------+
 444
 445 BECOMES....
 446         +---------------+-------+
 447         |   plock       | ex    | - different lock types.
 448         +---------------+-------+
 449 OR.... (merge)
 450         +-----------------------+
 451         |   ex                  | - same lock type.
 452         +-----------------------+
 453 **********************************************/
 454
 455         if ( (ex->start >= plock->start) &&
 456                                 (ex->start <= plock->start + plock->size) &&
 457                                 (ex->start + ex->size > plock->start + plock->size) ) {
 458
 459                 *lock_was_added = True;
 460
 461                 /* If the lock types are the same, we merge, if different, we
 462                    add the new lock before the old. */
 463
 464                 if (lock_types_differ) {
 465                         /* Add new. */
 466                         memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
 467                         memcpy(&lck_arr[1], ex, sizeof(struct lock_struct));
 468                         /* Adjust existing start and size. */
 469                         lck_arr[1].start = plock->start + plock->size;
 470                         lck_arr[1].size = (ex->start + ex->size) - (plock->start + plock->size);
 471                         return 2;
 472                 } else {
 473                         /* Merge. */
 474                         memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
 475                         /* Set new start and size. */
 476                         lck_arr[0].start = plock->start;
 477                         lck_arr[0].size = (ex->start + ex->size) - plock->start;
 478                         return 1;
 479                 }
 480         }
 481
 482 /*********************************************
 483    +-----------------------+
 484    |  ex                   |
 485    +-----------------------+
 486            +---------------+
 487            |   plock       |
 488            +---------------+
 489 OR....
 490    +-------+
 491    |  ex   |
 492    +-------+
 493            +---------------+
 494            |   plock       |
 495            +---------------+
 496 BECOMES....
 497    +-------+---------------+
 498    | ex    |   plock       | - different lock types
 499    +-------+---------------+
 500
 501 OR.... (merge)
 502    +-----------------------+
 503    | ex                    | - same lock type.
 504    +-----------------------+
 505
 506 **********************************************/
 507
 508         if ( (ex->start < plock->start) &&
 509                         (ex->start + ex->size >= plock->start) &&
 510                         (ex->start + ex->size <= plock->start + plock->size) ) {
 511
 512                 *lock_was_added = True;
 513
 514                 /* If the lock types are the same, we merge, if different, we
 515                    add the new lock after the old. */
 516
 517                 if (lock_types_differ) {
 518                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 519                         memcpy(&lck_arr[1], plock, sizeof(struct lock_struct));
 520                         /* Adjust existing size. */
 521                         lck_arr[0].size = plock->start - ex->start;
 522                         return 2;
 523                 } else {
 524                         /* Merge. */
 525                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 526                         /* Adjust existing size. */
 527                         lck_arr[0].size = (plock->start + plock->size) - ex->start;
 528                         return 1;
 529                 }
 530         }
 531
 532 /*********************************************
 533         +---------------------------+
 534         |        ex                 |
 535         +---------------------------+
 536                 +---------+
 537                 |  plock  |
 538                 +---------+
 539 BECOMES.....
 540         +-------+---------+---------+
 541         | ex    |  plock  | ex      | - different lock types.
 542         +-------+---------+---------+
 543 OR
 544         +---------------------------+
 545         |        ex                 | - same lock type.
 546         +---------------------------+
 547 **********************************************/
 548
 549         if ( (ex->start < plock->start) && (ex->start + ex->size > plock->start + plock->size) ) {
 550                 *lock_was_added = True;
 551
 552                 if (lock_types_differ) {
 553
 554                         /* We have to split ex into two locks here. */
 555
 556                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 557                         memcpy(&lck_arr[1], plock, sizeof(struct lock_struct));
 558                         memcpy(&lck_arr[2], ex, sizeof(struct lock_struct));
 559
 560                         /* Adjust first existing size. */
 561                         lck_arr[0].size = plock->start - ex->start;
 562
 563                         /* Adjust second existing start and size. */
 564                         lck_arr[2].start = plock->start + plock->size;
 565                         lck_arr[2].size = (ex->start + ex->size) - (plock->start + plock->size);
 566                         return 3;
 567                 } else {
 568                         /* Just eat plock. */
 569                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 570                         return 1;
 571                 }
 572         }
 573
 574         /* Never get here. */
 575         smb_panic("brlock_posix_split_merge\n");
 576         /* Notreached. */
 577         abort();
 578         /* Keep some compilers happy. */
 579         return 0;
 580 }
 581
 582 /****************************************************************************
