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 2 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, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 extern char *OutBuffer;
  24
  25 /****************************************************************************
  26  This is the structure to queue to implement blocking locks.
  27  notify. It consists of the requesting SMB and the expiry time.
  28 *****************************************************************************/
  29
  30 typedef struct {
  31   ubi_slNode msg_next;
  32   int com_type;
  33   files_struct *fsp;
  34   time_t expire_time;
  35   int lock_num;
  36   SMB_BIG_UINT offset;
  37   SMB_BIG_UINT count;
  38   uint16 lock_pid;
  39   char *inbuf;
  40   int length;
  41 } blocking_lock_record;
  42
  43 static ubi_slList blocking_lock_queue = { NULL, (ubi_slNodePtr)&blocking_lock_queue, 0};
  44
  45 /****************************************************************************
  46  Destructor for the above structure.
  47 ****************************************************************************/
  48
  49 static void free_blocking_lock_record(blocking_lock_record *blr)
  50 {
  51   SAFE_FREE(blr->inbuf);
  52   SAFE_FREE(blr);
  53 }
  54
  55 /****************************************************************************
  56  Get the files_struct given a particular queued SMB.
  57 *****************************************************************************/
  58
  59 static files_struct *get_fsp_from_pkt(char *inbuf)
  60 {
  61   switch(CVAL(inbuf,smb_com)) {
  62   case SMBlock:
  63   case SMBlockread:
  64     return file_fsp(inbuf,smb_vwv0);
  65   case SMBlockingX:
  66     return file_fsp(inbuf,smb_vwv2);
  67   default:
  68     DEBUG(0,("get_fsp_from_pkt: PANIC - unknown type on blocking lock queue - exiting.!\n"));
  69     exit_server("PANIC - unknown type on blocking lock queue");
  70   }
  71   return NULL; /* Keep compiler happy. */
  72 }
  73
  74 /****************************************************************************
  75  Determine if this is a secondary element of a chained SMB.
  76   **************************************************************************/
  77
  78 static BOOL in_chained_smb(void)
  79 {
  80   return (chain_size != 0);
  81 }
  82
  83 static void received_unlock_msg(int msg_type, pid_t src, void *buf, size_t len);
  84
  85 /****************************************************************************
  86  Function to push a blocking lock request onto the lock queue.
  87 ****************************************************************************/
  88
  89 BOOL push_blocking_lock_request( char *inbuf, int length, int lock_timeout,
  90                 int lock_num, uint16 lock_pid, SMB_BIG_UINT offset, SMB_BIG_UINT count)
  91 {
  92   static BOOL set_lock_msg;
  93   blocking_lock_record *blr;
  94   NTSTATUS status;
  95
  96   if(in_chained_smb() ) {
  97     DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
  98     return False;
  99   }
 100
 101   /*
 102    * Now queue an entry on the blocking lock queue. We setup
 103    * the expiration time here.
 104    */
 105
 106   if((blr = (blocking_lock_record *)malloc(sizeof(blocking_lock_record))) == NULL) {
 107     DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 108     return False;
 109   }
 110
 111   if((blr->inbuf = (char *)malloc(length)) == NULL) {
 112     DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 113     SAFE_FREE(blr);
 114     return False;
 115   }
 116
 117   blr->com_type = CVAL(inbuf,smb_com);
 118   blr->fsp = get_fsp_from_pkt(inbuf);
 119   blr->expire_time = (lock_timeout == -1) ? (time_t)-1 : time(NULL) + (time_t)lock_timeout;
 120   blr->lock_num = lock_num;
 121   blr->lock_pid = lock_pid;
 122   blr->offset = offset;
 123   blr->count = count;
 124   memcpy(blr->inbuf, inbuf, length);
 125   blr->length = length;
 126
 127   /* Add a pending lock record for this. */
 128   status = brl_lock(blr->fsp->dev, blr->fsp->inode, blr->fsp->fnum,
 129                 lock_pid, sys_getpid(), blr->fsp->conn->cnum,
 130                 offset, count,
 131                 PENDING_LOCK);
 132
 133   if (!NT_STATUS_IS_OK(status)) {
 134         DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 135         free_blocking_lock_record(blr);
 136         return False;
 137   }
 138
 139   ubi_slAddTail(&blocking_lock_queue, blr);
 140
 141   /* Ensure we'll receive messages when this is unlocked. */
 142   if (!set_lock_msg) {
 143           message_register(MSG_SMB_UNLOCK, received_unlock_msg);
 144           set_lock_msg = True;
 145   }
 146
 147   DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with expiry time %d (+%d) \
 148 for fnum = %d, name = %s\n", length, (int)blr->expire_time, lock_timeout,
 149         blr->fsp->fnum, blr->fsp->fsp_name ));
 150
 151   return True;
 152 }
 153
 154 /****************************************************************************
