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 3 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, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 /* This module implements a tdb based byte range locking service,
  24    replacing the fcntl() based byte range locking previously
  25    used. This allows us to provide the same semantics as NT */
  26
  27 #include "includes.h"
  28
  29 #undef DBGC_CLASS
  30 #define DBGC_CLASS DBGC_LOCKING
  31
  32 #define ZERO_ZERO 0
  33
  34 /* The open brlock.tdb database. */
  35
  36 static struct db_context *brlock_db;
  37
  38 /****************************************************************************
  39  Debug info at level 10 for lock struct.
  40 ****************************************************************************/
  41
  42 static void print_lock_struct(unsigned int i, struct lock_struct *pls)
  43 {
  44         DEBUG(10,("[%u]: smbpid = %u, tid = %u, pid = %s, ",
  45                         i,
  46                         (unsigned int)pls->context.smbpid,
  47                         (unsigned int)pls->context.tid,
  48                         procid_str_static(&pls->context.pid) ));
  49
  50         DEBUG(10,("start = %.0f, size = %.0f, fnum = %d, %s %s\n",
  51                 (double)pls->start,
  52                 (double)pls->size,
  53                 pls->fnum,
  54                 lock_type_name(pls->lock_type),
  55                 lock_flav_name(pls->lock_flav) ));
  56 }
  57
  58 /****************************************************************************
  59  See if two locking contexts are equal.
  60 ****************************************************************************/
  61
  62 BOOL brl_same_context(const struct lock_context *ctx1,
  63                              const struct lock_context *ctx2)
  64 {
  65         return (procid_equal(&ctx1->pid, &ctx2->pid) &&
  66                 (ctx1->smbpid == ctx2->smbpid) &&
  67                 (ctx1->tid == ctx2->tid));
  68 }
  69
  70 /****************************************************************************
  71  See if lck1 and lck2 overlap.
  72 ****************************************************************************/
  73
  74 static BOOL brl_overlap(const struct lock_struct *lck1,
  75                         const struct lock_struct *lck2)
  76 {
  77         /* this extra check is not redundent - it copes with locks
  78            that go beyond the end of 64 bit file space */
  79         if (lck1->size != 0 &&
  80             lck1->start == lck2->start &&
  81             lck1->size == lck2->size) {
  82                 return True;
  83         }
  84
  85         if (lck1->start >= (lck2->start+lck2->size) ||
  86             lck2->start >= (lck1->start+lck1->size)) {
  87                 return False;
  88         }
  89         return True;
  90 }
  91
  92 /****************************************************************************
  93  See if lock2 can be added when lock1 is in place.
  94 ****************************************************************************/
  95
  96 static BOOL brl_conflict(const struct lock_struct *lck1,
  97                          const struct lock_struct *lck2)
  98 {
  99         /* Ignore PENDING locks. */
 100         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 101                 return False;
 102
 103         /* Read locks never conflict. */
 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         return brl_overlap(lck1, lck2);
 114 }
 115
 116 /****************************************************************************
 117  See if lock2 can be added when lock1 is in place - when both locks are POSIX
 118  flavour. POSIX locks ignore fnum - they only care about dev/ino which we
 119  know already match.
 120 ****************************************************************************/
 121
 122 static BOOL brl_conflict_posix(const struct lock_struct *lck1,
 123                                 const struct lock_struct *lck2)
 124 {
 125 #if defined(DEVELOPER)
 126         SMB_ASSERT(lck1->lock_flav == POSIX_LOCK);
 127         SMB_ASSERT(lck2->lock_flav == POSIX_LOCK);
 128 #endif
 129
 130         /* Ignore PENDING locks. */
 131         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 132                 return False;
 133
 134         /* Read locks never conflict. */
 135         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 136                 return False;
 137         }
 138
 139         /* Locks on the same context con't conflict. Ignore fnum. */
 140         if (brl_same_context(&lck1->context, &lck2->context)) {
 141                 return False;
 142         }
 143
 144         /* One is read, the other write, or the context is different,
 145            do they overlap ? */
 146         return brl_overlap(lck1, lck2);
 147 }
 148
 149 #if ZERO_ZERO
 150 static BOOL brl_conflict1(const struct lock_struct *lck1,
 151                          const struct lock_struct *lck2)
 152 {
 153         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 154                 return False;
 155
 156         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 157                 return False;
 158         }
 159
 160         if (brl_same_context(&lck1->context, &lck2->context) &&
 161             lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
 162                 return False;
 163         }
 164
 165         if (lck2->start == 0 && lck2->size == 0 && lck1->size != 0) {
 166                 return True;
 167         }
 168
 169         if (lck1->start >= (lck2->start + lck2->size) ||
 170             lck2->start >= (lck1->start + lck1->size)) {
 171                 return False;
 172         }
 173
 174         return True;
 175 }
 176 #endif
 177
 178 /****************************************************************************
 179  Check to see if this lock conflicts, but ignore our own locks on the
 180  same fnum only. This is the read/write lock check code path.
 181  This is never used in the POSIX lock case.
 182 ****************************************************************************/
 183
 184 static BOOL brl_conflict_other(const struct lock_struct *lck1, const struct lock_struct *lck2)
 185 {
 186         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 187                 return False;
 188
 189         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
 190                 return False;
 191
 192         /* POSIX flavour locks never conflict here - this is only called
 193            in the read/write path. */
 194
 195         if (lck1->lock_flav == POSIX_LOCK && lck2->lock_flav == POSIX_LOCK)
 196                 return False;
 197
 198         /*
 199          * Incoming WRITE locks conflict with existing READ locks even
 200          * if the context is the same. JRA. See LOCKTEST7 in smbtorture.
 201          */
 202
 203         if (!(lck2->lock_type == WRITE_LOCK && lck1->lock_type == READ_LOCK)) {
 204                 if (brl_same_context(&lck1->context, &lck2->context) &&
 205                                         lck1->fnum == lck2->fnum)
 206                         return False;
 207         }
 208
 209         return brl_overlap(lck1, lck2);
 210 }
 211
 212 /****************************************************************************
 213  Check if an unlock overlaps a pending lock.
 214 ****************************************************************************/
 215
 216 static BOOL brl_pending_overlap(const struct lock_struct *lock, const struct lock_struct *pend_lock)
 217 {
 218         if ((lock->start <= pend_lock->start) && (lock->start + lock->size > pend_lock->start))
 219                 return True;
 220         if ((lock->start >= pend_lock->start) && (lock->start <= pend_lock->start + pend_lock->size))
 221                 return True;
 222         return False;
 223 }
 224
 225 /****************************************************************************
 226  Amazingly enough, w2k3 "remembers" whether the last lock failure on a fnum
 227  is the same as this one and changes its error code. I wonder if any
 228  app depends on this ?
 229 ****************************************************************************/
 230
 231 static NTSTATUS brl_lock_failed(files_struct *fsp, const struct lock_struct *lock, BOOL blocking_lock)
 232 {
 233         if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) {
 234                 /* amazing the little things you learn with a test
 235                    suite. Locks beyond this offset (as a 64 bit
 236                    number!) always generate the conflict error code,
 237                    unless the top bit is set */
 238                 if (!blocking_lock) {
 239                         fsp->last_lock_failure = *lock;
 240                 }
 241                 return NT_STATUS_FILE_LOCK_CONFLICT;
 242         }
 243
 244         if (procid_equal(&lock->context.pid, &fsp->last_lock_failure.context.pid) &&
 245                         lock->context.tid == fsp->last_lock_failure.context.tid &&
 246                         lock->fnum == fsp->last_lock_failure.fnum &&
 247                         lock->start == fsp->last_lock_failure.start) {
 248                 return NT_STATUS_FILE_LOCK_CONFLICT;
 249         }
 250
 251         if (!blocking_lock) {
 252                 fsp->last_lock_failure = *lock;
 253         }
 254         return NT_STATUS_LOCK_NOT_GRANTED;
 255 }
 256
 257 /****************************************************************************
