source3/smbd/blocking.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Blocking Locking functions
   4    Copyright (C) Jeremy Allison 1998-2003
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "smbd/globals.h"
  22
  23 #undef DBGC_CLASS
  24 #define DBGC_CLASS DBGC_LOCKING
  25
  26 /****************************************************************************
  27  Determine if this is a secondary element of a chained SMB.
  28   **************************************************************************/
  29
  30 static void received_unlock_msg(struct messaging_context *msg,
  31                                 void *private_data,
  32                                 uint32_t msg_type,
  33                                 struct server_id server_id,
  34                                 DATA_BLOB *data);
  35
  36 static void brl_timeout_fn(struct event_context *event_ctx,
  37                            struct timed_event *te,
  38                            struct timeval now,
  39                            void *private_data)
  40 {
  41         SMB_ASSERT(brl_timeout == te);
  42         TALLOC_FREE(brl_timeout);
  43
  44         change_to_root_user();  /* TODO: Possibly run all timed events as
  45                                  * root */
  46
  47         process_blocking_lock_queue();
  48 }
  49
  50 /****************************************************************************
  51  After a change to blocking_lock_queue, recalculate the timed_event for the
  52  next processing.
  53 ****************************************************************************/
  54
  55 static bool recalc_brl_timeout(void)
  56 {
  57         struct blocking_lock_record *blr;
  58         struct timeval next_timeout;
  59
  60         TALLOC_FREE(brl_timeout);
  61
  62         next_timeout = timeval_zero();
  63
  64         for (blr = blocking_lock_queue; blr; blr = blr->next) {
  65                 if (timeval_is_zero(&blr->expire_time)) {
  66                         /*
  67                          * If we're blocked on pid 0xFFFFFFFF this is
  68                          * a POSIX lock, so calculate a timeout of
  69                          * 10 seconds into the future.
  70                          */
  71                         if (blr->blocking_pid == 0xFFFFFFFF) {
  72                                 struct timeval psx_to = timeval_current_ofs(10, 0);
  73                                 next_timeout = timeval_min(&next_timeout, &psx_to);
  74                         }
  75
  76                         continue;
  77                 }
  78
  79                 if (timeval_is_zero(&next_timeout)) {
  80                         next_timeout = blr->expire_time;
  81                 }
  82                 else {
  83                         next_timeout = timeval_min(&next_timeout,
  84                                                    &blr->expire_time);
  85                 }
  86         }
  87
  88         if (timeval_is_zero(&next_timeout)) {
  89                 DEBUG(10, ("Next timeout = Infinite.\n"));
  90                 return True;
  91         }
  92
  93         if (DEBUGLVL(10)) {
  94                 struct timeval cur, from_now;
  95
  96                 cur = timeval_current();
  97                 from_now = timeval_until(&cur, &next_timeout);
  98                 DEBUG(10, ("Next timeout = %d.%d seconds from now.\n",
  99                     (int)from_now.tv_sec, (int)from_now.tv_usec));
 100         }
 101
 102         if (!(brl_timeout = event_add_timed(smbd_event_context(), NULL,
 103                                             next_timeout,
 104                                             brl_timeout_fn, NULL))) {
 105                 return False;
 106         }
 107
 108         return True;
 109 }
 110
 111
 112 /****************************************************************************
 113  Function to push a blocking lock request onto the lock queue.
 114 ****************************************************************************/
 115
 116 bool push_blocking_lock_request( struct byte_range_lock *br_lck,
 117                 struct smb_request *req,
 118                 files_struct *fsp,
 119                 int lock_timeout,
 120                 int lock_num,
 121                 uint32_t lock_pid,
 122                 enum brl_type lock_type,
 123                 enum brl_flavour lock_flav,
 124                 uint64_t offset,
 125                 uint64_t count,
 126                 uint32_t blocking_pid)
 127 {
 128         struct blocking_lock_record *blr;
 129         NTSTATUS status;
 130
 131         if(req_is_in_chain(req)) {
 132                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
 133                 return False;
 134         }
 135
 136         /*
 137          * Now queue an entry on the blocking lock queue. We setup
 138          * the expiration time here.
