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 #include "system/filesys.h"
  29 #include "locking/proto.h"
  30 #include "smbd/globals.h"
  31 #include "dbwrap/dbwrap.h"
  32 #include "dbwrap/dbwrap_open.h"
  33 #include "serverid.h"
  34 #include "messages.h"
  35 #include "util_tdb.h"
  36
  37 #undef DBGC_CLASS
  38 #define DBGC_CLASS DBGC_LOCKING
  39
  40 #define ZERO_ZERO 0
  41
  42 /* The open brlock.tdb database. */
  43
  44 static struct db_context *brlock_db;
  45
  46 struct byte_range_lock {
  47         struct files_struct *fsp;
  48         unsigned int num_locks;
  49         bool modified;
  50         bool read_only;
  51         struct file_id key;
  52         struct lock_struct *lock_data;
  53         struct db_record *record;
  54 };
  55
  56 /****************************************************************************
  57  Debug info at level 10 for lock struct.
  58 ****************************************************************************/
  59
  60 static void print_lock_struct(unsigned int i, const struct lock_struct *pls)
  61 {
  62         DEBUG(10,("[%u]: smblctx = %llu, tid = %u, pid = %s, ",
  63                         i,
  64                         (unsigned long long)pls->context.smblctx,
  65                         (unsigned int)pls->context.tid,
  66                         server_id_str(talloc_tos(), &pls->context.pid) ));
  67
  68         DEBUG(10,("start = %.0f, size = %.0f, fnum = %llu, %s %s\n",
  69                 (double)pls->start,
  70                 (double)pls->size,
  71                 (unsigned long long)pls->fnum,
  72                 lock_type_name(pls->lock_type),
  73                 lock_flav_name(pls->lock_flav) ));
  74 }
  75
  76 unsigned int brl_num_locks(const struct byte_range_lock *brl)
  77 {
  78         return brl->num_locks;
  79 }
  80
  81 struct files_struct *brl_fsp(struct byte_range_lock *brl)
  82 {
  83         return brl->fsp;
  84 }
  85
  86 /****************************************************************************
  87  See if two locking contexts are equal.
  88 ****************************************************************************/
  89
  90 static bool brl_same_context(const struct lock_context *ctx1,
  91                              const struct lock_context *ctx2)
  92 {
  93         return (serverid_equal(&ctx1->pid, &ctx2->pid) &&
  94                 (ctx1->smblctx == ctx2->smblctx) &&
  95                 (ctx1->tid == ctx2->tid));
  96 }
  97
  98 /****************************************************************************
  99  See if lck1 and lck2 overlap.
 100 ****************************************************************************/
 101
 102 static bool brl_overlap(const struct lock_struct *lck1,
 103                         const struct lock_struct *lck2)
 104 {
 105         /* XXX Remove for Win7 compatibility. */
 106         /* this extra check is not redundant - it copes with locks
 107            that go beyond the end of 64 bit file space */
 108         if (lck1->size != 0 &&
 109             lck1->start == lck2->start &&
 110             lck1->size == lck2->size) {
 111                 return True;
 112         }
 113
 114         if (lck1->start >= (lck2->start+lck2->size) ||
 115             lck2->start >= (lck1->start+lck1->size)) {
 116                 return False;
 117         }
 118         return True;
 119 }
 120
 121 /****************************************************************************
 122  See if lock2 can be added when lock1 is in place.
 123 ****************************************************************************/
 124
 125 static bool brl_conflict(const struct lock_struct *lck1,
 126                          const struct lock_struct *lck2)
 127 {
 128         /* Ignore PENDING locks. */
 129         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 130                 return False;
 131
 132         /* Read locks never conflict. */
 133         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 134                 return False;
 135         }
 136
 137         /* A READ lock can stack on top of a WRITE lock if they have the same
 138          * context & fnum. */
 139         if (lck1->lock_type == WRITE_LOCK && lck2->lock_type == READ_LOCK &&
 140             brl_same_context(&lck1->context, &lck2->context) &&
 141             lck1->fnum == lck2->fnum) {
 142                 return False;
 143         }
 144
 145         return brl_overlap(lck1, lck2);
 146 }
 147
 148 /****************************************************************************
 149  See if lock2 can be added when lock1 is in place - when both locks are POSIX
 150  flavour. POSIX locks ignore fnum - they only care about dev/ino which we
 151  know already match.
 152 ****************************************************************************/
 153
 154 static bool brl_conflict_posix(const struct lock_struct *lck1,
 155                                 const struct lock_struct *lck2)
 156 {
 157 #if defined(DEVELOPER)
 158         SMB_ASSERT(lck1->lock_flav == POSIX_LOCK);
 159         SMB_ASSERT(lck2->lock_flav == POSIX_LOCK);
 160 #endif
 161
 162         /* Ignore PENDING locks. */
 163         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 164                 return False;
 165
 166         /* Read locks never conflict. */
 167         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 168                 return False;
 169         }
 170
 171         /* Locks on the same context con't conflict. Ignore fnum. */
 172         if (brl_same_context(&lck1->context, &lck2->context)) {
 173                 return False;
 174         }
 175
 176         /* One is read, the other write, or the context is different,
 177            do they overlap ? */
 178         return brl_overlap(lck1, lck2);
 179 }
 180
 181 #if ZERO_ZERO
 182 static bool brl_conflict1(const struct lock_struct *lck1,
 183                          const struct lock_struct *lck2)
 184 {
 185         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 186                 return False;
 187
 188         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
 189                 return False;
 190         }
 191
 192         if (brl_same_context(&lck1->context, &lck2->context) &&
 193             lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
 194                 return False;
 195         }
 196
 197         if (lck2->start == 0 && lck2->size == 0 && lck1->size != 0) {
 198                 return True;
 199         }
 200
 201         if (lck1->start >= (lck2->start + lck2->size) ||
 202             lck2->start >= (lck1->start + lck1->size)) {
 203                 return False;
 204         }
 205
 206         return True;
 207 }
 208 #endif
 209
 210 /****************************************************************************
 211  Check to see if this lock conflicts, but ignore our own locks on the
 212  same fnum only. This is the read/write lock check code path.
 213  This is never used in the POSIX lock case.
 214 ****************************************************************************/
 215
 216 static bool brl_conflict_other(const struct lock_struct *lck1, const struct lock_struct *lck2)
 217 {
 218         if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
 219                 return False;
 220
 221         if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
 222                 return False;
 223
 224         /* POSIX flavour locks never conflict here - this is only called
 225            in the read/write path. */
 226
 227         if (lck1->lock_flav == POSIX_LOCK && lck2->lock_flav == POSIX_LOCK)
 228                 return False;
 229
 230         /*
 231          * Incoming WRITE locks conflict with existing READ locks even
 232          * if the context is the same. JRA. See LOCKTEST7 in smbtorture.
 233          */
 234
 235         if (!(lck2->lock_type == WRITE_LOCK && lck1->lock_type == READ_LOCK)) {
 236                 if (brl_same_context(&lck1->context, &lck2->context) &&
 237                                         lck1->fnum == lck2->fnum)
 238                         return False;
 239         }
 240
 241         return brl_overlap(lck1, lck2);
 242 }
 243
 244 /****************************************************************************
 245  Check if an unlock overlaps a pending lock.
 246 ****************************************************************************/
 247
 248 static bool brl_pending_overlap(const struct lock_struct *lock, const struct lock_struct *pend_lock)
 249 {
 250         if ((lock->start <= pend_lock->start) && (lock->start + lock->size > pend_lock->start))
 251                 return True;
 252         if ((lock->start >= pend_lock->start) && (lock->start <= pend_lock->start + pend_lock->size))
 253                 return True;
 254         return False;
 255 }
 256
 257 /****************************************************************************
 258  Amazingly enough, w2k3 "remembers" whether the last lock failure on a fnum
 259  is the same as this one and changes its error code. I wonder if any
 260  app depends on this ?
 261 ****************************************************************************/
 262
 263 static NTSTATUS brl_lock_failed(files_struct *fsp,
 264                                 const struct lock_struct *lock,
 265                                 bool blocking_lock)
 266 {
 267         if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) {
 268                 /* amazing the little things you learn with a test
 269                    suite. Locks beyond this offset (as a 64 bit
 270                    number!) always generate the conflict error code,
 271                    unless the top bit is set */
 272                 if (!blocking_lock) {
 273                         fsp->last_lock_failure = *lock;
 274                 }
 275                 return NT_STATUS_FILE_LOCK_CONFLICT;
 276         }
 277
 278         if (serverid_equal(&lock->context.pid, &fsp->last_lock_failure.context.pid) &&
 279                         lock->context.tid == fsp->last_lock_failure.context.tid &&
 280                         lock->fnum == fsp->last_lock_failure.fnum &&
 281                         lock->start == fsp->last_lock_failure.start) {
 282                 return NT_STATUS_FILE_LOCK_CONFLICT;
 283         }
 284
 285         if (!blocking_lock) {
 286                 fsp->last_lock_failure = *lock;
 287         }
 288         return NT_STATUS_LOCK_NOT_GRANTED;
 289 }
 290
 291 /****************************************************************************
 292  Open up the brlock.tdb database.
 293 ****************************************************************************/
 294
 295 void brl_init(bool read_only)
 296 {
 297         int tdb_flags;
 298
 299         if (brlock_db) {
 300                 return;
 301         }
 302
 303         tdb_flags = TDB_DEFAULT|TDB_VOLATILE|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH;
 304
 305         if (!lp_clustering()) {
 306                 /*
 307                  * We can't use the SEQNUM trick to cache brlock
 308                  * entries in the clustering case because ctdb seqnum
 309                  * propagation has a delay.
