source/smbd/oplock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    oplock processing
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 1998 - 2001
   6    Copyright (C) Volker Lendecke 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #define DBGC_CLASS DBGC_LOCKING
  23 #include "includes.h"
  24
  25 /* Current number of oplocks we have outstanding. */
  26 static int32 exclusive_oplocks_open = 0;
  27 static int32 level_II_oplocks_open = 0;
  28 bool global_client_failed_oplock_break = False;
  29
  30 extern uint32 global_client_caps;
  31
  32 static struct kernel_oplocks *koplocks;
  33
  34 /****************************************************************************
  35  Get the number of current exclusive oplocks.
  36 ****************************************************************************/
  37
  38 int32 get_number_of_exclusive_open_oplocks(void)
  39 {
  40   return exclusive_oplocks_open;
  41 }
  42
  43 /****************************************************************************
  44  Return True if an oplock message is pending.
  45 ****************************************************************************/
  46
  47 bool oplock_message_waiting(fd_set *fds)
  48 {
  49         if (koplocks && koplocks->msg_waiting(fds)) {
  50                 return True;
  51         }
  52
  53         return False;
  54 }
  55
  56 /****************************************************************************
  57  Find out if there are any kernel oplock messages waiting and process them
  58  if so. pfds is the fd_set from the main select loop (which contains any
  59  kernel oplock fd if that's what the system uses (IRIX). If may be NULL if
  60  we're calling this in a shutting down state.
  61 ****************************************************************************/
  62
  63 void process_kernel_oplocks(struct messaging_context *msg_ctx, fd_set *pfds)
  64 {
  65         /*
  66          * We need to check for kernel oplocks before going into the select
  67          * here, as the EINTR generated by the linux kernel oplock may have
  68          * already been eaten. JRA.
  69          */
  70
  71         if (!koplocks) {
  72                 return;
  73         }
  74
  75         while (koplocks->msg_waiting(pfds)) {
  76                 files_struct *fsp;
  77                 char msg[MSG_SMB_KERNEL_BREAK_SIZE];
  78
  79                 fsp = koplocks->receive_message(pfds);
  80
  81                 if (fsp == NULL) {
  82                         DEBUG(3, ("Kernel oplock message announced, but none "
  83                                   "received\n"));
  84                         return;
  85                 }
  86
  87                 /* Put the kernel break info into the message. */
  88                 push_file_id_16(msg, &fsp->file_id);
  89                 SIVAL(msg,16,fsp->fh->gen_id);
  90
  91                 /* Don't need to be root here as we're only ever
  92                    sending to ourselves. */
  93
  94                 messaging_send_buf(msg_ctx, procid_self(),
  95                                    MSG_SMB_KERNEL_BREAK,
  96                                    (uint8 *)&msg, MSG_SMB_KERNEL_BREAK_SIZE);
  97         }
  98 }
  99
 100 /****************************************************************************
 101  Attempt to set an oplock on a file. Always succeeds if kernel oplocks are
 102  disabled (just sets flags). Returns True if oplock set.
 103 ****************************************************************************/
 104
 105 bool set_file_oplock(files_struct *fsp, int oplock_type)
 106 {
 107         if ((fsp->oplock_type != NO_OPLOCK) &&
 108             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 109             koplocks &&
 110             !koplocks->set_oplock(fsp, oplock_type)) {
 111                 return False;
 112         }
 113
 114         fsp->oplock_type = oplock_type;
 115         fsp->sent_oplock_break = NO_BREAK_SENT;
 116         if (oplock_type == LEVEL_II_OPLOCK) {
 117                 level_II_oplocks_open++;
 118         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 119                 exclusive_oplocks_open++;
 120         }
 121
 122         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
 123                     "tv_sec = %x, tv_usec = %x\n",
 124                  fsp->fsp_name, file_id_string_tos(&fsp->file_id),
 125                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
 126                  (int)fsp->open_time.tv_usec ));
 127
 128         return True;
 129 }
 130
 131 /****************************************************************************