 155  Return a smd with a given size.
 156 *****************************************************************************/
 157
 158 static void send_blocking_reply(char *outbuf, int outsize)
 159 {
 160         if(outsize > 4)
 161                 smb_setlen(outbuf,outsize - 4);
 162
 163         if (!send_smb(smbd_server_fd(),outbuf))
 164                 exit_server("send_blocking_reply: send_smb failed.");
 165 }
 166
 167 /****************************************************************************
 168  Return a lockingX success SMB.
 169 *****************************************************************************/
 170
 171 static void reply_lockingX_success(blocking_lock_record *blr)
 172 {
 173   char *outbuf = OutBuffer;
 174   int bufsize = BUFFER_SIZE;
 175   char *inbuf = blr->inbuf;
 176   int outsize = 0;
 177
 178   construct_reply_common(inbuf, outbuf);
 179   set_message(outbuf,2,0,True);
 180
 181   /*
 182    * As this message is a lockingX call we must handle
 183    * any following chained message correctly.
 184    * This is normally handled in construct_reply(),
 185    * but as that calls switch_message, we can't use
 186    * that here and must set up the chain info manually.
 187    */
 188
 189   outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 190
 191   outsize += chain_size;
 192
 193   send_blocking_reply(outbuf,outsize);
 194 }
 195
 196 /****************************************************************************
 197  Return a generic lock fail error blocking call.
 198 *****************************************************************************/
 199
 200 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 201 {
 202         char *outbuf = OutBuffer;
 203         char *inbuf = blr->inbuf;
 204         construct_reply_common(inbuf, outbuf);
 205
 206         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 207            FILE_LOCK_CONFLICT! (tridge) */
 208         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 209                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 210         }
 211
 212         ERROR_NT(status);
 213         if (!send_smb(smbd_server_fd(),outbuf))
 214                 exit_server("generic_blocking_lock_error: send_smb failed.");
 215 }
 216
 217 /****************************************************************************
 218  Return a lock fail error for a lockingX call. Undo all the locks we have
 219  obtained first.
 220 *****************************************************************************/
 221
 222 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 223 {
 224         char *inbuf = blr->inbuf;
 225         files_struct *fsp = blr->fsp;
 226         connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
 227         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 228         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 229         uint16 lock_pid;
 230         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 231         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 232         char *data;
 233         int i;
 234
 235         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 236
 237         /*
 238          * Data now points at the beginning of the list
 239          * of smb_lkrng structs.
 240          */
 241
 242         /*
 243          * Ensure we don't do a remove on the lock that just failed,
 244          * as under POSIX rules, if we have a lock already there, we
 245          * will delete it (and we shouldn't) .....
 246          */
 247
 248         for(i = blr->lock_num - 1; i >= 0; i--) {
 249                 BOOL err;
 250
 251                 lock_pid = get_lock_pid( data, i, large_file_format);
 252                 count = get_lock_count( data, i, large_file_format);
 253                 offset = get_lock_offset( data, i, large_file_format, &err);
 254
 255                 /*
 256                  * We know err cannot be set as if it was the lock
 257                  * request would never have been queued. JRA.
 258                  */
 259
 260                 do_unlock(fsp,conn,lock_pid,count,offset);
 261         }
 262
 263         generic_blocking_lock_error(blr, status);
 264 }
 265
 266 /****************************************************************************
 267  Return a lock fail error.
 268 *****************************************************************************/
 269
 270 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 271 {
 272         switch(blr->com_type) {
 273         case SMBlock:
 274         case SMBlockread:
 275                 generic_blocking_lock_error(blr, status);
 276                 break;
 277         case SMBlockingX:
 278                 reply_lockingX_error(blr, status);
 279                 break;
 280         default:
 281                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 282                 exit_server("PANIC - unknown type on blocking lock queue");
 283         }
 284 }
 285
 286 /****************************************************************************