 310                  */
 311                 tdb_flags |= TDB_SEQNUM;
 312         }
 313
 314         brlock_db = db_open(NULL, lock_path("brlock.tdb"),
 315                             lp_open_files_db_hash_size(), tdb_flags,
 316                             read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644,
 317                             DBWRAP_LOCK_ORDER_2);
 318         if (!brlock_db) {
 319                 DEBUG(0,("Failed to open byte range locking database %s\n",
 320                         lock_path("brlock.tdb")));
 321                 return;
 322         }
 323 }
 324
 325 /****************************************************************************
 326  Close down the brlock.tdb database.
 327 ****************************************************************************/
 328
 329 void brl_shutdown(void)
 330 {
 331         TALLOC_FREE(brlock_db);
 332 }
 333
 334 #if ZERO_ZERO
 335 /****************************************************************************
 336  Compare two locks for sorting.
 337 ****************************************************************************/
 338
 339 static int lock_compare(const struct lock_struct *lck1,
 340                          const struct lock_struct *lck2)
 341 {
 342         if (lck1->start != lck2->start) {
 343                 return (lck1->start - lck2->start);
 344         }
 345         if (lck2->size != lck1->size) {
 346                 return ((int)lck1->size - (int)lck2->size);
 347         }
 348         return 0;
 349 }
 350 #endif
 351
 352 /****************************************************************************
 353  Lock a range of bytes - Windows lock semantics.
 354 ****************************************************************************/
 355
 356 NTSTATUS brl_lock_windows_default(struct byte_range_lock *br_lck,
 357     struct lock_struct *plock, bool blocking_lock)
 358 {
 359         unsigned int i;
 360         files_struct *fsp = br_lck->fsp;
 361         struct lock_struct *locks = br_lck->lock_data;
 362         NTSTATUS status;
 363
 364         SMB_ASSERT(plock->lock_type != UNLOCK_LOCK);
 365
 366         if ((plock->start + plock->size - 1 < plock->start) &&
 367                         plock->size != 0) {
 368                 return NT_STATUS_INVALID_LOCK_RANGE;
 369         }
 370
 371         for (i=0; i < br_lck->num_locks; i++) {
 372                 /* Do any Windows or POSIX locks conflict ? */
 373                 if (brl_conflict(&locks[i], plock)) {
 374                         /* Remember who blocked us. */
 375                         plock->context.smblctx = locks[i].context.smblctx;
 376                         return brl_lock_failed(fsp,plock,blocking_lock);
 377                 }
 378 #if ZERO_ZERO
 379                 if (plock->start == 0 && plock->size == 0 &&
 380                                 locks[i].size == 0) {
 381                         break;
 382                 }
 383 #endif
 384         }
 385
 386         if (!IS_PENDING_LOCK(plock->lock_type)) {
 387                 contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
 388         }
 389
 390         /* We can get the Windows lock, now see if it needs to
 391            be mapped into a lower level POSIX one, and if so can
 392            we get it ? */
 393
 394         if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(fsp->conn->params)) {
 395                 int errno_ret;
 396                 if (!set_posix_lock_windows_flavour(fsp,
 397                                 plock->start,
 398                                 plock->size,
 399                                 plock->lock_type,
 400                                 &plock->context,
 401                                 locks,
 402                                 br_lck->num_locks,
 403                                 &errno_ret)) {
 404
 405                         /* We don't know who blocked us. */
 406                         plock->context.smblctx = 0xFFFFFFFFFFFFFFFFLL;
 407
 408                         if (errno_ret == EACCES || errno_ret == EAGAIN) {
 409                                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 410                                 goto fail;
 411                         } else {
 412                                 status = map_nt_error_from_unix(errno);
 413                                 goto fail;
 414                         }
 415                 }
 416         }
 417
 418         /* no conflicts - add it to the list of locks */
 419         locks = (struct lock_struct *)SMB_REALLOC(locks, (br_lck->num_locks + 1) * sizeof(*locks));
 420         if (!locks) {
 421                 status = NT_STATUS_NO_MEMORY;
 422                 goto fail;
 423         }
 424
 425         memcpy(&locks[br_lck->num_locks], plock, sizeof(struct lock_struct));
 426         br_lck->num_locks += 1;
 427         br_lck->lock_data = locks;
 428         br_lck->modified = True;
 429
 430         return NT_STATUS_OK;
 431  fail:
 432         if (!IS_PENDING_LOCK(plock->lock_type)) {
 433                 contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
 434         }
 435         return status;
 436 }
 437
 438 /****************************************************************************
 439  Cope with POSIX range splits and merges.
 440 ****************************************************************************/
 441
 442 static unsigned int brlock_posix_split_merge(struct lock_struct *lck_arr,       /* Output array. */
 443                                                 struct lock_struct *ex,         /* existing lock. */
 444                                                 struct lock_struct *plock)      /* proposed lock. */
 445 {
 446         bool lock_types_differ = (ex->lock_type != plock->lock_type);
 447
 448         /* We can't merge non-conflicting locks on different context - ignore fnum. */
 449
 450         if (!brl_same_context(&ex->context, &plock->context)) {
 451                 /* Just copy. */
 452                 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 453                 return 1;
 454         }
 455
 456         /* We now know we have the same context. */
 457
 458         /* Did we overlap ? */
 459
 460 /*********************************************
 461                                         +---------+
 462                                         | ex      |
 463                                         +---------+
 464                          +-------+
 465                          | plock |
 466                          +-------+
 467 OR....
 468         +---------+
 469         |  ex     |
 470         +---------+
 471 **********************************************/
 472
 473         if ( (ex->start > (plock->start + plock->size)) ||
 474                 (plock->start > (ex->start + ex->size))) {
 475
 476                 /* No overlap with this lock - copy existing. */
 477
 478                 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 479                 return 1;
 480         }
 481
 482 /*********************************************
 483         +---------------------------+
 484         |          ex               |
 485         +---------------------------+
 486         +---------------------------+
 487         |       plock               | -> replace with plock.
 488         +---------------------------+
 489 OR
 490              +---------------+
 491              |       ex      |
 492              +---------------+
 493         +---------------------------+
 494         |       plock               | -> replace with plock.
 495         +---------------------------+
 496
 497 **********************************************/
 498
 499         if ( (ex->start >= plock->start) &&
 500                 (ex->start + ex->size <= plock->start + plock->size) ) {
 501
 502                 /* Replace - discard existing lock. */
 503
 504                 return 0;
 505         }
 506
 507 /*********************************************
 508 Adjacent after.
 509                         +-------+
 510                         |  ex   |
 511                         +-------+
 512         +---------------+
 513         |   plock       |
 514         +---------------+
 515
 516 BECOMES....
 517         +---------------+-------+
 518         |   plock       | ex    | - different lock types.
 519         +---------------+-------+
 520 OR.... (merge)
 521         +-----------------------+
 522         |   plock               | - same lock type.
 523         +-----------------------+
 524 **********************************************/
 525
 526         if (plock->start + plock->size == ex->start) {
 527
 528                 /* If the lock types are the same, we merge, if different, we
 529                    add the remainder of the old lock. */
 530
 531                 if (lock_types_differ) {
 532                         /* Add existing. */
 533                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 534                         return 1;
 535                 } else {
 536                         /* Merge - adjust incoming lock as we may have more
 537                          * merging to come. */
 538                         plock->size += ex->size;
 539                         return 0;
 540                 }
 541         }
 542
 543 /*********************************************
 544 Adjacent before.
 545         +-------+
 546         |  ex   |
 547         +-------+
 548                 +---------------+
 549                 |   plock       |
 550                 +---------------+
 551 BECOMES....
 552         +-------+---------------+
 553         | ex    |   plock       | - different lock types
 554         +-------+---------------+
 555
 556 OR.... (merge)
 557         +-----------------------+
 558         |      plock            | - same lock type.
 559         +-----------------------+
 560
 561 **********************************************/
 562
 563         if (ex->start + ex->size == plock->start) {
 564
 565                 /* If the lock types are the same, we merge, if different, we
 566                    add the existing lock. */
 567
 568                 if (lock_types_differ) {
 569                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 570                         return 1;
 571                 } else {
 572                         /* Merge - adjust incoming lock as we may have more
 573                          * merging to come. */
 574                         plock->start = ex->start;
 575                         plock->size += ex->size;
 576                         return 0;
 577                 }
 578         }
 579
 580 /*********************************************
 581 Overlap after.
 582         +-----------------------+
 583         |          ex           |
 584         +-----------------------+
 585         +---------------+
 586         |   plock       |
 587         +---------------+
 588 OR
 589                +----------------+
 590                |       ex       |
 591                +----------------+
 592         +---------------+
 593         |   plock       |
 594         +---------------+
 595
 596 BECOMES....
 597         +---------------+-------+
 598         |   plock       | ex    | - different lock types.
 599         +---------------+-------+
 600 OR.... (merge)
 601         +-----------------------+
 602         |   plock               | - same lock type.
 603         +-----------------------+
 604 **********************************************/
 605
 606         if ( (ex->start >= plock->start) &&
 607                 (ex->start <= plock->start + plock->size) &&
 608                 (ex->start + ex->size > plock->start + plock->size) ) {
 609
 610                 /* If the lock types are the same, we merge, if different, we
 611                    add the remainder of the old lock. */
 612
 613                 if (lock_types_differ) {
 614                         /* Add remaining existing. */
 615                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 616                         /* Adjust existing start and size. */
 617                         lck_arr[0].start = plock->start + plock->size;
 618                         lck_arr[0].size = (ex->start + ex->size) - (plock->start + plock->size);
 619                         return 1;
 620                 } else {
 621                         /* Merge - adjust incoming lock as we may have more
 622                          * merging to come. */
 623                         plock->size += (ex->start + ex->size) - (plock->start + plock->size);
 624                         return 0;
 625                 }
 626         }
 627
 628 /*********************************************
 629 Overlap before.
 630         +-----------------------+
 631         |  ex                   |
 632         +-----------------------+
 633                 +---------------+
 634                 |   plock       |
 635                 +---------------+
 636 OR
 637         +-------------+
 638         |  ex         |
 639         +-------------+
 640                 +---------------+
 641                 |   plock       |
 642                 +---------------+
 643
 644 BECOMES....
 645         +-------+---------------+
 646         | ex    |   plock       | - different lock types
 647         +-------+---------------+
 648
 649 OR.... (merge)
 650         +-----------------------+
 651         |      plock            | - same lock type.