 139          */
 140
 141         blr = talloc(NULL, struct blocking_lock_record);
 142         if (blr == NULL) {
 143                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 144                 return False;
 145         }
 146
 147         blr->next = NULL;
 148         blr->prev = NULL;
 149
 150         blr->fsp = fsp;
 151         if (lock_timeout == -1) {
 152                 blr->expire_time.tv_sec = 0;
 153                 blr->expire_time.tv_usec = 0; /* Never expire. */
 154         } else {
 155                 blr->expire_time = timeval_current_ofs(lock_timeout/1000,
 156                                         (lock_timeout % 1000) * 1000);
 157         }
 158         blr->lock_num = lock_num;
 159         blr->lock_pid = lock_pid;
 160         blr->blocking_pid = blocking_pid;
 161         blr->lock_flav = lock_flav;
 162         blr->lock_type = lock_type;
 163         blr->offset = offset;
 164         blr->count = count;
 165
 166         /* Specific brl_lock() implementations can fill this in. */
 167         blr->blr_private = NULL;
 168
 169         /* Add a pending lock record for this. */
 170         status = brl_lock(smbd_messaging_context(),
 171                         br_lck,
 172                         lock_pid,
 173                         procid_self(),
 174                         offset,
 175                         count,
 176                         lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
 177                         blr->lock_flav,
 178                         lock_timeout ? True : False, /* blocking_lock. */
 179                         NULL,
 180                         blr);
 181
 182         if (!NT_STATUS_IS_OK(status)) {
 183                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 184                 TALLOC_FREE(blr);
 185                 return False;
 186         }
 187
 188         SMB_PERFCOUNT_DEFER_OP(&req->pcd, &req->pcd);
 189         blr->req = talloc_move(blr, &req);
 190
 191         DLIST_ADD_END(blocking_lock_queue, blr, struct blocking_lock_record *);
 192         recalc_brl_timeout();
 193
 194         /* Ensure we'll receive messages when this is unlocked. */
 195         if (!blocking_lock_unlock_state) {
 196                 messaging_register(smbd_messaging_context(), NULL,
 197                                    MSG_SMB_UNLOCK, received_unlock_msg);
 198                 blocking_lock_unlock_state = true;
 199         }
 200
 201         DEBUG(3,("push_blocking_lock_request: lock request blocked with "
 202                 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
 203                 (unsigned int)blr->expire_time.tv_sec,
 204                 (unsigned int)blr->expire_time.tv_usec, lock_timeout,
 205                 blr->fsp->fnum, blr->fsp->fsp_name ));
 206
 207         return True;
 208 }
 209
 210 /****************************************************************************
 211  Return a lockingX success SMB.
 212 *****************************************************************************/
 213
 214 static void reply_lockingX_success(struct blocking_lock_record *blr)
 215 {
 216         reply_outbuf(blr->req, 2, 0);
 217
 218         /*
 219          * As this message is a lockingX call we must handle
 220          * any following chained message correctly.
 221          * This is normally handled in construct_reply(),
 222          * but as that calls switch_message, we can't use
 223          * that here and must set up the chain info manually.
 224          */
 225
 226         chain_reply(blr->req);
 227         TALLOC_FREE(blr->req->outbuf);
 228 }
 229
 230 /****************************************************************************