 583  Lock a range of bytes - POSIX lock semantics.
 584  We must cope with range splits and merges.
 585 ****************************************************************************/
 586
 587 static NTSTATUS brl_lock_posix(struct byte_range_lock *br_lck,
 588                         const struct lock_struct *plock)
 589 {
 590         unsigned int i, count;
 591         struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
 592         struct lock_struct *tp;
 593         BOOL lock_was_added = False;
 594         BOOL signal_pending_read = False;
 595
 596         /* No zero-zero locks for POSIX. */
 597         if (plock->start == 0 && plock->size == 0) {
 598                 return NT_STATUS_INVALID_PARAMETER;
 599         }
 600
 601         /* Don't allow 64-bit lock wrap. */
 602         if (plock->start + plock->size < plock->start ||
 603                         plock->start + plock->size < plock->size) {
 604                 return NT_STATUS_INVALID_PARAMETER;
 605         }
 606
 607         /* The worst case scenario here is we have to split an
 608            existing POSIX lock range into two, and add our lock,
 609            so we need at most 2 more entries. */
 610
 611         tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 2));
 612         if (!tp) {
 613                 return NT_STATUS_NO_MEMORY;
 614         }
 615
 616         count = 0;
 617         for (i=0; i < br_lck->num_locks; i++) {
 618                 struct lock_struct *curr_lock = &locks[i];
 619
 620                 /* If we have a pending read lock, a lock downgrade should
 621                    trigger a lock re-evaluation. */
 622                 if (curr_lock->lock_type == PENDING_READ_LOCK &&
 623                                 brl_pending_overlap(plock, curr_lock)) {
 624                         signal_pending_read = True;
 625                 }
 626
 627                 if (curr_lock->lock_flav == WINDOWS_LOCK) {
 628                         /* Do any Windows flavour locks conflict ? */
 629                         if (brl_conflict(curr_lock, plock)) {
 630                                 /* No games with error messages. */
 631                                 SAFE_FREE(tp);
 632                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 633                         }
 634                         /* Just copy the Windows lock into the new array. */
 635                         memcpy(&tp[count], curr_lock, sizeof(struct lock_struct));
 636                         count++;
 637                 } else {
 638                         /* POSIX conflict semantics are different. */
 639                         if (brl_conflict_posix(curr_lock, plock)) {
 640                                 /* Can't block ourselves with POSIX locks. */
 641                                 /* No games with error messages. */
 642                                 SAFE_FREE(tp);
 643                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 644                         }
 645
 646                         /* Work out overlaps. */
 647                         count += brlock_posix_split_merge(&tp[count], curr_lock, plock, &lock_was_added);
 648                 }
 649         }
 650
 651         if (!lock_was_added) {
 652                 memcpy(&tp[count], plock, sizeof(struct lock_struct));
 653                 count++;
 654         }
 655
 656         /* We can get the POSIX lock, now see if it needs to
 657            be mapped into a lower level POSIX one, and if so can
 658            we get it ? */
 659
 660         if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(br_lck->fsp->conn->params)) {
 661                 int errno_ret;
 662
 663                 /* The lower layer just needs to attempt to
 664                    get the system POSIX lock. We've weeded out
 665                    any conflicts above. */
 666
 667                 if (!set_posix_lock_posix_flavour(br_lck->fsp,
 668                                 plock->start,
 669                                 plock->size,
 670                                 plock->lock_type,
 671                                 &errno_ret)) {
 672                         if (errno_ret == EACCES || errno_ret == EAGAIN) {
 673                                 SAFE_FREE(tp);
 674                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 675                         } else {
 676                                 SAFE_FREE(tp);
 677                                 return map_nt_error_from_unix(errno);
 678                         }
 679                 }
 680         }
 681
 682         /* Realloc so we don't leak entries per lock call. */
 683         tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
 684         if (!tp) {
 685                 return NT_STATUS_NO_MEMORY;
 686         }
 687         br_lck->num_locks = count;
 688         SAFE_FREE(br_lck->lock_data);
 689         br_lck->lock_data = (void *)tp;
 690         locks = tp;
 691         br_lck->modified = True;
 692
 693         /* A successful downgrade from write to read lock can trigger a lock
 694            re-evalutation where waiting readers can now proceed. */
 695
 696         if (signal_pending_read) {
 697                 /* Send unlock messages to any pending read waiters that overlap. */
 698                 for (i=0; i < br_lck->num_locks; i++) {
 699                         struct lock_struct *pend_lock = &locks[i];
 700
 701                         /* Ignore non-pending locks. */
 702                         if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
 703                                 continue;
 704                         }
 705
 706                         if (pend_lock->lock_type == PENDING_READ_LOCK &&
 707                                         brl_pending_overlap(plock, pend_lock)) {
 708                                 DEBUG(10,("brl_lock_posix: sending unlock message to pid %s\n",
 709                                         procid_str_static(&pend_lock->context.pid )));
 710
 711                                 message_send_pid(pend_lock->context.pid,
 712                                                 MSG_SMB_UNLOCK,
 713                                                 NULL, 0, True);
 714                         }
 715                 }
 716         }
 717
 718         return NT_STATUS_OK;
 719 }
 720
 721 /****************************************************************************
 722  Lock a range of bytes.
 723 ****************************************************************************/
 724
 725 NTSTATUS brl_lock(struct byte_range_lock *br_lck,
 726                 uint32 smbpid,
 727                 struct process_id pid,
 728                 br_off start,
 729                 br_off size,
 730                 enum brl_type lock_type,
 731                 enum brl_flavour lock_flav,
 732                 BOOL blocking_lock)
 733 {
 734         NTSTATUS ret;
 735         struct lock_struct lock;
 736
 737 #if !ZERO_ZERO
 738         if (start == 0 && size == 0) {
 739                 DEBUG(0,("client sent 0/0 lock - please report this\n"));
 740         }
 741 #endif
 742
 743         lock.context.smbpid = smbpid;
 744         lock.context.pid = pid;
 745         lock.context.tid = br_lck->fsp->conn->cnum;
 746         lock.start = start;
 747         lock.size = size;
 748         lock.fnum = br_lck->fsp->fnum;
 749         lock.lock_type = lock_type;
 750         lock.lock_flav = lock_flav;
 751
 752         if (lock_flav == WINDOWS_LOCK) {
 753                 ret = brl_lock_windows(br_lck, &lock, blocking_lock);
 754         } else {
 755                 ret = brl_lock_posix(br_lck, &lock);
 756         }
 757
 758 #if ZERO_ZERO
 759         /* sort the lock list */
 760         qsort(br_lck->lock_data, (size_t)br_lck->num_locks, sizeof(lock), lock_compare);
 761 #endif
 762
 763         return ret;
 764 }
 765
 766 /****************************************************************************