 652         +-----------------------+
 653
 654 **********************************************/
 655
 656         if ( (ex->start < plock->start) &&
 657                         (ex->start + ex->size >= plock->start) &&
 658                         (ex->start + ex->size <= plock->start + plock->size) ) {
 659
 660                 /* If the lock types are the same, we merge, if different, we
 661                    add the truncated old lock. */
 662
 663                 if (lock_types_differ) {
 664                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 665                         /* Adjust existing size. */
 666                         lck_arr[0].size = plock->start - ex->start;
 667                         return 1;
 668                 } else {
 669                         /* Merge - adjust incoming lock as we may have more
 670                          * merging to come. MUST ADJUST plock SIZE FIRST ! */
 671                         plock->size += (plock->start - ex->start);
 672                         plock->start = ex->start;
 673                         return 0;
 674                 }
 675         }
 676
 677 /*********************************************
 678 Complete overlap.
 679         +---------------------------+
 680         |        ex                 |
 681         +---------------------------+
 682                 +---------+
 683                 |  plock  |
 684                 +---------+
 685 BECOMES.....
 686         +-------+---------+---------+
 687         | ex    |  plock  | ex      | - different lock types.
 688         +-------+---------+---------+
 689 OR
 690         +---------------------------+
 691         |        plock              | - same lock type.
 692         +---------------------------+
 693 **********************************************/
 694
 695         if ( (ex->start < plock->start) && (ex->start + ex->size > plock->start + plock->size) ) {
 696
 697                 if (lock_types_differ) {
 698
 699                         /* We have to split ex into two locks here. */
 700
 701                         memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
 702                         memcpy(&lck_arr[1], ex, sizeof(struct lock_struct));
 703
 704                         /* Adjust first existing size. */
 705                         lck_arr[0].size = plock->start - ex->start;
 706
 707                         /* Adjust second existing start and size. */
 708                         lck_arr[1].start = plock->start + plock->size;
 709                         lck_arr[1].size = (ex->start + ex->size) - (plock->start + plock->size);
 710                         return 2;
 711                 } else {
 712                         /* Just eat the existing locks, merge them into plock. */
 713                         plock->start = ex->start;
 714                         plock->size = ex->size;
 715                         return 0;
 716                 }
 717         }
 718
 719         /* Never get here. */
 720         smb_panic("brlock_posix_split_merge");
 721         /* Notreached. */
 722
 723         /* Keep some compilers happy. */
 724         return 0;
 725 }
 726
 727 /****************************************************************************
 728  Lock a range of bytes - POSIX lock semantics.
 729  We must cope with range splits and merges.
 730 ****************************************************************************/
 731
 732 static NTSTATUS brl_lock_posix(struct messaging_context *msg_ctx,
 733                                struct byte_range_lock *br_lck,
 734                                struct lock_struct *plock)
 735 {
 736         unsigned int i, count, posix_count;
 737         struct lock_struct *locks = br_lck->lock_data;
 738         struct lock_struct *tp;
 739         bool signal_pending_read = False;
 740         bool break_oplocks = false;
 741         NTSTATUS status;
 742
 743         /* No zero-zero locks for POSIX. */
 744         if (plock->start == 0 && plock->size == 0) {
 745                 return NT_STATUS_INVALID_PARAMETER;
 746         }
 747
 748         /* Don't allow 64-bit lock wrap. */
 749         if (plock->start + plock->size - 1 < plock->start) {
 750                 return NT_STATUS_INVALID_PARAMETER;
 751         }
 752
 753         /* The worst case scenario here is we have to split an
 754            existing POSIX lock range into two, and add our lock,
 755            so we need at most 2 more entries. */
 756
 757         tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 2));
 758         if (!tp) {
 759                 return NT_STATUS_NO_MEMORY;
 760         }
 761
 762         count = posix_count = 0;
 763
 764         for (i=0; i < br_lck->num_locks; i++) {
 765                 struct lock_struct *curr_lock = &locks[i];
 766
 767                 /* If we have a pending read lock, a lock downgrade should
 768                    trigger a lock re-evaluation. */
 769                 if (curr_lock->lock_type == PENDING_READ_LOCK &&
 770                                 brl_pending_overlap(plock, curr_lock)) {
 771                         signal_pending_read = True;
 772                 }
 773
 774                 if (curr_lock->lock_flav == WINDOWS_LOCK) {
 775                         /* Do any Windows flavour locks conflict ? */
 776                         if (brl_conflict(curr_lock, plock)) {
 777                                 /* No games with error messages. */
 778                                 SAFE_FREE(tp);
 779                                 /* Remember who blocked us. */
 780                                 plock->context.smblctx = curr_lock->context.smblctx;
 781                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 782                         }
 783                         /* Just copy the Windows lock into the new array. */
 784                         memcpy(&tp[count], curr_lock, sizeof(struct lock_struct));
 785                         count++;
 786                 } else {
 787                         unsigned int tmp_count = 0;
 788
 789                         /* POSIX conflict semantics are different. */
 790                         if (brl_conflict_posix(curr_lock, plock)) {
 791                                 /* Can't block ourselves with POSIX locks. */
 792                                 /* No games with error messages. */
 793                                 SAFE_FREE(tp);
 794                                 /* Remember who blocked us. */
 795                                 plock->context.smblctx = curr_lock->context.smblctx;
 796                                 return NT_STATUS_FILE_LOCK_CONFLICT;
 797                         }
 798
 799                         /* Work out overlaps. */
 800                         tmp_count += brlock_posix_split_merge(&tp[count], curr_lock, plock);
 801                         posix_count += tmp_count;
 802                         count += tmp_count;
 803                 }
 804         }
 805
 806         /*
 807          * Break oplocks while we hold a brl. Since lock() and unlock() calls
 808          * are not symetric with POSIX semantics, we cannot guarantee our
 809          * contend_level2_oplocks_begin/end calls will be acquired and
 810          * released one-for-one as with Windows semantics. Therefore we only
 811          * call contend_level2_oplocks_begin if this is the first POSIX brl on
 812          * the file.
 813          */
 814         break_oplocks = (!IS_PENDING_LOCK(plock->lock_type) &&
 815                          posix_count == 0);
 816         if (break_oplocks) {
 817                 contend_level2_oplocks_begin(br_lck->fsp,
 818                                              LEVEL2_CONTEND_POSIX_BRL);
 819         }
 820
 821         /* Try and add the lock in order, sorted by lock start. */
 822         for (i=0; i < count; i++) {
 823                 struct lock_struct *curr_lock = &tp[i];
 824
 825                 if (curr_lock->start <= plock->start) {
 826                         continue;
 827                 }
 828         }
 829
 830         if (i < count) {
 831                 memmove(&tp[i+1], &tp[i],
 832                         (count - i)*sizeof(struct lock_struct));
 833         }
 834         memcpy(&tp[i], plock, sizeof(struct lock_struct));
 835         count++;
 836
 837         /* We can get the POSIX lock, now see if it needs to
 838            be mapped into a lower level POSIX one, and if so can
 839            we get it ? */
 840
 841         if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(br_lck->fsp->conn->params)) {
 842                 int errno_ret;
 843
 844                 /* The lower layer just needs to attempt to
 845                    get the system POSIX lock. We've weeded out
 846                    any conflicts above. */
 847
 848                 if (!set_posix_lock_posix_flavour(br_lck->fsp,
 849                                 plock->start,
 850                                 plock->size,
 851                                 plock->lock_type,
 852                                 &errno_ret)) {
 853
 854                         /* We don't know who blocked us. */
 855                         plock->context.smblctx = 0xFFFFFFFFFFFFFFFFLL;
 856
 857                         if (errno_ret == EACCES || errno_ret == EAGAIN) {
 858                                 SAFE_FREE(tp);
 859                                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 860                                 goto fail;
 861                         } else {
 862                                 SAFE_FREE(tp);
 863                                 status = map_nt_error_from_unix(errno);
 864                                 goto fail;
 865                         }
 866                 }
 867         }
 868
 869         /* If we didn't use all the allocated size,
 870          * Realloc so we don't leak entries per lock call. */
 871         if (count < br_lck->num_locks + 2) {
 872                 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
 873                 if (!tp) {
 874                         status = NT_STATUS_NO_MEMORY;
 875                         goto fail;
 876                 }
 877         }
 878
 879         br_lck->num_locks = count;
 880         SAFE_FREE(br_lck->lock_data);
 881         br_lck->lock_data = tp;
 882         locks = tp;
 883         br_lck->modified = True;
 884
 885         /* A successful downgrade from write to read lock can trigger a lock
 886            re-evalutation where waiting readers can now proceed. */
 887
 888         if (signal_pending_read) {
 889                 /* Send unlock messages to any pending read waiters that overlap. */
 890                 for (i=0; i < br_lck->num_locks; i++) {
 891                         struct lock_struct *pend_lock = &locks[i];
 892
 893                         /* Ignore non-pending locks. */
 894                         if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
 895                                 continue;
 896                         }
 897
 898                         if (pend_lock->lock_type == PENDING_READ_LOCK &&
 899                                         brl_pending_overlap(plock, pend_lock)) {
 900                                 DEBUG(10,("brl_lock_posix: sending unlock message to pid %s\n",
 901                                         procid_str_static(&pend_lock->context.pid )));
 902
 903                                 messaging_send(msg_ctx, pend_lock->context.pid,
 904                                                MSG_SMB_UNLOCK, &data_blob_null);
 905                         }
 906                 }
 907         }
 908
 909         return NT_STATUS_OK;
 910  fail:
 911         if (break_oplocks) {
 912                 contend_level2_oplocks_end(br_lck->fsp,
 913                                            LEVEL2_CONTEND_POSIX_BRL);
 914         }
 915         return status;
 916 }
 917
 918 NTSTATUS smb_vfs_call_brl_lock_windows(struct vfs_handle_struct *handle,
 919                                        struct byte_range_lock *br_lck,
 920                                        struct lock_struct *plock,
 921                                        bool blocking_lock,
 922                                        struct blocking_lock_record *blr)
 923 {
 924         VFS_FIND(brl_lock_windows);
 925         return handle->fns->brl_lock_windows_fn(handle, br_lck, plock,
 926                                                 blocking_lock, blr);
 927 }
 928
 929 /****************************************************************************