 231  Return a generic lock fail error blocking call.
 232 *****************************************************************************/
 233
 234 static void generic_blocking_lock_error(struct blocking_lock_record *blr, NTSTATUS status)
 235 {
 236         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 237            FILE_LOCK_CONFLICT! (tridge) */
 238         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 239                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 240         }
 241
 242         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 243                 /* Store the last lock error. */
 244                 files_struct *fsp = blr->fsp;
 245
 246                 if (fsp) {
 247                         fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 248                         fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 249                         fsp->last_lock_failure.context.pid = procid_self();
 250                         fsp->last_lock_failure.start = blr->offset;
 251                         fsp->last_lock_failure.size = blr->count;
 252                         fsp->last_lock_failure.fnum = fsp->fnum;
 253                         fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 254                         fsp->last_lock_failure.lock_flav = blr->lock_flav;
 255                 }
 256         }
 257
 258         reply_nterror(blr->req, status);
 259         if (!srv_send_smb(smbd_server_fd(), (char *)blr->req->outbuf,
 260                           true, blr->req->seqnum+1,
 261                           blr->req->encrypted, NULL)) {
 262                 exit_server_cleanly("generic_blocking_lock_error: srv_send_smb failed.");
 263         }
 264         TALLOC_FREE(blr->req->outbuf);
 265 }
 266
 267 /****************************************************************************
 268  Return a lock fail error for a lockingX call. Undo all the locks we have
 269  obtained first.
 270 *****************************************************************************/
 271
 272 static void reply_lockingX_error(struct blocking_lock_record *blr, NTSTATUS status)
 273 {
 274         files_struct *fsp = blr->fsp;
 275         uint16 num_ulocks = SVAL(blr->req->vwv+6, 0);
 276         uint64_t count = (uint64_t)0, offset = (uint64_t) 0;
 277         uint32 lock_pid;
 278         unsigned char locktype = CVAL(blr->req->vwv+3, 0);
 279         bool large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 280         uint8_t *data;
 281         int i;
 282
 283         data = (uint8_t *)blr->req->buf
 284                 + ((large_file_format ? 20 : 10)*num_ulocks);
 285
 286         /*
 287          * Data now points at the beginning of the list
 288          * of smb_lkrng structs.
 289          */
 290
 291         /*
 292          * Ensure we don't do a remove on the lock that just failed,
 293          * as under POSIX rules, if we have a lock already there, we
 294          * will delete it (and we shouldn't) .....
 295          */
 296
 297         for(i = blr->lock_num - 1; i >= 0; i--) {
 298                 bool err;
 299
 300                 lock_pid = get_lock_pid( data, i, large_file_format);
 301                 count = get_lock_count( data, i, large_file_format);
 302                 offset = get_lock_offset( data, i, large_file_format, &err);
 303
 304                 /*
 305                  * We know err cannot be set as if it was the lock
 306                  * request would never have been queued. JRA.
 307                  */
 308
 309                 do_unlock(smbd_messaging_context(),
 310                         fsp,
 311                         lock_pid,
 312                         count,
 313                         offset,
 314                         WINDOWS_LOCK);
 315         }
 316
 317         generic_blocking_lock_error(blr, status);
 318 }
 319
 320 /****************************************************************************
 321  Return a lock fail error.
 322 *****************************************************************************/
 323
 324 static void blocking_lock_reply_error(struct blocking_lock_record *blr, NTSTATUS status)
 325 {
 326         DEBUG(10, ("Replying with error=%s. BLR = %p\n", nt_errstr(status), blr));
 327
 328         switch(blr->req->cmd) {
 329         case SMBlockingX:
 330                 reply_lockingX_error(blr, status);
 331                 break;
 332         case SMBtrans2:
 333         case SMBtranss2:
 334                 reply_nterror(blr->req, status);
 335
 336                 /*
 337                  * construct_reply_common has done us the favor to pre-fill
 338                  * the command field with SMBtranss2 which is wrong :-)
 339                  */
 340                 SCVAL(blr->req->outbuf,smb_com,SMBtrans2);
 341
 342                 if (!srv_send_smb(smbd_server_fd(),
 343                                   (char *)blr->req->outbuf,
 344                                   true, blr->req->seqnum+1,
 345                                   IS_CONN_ENCRYPTED(blr->fsp->conn),
 346                                   NULL)) {
 347                         exit_server_cleanly("blocking_lock_reply_error: "
 348                                             "srv_send_smb failed.");
 349                 }
 350                 TALLOC_FREE(blr->req->outbuf);
 351                 break;
 352         default:
 353                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 354                 exit_server("PANIC - unknown type on blocking lock queue");
 355         }
 356 }
 357
 358 /****************************************************************************