 767  Unlock a range of bytes - Windows semantics.
 768 ****************************************************************************/
 769
 770 static BOOL brl_unlock_windows(struct byte_range_lock *br_lck, const struct lock_struct *plock)
 771 {
 772         unsigned int i, j;
 773         struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
 774         enum brl_type deleted_lock_type = READ_LOCK; /* shut the compiler up.... */
 775
 776 #if ZERO_ZERO
 777         /* Delete write locks by preference... The lock list
 778            is sorted in the zero zero case. */
 779
 780         for (i = 0; i < br_lck->num_locks; i++) {
 781                 struct lock_struct *lock = &locks[i];
 782
 783                 if (lock->lock_type == WRITE_LOCK &&
 784                     brl_same_context(&lock->context, &plock->context) &&
 785                     lock->fnum == plock->fnum &&
 786                     lock->lock_flav == WINDOWS_LOCK &&
 787                     lock->start == plock->start &&
 788                     lock->size == plock->size) {
 789
 790                         /* found it - delete it */
 791                         deleted_lock_type = lock->lock_type;
 792                         break;
 793                 }
 794         }
 795
 796         if (i != br_lck->num_locks) {
 797                 /* We found it - don't search again. */
 798                 goto unlock_continue;
 799         }
 800 #endif
 801
 802         for (i = 0; i < br_lck->num_locks; i++) {
 803                 struct lock_struct *lock = &locks[i];
 804
 805                 /* Only remove our own locks that match in start, size, and flavour. */
 806                 if (brl_same_context(&lock->context, &plock->context) &&
 807                                         lock->fnum == plock->fnum &&
 808                                         lock->lock_flav == WINDOWS_LOCK &&
 809                                         lock->start == plock->start &&
 810                                         lock->size == plock->size ) {
 811                         deleted_lock_type = lock->lock_type;
 812                         break;
 813                 }
 814         }
 815
 816         if (i == br_lck->num_locks) {
 817                 /* we didn't find it */
 818                 return False;
 819         }
 820
 821 #if ZERO_ZERO
 822   unlock_continue:
 823 #endif
 824
 825         /* Actually delete the lock. */
 826         if (i < br_lck->num_locks - 1) {
 827                 memmove(&locks[i], &locks[i+1],
 828                         sizeof(*locks)*((br_lck->num_locks-1) - i));
 829         }
 830
 831         br_lck->num_locks -= 1;
 832         br_lck->modified = True;
 833
 834         /* Unlock the underlying POSIX regions. */
 835         if(lp_posix_locking(br_lck->fsp->conn->params)) {
 836                 release_posix_lock_windows_flavour(br_lck->fsp,
 837                                 plock->start,
 838                                 plock->size,
 839                                 deleted_lock_type,
 840                                 &plock->context,
 841                                 locks,
 842                                 br_lck->num_locks);
 843         }
 844
 845         /* Send unlock messages to any pending waiters that overlap. */
 846         for (j=0; j < br_lck->num_locks; j++) {
 847                 struct lock_struct *pend_lock = &locks[j];
 848
 849                 /* Ignore non-pending locks. */
 850                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
 851                         continue;
 852                 }
 853
 854                 /* We could send specific lock info here... */
 855                 if (brl_pending_overlap(plock, pend_lock)) {
 856                         DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
 857                                 procid_str_static(&pend_lock->context.pid )));
 858
 859                         message_send_pid(pend_lock->context.pid,
 860                                         MSG_SMB_UNLOCK,
 861                                         NULL, 0, True);
 862                 }
 863         }
 864
 865         return True;
 866 }
 867
 868 /****************************************************************************