 930  Lock a range of bytes.
 931 ****************************************************************************/
 932
 933 NTSTATUS brl_lock(struct messaging_context *msg_ctx,
 934                 struct byte_range_lock *br_lck,
 935                 uint64_t smblctx,
 936                 struct server_id pid,
 937                 br_off start,
 938                 br_off size,
 939                 enum brl_type lock_type,
 940                 enum brl_flavour lock_flav,
 941                 bool blocking_lock,
 942                 uint64_t *psmblctx,
 943                 struct blocking_lock_record *blr)
 944 {
 945         NTSTATUS ret;
 946         struct lock_struct lock;
 947
 948 #if !ZERO_ZERO
 949         if (start == 0 && size == 0) {
 950                 DEBUG(0,("client sent 0/0 lock - please report this\n"));
 951         }
 952 #endif
 953
 954 #ifdef DEVELOPER
 955         /* Quieten valgrind on test. */
 956         ZERO_STRUCT(lock);
 957 #endif
 958
 959         lock.context.smblctx = smblctx;
 960         lock.context.pid = pid;
 961         lock.context.tid = br_lck->fsp->conn->cnum;
 962         lock.start = start;
 963         lock.size = size;
 964         lock.fnum = br_lck->fsp->fnum;
 965         lock.lock_type = lock_type;
 966         lock.lock_flav = lock_flav;
 967
 968         if (lock_flav == WINDOWS_LOCK) {
 969                 ret = SMB_VFS_BRL_LOCK_WINDOWS(br_lck->fsp->conn, br_lck,
 970                     &lock, blocking_lock, blr);
 971         } else {
 972                 ret = brl_lock_posix(msg_ctx, br_lck, &lock);
 973         }
 974
 975 #if ZERO_ZERO
 976         /* sort the lock list */
 977         TYPESAFE_QSORT(br_lck->lock_data, (size_t)br_lck->num_locks, lock_compare);
 978 #endif
 979
 980         /* If we're returning an error, return who blocked us. */
 981         if (!NT_STATUS_IS_OK(ret) && psmblctx) {
 982                 *psmblctx = lock.context.smblctx;
 983         }
 984         return ret;
 985 }
 986
 987 /****************************************************************************
 988  Unlock a range of bytes - Windows semantics.
 989 ****************************************************************************/
 990
 991 bool brl_unlock_windows_default(struct messaging_context *msg_ctx,
 992                                struct byte_range_lock *br_lck,
 993                                const struct lock_struct *plock)
 994 {
 995         unsigned int i, j;
 996         struct lock_struct *locks = br_lck->lock_data;
 997         enum brl_type deleted_lock_type = READ_LOCK; /* shut the compiler up.... */
 998
 999         SMB_ASSERT(plock->lock_type == UNLOCK_LOCK);
1000
1001 #if ZERO_ZERO
1002         /* Delete write locks by preference... The lock list
1003            is sorted in the zero zero case. */
1004
1005         for (i = 0; i < br_lck->num_locks; i++) {
1006                 struct lock_struct *lock = &locks[i];
1007
1008                 if (lock->lock_type == WRITE_LOCK &&
1009                     brl_same_context(&lock->context, &plock->context) &&
1010                     lock->fnum == plock->fnum &&
1011                     lock->lock_flav == WINDOWS_LOCK &&
1012                     lock->start == plock->start &&
1013                     lock->size == plock->size) {
1014
1015                         /* found it - delete it */
1016                         deleted_lock_type = lock->lock_type;
1017                         break;
1018                 }
1019         }
1020
1021         if (i != br_lck->num_locks) {
1022                 /* We found it - don't search again. */
1023                 goto unlock_continue;
1024         }
1025 #endif
1026
1027         for (i = 0; i < br_lck->num_locks; i++) {
1028                 struct lock_struct *lock = &locks[i];
1029
1030                 if (IS_PENDING_LOCK(lock->lock_type)) {
1031                         continue;
1032                 }
1033
1034                 /* Only remove our own locks that match in start, size, and flavour. */
1035                 if (brl_same_context(&lock->context, &plock->context) &&
1036                                         lock->fnum == plock->fnum &&
1037                                         lock->lock_flav == WINDOWS_LOCK &&
1038                                         lock->start == plock->start &&
1039                                         lock->size == plock->size ) {
1040                         deleted_lock_type = lock->lock_type;
1041                         break;
1042                 }
1043         }
1044
1045         if (i == br_lck->num_locks) {
1046                 /* we didn't find it */
1047                 return False;
1048         }
1049
1050 #if ZERO_ZERO
1051   unlock_continue:
1052 #endif
1053
1054         /* Actually delete the lock. */
1055         if (i < br_lck->num_locks - 1) {
1056                 memmove(&locks[i], &locks[i+1],
1057                         sizeof(*locks)*((br_lck->num_locks-1) - i));
1058         }
1059
1060         br_lck->num_locks -= 1;
1061         br_lck->modified = True;
1062
1063         /* Unlock the underlying POSIX regions. */
1064         if(lp_posix_locking(br_lck->fsp->conn->params)) {
1065                 release_posix_lock_windows_flavour(br_lck->fsp,
1066                                 plock->start,
1067                                 plock->size,
1068                                 deleted_lock_type,
1069                                 &plock->context,
1070                                 locks,
1071                                 br_lck->num_locks);
1072         }
1073
1074         /* Send unlock messages to any pending waiters that overlap. */
1075         for (j=0; j < br_lck->num_locks; j++) {
1076                 struct lock_struct *pend_lock = &locks[j];
1077
1078                 /* Ignore non-pending locks. */
1079                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1080                         continue;
1081                 }
1082
1083                 /* We could send specific lock info here... */
1084                 if (brl_pending_overlap(plock, pend_lock)) {
1085                         DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1086                                 procid_str_static(&pend_lock->context.pid )));
1087
1088                         messaging_send(msg_ctx, pend_lock->context.pid,
1089                                        MSG_SMB_UNLOCK, &data_blob_null);
1090                 }
1091         }
1092
1093         contend_level2_oplocks_end(br_lck->fsp, LEVEL2_CONTEND_WINDOWS_BRL);
1094         return True;
1095 }
1096
1097 /****************************************************************************