 258  Open up the brlock.tdb database.
 259 ****************************************************************************/
 260
 261 void brl_init(int read_only)
 262 {
 263         if (brlock_db) {
 264                 return;
 265         }
 266         brlock_db = db_open(NULL, lock_path("brlock.tdb"), 0,
 267                             TDB_DEFAULT
 268                             |TDB_VOLATILE
 269                             |(read_only?0x0:TDB_CLEAR_IF_FIRST),
 270                             read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644 );
 271         if (!brlock_db) {
 272                 DEBUG(0,("Failed to open byte range locking database %s\n",
 273                         lock_path("brlock.tdb")));
 274                 return;
 275         }
 276 }
 277
 278 /****************************************************************************
 279  Close down the brlock.tdb database.
 280 ****************************************************************************/
 281
 282 void brl_shutdown(int read_only)
 283 {
 284         if (!brlock_db) {
 285                 return;
 286         }
 287         TALLOC_FREE(brlock_db);
 288 }
 289
 290 #if ZERO_ZERO
 291 /****************************************************************************
 292  Compare two locks for sorting.
 293 ****************************************************************************/
 294
 295 static int lock_compare(const struct lock_struct *lck1,
 296                          const struct lock_struct *lck2)
 297 {
 298         if (lck1->start != lck2->start) {
 299                 return (lck1->start - lck2->start);
 300         }
 301         if (lck2->size != lck1->size) {
 302                 return ((int)lck1->size - (int)lck2->size);
 303         }
 304         return 0;
 305 }
 306 #endif
 307
 308 /****************************************************************************
 309  Lock a range of bytes - Windows lock semantics.
 310 ****************************************************************************/
 311
 312 static NTSTATUS brl_lock_windows(struct byte_range_lock *br_lck,
 313                         struct lock_struct *plock, BOOL blocking_lock)
 314 {
 315         unsigned int i;
 316         files_struct *fsp = br_lck->fsp;
 317         struct lock_struct *locks = br_lck->lock_data;
 318
 319         for (i=0; i < br_lck->num_locks; i++) {
 320                 /* Do any Windows or POSIX locks conflict ? */
 321                 if (brl_conflict(&locks[i], plock)) {
 322                         /* Remember who blocked us. */
 323                         plock->context.smbpid = locks[i].context.smbpid;
 324                         return brl_lock_failed(fsp,plock,blocking_lock);
 325                 }
 326 #if ZERO_ZERO
 327                 if (plock->start == 0 && plock->size == 0 &&
 328                                 locks[i].size == 0) {
 329                         break;
 330                 }
 331 #endif
 332         }
 333
 334         /* We can get the Windows lock, now see if it needs to
 335            be mapped into a lower level POSIX one, and if so can
 336            we get it ? */
 337
 338         if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(fsp->conn->params)) {
 339                 int errno_ret;
 340                 if (!set_posix_lock_windows_flavour(fsp,
 341                                 plock->start,
 342                                 plock->size,
 343                                 plock->lock_type,
 344                                 &plock->context,
 345                                 locks,
 346                                 br_lck->num_locks,
 347                                 &errno_ret)) {
 348
 349                         /* We don't know who blocked us. */
 350                         plock->context.smbpid = 0xFFFFFFFF;
 351
 352                         if (errno_ret == EACCES || errno_ret == EAGAIN) {
 353                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 354                         } else {
 355                                 return map_nt_error_from_unix(errno);
 356                         }
 357                 }
 358         }
 359
 360         /* no conflicts - add it to the list of locks */
 361         locks = (struct lock_struct *)SMB_REALLOC(locks, (br_lck->num_locks + 1) * sizeof(*locks));
 362         if (!locks) {
 363                 return NT_STATUS_NO_MEMORY;
 364         }
 365
 366         memcpy(&locks[br_lck->num_locks], plock, sizeof(struct lock_struct));
 367         br_lck->num_locks += 1;
 368         br_lck->lock_data = locks;
 369         br_lck->modified = True;
 370
 371         return NT_STATUS_OK;
 372 }
 373
 374 /****************************************************************************
 375  Cope with POSIX range splits and merges.
 376 ****************************************************************************/
 377
 378 static unsigned int brlock_posix_split_merge(struct lock_struct *lck_arr,               /* Output array. */
 379                                                 const struct lock_struct *ex,           /* existing lock. */
 380                                                 const struct lock_struct *plock,        /* proposed lock. */
 381                                                 BOOL *lock_was_added)
 382 {
 383         BOOL lock_types_differ = (ex->lock_type != plock->lock_type);
 384
 385         /* We can't merge non-conflicting locks on different context - ignore fnum. */
 386
 387         if (!brl_same_context(&ex->context, &plock->context)) {
 388                 /* Just copy. */
 389                 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 390                 return 1;
 391         }
 392
 393         /* We now know we have the same context. */
 394
 395         /* Did we overlap ? */
 396
 397 /*********************************************
 398                                              +---------+
 399                                              | ex      |
 400                                              +---------+
 401                               +-------+
 402                               | plock |
 403                               +-------+
 404 OR....
 405              +---------+
 406              |  ex     |
 407              +---------+
 408 **********************************************/
 409
 410         if ( (ex->start > (plock->start + plock->size)) ||
 411                         (plock->start > (ex->start + ex->size))) {
 412                 /* No overlap with this lock - copy existing. */
 413                 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 414                 return 1;
 415         }
 416
 417 /*********************************************
 418         +---------------------------+
 419         |          ex               |
 420         +---------------------------+
 421         +---------------------------+
 422         |       plock               | -> replace with plock.
 423         +---------------------------+
 424 **********************************************/
 425
 426         if ( (ex->start >= plock->start) &&
 427                         (ex->start + ex->size <= plock->start + plock->size) ) {
 428                 memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
 429                 *lock_was_added = True;
 430                 return 1;
 431         }
 432
 433 /*********************************************
 434         +-----------------------+
 435         |          ex           |
 436         +-----------------------+
 437         +---------------+
 438         |   plock       |
 439         +---------------+
 440 OR....
 441                         +-------+
 442                         |  ex   |
 443                         +-------+
 444         +---------------+
 445         |   plock       |
 446         +---------------+
 447
 448 BECOMES....
 449         +---------------+-------+
 450         |   plock       | ex    | - different lock types.
 451         +---------------+-------+
 452 OR.... (merge)
 453         +-----------------------+
 454         |   ex                  | - same lock type.
 455         +-----------------------+
 456 **********************************************/
 457
 458         if ( (ex->start >= plock->start) &&
 459                                 (ex->start <= plock->start + plock->size) &&
 460                                 (ex->start + ex->size > plock->start + plock->size) ) {
 461
 462                 *lock_was_added = True;
 463
 464                 /* If the lock types are the same, we merge, if different, we
 465                    add the new lock before the old. */
 466
 467                 if (lock_types_differ) {
 468                         /* Add new. */
 469                         memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
 470                         memcpy(&lck_arr[1], ex, sizeof(struct lock_struct));
 471                         /* Adjust existing start and size. */
 472                         lck_arr[1].start = plock->start + plock->size;
 473                         lck_arr[1].size = (ex->start + ex->size) - (plock->start + plock->size);
 474                         return 2;
 475                 } else {
 476                         /* Merge. */
 477                         memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
 478                         /* Set new start and size. */
 479                         lck_arr[0].start = plock->start;
 480                         lck_arr[0].size = (ex->start + ex->size) - plock->start;
 481                         return 1;
 482                 }
 483         }
 484
 485 /*********************************************
 486    +-----------------------+
 487    |  ex                   |
 488    +-----------------------+
 489            +---------------+
 490            |   plock       |
 491            +---------------+
 492 OR....
 493    +-------+
 494    |  ex   |
 495    +-------+
 496            +---------------+
 497            |   plock       |
 498            +---------------+
 499 BECOMES....
 500    +-------+---------------+
 501    | ex    |   plock       | - different lock types
 502    +-------+---------------+
 503
 504 OR.... (merge)
 505    +-----------------------+
 506    | ex                    | - same lock type.