 869  Unlock a range of bytes - POSIX semantics.
 870 ****************************************************************************/
 871
 872 static BOOL brl_unlock_posix(struct byte_range_lock *br_lck, const struct lock_struct *plock)
 873 {
 874         unsigned int i, j, count;
 875         struct lock_struct *tp;
 876         struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
 877         BOOL overlap_found = False;
 878
 879         /* No zero-zero locks for POSIX. */
 880         if (plock->start == 0 && plock->size == 0) {
 881                 return False;
 882         }
 883
 884         /* Don't allow 64-bit lock wrap. */
 885         if (plock->start + plock->size < plock->start ||
 886                         plock->start + plock->size < plock->size) {
 887                 DEBUG(10,("brl_unlock_posix: lock wrap\n"));
 888                 return False;
 889         }
 890
 891         /* The worst case scenario here is we have to split an
 892            existing POSIX lock range into two, so we need at most
 893            1 more entry. */
 894
 895         tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 1));
 896         if (!tp) {
 897                 DEBUG(10,("brl_unlock_posix: malloc fail\n"));
 898                 return False;
 899         }
 900
 901         count = 0;
 902         for (i = 0; i < br_lck->num_locks; i++) {
 903                 struct lock_struct *lock = &locks[i];
 904                 struct lock_struct tmp_lock[3];
 905                 BOOL lock_was_added = False;
 906                 unsigned int tmp_count;
 907
 908                 /* Only remove our own locks - ignore fnum. */
 909                 if (IS_PENDING_LOCK(lock->lock_type) ||
 910                                 !brl_same_context(&lock->context, &plock->context)) {
 911                         memcpy(&tp[count], lock, sizeof(struct lock_struct));
 912                         count++;
 913                         continue;
 914                 }
 915
 916                 /* Work out overlaps. */
 917                 tmp_count = brlock_posix_split_merge(&tmp_lock[0], &locks[i], plock, &lock_was_added);
 918
 919                 if (tmp_count == 1) {
 920                         /* Ether the locks didn't overlap, or the unlock completely
 921                            overlapped this lock. If it didn't overlap, then there's
 922                            no change in the locks. */
 923                         if (tmp_lock[0].lock_type != UNLOCK_LOCK) {
 924                                 SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
 925                                 /* No change in this lock. */
 926                                 memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
 927                                 count++;
 928                         } else {
 929                                 SMB_ASSERT(tmp_lock[0].lock_type == UNLOCK_LOCK);
 930                                 overlap_found = True;
 931                         }
 932                         continue;
 933                 } else if (tmp_count == 2) {
 934                         /* The unlock overlapped an existing lock. Copy the truncated
 935                            lock into the lock array. */
 936                         if (tmp_lock[0].lock_type != UNLOCK_LOCK) {
 937                                 SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
 938                                 SMB_ASSERT(tmp_lock[1].lock_type == UNLOCK_LOCK);
 939                                 memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
 940                                 if (tmp_lock[0].size != locks[i].size) {
 941                                         overlap_found = True;
 942                                 }
 943                         } else {
 944                                 SMB_ASSERT(tmp_lock[0].lock_type == UNLOCK_LOCK);
 945                                 SMB_ASSERT(tmp_lock[1].lock_type == locks[i].lock_type);
 946                                 memcpy(&tp[count], &tmp_lock[1], sizeof(struct lock_struct));
 947                                 if (tmp_lock[1].start != locks[i].start) {
 948                                         overlap_found = True;
 949                                 }
 950                         }
 951                         count++;
 952                         continue;
 953                 } else {
 954                         /* tmp_count == 3 - (we split a lock range in two). */
 955                         SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
 956                         SMB_ASSERT(tmp_lock[1].lock_type == UNLOCK_LOCK);
 957                         SMB_ASSERT(tmp_lock[2].lock_type == locks[i].lock_type);
 958
 959                         memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
 960                         count++;
 961                         memcpy(&tp[count], &tmp_lock[2], sizeof(struct lock_struct));
 962                         count++;
 963                         overlap_found = True;
 964                         /* Optimisation... */
 965                         /* We know we're finished here as we can't overlap any
 966                            more POSIX locks. Copy the rest of the lock array. */
 967                         if (i < br_lck->num_locks - 1) {
 968                                 memcpy(&tp[count], &locks[i+1],
 969                                         sizeof(*locks)*((br_lck->num_locks-1) - i));
 970                                 count += ((br_lck->num_locks-1) - i);
 971                         }
 972                         break;
 973                 }
 974         }
 975
 976         if (!overlap_found) {
 977                 /* Just ignore - no change. */
 978                 SAFE_FREE(tp);
 979                 DEBUG(10,("brl_unlock_posix: No overlap - unlocked.\n"));
 980                 return True;
 981         }
 982
 983         /* Unlock any POSIX regions. */
 984         if(lp_posix_locking(br_lck->fsp->conn->params)) {
 985                 release_posix_lock_posix_flavour(br_lck->fsp,
 986                                                 plock->start,
 987                                                 plock->size,
 988                                                 &plock->context,
 989                                                 tp,
 990                                                 count);
 991         }
 992
 993         /* Realloc so we don't leak entries per unlock call. */
 994         if (count) {
 995                 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
 996                 if (!tp) {
 997                         DEBUG(10,("brl_unlock_posix: realloc fail\n"));
 998                         return False;
 999                 }
1000         } else {
1001                 /* We deleted the last lock. */
1002                 SAFE_FREE(tp);
1003                 tp = NULL;
1004         }
1005
1006         br_lck->num_locks = count;
1007         SAFE_FREE(br_lck->lock_data);
1008         locks = tp;
1009         br_lck->lock_data = (void *)tp;
1010         br_lck->modified = True;
1011
1012         /* Send unlock messages to any pending waiters that overlap. */
1013
1014         for (j=0; j < br_lck->num_locks; j++) {
1015                 struct lock_struct *pend_lock = &locks[j];
1016
1017                 /* Ignore non-pending locks. */
1018                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1019                         continue;
1020                 }
1021
1022                 /* We could send specific lock info here... */
1023                 if (brl_pending_overlap(plock, pend_lock)) {
1024                         DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1025                                 procid_str_static(&pend_lock->context.pid )));
1026
1027                         message_send_pid(pend_lock->context.pid,
1028                                         MSG_SMB_UNLOCK,
1029                                         NULL, 0, True);
1030                 }
1031         }
1032
1033         return True;
1034 }
1035
1036 /****************************************************************************