 132  Attempt to release an oplock on a file. Decrements oplock count.
 133 ****************************************************************************/
 134
 135 void release_file_oplock(files_struct *fsp)
 136 {
 137         if ((fsp->oplock_type != NO_OPLOCK) &&
 138             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 139             koplocks) {
 140                 koplocks->release_oplock(fsp);
 141         }
 142
 143         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 144                 level_II_oplocks_open--;
 145         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 146                 exclusive_oplocks_open--;
 147         }
 148
 149         SMB_ASSERT(exclusive_oplocks_open>=0);
 150         SMB_ASSERT(level_II_oplocks_open>=0);
 151
 152         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 153                 /* This doesn't matter for close. */
 154                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 155         } else {
 156                 fsp->oplock_type = NO_OPLOCK;
 157         }
 158         fsp->sent_oplock_break = NO_BREAK_SENT;
 159
 160         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 161
 162         TALLOC_FREE(fsp->oplock_timeout);
 163 }
 164
 165 /****************************************************************************
 166  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 167 ****************************************************************************/
 168
 169 static void downgrade_file_oplock(files_struct *fsp)
 170 {
 171         if (koplocks) {
 172                 koplocks->release_oplock(fsp);
 173         }
 174         fsp->oplock_type = LEVEL_II_OPLOCK;
 175         exclusive_oplocks_open--;
 176         level_II_oplocks_open++;
 177         fsp->sent_oplock_break = NO_BREAK_SENT;
 178 }
 179
 180 /****************************************************************************
 181  Remove a file oplock. Copes with level II and exclusive.
 182  Locks then unlocks the share mode lock. Client can decide to go directly
 183  to none even if a "break-to-level II" was sent.
 184 ****************************************************************************/
 185
 186 bool remove_oplock(files_struct *fsp)
 187 {
 188         bool ret;
 189         struct share_mode_lock *lck;
 190
 191         /* Remove the oplock flag from the sharemode. */
 192         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 193                                   NULL);
 194         if (lck == NULL) {
 195                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 196                          "file %s\n", fsp->fsp_name ));
 197                 return False;
 198         }
 199         ret = remove_share_oplock(lck, fsp);
 200         if (!ret) {
 201                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 202                          "file %s fnum %d, %s\n",
 203                          fsp->fsp_name, fsp->fnum, file_id_string_tos(&fsp->file_id)));
 204         }
 205         release_file_oplock(fsp);
 206         TALLOC_FREE(lck);
 207         return ret;
 208 }
 209
 210 /*
 211  * Deal with a reply when a break-to-level II was sent.
 212  */
 213 bool downgrade_oplock(files_struct *fsp)
 214 {
 215         bool ret;
 216         struct share_mode_lock *lck;
 217
 218         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 219                                   NULL);
 220         if (lck == NULL) {
 221                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 222                          "file %s\n", fsp->fsp_name ));
 223                 return False;
 224         }
 225         ret = downgrade_share_oplock(lck, fsp);
 226         if (!ret) {
 227                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 228                          "for file %s fnum %d, file_id %s\n",
 229                          fsp->fsp_name, fsp->fnum, file_id_string_tos(&fsp->file_id)));
 230         }
 231
 232         downgrade_file_oplock(fsp);
 233         TALLOC_FREE(lck);
 234         return ret;
 235 }
 236
 237 /****************************************************************************
 238  Return the fd (if any) used for receiving oplock notifications.
 239 ****************************************************************************/
 240
 241 int oplock_notify_fd(void)
 242 {
 243         if (koplocks) {
 244                 return koplocks->notification_fd;
 245         }
 246
 247         return -1;
 248 }
 249
 250 /****************************************************************************
 251  Set up an oplock break message.
 252 ****************************************************************************/
 253
 254 static char *new_break_smb_message(TALLOC_CTX *mem_ctx,
 255                                    files_struct *fsp, uint8 cmd)
 256 {
 257         char *result = TALLOC_ARRAY(mem_ctx, char, smb_size + 8*2 + 0);
 258
 259         if (result == NULL) {
 260                 DEBUG(0, ("talloc failed\n"));
 261                 return NULL;
 262         }
 263
 264         memset(result,'\0',smb_size);
 265         srv_set_message(result,8,0,true);
 266         SCVAL(result,smb_com,SMBlockingX);
 267         SSVAL(result,smb_tid,fsp->conn->cnum);
 268         SSVAL(result,smb_pid,0xFFFF);
 269         SSVAL(result,smb_uid,0);
 270         SSVAL(result,smb_mid,0xFFFF);
 271         SCVAL(result,smb_vwv0,0xFF);
 272         SSVAL(result,smb_vwv2,fsp->fnum);
 273         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 274         SCVAL(result,smb_vwv3+1,cmd);
 275         return result;
 276 }
 277
 278 /****************************************************************************
 279  Function to do the waiting before sending a local break.
 280 ****************************************************************************/
 281
 282 static void wait_before_sending_break(void)
 283 {
 284         long wait_time = (long)lp_oplock_break_wait_time();
 285
 286         if (wait_time) {
 287                 smb_msleep(wait_time);
 288         }
 289 }
 290
 291 /****************************************************************************
 292  Ensure that we have a valid oplock.
 293 ****************************************************************************/
 294
 295 static files_struct *initial_break_processing(struct file_id id, unsigned long file_id)
 296 {
 297         files_struct *fsp = NULL;
 298
 299         if( DEBUGLVL( 3 ) ) {
 300                 dbgtext( "initial_break_processing: called for %s/%u\n",
 301                          file_id_string_tos(&id), (int)file_id);
 302                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 303                         exclusive_oplocks_open, level_II_oplocks_open );
 304         }
 305
 306         /*
 307          * We need to search the file open table for the
 308          * entry containing this dev and inode, and ensure
 309          * we have an oplock on it.