 359  Attempt to finish off getting all pending blocking locks for a lockingX call.
 360  Returns True if we want to be removed from the list.
 361 *****************************************************************************/
 362
 363 static bool process_lockingX(struct blocking_lock_record *blr)
 364 {
 365         unsigned char locktype = CVAL(blr->req->vwv+3, 0);
 366         files_struct *fsp = blr->fsp;
 367         uint16 num_ulocks = SVAL(blr->req->vwv+6, 0);
 368         uint16 num_locks = SVAL(blr->req->vwv+7, 0);
 369         uint64_t count = (uint64_t)0, offset = (uint64_t)0;
 370         uint32 lock_pid;
 371         bool large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 372         uint8_t *data;
 373         NTSTATUS status = NT_STATUS_OK;
 374
 375         data = (uint8_t *)blr->req->buf
 376                 + ((large_file_format ? 20 : 10)*num_ulocks);
 377
 378         /*
 379          * Data now points at the beginning of the list
 380          * of smb_lkrng structs.
 381          */
 382
 383         for(; blr->lock_num < num_locks; blr->lock_num++) {
 384                 struct byte_range_lock *br_lck = NULL;
 385                 bool err;
 386
 387                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 388                 count = get_lock_count( data, blr->lock_num, large_file_format);
 389                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 390
 391                 /*
 392                  * We know err cannot be set as if it was the lock
 393                  * request would never have been queued. JRA.
 394                  */
 395                 errno = 0;
 396                 br_lck = do_lock(smbd_messaging_context(),
 397                                 fsp,
 398                                 lock_pid,
 399                                 count,
 400                                 offset,
 401                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 402                                         READ_LOCK : WRITE_LOCK),
 403                                 WINDOWS_LOCK,
 404                                 True,
 405                                 &status,
 406                                 &blr->blocking_pid,
 407                                 blr);
 408
 409                 TALLOC_FREE(br_lck);
 410
 411                 if (NT_STATUS_IS_ERR(status)) {
 412                         break;
 413                 }
 414         }
 415
 416         if(blr->lock_num == num_locks) {
 417                 /*
 418                  * Success - we got all the locks.
 419                  */
 420
 421                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 422                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 423
 424                 reply_lockingX_success(blr);
 425                 return True;
 426         }
 427
 428         if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 429             !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 430                 /*
 431                  * We have other than a "can't get lock"
 432                  * error. Free any locks we had and return an error.
 433                  * Return True so we get dequeued.
 434                  */
 435                 blocking_lock_reply_error(blr, status);
 436                 return True;
 437         }
 438
 439         /*
 440          * Still can't get all the locks - keep waiting.
 441          */
 442
 443         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 444 Waiting....\n",
 445                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 446
 447         return False;
 448 }
 449
 450 /****************************************************************************
 451  Attempt to get the posix lock request from a SMBtrans2 call.
 452  Returns True if we want to be removed from the list.
 453 *****************************************************************************/
 454
 455 static bool process_trans2(struct blocking_lock_record *blr)
 456 {
 457         char params[2];
 458         NTSTATUS status;
 459         struct byte_range_lock *br_lck = do_lock(smbd_messaging_context(),
 460                                                 blr->fsp,
 461                                                 blr->lock_pid,
 462                                                 blr->count,
 463                                                 blr->offset,
 464                                                 blr->lock_type,
 465                                                 blr->lock_flav,
 466                                                 True,
 467                                                 &status,
 468                                                 &blr->blocking_pid,
 469                                                 blr);
 470         TALLOC_FREE(br_lck);
 471
 472         if (!NT_STATUS_IS_OK(status)) {
 473                 if (ERROR_WAS_LOCK_DENIED(status)) {
 474                         /* Still can't get the lock, just keep waiting. */
 475                         return False;
 476                 }
 477                 /*
 478                  * We have other than a "can't get lock"
 479                  * error. Send an error and return True so we get dequeued.