 507    +-----------------------+
 508
 509 **********************************************/
 510
 511         if ( (ex->start < plock->start) &&
 512                         (ex->start + ex->size >= plock->start) &&
 513                         (ex->start + ex->size <= plock->start + plock->size) ) {
 514
 515                 *lock_was_added = True;
 516
 517                 /* If the lock types are the same, we merge, if different, we
 518                    add the new lock after the old. */
 519
 520                 if (lock_types_differ) {
 521                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 522                         memcpy(&lck_arr[1], plock, sizeof(struct lock_struct));
 523                         /* Adjust existing size. */
 524                         lck_arr[0].size = plock->start - ex->start;
 525                         return 2;
 526                 } else {
 527                         /* Merge. */
 528                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 529                         /* Adjust existing size. */
 530                         lck_arr[0].size = (plock->start + plock->size) - ex->start;
 531                         return 1;
 532                 }
 533         }
 534
 535 /*********************************************
 536         +---------------------------+
 537         |        ex                 |
 538         +---------------------------+
 539                 +---------+
 540                 |  plock  |
 541                 +---------+
 542 BECOMES.....
 543         +-------+---------+---------+
 544         | ex    |  plock  | ex      | - different lock types.
 545         +-------+---------+---------+
 546 OR
 547         +---------------------------+
 548         |        ex                 | - same lock type.
 549         +---------------------------+
 550 **********************************************/
 551
 552         if ( (ex->start < plock->start) && (ex->start + ex->size > plock->start + plock->size) ) {
 553                 *lock_was_added = True;
 554
 555                 if (lock_types_differ) {
 556
 557                         /* We have to split ex into two locks here. */
 558
 559                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 560                         memcpy(&lck_arr[1], plock, sizeof(struct lock_struct));
 561                         memcpy(&lck_arr[2], ex, sizeof(struct lock_struct));
 562
 563                         /* Adjust first existing size. */
 564                         lck_arr[0].size = plock->start - ex->start;
 565
 566                         /* Adjust second existing start and size. */
 567                         lck_arr[2].start = plock->start + plock->size;
 568                         lck_arr[2].size = (ex->start + ex->size) - (plock->start + plock->size);
 569                         return 3;
 570                 } else {
 571                         /* Just eat plock. */
 572                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 573                         return 1;
 574                 }
 575         }
 576
 577         /* Never get here. */
 578         smb_panic("brlock_posix_split_merge");
 579         /* Notreached. */
 580
 581         /* Keep some compilers happy. */
 582         return 0;
 583 }
 584
 585 /****************************************************************************
 586  Lock a range of bytes - POSIX lock semantics.
 587  We must cope with range splits and merges.
 588 ****************************************************************************/
 589
 590 static NTSTATUS brl_lock_posix(struct messaging_context *msg_ctx,
 591                                struct byte_range_lock *br_lck,
 592                                struct lock_struct *plock)
 593 {
 594         unsigned int i, count;
 595         struct lock_struct *locks = br_lck->lock_data;
 596         struct lock_struct *tp;
 597         BOOL lock_was_added = False;
 598         BOOL signal_pending_read = False;
 599
 600         /* No zero-zero locks for POSIX. */
 601         if (plock->start == 0 && plock->size == 0) {
 602                 return NT_STATUS_INVALID_PARAMETER;
 603         }
 604
 605         /* Don't allow 64-bit lock wrap. */
 606         if (plock->start + plock->size < plock->start ||
 607                         plock->start + plock->size < plock->size) {
 608                 return NT_STATUS_INVALID_PARAMETER;
 609         }
 610
 611         /* The worst case scenario here is we have to split an
 612            existing POSIX lock range into two, and add our lock,
 613            so we need at most 2 more entries. */
 614
 615         tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 2));
 616         if (!tp) {
 617                 return NT_STATUS_NO_MEMORY;
 618         }
 619
 620         count = 0;
 621         for (i=0; i < br_lck->num_locks; i++) {
 622                 struct lock_struct *curr_lock = &locks[i];
 623
 624                 /* If we have a pending read lock, a lock downgrade should
 625                    trigger a lock re-evaluation. */
 626                 if (curr_lock->lock_type == PENDING_READ_LOCK &&
 627                                 brl_pending_overlap(plock, curr_lock)) {
 628                         signal_pending_read = True;
 629                 }
 630
 631                 if (curr_lock->lock_flav == WINDOWS_LOCK) {
 632                         /* Do any Windows flavour locks conflict ? */
 633                         if (brl_conflict(curr_lock, plock)) {
 634                                 /* No games with error messages. */
 635                                 SAFE_FREE(tp);
 636                                 /* Remember who blocked us. */
 637                                 plock->context.smbpid = curr_lock->context.smbpid;
 638                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 639                         }
 640                         /* Just copy the Windows lock into the new array. */
 641                         memcpy(&tp[count], curr_lock, sizeof(struct lock_struct));
 642                         count++;
 643                 } else {
 644                         /* POSIX conflict semantics are different. */
 645                         if (brl_conflict_posix(curr_lock, plock)) {
 646                                 /* Can't block ourselves with POSIX locks. */
 647                                 /* No games with error messages. */
 648                                 SAFE_FREE(tp);
 649                                 /* Remember who blocked us. */
 650                                 plock->context.smbpid = curr_lock->context.smbpid;
 651                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 652                         }
 653
 654                         /* Work out overlaps. */
 655                         count += brlock_posix_split_merge(&tp[count], curr_lock, plock, &lock_was_added);
 656                 }
 657         }
 658
 659         if (!lock_was_added) {
 660                 memcpy(&tp[count], plock, sizeof(struct lock_struct));
 661                 count++;
 662         }
 663
 664         /* We can get the POSIX lock, now see if it needs to
 665            be mapped into a lower level POSIX one, and if so can
 666            we get it ? */
 667
 668         if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(br_lck->fsp->conn->params)) {
 669                 int errno_ret;
 670
 671                 /* The lower layer just needs to attempt to
 672                    get the system POSIX lock. We've weeded out
 673                    any conflicts above. */
 674
 675                 if (!set_posix_lock_posix_flavour(br_lck->fsp,
 676                                 plock->start,
 677                                 plock->size,
 678                                 plock->lock_type,
 679                                 &errno_ret)) {
 680
 681                         /* We don't know who blocked us. */
 682                         plock->context.smbpid = 0xFFFFFFFF;
 683
 684                         if (errno_ret == EACCES || errno_ret == EAGAIN) {
 685                                 SAFE_FREE(tp);
 686                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 687                         } else {
 688                                 SAFE_FREE(tp);
 689                                 return map_nt_error_from_unix(errno);
 690                         }
 691                 }
 692         }
 693
 694         /* Realloc so we don't leak entries per lock call. */
 695         tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
 696         if (!tp) {
 697                 return NT_STATUS_NO_MEMORY;
 698         }
 699         br_lck->num_locks = count;
 700         SAFE_FREE(br_lck->lock_data);
 701         br_lck->lock_data = tp;
 702         locks = tp;
 703         br_lck->modified = True;
 704
 705         /* A successful downgrade from write to read lock can trigger a lock
 706            re-evalutation where waiting readers can now proceed. */
 707
 708         if (signal_pending_read) {
 709                 /* Send unlock messages to any pending read waiters that overlap. */
 710                 for (i=0; i < br_lck->num_locks; i++) {
 711                         struct lock_struct *pend_lock = &locks[i];
 712
 713                         /* Ignore non-pending locks. */
 714                         if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
 715                                 continue;
 716                         }
 717
 718                         if (pend_lock->lock_type == PENDING_READ_LOCK &&
 719                                         brl_pending_overlap(plock, pend_lock)) {
 720                                 DEBUG(10,("brl_lock_posix: sending unlock message to pid %s\n",
 721                                         procid_str_static(&pend_lock->context.pid )));
 722
 723                                 messaging_send(msg_ctx, pend_lock->context.pid,
 724                                                MSG_SMB_UNLOCK, &data_blob_null);
 725                         }
 726                 }
 727         }
 728
 729         return NT_STATUS_OK;
 730 }
 731
 732 /****************************************************************************