 310          */
 311
 312         fsp = file_find_dif(id, file_id);
 313
 314         if(fsp == NULL) {
 315                 /* The file could have been closed in the meantime - return success. */
 316                 if( DEBUGLVL( 3 ) ) {
 317                         dbgtext( "initial_break_processing: cannot find open file with " );
 318                         dbgtext( "file_id %s gen_id = %lu", file_id_string_tos(&id), file_id);
 319                         dbgtext( "allowing break to succeed.\n" );
 320                 }
 321                 return NULL;
 322         }
 323
 324         /* Ensure we have an oplock on the file */
 325
 326         /*
 327          * There is a potential race condition in that an oplock could
 328          * have been broken due to another udp request, and yet there are
 329          * still oplock break messages being sent in the udp message
 330          * queue for this file. So return true if we don't have an oplock,
 331          * as we may have just freed it.
 332          */
 333
 334         if(fsp->oplock_type == NO_OPLOCK) {
 335                 if( DEBUGLVL( 3 ) ) {
 336                         dbgtext( "initial_break_processing: file %s ", fsp->fsp_name );
 337                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 338                                  file_id_string_tos(&id), fsp->fh->gen_id );
 339                         dbgtext( "Allowing break to succeed regardless.\n" );
 340                 }
 341                 return NULL;
 342         }
 343
 344         return fsp;
 345 }
 346
 347 static void oplock_timeout_handler(struct event_context *ctx,
 348                                    struct timed_event *te,
 349                                    const struct timeval *now,
 350                                    void *private_data)
 351 {
 352         files_struct *fsp = (files_struct *)private_data;
 353
 354         /* Remove the timed event handler. */
 355         TALLOC_FREE(fsp->oplock_timeout);
 356         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n", fsp->fsp_name));
 357         global_client_failed_oplock_break = True;
 358         remove_oplock(fsp);
 359         reply_to_oplock_break_requests(fsp);
 360 }
 361
 362 /*******************************************************************
 363  Add a timeout handler waiting for the client reply.
 364 *******************************************************************/
 365
 366 static void add_oplock_timeout_handler(files_struct *fsp)
 367 {
 368         if (fsp->oplock_timeout != NULL) {
 369                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 370                           "around\n"));
 371         }
 372
 373         fsp->oplock_timeout =
 374                 event_add_timed(smbd_event_context(), NULL,
 375                                 timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 376                                 "oplock_timeout_handler",
 377                                 oplock_timeout_handler, fsp);
 378
 379         if (fsp->oplock_timeout == NULL) {
 380                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 381         }
 382 }
 383
 384 /*******************************************************************
 385  This handles the case of a write triggering a break to none
 386  message on a level2 oplock.
 387  When we get this message we may be in any of three states :
 388  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 389  the client for LEVEL2.
 390 *******************************************************************/
 391
 392 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 393                                                       void *private_data,
 394                                                       uint32_t msg_type,
 395                                                       struct server_id src,
 396                                                       DATA_BLOB *data)
 397 {
 398         struct share_mode_entry msg;
 399         files_struct *fsp;
 400         char *break_msg;
 401         bool sign_state;
 402
 403         if (data->data == NULL) {
 404                 DEBUG(0, ("Got NULL buffer\n"));
 405                 return;
 406         }
 407
 408         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 409                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 410                 return;
 411         }
 412
 413         /* De-linearize incoming message. */
 414         message_to_share_mode_entry(&msg, (char *)data->data);
 415
 416         DEBUG(10, ("Got oplock async level 2 break message from pid %d: %s/%lu\n",
 417                    (int)procid_to_pid(&src), file_id_string_tos(&msg.id), msg.share_file_id));
 418
 419         fsp = initial_break_processing(msg.id, msg.share_file_id);
 420
 421         if (fsp == NULL) {
 422                 /* We hit a race here. Break messages are sent, and before we
 423                  * get to process this message, we have closed the file.