1098  Unlock a range of bytes - POSIX semantics.
1099 ****************************************************************************/
1100
1101 static bool brl_unlock_posix(struct messaging_context *msg_ctx,
1102                              struct byte_range_lock *br_lck,
1103                              struct lock_struct *plock)
1104 {
1105         unsigned int i, j, count;
1106         struct lock_struct *tp;
1107         struct lock_struct *locks = br_lck->lock_data;
1108         bool overlap_found = False;
1109
1110         /* No zero-zero locks for POSIX. */
1111         if (plock->start == 0 && plock->size == 0) {
1112                 return False;
1113         }
1114
1115         /* Don't allow 64-bit lock wrap. */
1116         if (plock->start + plock->size < plock->start ||
1117                         plock->start + plock->size < plock->size) {
1118                 DEBUG(10,("brl_unlock_posix: lock wrap\n"));
1119                 return False;
1120         }
1121
1122         /* The worst case scenario here is we have to split an
1123            existing POSIX lock range into two, so we need at most
1124            1 more entry. */
1125
1126         tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 1));
1127         if (!tp) {
1128                 DEBUG(10,("brl_unlock_posix: malloc fail\n"));
1129                 return False;
1130         }
1131
1132         count = 0;
1133         for (i = 0; i < br_lck->num_locks; i++) {
1134                 struct lock_struct *lock = &locks[i];
1135                 unsigned int tmp_count;
1136
1137                 /* Only remove our own locks - ignore fnum. */
1138                 if (IS_PENDING_LOCK(lock->lock_type) ||
1139                                 !brl_same_context(&lock->context, &plock->context)) {
1140                         memcpy(&tp[count], lock, sizeof(struct lock_struct));
1141                         count++;
1142                         continue;
1143                 }
1144
1145                 if (lock->lock_flav == WINDOWS_LOCK) {
1146                         /* Do any Windows flavour locks conflict ? */
1147                         if (brl_conflict(lock, plock)) {
1148                                 SAFE_FREE(tp);
1149                                 return false;
1150                         }
1151                         /* Just copy the Windows lock into the new array. */
1152                         memcpy(&tp[count], lock, sizeof(struct lock_struct));
1153                         count++;
1154                         continue;
1155                 }
1156
1157                 /* Work out overlaps. */
1158                 tmp_count = brlock_posix_split_merge(&tp[count], lock, plock);
1159
1160                 if (tmp_count == 0) {
1161                         /* plock overlapped the existing lock completely,
1162                            or replaced it. Don't copy the existing lock. */
1163                         overlap_found = true;
1164                 } else if (tmp_count == 1) {
1165                         /* Either no overlap, (simple copy of existing lock) or
1166                          * an overlap of an existing lock. */
1167                         /* If the lock changed size, we had an overlap. */
1168                         if (tp[count].size != lock->size) {
1169                                 overlap_found = true;
1170                         }
1171                         count += tmp_count;
1172                 } else if (tmp_count == 2) {
1173                         /* We split a lock range in two. */
1174                         overlap_found = true;
1175                         count += tmp_count;
1176
1177                         /* Optimisation... */
1178                         /* We know we're finished here as we can't overlap any
1179                            more POSIX locks. Copy the rest of the lock array. */
1180
1181                         if (i < br_lck->num_locks - 1) {
1182                                 memcpy(&tp[count], &locks[i+1],
1183                                         sizeof(*locks)*((br_lck->num_locks-1) - i));
1184                                 count += ((br_lck->num_locks-1) - i);
1185                         }
1186                         break;
1187                 }
1188
1189         }
1190
1191         if (!overlap_found) {
1192                 /* Just ignore - no change. */
1193                 SAFE_FREE(tp);
1194                 DEBUG(10,("brl_unlock_posix: No overlap - unlocked.\n"));
1195                 return True;
1196         }
1197
1198         /* Unlock any POSIX regions. */
1199         if(lp_posix_locking(br_lck->fsp->conn->params)) {
1200                 release_posix_lock_posix_flavour(br_lck->fsp,
1201                                                 plock->start,
1202                                                 plock->size,
1203                                                 &plock->context,
1204                                                 tp,
1205                                                 count);
1206         }
1207
1208         /* Realloc so we don't leak entries per unlock call. */
1209         if (count) {
1210                 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
1211                 if (!tp) {
1212                         DEBUG(10,("brl_unlock_posix: realloc fail\n"));
1213                         return False;
1214                 }
1215         } else {
1216                 /* We deleted the last lock. */
1217                 SAFE_FREE(tp);
1218                 tp = NULL;
1219         }
1220
1221         contend_level2_oplocks_end(br_lck->fsp,
1222                                    LEVEL2_CONTEND_POSIX_BRL);
1223
1224         br_lck->num_locks = count;
1225         SAFE_FREE(br_lck->lock_data);
1226         locks = tp;
1227         br_lck->lock_data = tp;
1228         br_lck->modified = True;
1229
1230         /* Send unlock messages to any pending waiters that overlap. */
1231
1232         for (j=0; j < br_lck->num_locks; j++) {
1233                 struct lock_struct *pend_lock = &locks[j];
1234
1235                 /* Ignore non-pending locks. */
1236                 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1237                         continue;
1238                 }
1239
1240                 /* We could send specific lock info here... */
1241                 if (brl_pending_overlap(plock, pend_lock)) {
1242                         DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1243                                 procid_str_static(&pend_lock->context.pid )));
1244
1245                         messaging_send(msg_ctx, pend_lock->context.pid,
1246                                        MSG_SMB_UNLOCK, &data_blob_null);
1247                 }
1248         }
1249
1250         return True;
1251 }
1252
1253 bool smb_vfs_call_brl_unlock_windows(struct vfs_handle_struct *handle,
1254                                      struct messaging_context *msg_ctx,
1255                                      struct byte_range_lock *br_lck,
1256                                      const struct lock_struct *plock)
1257 {
1258         VFS_FIND(brl_unlock_windows);
1259         return handle->fns->brl_unlock_windows_fn(handle, msg_ctx, br_lck,
1260                                                   plock);
1261 }
1262
1263 /****************************************************************************
1264  Unlock a range of bytes.
1265 ****************************************************************************/
1266
1267 bool brl_unlock(struct messaging_context *msg_ctx,
1268                 struct byte_range_lock *br_lck,
1269                 uint64_t smblctx,
1270                 struct server_id pid,
1271                 br_off start,
1272                 br_off size,
1273                 enum brl_flavour lock_flav)
1274 {
1275         struct lock_struct lock;
1276
1277         lock.context.smblctx = smblctx;
1278         lock.context.pid = pid;
1279         lock.context.tid = br_lck->fsp->conn->cnum;
1280         lock.start = start;
1281         lock.size = size;
1282         lock.fnum = br_lck->fsp->fnum;
1283         lock.lock_type = UNLOCK_LOCK;
1284         lock.lock_flav = lock_flav;
1285
1286         if (lock_flav == WINDOWS_LOCK) {
1287                 return SMB_VFS_BRL_UNLOCK_WINDOWS(br_lck->fsp->conn, msg_ctx,
1288                     br_lck, &lock);
1289         } else {
1290                 return brl_unlock_posix(msg_ctx, br_lck, &lock);
1291         }
1292 }
1293
1294 /****************************************************************************
1295  Test if we could add a lock if we wanted to.
1296  Returns True if the region required is currently unlocked, False if locked.
1297 ****************************************************************************/
1298
1299 bool brl_locktest(struct byte_range_lock *br_lck,
1300                 uint64_t smblctx,
1301                 struct server_id pid,
1302                 br_off start,
1303                 br_off size,
1304                 enum brl_type lock_type,
1305                 enum brl_flavour lock_flav)
1306 {
1307         bool ret = True;
1308         unsigned int i;
1309         struct lock_struct lock;
1310         const struct lock_struct *locks = br_lck->lock_data;
1311         files_struct *fsp = br_lck->fsp;
1312
1313         lock.context.smblctx = smblctx;
1314         lock.context.pid = pid;
1315         lock.context.tid = br_lck->fsp->conn->cnum;
1316         lock.start = start;
1317         lock.size = size;
1318         lock.fnum = fsp->fnum;
1319         lock.lock_type = lock_type;
1320         lock.lock_flav = lock_flav;
1321
1322         /* Make sure existing locks don't conflict */
1323         for (i=0; i < br_lck->num_locks; i++) {
1324                 /*
1325                  * Our own locks don't conflict.
1326                  */
1327                 if (brl_conflict_other(&locks[i], &lock)) {
1328                         return False;
1329                 }
1330         }
1331
1332         /*
1333          * There is no lock held by an SMB daemon, check to
1334          * see if there is a POSIX lock from a UNIX or NFS process.
1335          * This only conflicts with Windows locks, not POSIX locks.
1336          */
1337
1338         if(lp_posix_locking(fsp->conn->params) && (lock_flav == WINDOWS_LOCK)) {
1339                 ret = is_posix_locked(fsp, &start, &size, &lock_type, WINDOWS_LOCK);
1340
1341                 DEBUG(10,("brl_locktest: posix start=%.0f len=%.0f %s for %s file %s\n",
1342                         (double)start, (double)size, ret ? "locked" : "unlocked",
1343                         fsp_fnum_dbg(fsp), fsp_str_dbg(fsp)));
1344
1345                 /* We need to return the inverse of is_posix_locked. */
1346                 ret = !ret;
1347         }
1348
1349         /* no conflicts - we could have added it */
1350         return ret;
1351 }
1352
1353 /****************************************************************************
1354  Query for existing locks.
1355 ****************************************************************************/
1356
1357 NTSTATUS brl_lockquery(struct byte_range_lock *br_lck,
1358                 uint64_t *psmblctx,
1359                 struct server_id pid,
1360                 br_off *pstart,
1361                 br_off *psize,
1362                 enum brl_type *plock_type,
1363                 enum brl_flavour lock_flav)
1364 {
1365         unsigned int i;
1366         struct lock_struct lock;
1367         const struct lock_struct *locks = br_lck->lock_data;
1368         files_struct *fsp = br_lck->fsp;
1369
1370         lock.context.smblctx = *psmblctx;
1371         lock.context.pid = pid;
1372         lock.context.tid = br_lck->fsp->conn->cnum;
1373         lock.start = *pstart;
1374         lock.size = *psize;
1375         lock.fnum = fsp->fnum;
1376         lock.lock_type = *plock_type;
1377         lock.lock_flav = lock_flav;
1378
1379         /* Make sure existing locks don't conflict */
1380         for (i=0; i < br_lck->num_locks; i++) {
1381                 const struct lock_struct *exlock = &locks[i];
1382                 bool conflict = False;
1383
1384                 if (exlock->lock_flav == WINDOWS_LOCK) {
1385                         conflict = brl_conflict(exlock, &lock);
1386                 } else {
1387                         conflict = brl_conflict_posix(exlock, &lock);
1388                 }
1389
1390                 if (conflict) {
1391                         *psmblctx = exlock->context.smblctx;
1392                         *pstart = exlock->start;
1393                         *psize = exlock->size;
1394                         *plock_type = exlock->lock_type;
1395                         return NT_STATUS_LOCK_NOT_GRANTED;
1396                 }
1397         }
1398
1399         /*
1400          * There is no lock held by an SMB daemon, check to
1401          * see if there is a POSIX lock from a UNIX or NFS process.