 733  Lock a range of bytes.
 734 ****************************************************************************/
 735
 736 NTSTATUS brl_lock(struct messaging_context *msg_ctx,
 737                 struct byte_range_lock *br_lck,
 738                 uint32 smbpid,
 739                 struct server_id pid,
 740                 br_off start,
 741                 br_off size,
 742                 enum brl_type lock_type,
 743                 enum brl_flavour lock_flav,
 744                 BOOL blocking_lock,
 745                 uint32 *psmbpid)
 746 {
 747         NTSTATUS ret;
 748         struct lock_struct lock;
 749
 750 #if !ZERO_ZERO
 751         if (start == 0 && size == 0) {
 752                 DEBUG(0,("client sent 0/0 lock - please report this\n"));
 753         }
 754 #endif
 755
 756         lock.context.smbpid = smbpid;
 757         lock.context.pid = pid;
 758         lock.context.tid = br_lck->fsp->conn->cnum;
 759         lock.start = start;
 760         lock.size = size;
 761         lock.fnum = br_lck->fsp->fnum;
 762         lock.lock_type = lock_type;
 763         lock.lock_flav = lock_flav;
 764
 765         if (lock_flav == WINDOWS_LOCK) {
 766                 ret = brl_lock_windows(br_lck, &lock, blocking_lock);
 767         } else {
 768                 ret = brl_lock_posix(msg_ctx, br_lck, &lock);
 769         }
 770
 771 #if ZERO_ZERO
 772         /* sort the lock list */
 773         qsort(br_lck->lock_data, (size_t)br_lck->num_locks, sizeof(lock), lock_compare);
 774 #endif
 775
 776         /* If we're returning an error, return who blocked us. */
 777         if (!NT_STATUS_IS_OK(ret) && psmbpid) {
 778                 *psmbpid = lock.context.smbpid;
 779         }
 780         return ret;
 781 }
 782
 783 /****************************************************************************
 784  Unlock a range of bytes - Windows semantics.
 785 ****************************************************************************/
 786
 787 static BOOL brl_unlock_windows(struct messaging_context *msg_ctx,
 788                                struct byte_range_lock *br_lck,
 789                                const struct lock_struct *plock)
 790 {
 791         unsigned int i, j;
 792         struct lock_struct *locks = br_lck->lock_data;
 793         enum brl_type deleted_lock_type = READ_LOCK; /* shut the compiler up.... */
 794
 795 #if ZERO_ZERO
 796         /* Delete write locks by preference... The lock list
 797            is sorted in the zero zero case. */
 798
 799         for (i = 0; i < br_lck->num_locks; i++) {
 800                 struct lock_struct *lock = &locks[i];
 801
 802                 if (lock->lock_type == WRITE_LOCK &&
 803                     brl_same_context(&lock->context, &plock->context) &&
 804                     lock->fnum == plock->fnum &&
 805                     lock->lock_flav == WINDOWS_LOCK &&
 806                     lock->start == plock->start &&
 807                     lock->size == plock->size) {
 808
 809                         /* found it - delete it */
 810                         deleted_lock_type = lock->lock_type;
 811                         break;
 812                 }
 813         }
 814
 815         if (i != br_lck->num_locks) {
 816                 /* We found it - don't search again. */
 817                 goto unlock_continue;
 818         }
 819 #endif
 820
 821         for (i = 0; i < br_lck->num_locks; i++) {
 822                 struct lock_struct *lock = &locks[i];
 823
 824                 /* Only remove our own locks that match in start, size, and flavour. */
 825                 if (brl_same_context(&lock->context, &plock->context) &&
 826                                         lock->fnum == plock->fnum &&
 827                                         lock->lock_flav == WINDOWS_LOCK &&
 828                                         lock->start == plock->start &&
 829                                         lock->size == plock->size ) {
 830                         deleted_lock_type = lock->lock_type;
 831                         break;
 832                 }
 833         }
 834
 835         if (i == br_lck->num_locks) {
 836                 /* we didn't find it */
 837                 return False;
 838         }
 839
 840 #if ZERO_ZERO
 841   unlock_continue:
 842 #endif
 843
 844         /* Actually delete the lock. */
 845         if (i < br_lck->num_locks - 1) {
 846                 memmove(&locks[i], &locks[i+1],
 847                         sizeof(*locks)*((br_lck->num_locks-1) - i));
 848         }
 849
 850         br_lck->num_locks -= 1;
 851         br_lck->modified = True;
 852
 853         /* Unlock the underlying POSIX regions. */
 854         if(lp_posix_locking(br_lck->fsp->conn->params)) {
 855                 release_posix_lock_windows_flavour(br_lck->fsp,
 856                                 plock->start,
 857                                 plock->size,
 858                                 deleted_lock_type,
 859                                 &plock->context,
 860                                 locks,
 861                                 br_lck->num_locks);
 862         }
 863
 864         /* Send unlock messages to any pending waiters that overlap. */
 865         for (j=0; j < br_lck->num_locks; j++) {
 866                 struct lock_struct *pend_lock = &locks[j];
 867
 868                 /* Ignore non-pending locks. */
 869                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
 870                         continue;
 871                 }
 872
 873                 /* We could send specific lock info here... */
 874                 if (brl_pending_overlap(plock, pend_lock)) {
 875                         DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
 876                                 procid_str_static(&pend_lock->context.pid )));
 877
 878                         messaging_send(msg_ctx, pend_lock->context.pid,
 879                                        MSG_SMB_UNLOCK, &data_blob_null);
 880                 }
 881         }
 882
 883         return True;
 884 }
 885
 886 /****************************************************************************