 424                  * No need to reply as this is an async message. */
 425                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 426                 return;
 427         }
 428
 429         if (fsp->oplock_type == NO_OPLOCK) {
 430                 /* We already got a "break to none" message and we've handled it.
 431                  * just ignore. */
 432                 DEBUG(3, ("process_oplock_async_level2_break_message: already broken to none, ignoring.\n"));
 433                 return;
 434         }
 435
 436         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 437                 /* Don't tell the client, just downgrade. */
 438                 DEBUG(3, ("process_oplock_async_level2_break_message: downgrading fake level 2 oplock.\n"));
 439                 remove_oplock(fsp);
 440                 return;
 441         }
 442
 443         /* Ensure we're really at level2 state. */
 444         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 445
 446         DEBUG(10,("process_oplock_async_level2_break_message: sending break to "
 447                 "none message for fid %d, file %s\n",
 448                 fsp->fnum,
 449                 fsp->fsp_name));
 450
 451         /* Now send a break to none message to our client. */
 452
 453         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 454         if (break_msg == NULL) {
 455                 exit_server("Could not talloc break_msg\n");
 456         }
 457
 458         /* Need to wait before sending a break message if we sent ourselves this message. */
 459         if (procid_to_pid(&src) == sys_getpid()) {
 460                 wait_before_sending_break();
 461         }
 462
 463         /* Save the server smb signing state. */
 464         sign_state = srv_oplock_set_signing(False);
 465
 466         show_msg(break_msg);
 467         if (!srv_send_smb(smbd_server_fd(),
 468                         break_msg,
 469                         IS_CONN_ENCRYPTED(fsp->conn))) {
 470                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 471         }
 472
 473         /* Restore the sign state to what it was. */
 474         srv_oplock_set_signing(sign_state);
 475
 476         TALLOC_FREE(break_msg);
 477
 478         /* Async level2 request, don't send a reply, just remove the oplock. */
 479         remove_oplock(fsp);
 480 }
 481
 482 /*******************************************************************
 483  This handles the generic oplock break message from another smbd.
 484 *******************************************************************/
 485
 486 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 487                                          void *private_data,
 488                                          uint32_t msg_type,
 489                                          struct server_id src,
 490                                          DATA_BLOB *data)
 491 {
 492         struct share_mode_entry msg;
 493         files_struct *fsp;
 494         char *break_msg;
 495         bool break_to_level2 = False;
 496         bool sign_state;
 497
 498         if (data->data == NULL) {
 499                 DEBUG(0, ("Got NULL buffer\n"));
 500                 return;
 501         }
 502
 503         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 504                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 505                 return;
 506         }
 507
 508         /* De-linearize incoming message. */
 509         message_to_share_mode_entry(&msg, (char *)data->data);
 510
 511         DEBUG(10, ("Got oplock break message from pid %d: %s/%lu\n",
 512                    (int)procid_to_pid(&src), file_id_string_tos(&msg.id), msg.share_file_id));
 513
 514         fsp = initial_break_processing(msg.id, msg.share_file_id);
 515
 516         if (fsp == NULL) {
 517                 /* a We hit race here. Break messages are sent, and before we
 518                  * get to process this message, we have closed the file. Reply
 519                  * with 'ok, oplock broken' */
 520                 DEBUG(3, ("Did not find fsp\n"));
 521
 522                 /* We just send the same message back. */
 523                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 524                                    (uint8 *)data->data,
 525                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 526                 return;
 527         }
 528
 529         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 530                 /* Remember we have to inform the requesting PID when the
 531                  * client replies */
 532                 msg.pid = src;
 533                 ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 534                              &fsp->pending_break_messages,
 535                              &fsp->num_pending_break_messages);
 536                 return;
 537         }
 538
 539         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 540             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 541                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 542                           file_id_string_tos(&fsp->file_id),
 543                           fsp->fsp_name));
 544                 /* We just send the same message back. */
 545                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 546                                    (uint8 *)data->data,
 547                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 548                 return;
 549         }
 550
 551         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 552             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 553             !koplocks && /* NOTE: we force levelII off for kernel oplocks -
 554                           * this will change when it is supported */
 555             lp_level2_oplocks(SNUM(fsp->conn))) {
 556                 break_to_level2 = True;
 557         }
 558
 559         break_msg = new_break_smb_message(NULL, fsp, break_to_level2 ?