1402          */
1403
1404         if(lp_posix_locking(fsp->conn->params)) {
1405                 bool ret = is_posix_locked(fsp, pstart, psize, plock_type, POSIX_LOCK);
1406
1407                 DEBUG(10,("brl_lockquery: posix start=%.0f len=%.0f %s for %s file %s\n",
1408                         (double)*pstart, (double)*psize, ret ? "locked" : "unlocked",
1409                         fsp_fnum_dbg(fsp), fsp_str_dbg(fsp)));
1410
1411                 if (ret) {
1412                         /* Hmmm. No clue what to set smblctx to - use -1. */
1413                         *psmblctx = 0xFFFFFFFFFFFFFFFFLL;
1414                         return NT_STATUS_LOCK_NOT_GRANTED;
1415                 }
1416         }
1417
1418         return NT_STATUS_OK;
1419 }
1420
1421
1422 bool smb_vfs_call_brl_cancel_windows(struct vfs_handle_struct *handle,
1423                                      struct byte_range_lock *br_lck,
1424                                      struct lock_struct *plock,
1425                                      struct blocking_lock_record *blr)
1426 {
1427         VFS_FIND(brl_cancel_windows);
1428         return handle->fns->brl_cancel_windows_fn(handle, br_lck, plock, blr);
1429 }
1430
1431 /****************************************************************************
1432  Remove a particular pending lock.
1433 ****************************************************************************/
1434 bool brl_lock_cancel(struct byte_range_lock *br_lck,
1435                 uint64_t smblctx,
1436                 struct server_id pid,
1437                 br_off start,
1438                 br_off size,
1439                 enum brl_flavour lock_flav,
1440                 struct blocking_lock_record *blr)
1441 {
1442         bool ret;
1443         struct lock_struct lock;
1444
1445         lock.context.smblctx = smblctx;
1446         lock.context.pid = pid;
1447         lock.context.tid = br_lck->fsp->conn->cnum;
1448         lock.start = start;
1449         lock.size = size;
1450         lock.fnum = br_lck->fsp->fnum;
1451         lock.lock_flav = lock_flav;
1452         /* lock.lock_type doesn't matter */
1453
1454         if (lock_flav == WINDOWS_LOCK) {
1455                 ret = SMB_VFS_BRL_CANCEL_WINDOWS(br_lck->fsp->conn, br_lck,
1456                     &lock, blr);
1457         } else {
1458                 ret = brl_lock_cancel_default(br_lck, &lock);
1459         }
1460
1461         return ret;
1462 }
1463
1464 bool brl_lock_cancel_default(struct byte_range_lock *br_lck,
1465                 struct lock_struct *plock)
1466 {
1467         unsigned int i;
1468         struct lock_struct *locks = br_lck->lock_data;
1469
1470         SMB_ASSERT(plock);
1471
1472         for (i = 0; i < br_lck->num_locks; i++) {
1473                 struct lock_struct *lock = &locks[i];
1474
1475                 /* For pending locks we *always* care about the fnum. */
1476                 if (brl_same_context(&lock->context, &plock->context) &&
1477                                 lock->fnum == plock->fnum &&
1478                                 IS_PENDING_LOCK(lock->lock_type) &&
1479                                 lock->lock_flav == plock->lock_flav &&
1480                                 lock->start == plock->start &&
1481                                 lock->size == plock->size) {
1482                         break;
1483                 }
1484         }
1485
1486         if (i == br_lck->num_locks) {
1487                 /* Didn't find it. */
1488                 return False;
1489         }
1490
1491         if (i < br_lck->num_locks - 1) {
1492                 /* Found this particular pending lock - delete it */
1493                 memmove(&locks[i], &locks[i+1],
1494                         sizeof(*locks)*((br_lck->num_locks-1) - i));
1495         }
1496
1497         br_lck->num_locks -= 1;
1498         br_lck->modified = True;
1499         return True;
1500 }
1501
1502 /****************************************************************************
1503  Remove any locks associated with a open file.
1504  We return True if this process owns any other Windows locks on this
1505  fd and so we should not immediately close the fd.
1506 ****************************************************************************/
1507
1508 void brl_close_fnum(struct messaging_context *msg_ctx,
1509                     struct byte_range_lock *br_lck)
1510 {
1511         files_struct *fsp = br_lck->fsp;
1512         uint32_t tid = fsp->conn->cnum;
1513         uint64_t fnum = fsp->fnum;
1514         unsigned int i;
1515         struct lock_struct *locks = br_lck->lock_data;
1516         struct server_id pid = messaging_server_id(fsp->conn->sconn->msg_ctx);
1517         struct lock_struct *locks_copy;
1518         unsigned int num_locks_copy;
1519
1520         /* Copy the current lock array. */
1521         if (br_lck->num_locks) {
1522                 locks_copy = (struct lock_struct *)talloc_memdup(br_lck, locks, br_lck->num_locks * sizeof(struct lock_struct));
1523                 if (!locks_copy) {
1524                         smb_panic("brl_close_fnum: talloc failed");
1525                         }
1526         } else {
1527                 locks_copy = NULL;
1528         }
1529
1530         num_locks_copy = br_lck->num_locks;
1531
1532         for (i=0; i < num_locks_copy; i++) {
1533                 struct lock_struct *lock = &locks_copy[i];
1534
1535                 if (lock->context.tid == tid && serverid_equal(&lock->context.pid, &pid) &&
1536                                 (lock->fnum == fnum)) {
1537                         brl_unlock(msg_ctx,
1538                                 br_lck,
1539                                 lock->context.smblctx,
1540                                 pid,
1541                                 lock->start,
1542                                 lock->size,
1543                                 lock->lock_flav);
1544                 }
1545         }
1546 }
1547
1548 bool brl_mark_disconnected(struct files_struct *fsp)
1549 {
1550         uint32_t tid = fsp->conn->cnum;
1551         uint64_t smblctx = fsp->op->global->open_persistent_id;
1552         uint64_t fnum = fsp->fnum;
1553         unsigned int i;
1554         struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
1555         struct byte_range_lock *br_lck = NULL;
1556
1557         if (!fsp->op->global->durable) {
1558                 return false;
1559         }
1560
1561         if (fsp->current_lock_count == 0) {
1562                 return true;
1563         }
1564
1565         br_lck = brl_get_locks(talloc_tos(), fsp);
1566         if (br_lck == NULL) {
1567                 return false;
1568         }
1569
1570         for (i=0; i < br_lck->num_locks; i++) {
1571                 struct lock_struct *lock = &br_lck->lock_data[i];
1572
1573                 /*
1574                  * as this is a durable handle, we only expect locks
1575                  * of the current file handle!
1576                  */
1577
1578                 if (lock->context.smblctx != smblctx) {
1579                         TALLOC_FREE(br_lck);
1580                         return false;
1581                 }
1582
1583                 if (lock->context.tid != tid) {
1584                         TALLOC_FREE(br_lck);
1585                         return false;
1586                 }
1587
1588                 if (!serverid_equal(&lock->context.pid, &self)) {
1589                         TALLOC_FREE(br_lck);
1590                         return false;
1591                 }
1592
1593                 if (lock->fnum != fnum) {
1594                         TALLOC_FREE(br_lck);
1595                         return false;
1596                 }
1597
1598                 server_id_set_disconnected(&lock->context.pid);
1599                 lock->context.tid = TID_FIELD_INVALID;
1600                 lock->fnum = FNUM_FIELD_INVALID;
1601         }
1602
1603         br_lck->modified = true;
1604         TALLOC_FREE(br_lck);
1605         return true;
1606 }
1607
1608 bool brl_reconnect_disconnected(struct files_struct *fsp)
1609 {
1610         uint32_t tid = fsp->conn->cnum;
1611         uint64_t smblctx = fsp->op->global->open_persistent_id;
1612         uint64_t fnum = fsp->fnum;
1613         unsigned int i;
1614         struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
1615         struct byte_range_lock *br_lck = NULL;
1616
1617         if (!fsp->op->global->durable) {
1618                 return false;
1619         }
1620
1621         /*
1622          * When reconnecting, we do not want to validate the brlock entries
1623          * and thereby remove our own (disconnected) entries but reactivate
1624          * them instead.
1625          */
1626         fsp->lockdb_clean = true;
1627
1628         br_lck = brl_get_locks(talloc_tos(), fsp);
1629         if (br_lck == NULL) {
1630                 return false;
1631         }
1632
1633         if (br_lck->num_locks == 0) {
1634                 TALLOC_FREE(br_lck);
1635                 return true;
1636         }
1637
1638         for (i=0; i < br_lck->num_locks; i++) {
1639                 struct lock_struct *lock = &br_lck->lock_data[i];
1640
1641                 /*
1642                  * as this is a durable handle we only expect locks
1643                  * of the current file handle!
1644                  */
1645
1646                 if (lock->context.smblctx != smblctx) {
1647                         TALLOC_FREE(br_lck);
1648                         return false;
1649                 }
1650
1651                 if (lock->context.tid != TID_FIELD_INVALID) {
1652                         TALLOC_FREE(br_lck);
1653                         return false;
1654                 }
1655
1656                 if (!server_id_is_disconnected(&lock->context.pid)) {
1657                         TALLOC_FREE(br_lck);
1658                         return false;
1659                 }
1660
1661                 if (lock->fnum != FNUM_FIELD_INVALID) {
1662                         TALLOC_FREE(br_lck);
1663                         return false;
1664                 }
1665
1666                 lock->context.pid = self;
1667                 lock->context.tid = tid;
1668                 lock->fnum = fnum;
1669         }
1670
1671         fsp->current_lock_count = br_lck->num_locks;
1672         br_lck->modified = true;
1673         TALLOC_FREE(br_lck);
1674         return true;
1675 }
1676
1677 /****************************************************************************
