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