 480                  */
 481                 blocking_lock_reply_error(blr, status);
 482                 return True;
 483         }
 484
 485         /* We finally got the lock, return success. */
 486
 487         SSVAL(params,0,0);
 488         /* Fake up max_data_bytes here - we know it fits. */
 489         send_trans2_replies(blr->fsp->conn, blr->req, params, 2, NULL, 0, 0xffff);
 490         return True;
 491 }
 492
 493
 494 /****************************************************************************
 495  Process a blocking lock SMB.
 496  Returns True if we want to be removed from the list.
 497 *****************************************************************************/
 498
 499 static bool blocking_lock_record_process(struct blocking_lock_record *blr)
 500 {
 501         switch(blr->req->cmd) {
 502                 case SMBlockingX:
 503                         return process_lockingX(blr);
 504                 case SMBtrans2:
 505                 case SMBtranss2:
 506                         return process_trans2(blr);
 507                 default:
 508                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 509                         exit_server("PANIC - unknown type on blocking lock queue");
 510         }
 511         return False; /* Keep compiler happy. */
 512 }
 513
 514 /****************************************************************************
 515  Cancel entries by fnum from the blocking lock pending queue.
 516 *****************************************************************************/
 517
 518 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 519 {
 520         struct blocking_lock_record *blr, *blr_cancelled, *next = NULL;
 521
 522         for(blr = blocking_lock_queue; blr; blr = next) {
 523                 unsigned char locktype = 0;
 524
 525                 next = blr->next;
 526                 if (blr->fsp->fnum != fsp->fnum) {
 527                         continue;
 528                 }
 529
 530                 if (blr->req->cmd == SMBlockingX) {
 531                         locktype = CVAL(blr->req->vwv+3, 0);
 532                 }
 533
 534                 DEBUG(10, ("remove_pending_lock_requests_by_fid - removing "
 535                            "request type %d for file %s fnum = %d\n",
 536                            blr->req->cmd, fsp->fsp_name, fsp->fnum));
 537
 538                 blr_cancelled = blocking_lock_cancel(fsp,
 539                                      blr->lock_pid,
 540                                      blr->offset,
 541                                      blr->count,
 542                                      blr->lock_flav,
 543                                      locktype,
 544                                      NT_STATUS_RANGE_NOT_LOCKED);
 545
 546                 SMB_ASSERT(blr_cancelled == blr);
 547
 548                 brl_lock_cancel(br_lck,
 549                                 blr->lock_pid,
 550                                 procid_self(),
 551                                 blr->offset,
 552                                 blr->count,
 553                                 blr->lock_flav,
 554                                 blr);
 555
 556                 /* We're closing the file fsp here, so ensure
 557                  * we don't have a dangling pointer. */
 558                 blr->fsp = NULL;
 559         }
 560 }
 561
 562 /****************************************************************************
 563  Delete entries by mid from the blocking lock pending queue. Always send reply.
 564 *****************************************************************************/
 565
 566 void remove_pending_lock_requests_by_mid(int mid)
 567 {
 568         struct blocking_lock_record *blr, *next = NULL;
 569
 570         for(blr = blocking_lock_queue; blr; blr = next) {
 571                 files_struct *fsp;
 572                 struct byte_range_lock *br_lck;
 573
 574                 next = blr->next;
 575
 576                 if (blr->req->mid != mid) {
 577                         continue;
 578                 }
 579
 580                 fsp = blr->fsp;
 581                 br_lck = brl_get_locks(talloc_tos(), fsp);
 582
 583                 if (br_lck) {
 584                         DEBUG(10, ("remove_pending_lock_requests_by_mid - "
 585                                    "removing request type %d for file %s fnum "
 586                                    "= %d\n", blr->req->cmd, fsp->fsp_name,
 587                                    fsp->fnum ));
 588
 589                         brl_lock_cancel(br_lck,
 590                                         blr->lock_pid,
 591                                         procid_self(),
 592                                         blr->offset,
 593                                         blr->count,
 594                                         blr->lock_flav,
 595                                         blr);
 596                         TALLOC_FREE(br_lck);
 597                 }
 598
 599                 blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 600                 DLIST_REMOVE(blocking_lock_queue, blr);
 601                 TALLOC_FREE(blr);
 602         }
 603 }
 604
 605 /****************************************************************************