1678  Ensure this set of lock entries is valid.
1679 ****************************************************************************/
1680 static bool validate_lock_entries(unsigned int *pnum_entries, struct lock_struct **pplocks,
1681                                   bool keep_disconnected)
1682 {
1683         unsigned int i;
1684         unsigned int num_valid_entries = 0;
1685         struct lock_struct *locks = *pplocks;
1686         TALLOC_CTX *frame = talloc_stackframe();
1687         struct server_id *ids;
1688         bool *exists;
1689
1690         ids = talloc_array(frame, struct server_id, *pnum_entries);
1691         if (ids == NULL) {
1692                 DEBUG(0, ("validate_lock_entries: "
1693                           "talloc_array(struct server_id, %u) failed\n",
1694                           *pnum_entries));
1695                 talloc_free(frame);
1696                 return false;
1697         }
1698
1699         exists = talloc_array(frame, bool, *pnum_entries);
1700         if (exists == NULL) {
1701                 DEBUG(0, ("validate_lock_entries: "
1702                           "talloc_array(bool, %u) failed\n",
1703                           *pnum_entries));
1704                 talloc_free(frame);
1705                 return false;
1706         }
1707
1708         for (i = 0; i < *pnum_entries; i++) {
1709                 ids[i] = locks[i].context.pid;
1710         }
1711
1712         if (!serverids_exist(ids, *pnum_entries, exists)) {
1713                 DEBUG(3, ("validate_lock_entries: serverids_exists failed\n"));
1714                 talloc_free(frame);
1715                 return false;
1716         }
1717
1718         for (i = 0; i < *pnum_entries; i++) {
1719                 if (exists[i]) {
1720                         num_valid_entries++;
1721                         continue;
1722                 }
1723
1724                 if (keep_disconnected &&
1725                     server_id_is_disconnected(&ids[i]))
1726                 {
1727                         num_valid_entries++;
1728                         continue;
1729                 }
1730
1731                 /* This process no longer exists - mark this
1732                    entry as invalid by zeroing it. */
1733                 ZERO_STRUCTP(&locks[i]);
1734         }
1735         TALLOC_FREE(frame);
1736
1737         if (num_valid_entries != *pnum_entries) {
1738                 struct lock_struct *new_lock_data = NULL;
1739
1740                 if (num_valid_entries) {
1741                         new_lock_data = SMB_MALLOC_ARRAY(struct lock_struct, num_valid_entries);
1742                         if (!new_lock_data) {
1743                                 DEBUG(3, ("malloc fail\n"));
1744                                 return False;
1745                         }
1746
1747                         num_valid_entries = 0;
1748                         for (i = 0; i < *pnum_entries; i++) {
1749                                 struct lock_struct *lock_data = &locks[i];
1750                                 if (lock_data->context.smblctx &&
1751                                                 lock_data->context.tid) {
1752                                         /* Valid (nonzero) entry - copy it. */
1753                                         memcpy(&new_lock_data[num_valid_entries],
1754                                                 lock_data, sizeof(struct lock_struct));
1755                                         num_valid_entries++;
1756                                 }
1757                         }
1758                 }
1759
1760                 SAFE_FREE(*pplocks);
1761                 *pplocks = new_lock_data;
1762                 *pnum_entries = num_valid_entries;
1763         }
1764
1765         return True;
1766 }
1767
1768 struct brl_forall_cb {
1769         void (*fn)(struct file_id id, struct server_id pid,
1770                    enum brl_type lock_type,
1771                    enum brl_flavour lock_flav,
1772                    br_off start, br_off size,
1773                    void *private_data);
1774         void *private_data;
1775 };
1776
1777 /****************************************************************************
1778  Traverse the whole database with this function, calling traverse_callback
1779  on each lock.
1780 ****************************************************************************/
1781
1782 static int brl_traverse_fn(struct db_record *rec, void *state)
1783 {
1784         struct brl_forall_cb *cb = (struct brl_forall_cb *)state;
1785         struct lock_struct *locks;
1786         struct file_id *key;
1787         unsigned int i;
1788         unsigned int num_locks = 0;
1789         unsigned int orig_num_locks = 0;
1790         TDB_DATA dbkey;
1791         TDB_DATA value;
1792
1793         dbkey = dbwrap_record_get_key(rec);
1794         value = dbwrap_record_get_value(rec);
1795
1796         /* In a traverse function we must make a copy of
1797            dbuf before modifying it. */
1798
1799         locks = (struct lock_struct *)memdup(value.dptr, value.dsize);
1800         if (!locks) {
1801                 return -1; /* Terminate traversal. */
1802         }
1803
1804         key = (struct file_id *)dbkey.dptr;
1805         orig_num_locks = num_locks = value.dsize/sizeof(*locks);
1806
1807         /* Ensure the lock db is clean of entries from invalid processes. */
1808
1809         if (!validate_lock_entries(&num_locks, &locks, true)) {
1810                 SAFE_FREE(locks);
1811                 return -1; /* Terminate traversal */
1812         }
1813
1814         if (orig_num_locks != num_locks) {
1815                 if (num_locks) {
1816                         TDB_DATA data;
1817                         data.dptr = (uint8_t *)locks;
1818                         data.dsize = num_locks*sizeof(struct lock_struct);
1819                         dbwrap_record_store(rec, data, TDB_REPLACE);
1820                 } else {
1821                         dbwrap_record_delete(rec);
1822                 }
1823         }
1824
1825         if (cb->fn) {
1826                 for ( i=0; i<num_locks; i++) {
1827                         cb->fn(*key,
1828                                 locks[i].context.pid,
1829                                 locks[i].lock_type,
1830                                 locks[i].lock_flav,
1831                                 locks[i].start,
1832                                 locks[i].size,
1833                                 cb->private_data);
1834                 }
1835         }
1836
1837         SAFE_FREE(locks);
1838         return 0;
1839 }
1840
1841 /*******************************************************************
1842  Call the specified function on each lock in the database.
1843 ********************************************************************/
1844
1845 int brl_forall(void (*fn)(struct file_id id, struct server_id pid,
1846                           enum brl_type lock_type,
1847                           enum brl_flavour lock_flav,
1848                           br_off start, br_off size,
1849                           void *private_data),
1850                void *private_data)
1851 {
1852         struct brl_forall_cb cb;
1853         NTSTATUS status;
1854         int count = 0;
1855
1856         if (!brlock_db) {
1857                 return 0;
1858         }
1859         cb.fn = fn;
1860         cb.private_data = private_data;
1861         status = dbwrap_traverse(brlock_db, brl_traverse_fn, &cb, &count);
1862
1863         if (!NT_STATUS_IS_OK(status)) {
1864                 return -1;
1865         } else {
1866                 return count;
1867         }
1868 }
1869
1870 /*******************************************************************
1871  Store a potentially modified set of byte range lock data back into
1872  the database.
1873  Unlock the record.
1874 ********************************************************************/
1875
1876 static void byte_range_lock_flush(struct byte_range_lock *br_lck)
1877 {
1878         if (br_lck->read_only) {
1879                 SMB_ASSERT(!br_lck->modified);
1880         }
1881
1882         if (!br_lck->modified) {
1883                 goto done;
1884         }
1885
1886         if (br_lck->num_locks == 0) {
1887                 /* No locks - delete this entry. */
1888                 NTSTATUS status = dbwrap_record_delete(br_lck->record);
1889                 if (!NT_STATUS_IS_OK(status)) {
1890                         DEBUG(0, ("delete_rec returned %s\n",
1891                                   nt_errstr(status)));
1892                         smb_panic("Could not delete byte range lock entry");
1893                 }
1894         } else {
1895                 TDB_DATA data;
1896                 NTSTATUS status;
1897
1898                 data.dptr = (uint8 *)br_lck->lock_data;
1899                 data.dsize = br_lck->num_locks * sizeof(struct lock_struct);
1900
1901                 status = dbwrap_record_store(br_lck->record, data, TDB_REPLACE);
1902                 if (!NT_STATUS_IS_OK(status)) {
1903                         DEBUG(0, ("store returned %s\n", nt_errstr(status)));
1904                         smb_panic("Could not store byte range mode entry");
1905                 }
1906         }
1907
1908  done:
1909
1910         br_lck->read_only = true;
1911         br_lck->modified = false;
1912
1913         TALLOC_FREE(br_lck->record);
1914 }
1915
1916 static int byte_range_lock_destructor(struct byte_range_lock *br_lck)
1917 {
1918         byte_range_lock_flush(br_lck);
1919         SAFE_FREE(br_lck->lock_data);
1920         return 0;
1921 }
1922
1923 /*******************************************************************
1924  Fetch a set of byte range lock data from the database.
1925  Leave the record locked.
1926  TALLOC_FREE(brl) will release the lock in the destructor.
1927 ********************************************************************/
1928
1929 static struct byte_range_lock *brl_get_locks_internal(TALLOC_CTX *mem_ctx,
1930                                         files_struct *fsp, bool read_only)
1931 {
1932         TDB_DATA key, data;
1933         struct byte_range_lock *br_lck = talloc(mem_ctx, struct byte_range_lock);
1934         bool do_read_only = read_only;
1935
1936         if (br_lck == NULL) {
1937                 return NULL;
1938         }
1939
1940         br_lck->fsp = fsp;
1941         br_lck->num_locks = 0;
1942         br_lck->modified = False;
1943         br_lck->key = fsp->file_id;
1944
1945         key.dptr = (uint8 *)&br_lck->key;
1946         key.dsize = sizeof(struct file_id);
1947
1948         if (!fsp->lockdb_clean) {
1949                 /* We must be read/write to clean
1950                    the dead entries. */
1951                 do_read_only = false;
1952         }
1953
1954         if (do_read_only) {
1955                 NTSTATUS status;
1956                 status = dbwrap_fetch(brlock_db, br_lck, key, &data);
1957                 if (!NT_STATUS_IS_OK(status)) {
1958                         DEBUG(3, ("Could not fetch byte range lock record\n"));
1959                         TALLOC_FREE(br_lck);
1960                         return NULL;
1961                 }
1962                 br_lck->record = NULL;
1963         } else {
1964                 br_lck->record = dbwrap_fetch_locked(brlock_db, br_lck, key);
1965
1966                 if (br_lck->record == NULL) {
1967                         DEBUG(3, ("Could not lock byte range lock entry\n"));
1968                         TALLOC_FREE(br_lck);
1969                         return NULL;
1970                 }
1971
1972                 data = dbwrap_record_get_value(br_lck->record);
1973         }
1974
1975         br_lck->read_only = do_read_only;
1976         br_lck->lock_data = NULL;
1977
1978         talloc_set_destructor(br_lck, byte_range_lock_destructor);
1979
1980         br_lck->num_locks = data.dsize / sizeof(struct lock_struct);
1981
1982         if (br_lck->num_locks != 0) {
1983                 br_lck->lock_data = SMB_MALLOC_ARRAY(struct lock_struct,
1984                                                      br_lck->num_locks);
1985                 if (br_lck->lock_data == NULL) {
1986                         DEBUG(0, ("malloc failed\n"));
1987                         TALLOC_FREE(br_lck);
1988                         return NULL;
1989                 }
1990
1991                 memcpy(br_lck->lock_data, data.dptr, data.dsize);
1992         }
1993
1994         if (!fsp->lockdb_clean) {
1995                 int orig_num_locks = br_lck->num_locks;
1996
1997                 /*
1998                  * This is the first time we access the byte range lock
1999                  * record with this fsp. Go through and ensure all entries
2000                  * are valid - remove any that don't.