 287  Attempt to finish off getting all pending blocking locks for a lockread call.
 288  Returns True if we want to be removed from the list.
 289 *****************************************************************************/
 290
 291 static BOOL process_lockread(blocking_lock_record *blr)
 292 {
 293         char *outbuf = OutBuffer;
 294         char *inbuf = blr->inbuf;
 295         ssize_t nread = -1;
 296         char *data, *p;
 297         int outsize = 0;
 298         SMB_BIG_UINT startpos;
 299         size_t numtoread;
 300         NTSTATUS status;
 301         connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
 302         files_struct *fsp = blr->fsp;
 303
 304         numtoread = SVAL(inbuf,smb_vwv1);
 305         startpos = (SMB_BIG_UINT)IVAL(inbuf,smb_vwv2);
 306
 307         numtoread = MIN(BUFFER_SIZE-outsize,numtoread);
 308         data = smb_buf(outbuf) + 3;
 309
 310         status = do_lock_spin( fsp, conn, SVAL(inbuf,smb_pid), (SMB_BIG_UINT)numtoread,
 311                           startpos, READ_LOCK);
 312         if (NT_STATUS_V(status)) {
 313                 if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 314                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 315                         /*
 316                          * We have other than a "can't get lock"
 317                          * error. Send an error.
 318                          * Return True so we get dequeued.
 319                          */
 320                         generic_blocking_lock_error(blr, status);
 321                         return True;
 322                 }
 323
 324                 /*
 325                  * Still waiting for lock....
 326                  */
 327
 328                 DEBUG(10,("process_lockread: failed to get lock for file = %s. Still waiting....\n",
 329                           fsp->fsp_name));
 330                 return False;
 331         }
 332
 333         nread = read_file(fsp,data,startpos,numtoread);
 334
 335         if (nread < 0) {
 336                 generic_blocking_lock_error(blr,NT_STATUS_ACCESS_DENIED);
 337                 return True;
 338         }
 339
 340         construct_reply_common(inbuf, outbuf);
 341         outsize = set_message(outbuf,5,0,True);
 342
 343         outsize += nread;
 344         SSVAL(outbuf,smb_vwv0,nread);
 345         SSVAL(outbuf,smb_vwv5,nread+3);
 346         p = smb_buf(outbuf);
 347         *p++ = 1;
 348         SSVAL(p,0,nread); p += 2;
 349         set_message_end(outbuf, p+nread);
 350
 351         DEBUG(3, ( "process_lockread file = %s, fnum=%d num=%d nread=%d\n",
 352                    fsp->fsp_name, fsp->fnum, (int)numtoread, (int)nread ) );
 353
 354         send_blocking_reply(outbuf,outsize);
 355         return True;
 356 }
 357
 358 /****************************************************************************
 359  Attempt to finish off getting all pending blocking locks for a lock call.
 360  Returns True if we want to be removed from the list.
 361 *****************************************************************************/
 362
 363 static BOOL process_lock(blocking_lock_record *blr)
 364 {
 365         char *outbuf = OutBuffer;
 366         char *inbuf = blr->inbuf;
 367         int outsize;
 368         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 369         NTSTATUS status;
 370         connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
 371         files_struct *fsp = blr->fsp;
 372
 373         count = IVAL_TO_SMB_OFF_T(inbuf,smb_vwv1);
 374         offset = IVAL_TO_SMB_OFF_T(inbuf,smb_vwv3);
 375
 376         errno = 0;
 377         status = do_lock_spin(fsp, conn, SVAL(inbuf,smb_pid), count,
 378                          offset, WRITE_LOCK);
 379         if (NT_STATUS_IS_ERR(status)) {
 380                 if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 381                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 382                         /*
 383                          * We have other than a "can't get lock"
 384                          * error. Send an error.
 385                          * Return True so we get dequeued.
 386                          */
 387
 388                         blocking_lock_reply_error(blr, status);
 389                         return True;
 390                 }
 391                 /*
 392                  * Still can't get the lock - keep waiting.
 393                  */
 394                 DEBUG(10,("process_lock: failed to get lock for file = %s. Still waiting....\n",
 395                           fsp->fsp_name));
 396                 return False;
 397         }
 398
 399         /*
 400          * Success - we got the lock.