 887  Unlock a range of bytes - POSIX semantics.
 888 ****************************************************************************/
 889
 890 static BOOL brl_unlock_posix(struct messaging_context *msg_ctx,
 891                              struct byte_range_lock *br_lck,
 892                              const struct lock_struct *plock)
 893 {
 894         unsigned int i, j, count;
 895         struct lock_struct *tp;
 896         struct lock_struct *locks = br_lck->lock_data;
 897         BOOL overlap_found = False;
 898
 899         /* No zero-zero locks for POSIX. */
 900         if (plock->start == 0 && plock->size == 0) {
 901                 return False;
 902         }
 903
 904         /* Don't allow 64-bit lock wrap. */
 905         if (plock->start + plock->size < plock->start ||
 906                         plock->start + plock->size < plock->size) {
 907                 DEBUG(10,("brl_unlock_posix: lock wrap\n"));
 908                 return False;
 909         }
 910
 911         /* The worst case scenario here is we have to split an
 912            existing POSIX lock range into two, so we need at most
 913            1 more entry. */
 914
 915         tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 1));
 916         if (!tp) {
 917                 DEBUG(10,("brl_unlock_posix: malloc fail\n"));
 918                 return False;
 919         }
 920
 921         count = 0;
 922         for (i = 0; i < br_lck->num_locks; i++) {
 923                 struct lock_struct *lock = &locks[i];
 924                 struct lock_struct tmp_lock[3];
 925                 BOOL lock_was_added = False;
 926                 unsigned int tmp_count;
 927
 928                 /* Only remove our own locks - ignore fnum. */
 929                 if (IS_PENDING_LOCK(lock->lock_type) ||
 930                                 !brl_same_context(&lock->context, &plock->context)) {
 931                         memcpy(&tp[count], lock, sizeof(struct lock_struct));
 932                         count++;
 933                         continue;
 934                 }
 935
 936                 /* Work out overlaps. */
 937                 tmp_count = brlock_posix_split_merge(&tmp_lock[0], &locks[i], plock, &lock_was_added);
 938
 939                 if (tmp_count == 1) {
 940                         /* Ether the locks didn't overlap, or the unlock completely
 941                            overlapped this lock. If it didn't overlap, then there's
 942                            no change in the locks. */
 943                         if (tmp_lock[0].lock_type != UNLOCK_LOCK) {
 944                                 SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
 945                                 /* No change in this lock. */
 946                                 memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
 947                                 count++;
 948                         } else {
 949                                 SMB_ASSERT(tmp_lock[0].lock_type == UNLOCK_LOCK);
 950                                 overlap_found = True;
 951                         }
 952                         continue;
 953                 } else if (tmp_count == 2) {
 954                         /* The unlock overlapped an existing lock. Copy the truncated
 955                            lock into the lock array. */
 956                         if (tmp_lock[0].lock_type != UNLOCK_LOCK) {
 957                                 SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
 958                                 SMB_ASSERT(tmp_lock[1].lock_type == UNLOCK_LOCK);
 959                                 memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
 960                                 if (tmp_lock[0].size != locks[i].size) {
 961                                         overlap_found = True;
 962                                 }
 963                         } else {
 964                                 SMB_ASSERT(tmp_lock[0].lock_type == UNLOCK_LOCK);
 965                                 SMB_ASSERT(tmp_lock[1].lock_type == locks[i].lock_type);
 966                                 memcpy(&tp[count], &tmp_lock[1], sizeof(struct lock_struct));
 967                                 if (tmp_lock[1].start != locks[i].start) {
 968                                         overlap_found = True;
 969                                 }
 970                         }
 971                         count++;
 972                         continue;
 973                 } else {
 974                         /* tmp_count == 3 - (we split a lock range in two). */
 975                         SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
 976                         SMB_ASSERT(tmp_lock[1].lock_type == UNLOCK_LOCK);
 977                         SMB_ASSERT(tmp_lock[2].lock_type == locks[i].lock_type);
 978
 979                         memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
 980                         count++;
 981                         memcpy(&tp[count], &tmp_lock[2], sizeof(struct lock_struct));
 982                         count++;
 983                         overlap_found = True;
 984                         /* Optimisation... */
 985                         /* We know we're finished here as we can't overlap any
 986                            more POSIX locks. Copy the rest of the lock array. */
 987                         if (i < br_lck->num_locks - 1) {
 988                                 memcpy(&tp[count], &locks[i+1],
 989                                         sizeof(*locks)*((br_lck->num_locks-1) - i));
 990                                 count += ((br_lck->num_locks-1) - i);
 991                         }
 992                         break;
 993                 }
 994         }
 995
 996         if (!overlap_found) {
 997                 /* Just ignore - no change. */
 998                 SAFE_FREE(tp);
 999                 DEBUG(10,("brl_unlock_posix: No overlap - unlocked.\n"));
1000                 return True;
1001         }
1002
1003         /* Unlock any POSIX regions. */
1004         if(lp_posix_locking(br_lck->fsp->conn->params)) {
1005                 release_posix_lock_posix_flavour(br_lck->fsp,
1006                                                 plock->start,
1007                                                 plock->size,
1008                                                 &plock->context,
1009                                                 tp,
1010                                                 count);
1011         }
1012
1013         /* Realloc so we don't leak entries per unlock call. */
1014         if (count) {
1015                 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
1016                 if (!tp) {
1017                         DEBUG(10,("brl_unlock_posix: realloc fail\n"));
1018                         return False;
1019                 }
1020         } else {
1021                 /* We deleted the last lock. */
1022                 SAFE_FREE(tp);
1023                 tp = NULL;
1024         }
1025
1026         br_lck->num_locks = count;
1027         SAFE_FREE(br_lck->lock_data);
1028         locks = tp;
1029         br_lck->lock_data = tp;
1030         br_lck->modified = True;
1031
1032         /* Send unlock messages to any pending waiters that overlap. */
1033
1034         for (j=0; j < br_lck->num_locks; j++) {
1035                 struct lock_struct *pend_lock = &locks[j];
1036
1037                 /* Ignore non-pending locks. */
1038                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1039                         continue;
1040                 }
1041
1042                 /* We could send specific lock info here... */
1043                 if (brl_pending_overlap(plock, pend_lock)) {
1044                         DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1045                                 procid_str_static(&pend_lock->context.pid )));
1046
1047                         messaging_send(msg_ctx, pend_lock->context.pid,
1048                                        MSG_SMB_UNLOCK, &data_blob_null);
1049                 }
1050         }
1051
1052         return True;
1053 }
1054
1055 /****************************************************************************
1056  Unlock a range of bytes.
1057 ****************************************************************************/
1058
1059 BOOL brl_unlock(struct messaging_context *msg_ctx,
1060                 struct byte_range_lock *br_lck,
1061                 uint32 smbpid,
1062                 struct server_id pid,
1063                 br_off start,
1064                 br_off size,
1065                 enum brl_flavour lock_flav)
1066 {
1067         struct lock_struct lock;
1068
1069         lock.context.smbpid = smbpid;
1070         lock.context.pid = pid;
1071         lock.context.tid = br_lck->fsp->conn->cnum;
1072         lock.start = start;
1073         lock.size = size;
1074         lock.fnum = br_lck->fsp->fnum;
1075         lock.lock_type = UNLOCK_LOCK;
1076         lock.lock_flav = lock_flav;
1077
1078         if (lock_flav == WINDOWS_LOCK) {
1079                 return brl_unlock_windows(msg_ctx, br_lck, &lock);
1080         } else {
1081                 return brl_unlock_posix(msg_ctx, br_lck, &lock);
1082         }
1083 }
1084
1085 /****************************************************************************
1086  Test if we could add a lock if we wanted to.
1087  Returns True if the region required is currently unlocked, False if locked.
1088 ****************************************************************************/
1089
1090 BOOL brl_locktest(struct byte_range_lock *br_lck,
1091                 uint32 smbpid,
1092                 struct server_id pid,
1093                 br_off start,
1094                 br_off size,
1095                 enum brl_type lock_type,
1096                 enum brl_flavour lock_flav)
1097 {
1098         BOOL ret = True;
1099         unsigned int i;
1100         struct lock_struct lock;
1101         const struct lock_struct *locks = br_lck->lock_data;
1102         files_struct *fsp = br_lck->fsp;
1103
1104         lock.context.smbpid = smbpid;
1105         lock.context.pid = pid;
1106         lock.context.tid = br_lck->fsp->conn->cnum;
1107         lock.start = start;
1108         lock.size = size;
1109         lock.fnum = fsp->fnum;
1110         lock.lock_type = lock_type;
1111         lock.lock_flav = lock_flav;
1112
1113         /* Make sure existing locks don't conflict */
1114         for (i=0; i < br_lck->num_locks; i++) {
1115                 /*
1116                  * Our own locks don't conflict.
1117                  */
1118                 if (brl_conflict_other(&locks[i], &lock)) {
1119                         return False;
1120                 }
1121         }
1122
1123         /*
1124          * There is no lock held by an SMB daemon, check to
1125          * see if there is a POSIX lock from a UNIX or NFS process.
1126          * This only conflicts with Windows locks, not POSIX locks.