1037  Unlock a range of bytes.
1038 ****************************************************************************/
1039
1040 BOOL brl_unlock(struct byte_range_lock *br_lck,
1041                 uint32 smbpid,
1042                 struct process_id pid,
1043                 br_off start,
1044                 br_off size,
1045                 enum brl_flavour lock_flav)
1046 {
1047         struct lock_struct lock;
1048
1049         lock.context.smbpid = smbpid;
1050         lock.context.pid = pid;
1051         lock.context.tid = br_lck->fsp->conn->cnum;
1052         lock.start = start;
1053         lock.size = size;
1054         lock.fnum = br_lck->fsp->fnum;
1055         lock.lock_type = UNLOCK_LOCK;
1056         lock.lock_flav = lock_flav;
1057
1058         if (lock_flav == WINDOWS_LOCK) {
1059                 return brl_unlock_windows(br_lck, &lock);
1060         } else {
1061                 return brl_unlock_posix(br_lck, &lock);
1062         }
1063 }
1064
1065 /****************************************************************************
1066  Test if we could add a lock if we wanted to.
1067  Returns True if the region required is currently unlocked, False if locked.
1068 ****************************************************************************/
1069
1070 BOOL brl_locktest(struct byte_range_lock *br_lck,
1071                 uint32 smbpid,
1072                 struct process_id pid,
1073                 br_off start,
1074                 br_off size,
1075                 enum brl_type lock_type,
1076                 enum brl_flavour lock_flav)
1077 {
1078         BOOL ret = True;
1079         unsigned int i;
1080         struct lock_struct lock;
1081         const struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1082         files_struct *fsp = br_lck->fsp;
1083
1084         lock.context.smbpid = smbpid;
1085         lock.context.pid = pid;
1086         lock.context.tid = br_lck->fsp->conn->cnum;
1087         lock.start = start;
1088         lock.size = size;
1089         lock.fnum = fsp->fnum;
1090         lock.lock_type = lock_type;
1091         lock.lock_flav = lock_flav;
1092
1093         /* Make sure existing locks don't conflict */
1094         for (i=0; i < br_lck->num_locks; i++) {
1095                 /*
1096                  * Our own locks don't conflict.
1097                  */
1098                 if (brl_conflict_other(&locks[i], &lock)) {
1099                         return False;
1100                 }
1101         }
1102
1103         /*
1104          * There is no lock held by an SMB daemon, check to
1105          * see if there is a POSIX lock from a UNIX or NFS process.
1106          * This only conflicts with Windows locks, not POSIX locks.
1107          */
1108
1109         if(lp_posix_locking(fsp->conn->params) && (lock_flav == WINDOWS_LOCK)) {
1110                 ret = is_posix_locked(fsp, &start, &size, &lock_type, WINDOWS_LOCK);
1111
1112                 DEBUG(10,("brl_locktest: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1113                         (double)start, (double)size, ret ? "locked" : "unlocked",
1114                         fsp->fnum, fsp->fsp_name ));
1115
1116                 /* We need to return the inverse of is_posix_locked. */
1117                 ret = !ret;
1118         }
1119
1120         /* no conflicts - we could have added it */
1121         return ret;
1122 }
1123
1124 /****************************************************************************
1125  Query for existing locks.
1126 ****************************************************************************/
1127
1128 NTSTATUS brl_lockquery(struct byte_range_lock *br_lck,
1129                 uint32 *psmbpid,
1130                 struct process_id pid,
1131                 br_off *pstart,
1132                 br_off *psize,
1133                 enum brl_type *plock_type,
1134                 enum brl_flavour lock_flav)
1135 {
1136         unsigned int i;
1137         struct lock_struct lock;
1138         const struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1139         files_struct *fsp = br_lck->fsp;
1140
1141         lock.context.smbpid = *psmbpid;
1142         lock.context.pid = pid;
1143         lock.context.tid = br_lck->fsp->conn->cnum;
1144         lock.start = *pstart;
1145         lock.size = *psize;
1146         lock.fnum = fsp->fnum;
1147         lock.lock_type = *plock_type;
1148         lock.lock_flav = lock_flav;
1149
1150         /* Make sure existing locks don't conflict */
1151         for (i=0; i < br_lck->num_locks; i++) {
1152                 const struct lock_struct *exlock = &locks[i];
1153                 BOOL conflict = False;
1154
1155                 if (exlock->lock_flav == WINDOWS_LOCK) {
1156                         conflict = brl_conflict(exlock, &lock);
1157                 } else {
1158                         conflict = brl_conflict_posix(exlock, &lock);
1159                 }
1160
1161                 if (conflict) {
1162                         *psmbpid = exlock->context.smbpid;
1163                         *pstart = exlock->start;
1164                         *psize = exlock->size;
1165                         *plock_type = exlock->lock_type;
1166                         return NT_STATUS_LOCK_NOT_GRANTED;
1167                 }
1168         }
1169
1170         /*
1171          * There is no lock held by an SMB daemon, check to
1172          * see if there is a POSIX lock from a UNIX or NFS process.