 401          */
 402
 403         DEBUG(3,("process_lock : file=%s fnum=%d offset=%.0f count=%.0f\n",
 404                  fsp->fsp_name, fsp->fnum, (double)offset, (double)count));
 405
 406         construct_reply_common(inbuf, outbuf);
 407         outsize = set_message(outbuf,0,0,True);
 408         send_blocking_reply(outbuf,outsize);
 409         return True;
 410 }
 411
 412 /****************************************************************************
 413  Attempt to finish off getting all pending blocking locks for a lockingX call.
 414  Returns True if we want to be removed from the list.
 415 *****************************************************************************/
 416
 417 static BOOL process_lockingX(blocking_lock_record *blr)
 418 {
 419         char *inbuf = blr->inbuf;
 420         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 421         files_struct *fsp = blr->fsp;
 422         connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
 423         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 424         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 425         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 426         uint16 lock_pid;
 427         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 428         char *data;
 429         NTSTATUS status = NT_STATUS_OK;
 430
 431         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 432
 433         /*
 434          * Data now points at the beginning of the list
 435          * of smb_lkrng structs.
 436          */
 437
 438         for(; blr->lock_num < num_locks; blr->lock_num++) {
 439                 BOOL err;
 440
 441                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 442                 count = get_lock_count( data, blr->lock_num, large_file_format);
 443                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 444
 445                 /*
 446                  * We know err cannot be set as if it was the lock
 447                  * request would never have been queued. JRA.
 448                  */
 449                 errno = 0;
 450                 status = do_lock_spin(fsp,conn,lock_pid,count,offset,
 451                                  ((locktype & 1) ? READ_LOCK : WRITE_LOCK));
 452                 if (NT_STATUS_IS_ERR(status)) break;
 453         }
 454
 455         if(blr->lock_num == num_locks) {
 456                 /*
 457                  * Success - we got all the locks.
 458                  */
 459
 460                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 461                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 462
 463                 reply_lockingX_success(blr);
 464                 return True;
 465         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 466                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 467                         /*
 468                          * We have other than a "can't get lock"
 469                          * error. Free any locks we had and return an error.
 470                          * Return True so we get dequeued.
 471                          */
 472
 473                 blocking_lock_reply_error(blr, status);
 474                 return True;
 475         }
 476
 477         /*
 478          * Still can't get all the locks - keep waiting.
 479          */
 480
 481         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 482 Waiting....\n",
 483                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 484
 485         return False;
 486 }
 487
 488 /****************************************************************************
 489  Process a blocking lock SMB.
 490  Returns True if we want to be removed from the list.
 491 *****************************************************************************/
 492
 493 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 494 {
 495   switch(blr->com_type) {
 496   case SMBlock:
 497     return process_lock(blr);
 498   case SMBlockread:
 499     return process_lockread(blr);
 500   case SMBlockingX:
 501     return process_lockingX(blr);
 502   default:
 503     DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 504     exit_server("PANIC - unknown type on blocking lock queue");
 505   }
 506   return False; /* Keep compiler happy. */
 507 }
 508
 509 /****************************************************************************
 510  Delete entries by fnum from the blocking lock pending queue.
 511 *****************************************************************************/
 512
 513 void remove_pending_lock_requests_by_fid(files_struct *fsp)
 514 {
 515   blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
 516   blocking_lock_record *prev = NULL;
 517
 518   while(blr != NULL) {
 519     if(blr->fsp->fnum == fsp->fnum) {
 520
 521       DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 522 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 523
 524       brl_unlock(blr->fsp->dev, blr->fsp->inode, blr->fsp->fnum,
 525                 blr->lock_pid, sys_getpid(), blr->fsp->conn->cnum,
 526                 blr->offset, blr->count, True, NULL, NULL);
 527
 528       free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
 529       blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
 530       continue;
 531     }
 532
 533     prev = blr;
 534     blr = (blocking_lock_record *)ubi_slNext(blr);
 535   }
 536 }
 537
 538 /****************************************************************************
 539  Delete entries by mid from the blocking lock pending queue. Always send reply.
 540 *****************************************************************************/
 541
 542 void remove_pending_lock_requests_by_mid(int mid)
 543 {
 544   blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
 545   blocking_lock_record *prev = NULL;
 546
 547   while(blr != NULL) {
 548     if(SVAL(blr->inbuf,smb_mid) == mid) {
 549       files_struct *fsp = blr->fsp;
 550
 551       DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 552 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 553
 554       blocking_lock_reply_error(blr,NT_STATUS_CANCELLED);
 555       brl_unlock(blr->fsp->dev, blr->fsp->inode, blr->fsp->fnum,
 556                 blr->lock_pid, sys_getpid(), blr->fsp->conn->cnum,
 557                 blr->offset, blr->count, True, NULL, NULL);
 558       free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
 559       blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
 560       continue;
 561     }
 562
 563     prev = blr;
 564     blr = (blocking_lock_record *)ubi_slNext(blr);
 565   }
 566 }
 567
 568 /****************************************************************************