1127          */
1128
1129         if(lp_posix_locking(fsp->conn->params) && (lock_flav == WINDOWS_LOCK)) {
1130                 ret = is_posix_locked(fsp, &start, &size, &lock_type, WINDOWS_LOCK);
1131
1132                 DEBUG(10,("brl_locktest: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1133                         (double)start, (double)size, ret ? "locked" : "unlocked",
1134                         fsp->fnum, fsp->fsp_name ));
1135
1136                 /* We need to return the inverse of is_posix_locked. */
1137                 ret = !ret;
1138         }
1139
1140         /* no conflicts - we could have added it */
1141         return ret;
1142 }
1143
1144 /****************************************************************************
1145  Query for existing locks.
1146 ****************************************************************************/
1147
1148 NTSTATUS brl_lockquery(struct byte_range_lock *br_lck,
1149                 uint32 *psmbpid,
1150                 struct server_id pid,
1151                 br_off *pstart,
1152                 br_off *psize,
1153                 enum brl_type *plock_type,
1154                 enum brl_flavour lock_flav)
1155 {
1156         unsigned int i;
1157         struct lock_struct lock;
1158         const struct lock_struct *locks = br_lck->lock_data;
1159         files_struct *fsp = br_lck->fsp;
1160
1161         lock.context.smbpid = *psmbpid;
1162         lock.context.pid = pid;
1163         lock.context.tid = br_lck->fsp->conn->cnum;
1164         lock.start = *pstart;
1165         lock.size = *psize;
1166         lock.fnum = fsp->fnum;
1167         lock.lock_type = *plock_type;
1168         lock.lock_flav = lock_flav;
1169
1170         /* Make sure existing locks don't conflict */
1171         for (i=0; i < br_lck->num_locks; i++) {
1172                 const struct lock_struct *exlock = &locks[i];
1173                 BOOL conflict = False;
1174
1175                 if (exlock->lock_flav == WINDOWS_LOCK) {
1176                         conflict = brl_conflict(exlock, &lock);
1177                 } else {
1178                         conflict = brl_conflict_posix(exlock, &lock);
1179                 }
1180
1181                 if (conflict) {
1182                         *psmbpid = exlock->context.smbpid;
1183                         *pstart = exlock->start;
1184                         *psize = exlock->size;
1185                         *plock_type = exlock->lock_type;
1186                         return NT_STATUS_LOCK_NOT_GRANTED;
1187                 }
1188         }
1189
1190         /*
1191          * There is no lock held by an SMB daemon, check to
1192          * see if there is a POSIX lock from a UNIX or NFS process.
1193          */
1194
1195         if(lp_posix_locking(fsp->conn->params)) {
1196                 BOOL ret = is_posix_locked(fsp, pstart, psize, plock_type, POSIX_LOCK);
1197
1198                 DEBUG(10,("brl_lockquery: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1199                         (double)*pstart, (double)*psize, ret ? "locked" : "unlocked",
1200                         fsp->fnum, fsp->fsp_name ));
1201
1202                 if (ret) {
1203                         /* Hmmm. No clue what to set smbpid to - use -1. */
1204                         *psmbpid = 0xFFFF;
1205                         return NT_STATUS_LOCK_NOT_GRANTED;
1206                 }
1207         }
1208
1209         return NT_STATUS_OK;
1210 }
1211
1212 /****************************************************************************
1213  Remove a particular pending lock.
1214 ****************************************************************************/
1215
1216 BOOL brl_lock_cancel(struct byte_range_lock *br_lck,
1217                 uint32 smbpid,
1218                 struct server_id pid,
1219                 br_off start,
1220                 br_off size,
1221                 enum brl_flavour lock_flav)
1222 {
1223         unsigned int i;
1224         struct lock_struct *locks = br_lck->lock_data;
1225         struct lock_context context;
1226
1227         context.smbpid = smbpid;
1228         context.pid = pid;
1229         context.tid = br_lck->fsp->conn->cnum;
1230
1231         for (i = 0; i < br_lck->num_locks; i++) {
1232                 struct lock_struct *lock = &locks[i];
1233
1234                 /* For pending locks we *always* care about the fnum. */
1235                 if (brl_same_context(&lock->context, &context) &&
1236                                 lock->fnum == br_lck->fsp->fnum &&
1237                                 IS_PENDING_LOCK(lock->lock_type) &&
1238                                 lock->lock_flav == lock_flav &&
1239                                 lock->start == start &&
1240                                 lock->size == size) {
1241                         break;
1242                 }
1243         }
1244
1245         if (i == br_lck->num_locks) {
1246                 /* Didn't find it. */
1247                 return False;
1248         }
1249
1250         if (i < br_lck->num_locks - 1) {
1251                 /* Found this particular pending lock - delete it */
1252                 memmove(&locks[i], &locks[i+1],
1253                         sizeof(*locks)*((br_lck->num_locks-1) - i));
1254         }
1255
1256         br_lck->num_locks -= 1;
1257         br_lck->modified = True;
1258         return True;
1259 }
1260
1261 /****************************************************************************
1262  Remove any locks associated with a open file.
1263  We return True if this process owns any other Windows locks on this
1264  fd and so we should not immediately close the fd.
1265 ****************************************************************************/
1266
1267 void brl_close_fnum(struct messaging_context *msg_ctx,
1268                     struct byte_range_lock *br_lck)
1269 {
1270         files_struct *fsp = br_lck->fsp;
1271         uint16 tid = fsp->conn->cnum;
1272         int fnum = fsp->fnum;
1273         unsigned int i, j, dcount=0;
1274         int num_deleted_windows_locks = 0;
1275         struct lock_struct *locks = br_lck->lock_data;
1276         struct server_id pid = procid_self();
1277         BOOL unlock_individually = False;
1278
1279         if(lp_posix_locking(fsp->conn->params)) {
1280
1281                 /* Check if there are any Windows locks associated with this dev/ino
1282                    pair that are not this fnum. If so we need to call unlock on each
1283                    one in order to release the system POSIX locks correctly. */
1284
1285                 for (i=0; i < br_lck->num_locks; i++) {
1286                         struct lock_struct *lock = &locks[i];
1287
1288                         if (!procid_equal(&lock->context.pid, &pid)) {
1289                                 continue;
1290                         }
1291
1292                         if (lock->lock_type != READ_LOCK && lock->lock_type != WRITE_LOCK) {
1293                                 continue; /* Ignore pending. */
1294                         }
1295
1296                         if (lock->context.tid != tid || lock->fnum != fnum) {
1297                                 unlock_individually = True;
1298                                 break;
1299                         }
1300                 }
1301
1302                 if (unlock_individually) {
1303                         struct lock_struct *locks_copy;
1304                         unsigned int num_locks_copy;
1305
1306                         /* Copy the current lock array. */
1307                         if (br_lck->num_locks) {
1308                                 locks_copy = (struct lock_struct *)TALLOC_MEMDUP(br_lck, locks, br_lck->num_locks * sizeof(struct lock_struct));
1309                                 if (!locks_copy) {
1310                                         smb_panic("brl_close_fnum: talloc failed");
1311                                 }
1312                         } else {
1313                                 locks_copy = NULL;
1314                         }
1315
1316                         num_locks_copy = br_lck->num_locks;
1317
1318                         for (i=0; i < num_locks_copy; i++) {
1319                                 struct lock_struct *lock = &locks_copy[i];
1320
1321                                 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid) &&
1322                                                 (lock->fnum == fnum)) {
1323                                         brl_unlock(msg_ctx,
1324                                                 br_lck,
1325                                                 lock->context.smbpid,
1326                                                 pid,
1327                                                 lock->start,
1328                                                 lock->size,
1329                                                 lock->lock_flav);
1330                                 }
1331                         }
1332                         return;
1333                 }
1334         }
1335
1336         /* We can bulk delete - any POSIX locks will be removed when the fd closes. */
1337
1338         /* Remove any existing locks for this fnum (or any fnum if they're POSIX). */
1339
1340         for (i=0; i < br_lck->num_locks; i++) {
1341                 struct lock_struct *lock = &locks[i];
1342                 BOOL del_this_lock = False;
1343
1344                 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid)) {
1345                         if ((lock->lock_flav == WINDOWS_LOCK) && (lock->fnum == fnum)) {
1346                                 del_this_lock = True;
1347                                 num_deleted_windows_locks++;
1348                         } else if (lock->lock_flav == POSIX_LOCK) {
1349                                 del_this_lock = True;
1350                         }
1351                 }
1352
1353                 if (del_this_lock) {
1354                         /* Send unlock messages to any pending waiters that overlap. */
1355                         for (j=0; j < br_lck->num_locks; j++) {
1356                                 struct lock_struct *pend_lock = &locks[j];
1357
1358                                 /* Ignore our own or non-pending locks. */
1359                                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1360                                         continue;
1361                                 }
1362
1363                                 /* Optimisation - don't send to this fnum as we're
1364                                    closing it. */
1365                                 if (pend_lock->context.tid == tid &&
1366                                     procid_equal(&pend_lock->context.pid, &pid) &&
1367                                     pend_lock->fnum == fnum) {
1368                                         continue;
1369                                 }
1370
1371                                 /* We could send specific lock info here... */
1372                                 if (brl_pending_overlap(lock, pend_lock)) {
1373                                         messaging_send(msg_ctx, pend_lock->context.pid,
1374                                                        MSG_SMB_UNLOCK, &data_blob_null);
1375                                 }
1376                         }
1377
1378                         /* found it - delete it */
1379                         if (br_lck->num_locks > 1 && i < br_lck->num_locks - 1) {
1380                                 memmove(&locks[i], &locks[i+1],
1381                                         sizeof(*locks)*((br_lck->num_locks-1) - i));
1382                         }
1383                         br_lck->num_locks--;
1384                         br_lck->modified = True;
1385                         i--;
1386                         dcount++;
1387                 }
1388         }
1389
1390         if(lp_posix_locking(fsp->conn->params) && num_deleted_windows_locks) {
1391                 /* Reduce the Windows lock POSIX reference count on this dev/ino pair. */
1392                 reduce_windows_lock_ref_count(fsp, num_deleted_windows_locks);
1393         }
1394 }
1395
1396 /****************************************************************************