1173          */
1174
1175         if(lp_posix_locking(fsp->conn->params)) {
1176                 BOOL ret = is_posix_locked(fsp, pstart, psize, plock_type, POSIX_LOCK);
1177
1178                 DEBUG(10,("brl_lockquery: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1179                         (double)*pstart, (double)*psize, ret ? "locked" : "unlocked",
1180                         fsp->fnum, fsp->fsp_name ));
1181
1182                 if (ret) {
1183                         /* Hmmm. No clue what to set smbpid to - use -1. */
1184                         *psmbpid = 0xFFFF;
1185                         return NT_STATUS_LOCK_NOT_GRANTED;
1186                 }
1187         }
1188
1189         return NT_STATUS_OK;
1190 }
1191
1192 /****************************************************************************
1193  Remove a particular pending lock.
1194 ****************************************************************************/
1195
1196 BOOL brl_lock_cancel(struct byte_range_lock *br_lck,
1197                 uint32 smbpid,
1198                 struct process_id pid,
1199                 br_off start,
1200                 br_off size,
1201                 enum brl_flavour lock_flav)
1202 {
1203         unsigned int i;
1204         struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1205         struct lock_context context;
1206
1207         context.smbpid = smbpid;
1208         context.pid = pid;
1209         context.tid = br_lck->fsp->conn->cnum;
1210
1211         for (i = 0; i < br_lck->num_locks; i++) {
1212                 struct lock_struct *lock = &locks[i];
1213
1214                 /* For pending locks we *always* care about the fnum. */
1215                 if (brl_same_context(&lock->context, &context) &&
1216                                 lock->fnum == br_lck->fsp->fnum &&
1217                                 IS_PENDING_LOCK(lock->lock_type) &&
1218                                 lock->lock_flav == lock_flav &&
1219                                 lock->start == start &&
1220                                 lock->size == size) {
1221                         break;
1222                 }
1223         }
1224
1225         if (i == br_lck->num_locks) {
1226                 /* Didn't find it. */
1227                 return False;
1228         }
1229
1230         if (i < br_lck->num_locks - 1) {
1231                 /* Found this particular pending lock - delete it */
1232                 memmove(&locks[i], &locks[i+1],
1233                         sizeof(*locks)*((br_lck->num_locks-1) - i));
1234         }
1235
1236         br_lck->num_locks -= 1;
1237         br_lck->modified = True;
1238         return True;
1239 }
1240
1241 /****************************************************************************
1242  Remove any locks associated with a open file.
1243  We return True if this process owns any other Windows locks on this
1244  fd and so we should not immediately close the fd.
1245 ****************************************************************************/
1246
1247 void brl_close_fnum(struct byte_range_lock *br_lck)
1248 {
1249         files_struct *fsp = br_lck->fsp;
1250         uint16 tid = fsp->conn->cnum;
1251         int fnum = fsp->fnum;
1252         unsigned int i, j, dcount=0;
1253         int num_deleted_windows_locks = 0;
1254         struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1255         struct process_id pid = procid_self();
1256         BOOL unlock_individually = False;
1257
1258         if(lp_posix_locking(fsp->conn->params)) {
1259
1260                 /* Check if there are any Windows locks associated with this dev/ino
1261                    pair that are not this fnum. If so we need to call unlock on each
1262                    one in order to release the system POSIX locks correctly. */
1263
1264                 for (i=0; i < br_lck->num_locks; i++) {
1265                         struct lock_struct *lock = &locks[i];
1266
1267                         if (!procid_equal(&lock->context.pid, &pid)) {
1268                                 continue;
1269                         }
1270
1271                         if (lock->lock_type != READ_LOCK && lock->lock_type != WRITE_LOCK) {
1272                                 continue; /* Ignore pending. */
1273                         }
1274
1275                         if (lock->context.tid != tid || lock->fnum != fnum) {
1276                                 unlock_individually = True;
1277                                 break;
1278                         }
1279                 }
1280
1281                 if (unlock_individually) {
1282                         struct lock_struct *locks_copy;
1283                         unsigned int num_locks_copy;
1284
1285                         /* Copy the current lock array. */
1286                         locks_copy = (struct lock_struct *)TALLOC_MEMDUP(br_lck, locks, br_lck->num_locks * sizeof(struct lock_struct));
1287                         if (!locks_copy) {
1288                                 smb_panic("brl_close_fnum: talloc fail.\n");
1289                         }
1290                         num_locks_copy = br_lck->num_locks;
1291
1292                         for (i=0; i < num_locks_copy; i++) {
1293                                 struct lock_struct *lock = &locks_copy[i];
1294
1295                                 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid) &&
1296                                                 (lock->fnum == fnum)) {
1297                                         brl_unlock(br_lck,
1298                                                 lock->context.smbpid,
1299                                                 pid,
1300                                                 lock->start,
1301                                                 lock->size,
1302                                                 lock->lock_flav);
1303                                 }
1304                         }
1305                         return;
1306                 }
1307         }
1308
1309         /* We can bulk delete - any POSIX locks will be removed when the fd closes. */
1310
1311         /* Remove any existing locks for this fnum (or any fnum if they're POSIX). */
1312
1313         for (i=0; i < br_lck->num_locks; i++) {
1314                 struct lock_struct *lock = &locks[i];
1315                 BOOL del_this_lock = False;
1316
1317                 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid)) {
1318                         if ((lock->lock_flav == WINDOWS_LOCK) && (lock->fnum == fnum)) {
1319                                 del_this_lock = True;
1320                                 num_deleted_windows_locks++;
1321                         } else if (lock->lock_flav == POSIX_LOCK) {
1322                                 del_this_lock = True;
1323                         }
1324                 }
1325
1326                 if (del_this_lock) {
1327                         /* Send unlock messages to any pending waiters that overlap. */
1328                         for (j=0; j < br_lck->num_locks; j++) {
1329                                 struct lock_struct *pend_lock = &locks[j];
1330
1331                                 /* Ignore our own or non-pending locks. */
1332                                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1333                                         continue;
1334                                 }
1335
1336                                 /* Optimisation - don't send to this fnum as we're
1337                                    closing it. */
1338                                 if (pend_lock->context.tid == tid &&
1339                                     procid_equal(&pend_lock->context.pid, &pid) &&
1340                                     pend_lock->fnum == fnum) {
1341                                         continue;
1342                                 }
1343
1344                                 /* We could send specific lock info here... */
1345                                 if (brl_pending_overlap(lock, pend_lock)) {
1346                                         message_send_pid(pend_lock->context.pid,
1347                                                         MSG_SMB_UNLOCK,
1348                                                         NULL, 0, True);
1349                                 }
1350                         }
1351
1352                         /* found it - delete it */
1353                         if (br_lck->num_locks > 1 && i < br_lck->num_locks - 1) {
1354                                 memmove(&locks[i], &locks[i+1],
1355                                         sizeof(*locks)*((br_lck->num_locks-1) - i));
1356                         }
1357                         br_lck->num_locks--;
1358                         br_lck->modified = True;
1359                         i--;
1360                         dcount++;
1361                 }
1362         }
1363
1364         if(lp_posix_locking(fsp->conn->params) && num_deleted_windows_locks) {
1365                 /* Reduce the Windows lock POSIX reference count on this dev/ino pair. */
1366                 reduce_windows_lock_ref_count(fsp, num_deleted_windows_locks);
1367         }
1368 }
1369
1370 /****************************************************************************