2001                  * This makes the lockdb self cleaning at low cost.
2002                  *
2003                  * Note: Disconnected entries belong to disconnected
2004                  * durable handles. So at this point, we have a new
2005                  * handle on the file and the disconnected durable has
2006                  * already been closed (we are not a durable reconnect).
2007                  * So we need to clean the disconnected brl entry.
2008                  */
2009
2010                 if (!validate_lock_entries(&br_lck->num_locks,
2011                                            &br_lck->lock_data, false)) {
2012                         SAFE_FREE(br_lck->lock_data);
2013                         TALLOC_FREE(br_lck);
2014                         return NULL;
2015                 }
2016
2017                 /* Ensure invalid locks are cleaned up in the destructor. */
2018                 if (orig_num_locks != br_lck->num_locks) {
2019                         br_lck->modified = True;
2020                 }
2021
2022                 /* Mark the lockdb as "clean" as seen from this open file. */
2023                 fsp->lockdb_clean = True;
2024         }
2025
2026         if (DEBUGLEVEL >= 10) {
2027                 unsigned int i;
2028                 struct lock_struct *locks = br_lck->lock_data;
2029                 DEBUG(10,("brl_get_locks_internal: %u current locks on file_id %s\n",
2030                         br_lck->num_locks,
2031                           file_id_string_tos(&fsp->file_id)));
2032                 for( i = 0; i < br_lck->num_locks; i++) {
2033                         print_lock_struct(i, &locks[i]);
2034                 }
2035         }
2036
2037         if (do_read_only != read_only) {
2038                 /*
2039                  * this stores the record and gets rid of
2040                  * the write lock that is needed for a cleanup
2041                  */
2042                 byte_range_lock_flush(br_lck);
2043         }
2044
2045         return br_lck;
2046 }
2047
2048 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx,
2049                                         files_struct *fsp)
2050 {
2051         return brl_get_locks_internal(mem_ctx, fsp, False);
2052 }
2053
2054 struct byte_range_lock *brl_get_locks_readonly(files_struct *fsp)
2055 {
2056         struct byte_range_lock *br_lock;
2057
2058         if (lp_clustering()) {
2059                 return brl_get_locks_internal(talloc_tos(), fsp, true);
2060         }
2061
2062         if ((fsp->brlock_rec != NULL)
2063             && (dbwrap_get_seqnum(brlock_db) == fsp->brlock_seqnum)) {
2064                 return fsp->brlock_rec;
2065         }
2066
2067         TALLOC_FREE(fsp->brlock_rec);
2068
2069         br_lock = brl_get_locks_internal(talloc_tos(), fsp, true);
2070         if (br_lock == NULL) {
2071                 return NULL;
2072         }
2073         fsp->brlock_seqnum = dbwrap_get_seqnum(brlock_db);
2074
2075         fsp->brlock_rec = talloc_move(fsp, &br_lock);
2076
2077         return fsp->brlock_rec;
2078 }
2079
2080 struct brl_revalidate_state {
2081         ssize_t array_size;
2082         uint32 num_pids;
2083         struct server_id *pids;
2084 };
2085
2086 /*
2087  * Collect PIDs of all processes with pending entries
2088  */
2089
2090 static void brl_revalidate_collect(struct file_id id, struct server_id pid,
2091                                    enum brl_type lock_type,
2092                                    enum brl_flavour lock_flav,
2093                                    br_off start, br_off size,
2094                                    void *private_data)
2095 {
2096         struct brl_revalidate_state *state =
2097                 (struct brl_revalidate_state *)private_data;
2098
2099         if (!IS_PENDING_LOCK(lock_type)) {
2100                 return;
2101         }
2102
2103         add_to_large_array(state, sizeof(pid), (void *)&pid,
2104                            &state->pids, &state->num_pids,
2105                            &state->array_size);
2106 }
2107
2108 /*
2109  * qsort callback to sort the processes
2110  */
2111
2112 static int compare_procids(const void *p1, const void *p2)
2113 {
2114         const struct server_id *i1 = (const struct server_id *)p1;
2115         const struct server_id *i2 = (const struct server_id *)p2;
2116
2117         if (i1->pid < i2->pid) return -1;
2118         if (i2->pid > i2->pid) return 1;
2119         return 0;
2120 }
2121
2122 /*
2123  * Send a MSG_SMB_UNLOCK message to all processes with pending byte range
2124  * locks so that they retry. Mainly used in the cluster code after a node has
2125  * died.
2126  *
2127  * Done in two steps to avoid double-sends: First we collect all entries in an
2128  * array, then qsort that array and only send to non-dupes.
2129  */
2130
2131 void brl_revalidate(struct messaging_context *msg_ctx,
2132                     void *private_data,
2133                     uint32_t msg_type,
2134                     struct server_id server_id,
2135                     DATA_BLOB *data)
2136 {
2137         struct brl_revalidate_state *state;
2138         uint32 i;
2139         struct server_id last_pid;
2140
2141         if (!(state = talloc_zero(NULL, struct brl_revalidate_state))) {
2142                 DEBUG(0, ("talloc failed\n"));
2143                 return;
2144         }
2145
2146         brl_forall(brl_revalidate_collect, state);
2147
2148         if (state->array_size == -1) {
2149                 DEBUG(0, ("talloc failed\n"));
2150                 goto done;
2151         }
2152
2153         if (state->num_pids == 0) {
2154                 goto done;
2155         }
2156
2157         TYPESAFE_QSORT(state->pids, state->num_pids, compare_procids);
2158
2159         ZERO_STRUCT(last_pid);
2160
2161         for (i=0; i<state->num_pids; i++) {
2162                 if (serverid_equal(&last_pid, &state->pids[i])) {
2163                         /*
2164                          * We've seen that one already
2165                          */
2166                         continue;
2167                 }
2168
2169                 messaging_send(msg_ctx, state->pids[i], MSG_SMB_UNLOCK,
2170                                &data_blob_null);
2171                 last_pid = state->pids[i];
2172         }
2173
2174  done:
2175         TALLOC_FREE(state);
2176         return;
2177 }
2178
2179 bool brl_cleanup_disconnected(struct file_id fid, uint64_t open_persistent_id)
2180 {
2181         bool ret = false;
2182         TALLOC_CTX *frame = talloc_stackframe();
2183         TDB_DATA key, val;
2184         struct db_record *rec;
2185         struct lock_struct *lock;
2186         unsigned n, num;
2187         NTSTATUS status;
2188
2189         key = make_tdb_data((void*)&fid, sizeof(fid));
2190
2191         rec = dbwrap_fetch_locked(brlock_db, frame, key);
2192         if (rec == NULL) {
2193                 DEBUG(5, ("brl_cleanup_disconnected: failed to fetch record "
2194                           "for file %s\n", file_id_string(frame, &fid)));
2195                 goto done;
2196         }
2197
2198         val = dbwrap_record_get_value(rec);
2199         lock = (struct lock_struct*)val.dptr;
2200         num = val.dsize / sizeof(struct lock_struct);
2201         if (lock == NULL) {
2202                 DEBUG(10, ("brl_cleanup_disconnected: no byte range locks for "
2203                            "file %s\n", file_id_string(frame, &fid)));
2204                 ret = true;
2205                 goto done;
2206         }
2207
2208         for (n=0; n<num; n++) {
2209                 struct lock_context *ctx = &lock[n].context;
2210
2211                 if (!server_id_is_disconnected(&ctx->pid)) {
2212                         DEBUG(5, ("brl_cleanup_disconnected: byte range lock "
2213                                   "%s used by server %s, do not cleanup\n",
2214                                   file_id_string(frame, &fid),
2215                                   server_id_str(frame, &ctx->pid)));
2216                         goto done;
2217                 }
2218
2219                 if (ctx->smblctx != open_persistent_id) {
2220                         DEBUG(5, ("brl_cleanup_disconnected: byte range lock "
2221                                   "%s expected smblctx %llu but found %llu"
2222                                   ", do not cleanup\n",
2223                                   file_id_string(frame, &fid),
2224                                   (unsigned long long)open_persistent_id,
2225                                   (unsigned long long)ctx->smblctx));
2226                         goto done;
2227                 }
2228         }
2229
2230         status = dbwrap_record_delete(rec);
2231         if (!NT_STATUS_IS_OK(status)) {
2232                 DEBUG(5, ("brl_cleanup_disconnected: failed to delete record "
2233                           "for file %s from %s, open %llu: %s\n",
2234                           file_id_string(frame, &fid), dbwrap_name(brlock_db),
2235                           (unsigned long long)open_persistent_id,
2236                           nt_errstr(status)));
2237                 goto done;
2238         }
2239
2240         DEBUG(10, ("brl_cleanup_disconnected: "
2241                    "file %s cleaned up %u entries from open %llu\n",
2242                    file_id_string(frame, &fid), num,
2243                    (unsigned long long)open_persistent_id));
2244
2245         ret = true;
2246 done:
2247         talloc_free(frame);
2248         return ret;
2249 }