 569   Set a flag as an unlock request affects one of our pending locks.
 570 *****************************************************************************/
 571
 572 static void received_unlock_msg(int msg_type, pid_t src, void *buf, size_t len)
 573 {
 574         DEBUG(10,("received_unlock_msg\n"));
 575         process_blocking_lock_queue(time(NULL));
 576 }
 577
 578 /****************************************************************************
 579  Return the number of seconds to the next blocking locks timeout, or default_timeout
 580 *****************************************************************************/
 581
 582 unsigned blocking_locks_timeout(unsigned default_timeout)
 583 {
 584         unsigned timeout = default_timeout;
 585         time_t t;
 586         blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst(&blocking_lock_queue);
 587
 588         /* note that we avoid the time() syscall if there are no blocking locks */
 589         if (!blr)
 590                 return timeout;
 591
 592         t = time(NULL);
 593
 594         while (blr) {
 595                 if ((blr->expire_time != (time_t)-1) &&
 596                                         (timeout > (blr->expire_time - t))) {
 597                         timeout = blr->expire_time - t;
 598                 }
 599                 blr = (blocking_lock_record *)ubi_slNext(blr);
 600         }
 601
 602         if (timeout < 1)
 603                 timeout = 1;
 604
 605         return timeout;
 606 }
 607
 608 /****************************************************************************
 609  Process the blocking lock queue. Note that this is only called as root.
 610 *****************************************************************************/
 611
 612 void process_blocking_lock_queue(time_t t)
 613 {
 614   blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
 615   blocking_lock_record *prev = NULL;
 616
 617   if(blr == NULL)
 618     return;
 619
 620   /*
 621    * Go through the queue and see if we can get any of the locks.
 622    */
 623
 624   while(blr != NULL) {
 625     connection_struct *conn = NULL;
 626     uint16 vuid;
 627     files_struct *fsp = NULL;
 628
 629     /*
 630      * Ensure we don't have any old chain_fsp values
 631      * sitting around....
 632      */
 633     chain_size = 0;
 634     file_chain_reset();
 635     fsp = blr->fsp;
 636
 637     conn = conn_find(SVAL(blr->inbuf,smb_tid));
 638     vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 639                   SVAL(blr->inbuf,smb_uid);
 640
 641     DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 642           fsp->fnum, fsp->fsp_name ));
 643
 644     if((blr->expire_time != -1) && (blr->expire_time <= t)) {
 645       /*
 646        * Lock expired - throw away all previously
 647        * obtained locks and return lock error.
 648        */
 649       DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 650           fsp->fnum, fsp->fsp_name ));
 651
 652       brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 653                 blr->lock_pid, sys_getpid(), conn->cnum,
 654                 blr->offset, blr->count, True, NULL, NULL);
 655
 656       blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 657       free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
 658       blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
 659       continue;
 660     }
 661
 662     if(!change_to_user(conn,vuid)) {
 663       DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 664             vuid ));
 665       /*
 666        * Remove the entry and return an error to the client.
 667        */
 668       blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 669
 670       brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 671                 blr->lock_pid, sys_getpid(), conn->cnum,
 672                 blr->offset, blr->count, True, NULL, NULL);
 673
 674       free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
 675       blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
 676       continue;
 677     }
 678
 679     if(!set_current_service(conn,True)) {
 680       DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 681       /*
 682        * Remove the entry and return an error to the client.
 683        */
 684       blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 685
 686       brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 687                 blr->lock_pid, sys_getpid(), conn->cnum,
 688                 blr->offset, blr->count, True, NULL, NULL);
 689
 690       free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
 691       blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
 692       change_to_root_user();
 693       continue;
 694     }
 695
 696     /*
 697      * Go through the remaining locks and try and obtain them.
 698      * The call returns True if all locks were obtained successfully
 699      * and False if we still need to wait.
 700      */
 701
 702     if(blocking_lock_record_process(blr)) {
 703
 704       brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 705                 blr->lock_pid, sys_getpid(), conn->cnum,
 706                 blr->offset, blr->count, True, NULL, NULL);
 707
 708       free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
 709       blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
 710       change_to_root_user();
 711       continue;
 712     }
 713
 714     change_to_root_user();
 715
 716     /*
 717      * Move to the next in the list.
 718      */
 719     prev = blr;
 720     blr = (blocking_lock_record *)ubi_slNext(blr);
 721   }
 722 }