1371  Ensure this set of lock entries is valid.
1372 ****************************************************************************/
1373
1374 static BOOL validate_lock_entries(unsigned int *pnum_entries, struct lock_struct **pplocks)
1375 {
1376         unsigned int i;
1377         unsigned int num_valid_entries = 0;
1378         struct lock_struct *locks = *pplocks;
1379
1380         for (i = 0; i < *pnum_entries; i++) {
1381                 struct lock_struct *lock_data = &locks[i];
1382                 if (!process_exists(lock_data->context.pid)) {
1383                         /* This process no longer exists - mark this
1384                            entry as invalid by zeroing it. */
1385                         ZERO_STRUCTP(lock_data);
1386                 } else {
1387                         num_valid_entries++;
1388                 }
1389         }
1390
1391         if (num_valid_entries != *pnum_entries) {
1392                 struct lock_struct *new_lock_data = NULL;
1393
1394                 if (num_valid_entries) {
1395                         new_lock_data = SMB_MALLOC_ARRAY(struct lock_struct, num_valid_entries);
1396                         if (!new_lock_data) {
1397                                 DEBUG(3, ("malloc fail\n"));
1398                                 return False;
1399                         }
1400
1401                         num_valid_entries = 0;
1402                         for (i = 0; i < *pnum_entries; i++) {
1403                                 struct lock_struct *lock_data = &locks[i];
1404                                 if (lock_data->context.smbpid &&
1405                                                 lock_data->context.tid) {
1406                                         /* Valid (nonzero) entry - copy it. */
1407                                         memcpy(&new_lock_data[num_valid_entries],
1408                                                 lock_data, sizeof(struct lock_struct));
1409                                         num_valid_entries++;
1410                                 }
1411                         }
1412                 }
1413
1414                 SAFE_FREE(*pplocks);
1415                 *pplocks = new_lock_data;
1416                 *pnum_entries = num_valid_entries;
1417         }
1418
1419         return True;
1420 }
1421
1422 /****************************************************************************
1423  Traverse the whole database with this function, calling traverse_callback
1424  on each lock.
1425 ****************************************************************************/
1426
1427 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
1428 {
1429         struct lock_struct *locks;
1430         struct lock_key *key;
1431         unsigned int i;
1432         unsigned int num_locks = 0;
1433         unsigned int orig_num_locks = 0;
1434
1435         BRLOCK_FN(traverse_callback) = (BRLOCK_FN_CAST())state;
1436
1437         /* In a traverse function we must make a copy of
1438            dbuf before modifying it. */
1439
1440         locks = (struct lock_struct *)memdup(dbuf.dptr, dbuf.dsize);
1441         if (!locks) {
1442                 return -1; /* Terminate traversal. */
1443         }
1444
1445         key = (struct lock_key *)kbuf.dptr;
1446         orig_num_locks = num_locks = dbuf.dsize/sizeof(*locks);
1447
1448         /* Ensure the lock db is clean of entries from invalid processes. */
1449
1450         if (!validate_lock_entries(&num_locks, &locks)) {
1451                 SAFE_FREE(locks);
1452                 return -1; /* Terminate traversal */
1453         }
1454
1455         if (orig_num_locks != num_locks) {
1456                 dbuf.dptr = (uint8 *)locks;
1457                 dbuf.dsize = num_locks * sizeof(*locks);
1458
1459                 if (dbuf.dsize) {
1460                         tdb_store(ttdb, kbuf, dbuf, TDB_REPLACE);
1461                 } else {
1462                         tdb_delete(ttdb, kbuf);
1463                 }
1464         }
1465
1466         for ( i=0; i<num_locks; i++) {
1467                 traverse_callback(key->device,
1468                                   key->inode,
1469                                   locks[i].context.pid,
1470                                   locks[i].lock_type,
1471                                   locks[i].lock_flav,
1472                                   locks[i].start,
1473                                   locks[i].size);
1474         }
1475
1476         SAFE_FREE(locks);
1477         return 0;
1478 }
1479
1480 /*******************************************************************
1481  Call the specified function on each lock in the database.
1482 ********************************************************************/
1483
1484 int brl_forall(BRLOCK_FN(fn))
1485 {
1486         if (!tdb) {
1487                 return 0;
1488         }
1489         return tdb_traverse(tdb, traverse_fn, (void *)fn);
1490 }
1491
1492 /*******************************************************************
1493  Store a potentially modified set of byte range lock data back into
1494  the database.