1397  Ensure this set of lock entries is valid.
1398 ****************************************************************************/
1399
1400 static BOOL validate_lock_entries(unsigned int *pnum_entries, struct lock_struct **pplocks)
1401 {
1402         unsigned int i;
1403         unsigned int num_valid_entries = 0;
1404         struct lock_struct *locks = *pplocks;
1405
1406         for (i = 0; i < *pnum_entries; i++) {
1407                 struct lock_struct *lock_data = &locks[i];
1408                 if (!process_exists(lock_data->context.pid)) {
1409                         /* This process no longer exists - mark this
1410                            entry as invalid by zeroing it. */
1411                         ZERO_STRUCTP(lock_data);
1412                 } else {
1413                         num_valid_entries++;
1414                 }
1415         }
1416
1417         if (num_valid_entries != *pnum_entries) {
1418                 struct lock_struct *new_lock_data = NULL;
1419
1420                 if (num_valid_entries) {
1421                         new_lock_data = SMB_MALLOC_ARRAY(struct lock_struct, num_valid_entries);
1422                         if (!new_lock_data) {
1423                                 DEBUG(3, ("malloc fail\n"));
1424                                 return False;
1425                         }
1426
1427                         num_valid_entries = 0;
1428                         for (i = 0; i < *pnum_entries; i++) {
1429                                 struct lock_struct *lock_data = &locks[i];
1430                                 if (lock_data->context.smbpid &&
1431                                                 lock_data->context.tid) {
1432                                         /* Valid (nonzero) entry - copy it. */
1433                                         memcpy(&new_lock_data[num_valid_entries],
1434                                                 lock_data, sizeof(struct lock_struct));
1435                                         num_valid_entries++;
1436                                 }
1437                         }
1438                 }
1439
1440                 SAFE_FREE(*pplocks);
1441                 *pplocks = new_lock_data;
1442                 *pnum_entries = num_valid_entries;
1443         }
1444
1445         return True;
1446 }
1447
1448 struct brl_forall_cb {
1449         void (*fn)(struct file_id id, struct server_id pid,
1450                    enum brl_type lock_type,
1451                    enum brl_flavour lock_flav,
1452                    br_off start, br_off size,
1453                    void *private_data);
1454         void *private_data;
1455 };
1456
1457 /****************************************************************************
1458  Traverse the whole database with this function, calling traverse_callback
1459  on each lock.
1460 ****************************************************************************/
1461
1462 static int traverse_fn(struct db_record *rec, void *state)
1463 {
1464         struct brl_forall_cb *cb = (struct brl_forall_cb *)state;
1465         struct lock_struct *locks;
1466         struct file_id *key;
1467         unsigned int i;
1468         unsigned int num_locks = 0;
1469         unsigned int orig_num_locks = 0;
1470
1471         /* In a traverse function we must make a copy of
1472            dbuf before modifying it. */
1473
1474         locks = (struct lock_struct *)memdup(rec->value.dptr,
1475                                              rec->value.dsize);
1476         if (!locks) {
1477                 return -1; /* Terminate traversal. */
1478         }
1479
1480         key = (struct file_id *)rec->key.dptr;
1481         orig_num_locks = num_locks = rec->value.dsize/sizeof(*locks);
1482
1483         /* Ensure the lock db is clean of entries from invalid processes. */
1484
1485         if (!validate_lock_entries(&num_locks, &locks)) {
1486                 SAFE_FREE(locks);
1487                 return -1; /* Terminate traversal */
1488         }
1489
1490         if (orig_num_locks != num_locks) {
1491                 if (num_locks) {
1492                         TDB_DATA data;
1493                         data.dptr = (uint8_t *)locks;
1494                         data.dsize = num_locks*sizeof(struct lock_struct);
1495                         rec->store(rec, data, TDB_REPLACE);
1496                 } else {
1497                         rec->delete_rec(rec);
1498                 }
1499         }
1500
1501         for ( i=0; i<num_locks; i++) {
1502                 cb->fn(*key,
1503                        locks[i].context.pid,
1504                        locks[i].lock_type,
1505                        locks[i].lock_flav,
1506                        locks[i].start,
1507                        locks[i].size,
1508                        cb->private_data);
1509         }
1510
1511         SAFE_FREE(locks);
1512         return 0;
1513 }
1514
1515 /*******************************************************************
1516  Call the specified function on each lock in the database.
1517 ********************************************************************/
1518
1519 int brl_forall(void (*fn)(struct file_id id, struct server_id pid,
1520                           enum brl_type lock_type,
1521                           enum brl_flavour lock_flav,
1522                           br_off start, br_off size,
1523                           void *private_data),
1524                void *private_data)
1525 {
1526         struct brl_forall_cb cb;
1527
1528         if (!brlock_db) {
1529                 return 0;
1530         }
1531         cb.fn = fn;
1532         cb.private_data = private_data;
1533         return brlock_db->traverse(brlock_db, traverse_fn, &cb);
1534 }
1535
1536 /*******************************************************************
1537  Store a potentially modified set of byte range lock data back into
1538  the database.
1539  Unlock the record.
1540 ********************************************************************/
1541
1542 static int byte_range_lock_destructor(struct byte_range_lock *br_lck)
1543 {
1544         TDB_DATA key;
1545
1546         key.dptr = (uint8 *)&br_lck->key;
1547         key.dsize = sizeof(struct file_id);
1548
1549         if (br_lck->read_only) {
1550                 SMB_ASSERT(!br_lck->modified);
1551         }
1552
1553         if (!br_lck->modified) {
1554                 goto done;
1555         }
1556
1557         if (br_lck->num_locks == 0) {
1558                 /* No locks - delete this entry. */
1559                 NTSTATUS status = br_lck->record->delete_rec(br_lck->record);
1560                 if (!NT_STATUS_IS_OK(status)) {
1561                         DEBUG(0, ("delete_rec returned %s\n",
1562                                   nt_errstr(status)));
1563                         smb_panic("Could not delete byte range lock entry");
1564                 }
1565         } else {
1566                 TDB_DATA data;
1567                 NTSTATUS status;
1568
1569                 data.dptr = (uint8 *)br_lck->lock_data;
1570                 data.dsize = br_lck->num_locks * sizeof(struct lock_struct);
1571
1572                 status = br_lck->record->store(br_lck->record, data,
1573                                                TDB_REPLACE);
1574                 if (!NT_STATUS_IS_OK(status)) {
1575                         DEBUG(0, ("store returned %s\n", nt_errstr(status)));
1576                         smb_panic("Could not store byte range mode entry");
1577                 }
1578         }
1579
1580  done:
1581
1582         SAFE_FREE(br_lck->lock_data);
1583         TALLOC_FREE(br_lck->record);
1584         return 0;