 606  Is this mid a blocking lock request on the queue ?
 607 *****************************************************************************/
 608
 609 bool blocking_lock_was_deferred(int mid)
 610 {
 611         struct blocking_lock_record *blr, *next = NULL;
 612
 613         for(blr = blocking_lock_queue; blr; blr = next) {
 614                 next = blr->next;
 615                 if(blr->req->mid == mid) {
 616                         return True;
 617                 }
 618         }
 619         return False;
 620 }
 621
 622 /****************************************************************************
 623   Set a flag as an unlock request affects one of our pending locks.
 624 *****************************************************************************/
 625
 626 static void received_unlock_msg(struct messaging_context *msg,
 627                                 void *private_data,
 628                                 uint32_t msg_type,
 629                                 struct server_id server_id,
 630                                 DATA_BLOB *data)
 631 {
 632         DEBUG(10,("received_unlock_msg\n"));
 633         process_blocking_lock_queue();
 634 }
 635
 636 /****************************************************************************
 637  Process the blocking lock queue. Note that this is only called as root.
 638 *****************************************************************************/
 639
 640 void process_blocking_lock_queue(void)
 641 {
 642         struct timeval tv_curr = timeval_current();
 643         struct blocking_lock_record *blr, *next = NULL;
 644         bool recalc_timeout = False;
 645
 646         /*
 647          * Go through the queue and see if we can get any of the locks.
 648          */
 649
 650         for (blr = blocking_lock_queue; blr; blr = next) {
 651
 652                 next = blr->next;
 653
 654                 /*
 655                  * Go through the remaining locks and try and obtain them.
 656                  * The call returns True if all locks were obtained successfully
 657                  * and False if we still need to wait.
 658                  */
 659
 660                 DEBUG(10, ("Processing BLR = %p\n", blr));
 661
 662                 if(blocking_lock_record_process(blr)) {
 663                         struct byte_range_lock *br_lck = brl_get_locks(
 664                                 talloc_tos(), blr->fsp);
 665
 666                         DEBUG(10, ("BLR_process returned true: cancelling and "
 667                             "removing lock. BLR = %p\n", blr));
 668
 669                         if (br_lck) {
 670                                 brl_lock_cancel(br_lck,
 671                                         blr->lock_pid,
 672                                         procid_self(),
 673                                         blr->offset,
 674                                         blr->count,
 675                                         blr->lock_flav,
 676                                         blr);
 677                                 TALLOC_FREE(br_lck);
 678                         }
 679
 680                         DLIST_REMOVE(blocking_lock_queue, blr);
 681                         TALLOC_FREE(blr);
 682                         recalc_timeout = True;
 683                         continue;
 684                 }
 685
 686                 /*
 687                  * We couldn't get the locks for this record on the list.
 688                  * If the time has expired, return a lock error.
 689                  */
 690
 691                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 692                         struct byte_range_lock *br_lck = brl_get_locks(
 693                                 talloc_tos(), blr->fsp);
 694
 695                         DEBUG(10, ("Lock timed out! BLR = %p\n", blr));
 696
 697                         /*
 698                          * Lock expired - throw away all previously
 699                          * obtained locks and return lock error.