1495  Unlock the record.
1496 ********************************************************************/
1497
1498 static int byte_range_lock_destructor(struct byte_range_lock *br_lck)
1499 {
1500         TDB_DATA key;
1501
1502         key.dptr = (uint8 *)&br_lck->key;
1503         key.dsize = sizeof(struct lock_key);
1504
1505         if (br_lck->read_only) {
1506                 SMB_ASSERT(!br_lck->modified);
1507         }
1508
1509         if (!br_lck->modified) {
1510                 goto done;
1511         }
1512
1513         if (br_lck->num_locks == 0) {
1514                 /* No locks - delete this entry. */
1515                 if (tdb_delete(tdb, key) == -1) {
1516                         smb_panic("Could not delete byte range lock entry\n");
1517                 }
1518         } else {
1519                 TDB_DATA data;
1520                 data.dptr = (uint8 *)br_lck->lock_data;
1521                 data.dsize = br_lck->num_locks * sizeof(struct lock_struct);
1522
1523                 if (tdb_store(tdb, key, data, TDB_REPLACE) == -1) {
1524                         smb_panic("Could not store byte range mode entry\n");
1525                 }
1526         }
1527
1528  done:
1529
1530         if (!br_lck->read_only) {
1531                 tdb_chainunlock(tdb, key);
1532         }
1533         SAFE_FREE(br_lck->lock_data);
1534         return 0;
1535 }
1536
1537 /*******************************************************************
1538  Fetch a set of byte range lock data from the database.
1539  Leave the record locked.
1540  TALLOC_FREE(brl) will release the lock in the destructor.
1541 ********************************************************************/
1542
1543 static struct byte_range_lock *brl_get_locks_internal(TALLOC_CTX *mem_ctx,
1544                                         files_struct *fsp, BOOL read_only)
1545 {
1546         TDB_DATA key;
1547         TDB_DATA data;
1548         struct byte_range_lock *br_lck = TALLOC_P(mem_ctx, struct byte_range_lock);
1549
1550         if (br_lck == NULL) {
1551                 return NULL;
1552         }
1553
1554         br_lck->fsp = fsp;
1555         br_lck->num_locks = 0;
1556         br_lck->modified = False;
1557         memset(&br_lck->key, '\0', sizeof(struct lock_key));
1558         br_lck->key.device = fsp->dev;
1559         br_lck->key.inode = fsp->inode;
1560
1561         key.dptr = (uint8 *)&br_lck->key;
1562         key.dsize = sizeof(struct lock_key);
1563
1564         if (!fsp->lockdb_clean) {
1565                 /* We must be read/write to clean
1566                    the dead entries. */
1567                 read_only = False;
1568         }
1569
1570         if (read_only) {
1571                 br_lck->read_only = True;
1572         } else {
1573                 if (tdb_chainlock(tdb, key) != 0) {
1574                         DEBUG(3, ("Could not lock byte range lock entry\n"));
1575                         TALLOC_FREE(br_lck);
1576                         return NULL;
1577                 }
1578                 br_lck->read_only = False;
1579         }
1580
1581         talloc_set_destructor(br_lck, byte_range_lock_destructor);
1582
1583         data = tdb_fetch(tdb, key);
1584         br_lck->lock_data = (void *)data.dptr;
1585         br_lck->num_locks = data.dsize / sizeof(struct lock_struct);
1586
1587         if (!fsp->lockdb_clean) {
1588
1589                 /* This is the first time we've accessed this. */
1590                 /* Go through and ensure all entries exist - remove any that don't. */
1591                 /* Makes the lockdb self cleaning at low cost. */
1592
1593                 struct lock_struct *locks =
1594                         (struct lock_struct *)br_lck->lock_data;
1595
1596                 if (!validate_lock_entries(&br_lck->num_locks, &locks)) {
1597                         SAFE_FREE(br_lck->lock_data);
1598                         TALLOC_FREE(br_lck);
1599                         return NULL;
1600                 }
1601
1602                 /*
1603                  * validate_lock_entries might have changed locks. We can't
1604                  * use a direct pointer here because otherwise gcc warnes
1605                  * about strict aliasing rules being violated.
1606                  */
1607                 br_lck->lock_data = locks;
1608
1609                 /* Mark the lockdb as "clean" as seen from this open file. */
1610                 fsp->lockdb_clean = True;
1611         }
1612
1613         if (DEBUGLEVEL >= 10) {
1614                 unsigned int i;
1615                 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1616                 DEBUG(10,("brl_get_locks_internal: %u current locks on dev=%.0f, inode=%.0f\n",
1617                         br_lck->num_locks,
1618                         (double)fsp->dev, (double)fsp->inode ));
1619                 for( i = 0; i < br_lck->num_locks; i++) {
1620                         print_lock_struct(i, &locks[i]);
1621                 }
1622         }
1623         return br_lck;
1624 }
1625
1626 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx,
1627                                         files_struct *fsp)
1628 {
1629         return brl_get_locks_internal(mem_ctx, fsp, False);
1630 }
1631
1632 struct byte_range_lock *brl_get_locks_readonly(TALLOC_CTX *mem_ctx,
1633                                         files_struct *fsp)
1634 {
1635         return brl_get_locks_internal(mem_ctx, fsp, True);
1636 }