1585 }
1586
1587 /*******************************************************************
1588  Fetch a set of byte range lock data from the database.
1589  Leave the record locked.
1590  TALLOC_FREE(brl) will release the lock in the destructor.
1591 ********************************************************************/
1592
1593 static struct byte_range_lock *brl_get_locks_internal(TALLOC_CTX *mem_ctx,
1594                                         files_struct *fsp, BOOL read_only)
1595 {
1596         TDB_DATA key, data;
1597         struct byte_range_lock *br_lck = TALLOC_P(mem_ctx, struct byte_range_lock);
1598
1599         if (br_lck == NULL) {
1600                 return NULL;
1601         }
1602
1603         br_lck->fsp = fsp;
1604         br_lck->num_locks = 0;
1605         br_lck->modified = False;
1606         memset(&br_lck->key, '\0', sizeof(struct file_id));
1607         br_lck->key = fsp->file_id;
1608
1609         key.dptr = (uint8 *)&br_lck->key;
1610         key.dsize = sizeof(struct file_id);
1611
1612         if (!fsp->lockdb_clean) {
1613                 /* We must be read/write to clean
1614                    the dead entries. */
1615                 read_only = False;
1616         }
1617
1618         if (read_only) {
1619                 if (brlock_db->fetch(brlock_db, br_lck, key, &data) == -1) {
1620                         DEBUG(3, ("Could not fetch byte range lock record\n"));
1621                         TALLOC_FREE(br_lck);
1622                         return NULL;
1623                 }
1624                 br_lck->record = NULL;
1625         }
1626         else {
1627                 br_lck->record = brlock_db->fetch_locked(brlock_db, br_lck, key);
1628
1629                 if (br_lck->record == NULL) {
1630                         DEBUG(3, ("Could not lock byte range lock entry\n"));
1631                         TALLOC_FREE(br_lck);
1632                         return NULL;
1633                 }
1634
1635                 data = br_lck->record->value;
1636         }
1637
1638         br_lck->read_only = read_only;
1639         br_lck->lock_data = NULL;
1640
1641         talloc_set_destructor(br_lck, byte_range_lock_destructor);
1642
1643         br_lck->num_locks = data.dsize / sizeof(struct lock_struct);
1644
1645         if (br_lck->num_locks != 0) {
1646                 br_lck->lock_data = SMB_MALLOC_ARRAY(struct lock_struct,
1647                                                      br_lck->num_locks);
1648                 if (br_lck->lock_data == NULL) {
1649                         DEBUG(0, ("malloc failed\n"));
1650                         TALLOC_FREE(br_lck);
1651                         return NULL;
1652                 }
1653
1654                 memcpy(br_lck->lock_data, data.dptr, data.dsize);
1655         }
1656
1657         if (!fsp->lockdb_clean) {
1658                 int orig_num_locks = br_lck->num_locks;
1659
1660                 /* This is the first time we've accessed this. */
1661                 /* Go through and ensure all entries exist - remove any that don't. */
1662                 /* Makes the lockdb self cleaning at low cost. */
1663
1664                 if (!validate_lock_entries(&br_lck->num_locks,
1665                                            &br_lck->lock_data)) {
1666                         SAFE_FREE(br_lck->lock_data);
1667                         TALLOC_FREE(br_lck);
1668                         return NULL;
1669                 }
1670
1671                 /* Ensure invalid locks are cleaned up in the destructor. */
1672                 if (orig_num_locks != br_lck->num_locks) {
1673                         br_lck->modified = True;
1674                 }
1675
1676                 /* Mark the lockdb as "clean" as seen from this open file. */
1677                 fsp->lockdb_clean = True;
1678         }
1679
1680         if (DEBUGLEVEL >= 10) {
1681                 unsigned int i;
1682                 struct lock_struct *locks = br_lck->lock_data;
1683                 DEBUG(10,("brl_get_locks_internal: %u current locks on file_id %s\n",
1684                         br_lck->num_locks,
1685                           file_id_string_tos(&fsp->file_id)));
1686                 for( i = 0; i < br_lck->num_locks; i++) {
1687                         print_lock_struct(i, &locks[i]);
1688                 }
1689         }
1690         return br_lck;
1691 }
1692
1693 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx,
1694                                         files_struct *fsp)
1695 {
1696         return brl_get_locks_internal(mem_ctx, fsp, False);
1697 }
1698
1699 struct byte_range_lock *brl_get_locks_readonly(TALLOC_CTX *mem_ctx,
1700                                         files_struct *fsp)
1701 {
1702         return brl_get_locks_internal(mem_ctx, fsp, True);
1703 }
1704
1705 struct brl_revalidate_state {
1706         ssize_t array_size;
1707         uint32 num_pids;
1708         struct server_id *pids;
1709 };
1710
1711 /*
1712  * Collect PIDs of all processes with pending entries
1713  */
1714
1715 static void brl_revalidate_collect(struct file_id id, struct server_id pid,
1716                                    enum brl_type lock_type,
1717                                    enum brl_flavour lock_flav,
1718                                    br_off start, br_off size,
1719                                    void *private_data)
1720 {
1721         struct brl_revalidate_state *state =
1722                 (struct brl_revalidate_state *)private_data;
1723
1724         if (!IS_PENDING_LOCK(lock_type)) {
1725                 return;
1726         }
1727
1728         add_to_large_array(state, sizeof(pid), (void *)&pid,
1729                            &state->pids, &state->num_pids,
1730                            &state->array_size);
1731 }
1732
1733 /*
1734  * qsort callback to sort the processes
1735  */
1736
1737 static int compare_procids(const void *p1, const void *p2)
1738 {
1739         const struct server_id *i1 = (struct server_id *)p1;
1740         const struct server_id *i2 = (struct server_id *)p2;
1741
1742         if (i1->pid < i2->pid) return -1;
1743         if (i2->pid > i2->pid) return 1;
1744         return 0;
1745 }
1746
1747 /*
1748  * Send a MSG_SMB_UNLOCK message to all processes with pending byte range
1749  * locks so that they retry. Mainly used in the cluster code after a node has
1750  * died.
1751  *
1752  * Done in two steps to avoid double-sends: First we collect all entries in an
1753  * array, then qsort that array and only send to non-dupes.
1754  */
1755
1756 static void brl_revalidate(struct messaging_context *msg_ctx,
1757                            void *private_data,
1758                            uint32_t msg_type,
1759                            struct server_id server_id,
1760                            DATA_BLOB *data)
1761 {
1762         struct brl_revalidate_state *state;
1763         uint32 i;
1764         struct server_id last_pid;
1765
1766         if (!(state = TALLOC_ZERO_P(NULL, struct brl_revalidate_state))) {
1767                 DEBUG(0, ("talloc failed\n"));
1768                 return;
1769         }
1770
1771         brl_forall(brl_revalidate_collect, state);
1772
1773         if (state->array_size == -1) {
1774                 DEBUG(0, ("talloc failed\n"));
1775                 goto done;
1776         }
1777
1778         if (state->num_pids == 0) {
1779                 goto done;
1780         }
1781
1782         qsort(state->pids, state->num_pids, sizeof(state->pids[0]),
1783               compare_procids);
1784
1785         ZERO_STRUCT(last_pid);
1786
1787         for (i=0; i<state->num_pids; i++) {
1788                 if (procid_equal(&last_pid, &state->pids[i])) {
1789                         /*
1790                          * We've seen that one already
1791                          */
1792                         continue;
1793                 }
1794
1795                 messaging_send(msg_ctx, state->pids[i], MSG_SMB_UNLOCK,
1796                                &data_blob_null);
1797                 last_pid = state->pids[i];
1798         }
1799
1800  done:
1801         TALLOC_FREE(state);
1802         return;
1803 }
1804
1805 void brl_register_msgs(struct messaging_context *msg_ctx)
1806 {
1807         messaging_register(msg_ctx, NULL, MSG_SMB_BRL_VALIDATE,
1808                            brl_revalidate);
1809 }