 700                          */
 701
 702                         if (br_lck) {
 703                                 DEBUG(5,("process_blocking_lock_queue: "
 704                                          "pending lock fnum = %d for file %s "
 705                                          "timed out.\n", blr->fsp->fnum,
 706                                          blr->fsp->fsp_name ));
 707
 708                                 brl_lock_cancel(br_lck,
 709                                         blr->lock_pid,
 710                                         procid_self(),
 711                                         blr->offset,
 712                                         blr->count,
 713                                         blr->lock_flav,
 714                                         blr);
 715                                 TALLOC_FREE(br_lck);
 716                         }
 717
 718                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 719                         DLIST_REMOVE(blocking_lock_queue, blr);
 720                         TALLOC_FREE(blr);
 721                         recalc_timeout = True;
 722                 }
 723         }
 724
 725         if (recalc_timeout) {
 726                 recalc_brl_timeout();
 727         }
 728 }
 729
 730 /****************************************************************************
 731  Handle a cancel message. Lock already moved onto the cancel queue.
 732 *****************************************************************************/
 733
 734 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(struct blocking_lock_record *) + sizeof(NTSTATUS))
 735
 736 static void process_blocking_lock_cancel_message(struct messaging_context *ctx,
 737                                                  void *private_data,
 738                                                  uint32_t msg_type,
 739                                                  struct server_id server_id,
 740                                                  DATA_BLOB *data)
 741 {
 742         NTSTATUS err;
 743         const char *msg = (const char *)data->data;
 744         struct blocking_lock_record *blr;
 745
 746         if (data->data == NULL) {
 747                 smb_panic("process_blocking_lock_cancel_message: null msg");
 748         }
 749
 750         if (data->length != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 751                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 752                           "Got invalid msg len %d\n", (int)data->length));
 753                 smb_panic("process_blocking_lock_cancel_message: bad msg");
 754         }
 755
 756         memcpy(&blr, msg, sizeof(blr));
 757         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 758
 759         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 760                 nt_errstr(err) ));
 761
 762         blocking_lock_reply_error(blr, err);
 763         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 764         TALLOC_FREE(blr);
 765 }
 766
 767 /****************************************************************************
 768  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 769  Returns the blocking_lock_record that is being cancelled.
 770 *****************************************************************************/
 771
 772 struct blocking_lock_record *blocking_lock_cancel(files_struct *fsp,
 773                         uint32 lock_pid,
 774                         uint64_t offset,
 775                         uint64_t count,
 776                         enum brl_flavour lock_flav,
 777                         unsigned char locktype,
 778                         NTSTATUS err)
 779 {
 780         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 781         struct blocking_lock_record *blr;
 782
 783         if (!blocking_lock_cancel_state) {
 784                 /* Register our message. */
 785                 messaging_register(smbd_messaging_context(), NULL,
 786                                    MSG_SMB_BLOCKING_LOCK_CANCEL,
 787                                    process_blocking_lock_cancel_message);
 788
 789                 blocking_lock_cancel_state = True;
 790         }
 791
 792         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 793                 if (fsp == blr->fsp &&
 794                                 lock_pid == blr->lock_pid &&
 795                                 offset == blr->offset &&
 796                                 count == blr->count &&
 797                                 lock_flav == blr->lock_flav) {
 798                         break;
 799                 }
 800         }
 801
 802         if (!blr) {
 803                 return NULL;
 804         }
 805
 806         /* Check the flags are right. */
 807         if (blr->req->cmd == SMBlockingX &&
 808                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 809                         (CVAL(blr->req->vwv+3, 0) & LOCKING_ANDX_LARGE_FILES)) {
 810                 return NULL;
 811         }
 812
 813         /* Move to cancelled queue. */
 814         DLIST_REMOVE(blocking_lock_queue, blr);
 815         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 816
 817         /* Create the message. */
 818         memcpy(msg, &blr, sizeof(blr));
 819         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 820
 821         messaging_send_buf(smbd_messaging_context(), procid_self(),
 822                            MSG_SMB_BLOCKING_LOCK_CANCEL,
 823                            (uint8 *)&msg, sizeof(msg));
 824
 825         return blr;
 826 }