 560                                           OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 561         if (break_msg == NULL) {
 562                 exit_server("Could not talloc break_msg\n");
 563         }
 564
 565         /* Need to wait before sending a break message if we sent ourselves this message. */
 566         if (procid_to_pid(&src) == sys_getpid()) {
 567                 wait_before_sending_break();
 568         }
 569
 570         /* Save the server smb signing state. */
 571         sign_state = srv_oplock_set_signing(False);
 572
 573         show_msg(break_msg);
 574         if (!srv_send_smb(smbd_server_fd(),
 575                         break_msg,
 576                         IS_CONN_ENCRYPTED(fsp->conn))) {
 577                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 578         }
 579
 580         /* Restore the sign state to what it was. */
 581         srv_oplock_set_signing(sign_state);
 582
 583         TALLOC_FREE(break_msg);
 584
 585         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 586
 587         msg.pid = src;
 588         ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 589                      &fsp->pending_break_messages,
 590                      &fsp->num_pending_break_messages);
 591
 592         add_oplock_timeout_handler(fsp);
 593 }
 594
 595 /*******************************************************************
 596  This handles the kernel oplock break message.
 597 *******************************************************************/
 598
 599 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 600                                         void *private_data,
 601                                         uint32_t msg_type,
 602                                         struct server_id src,
 603                                         DATA_BLOB *data)
 604 {
 605         struct file_id id;
 606         unsigned long file_id;
 607         files_struct *fsp;
 608         char *break_msg;
 609         bool sign_state;
 610
 611         if (data->data == NULL) {
 612                 DEBUG(0, ("Got NULL buffer\n"));
 613                 return;
 614         }
 615
 616         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 617                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 618                 return;
 619         }
 620
 621         /* Pull the data from the message. */
 622         pull_file_id_16((char *)data->data, &id);
 623         file_id = (unsigned long)IVAL(data->data, 16);
 624
 625         DEBUG(10, ("Got kernel oplock break message from pid %d: %s/%u\n",
 626                    (int)procid_to_pid(&src), file_id_string_tos(&id),
 627                    (unsigned int)file_id));
 628
 629         fsp = initial_break_processing(id, file_id);
 630
 631         if (fsp == NULL) {
 632                 DEBUG(3, ("Got a kernel oplock break message for a file "
 633                           "I don't know about\n"));
 634                 return;
 635         }
 636
 637         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 638                 /* This is ok, kernel oplocks come in completely async */
 639                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 640                           "break reply\n"));
 641                 return;
 642         }
 643
 644         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 645         if (break_msg == NULL) {
 646                 exit_server("Could not talloc break_msg\n");
 647         }
 648
 649         /* Save the server smb signing state. */
 650         sign_state = srv_oplock_set_signing(False);
 651
 652         show_msg(break_msg);
 653         if (!srv_send_smb(smbd_server_fd(),
 654                         break_msg,
 655                         IS_CONN_ENCRYPTED(fsp->conn))) {
 656                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 657         }
 658
 659         /* Restore the sign state to what it was. */
 660         srv_oplock_set_signing(sign_state);
 661
 662         TALLOC_FREE(break_msg);
 663
 664         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 665
 666         add_oplock_timeout_handler(fsp);
 667 }
 668
 669 void reply_to_oplock_break_requests(files_struct *fsp)
 670 {
 671         int i;
 672
 673         for (i=0; i<fsp->num_pending_break_messages; i++) {
 674                 struct share_mode_entry *e = &fsp->pending_break_messages[i];
 675                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 676
 677                 share_mode_entry_to_message(msg, e);
 678
 679                 messaging_send_buf(smbd_messaging_context(), e->pid,
 680                                    MSG_SMB_BREAK_RESPONSE,
 681                                    (uint8 *)msg,
 682                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 683         }
 684
 685         SAFE_FREE(fsp->pending_break_messages);
 686         fsp->num_pending_break_messages = 0;
 687         if (fsp->oplock_timeout != NULL) {
 688                 /* Remove the timed event handler. */
 689                 TALLOC_FREE(fsp->oplock_timeout);
 690                 fsp->oplock_timeout = NULL;
 691         }
 692         return;
 693 }
 694
 695 static void process_oplock_break_response(struct messaging_context *msg_ctx,
 696                                           void *private_data,
 697                                           uint32_t msg_type,
 698                                           struct server_id src,
 699                                           DATA_BLOB *data)
 700 {
 701         struct share_mode_entry msg;
 702
 703         if (data->data == NULL) {
 704                 DEBUG(0, ("Got NULL buffer\n"));
 705                 return;
 706         }
 707
 708         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 709                 DEBUG(0, ("Got invalid msg len %u\n",
 710                           (unsigned int)data->length));
 711                 return;
 712         }
 713
 714         /* De-linearize incoming message. */
 715         message_to_share_mode_entry(&msg, (char *)data->data);
 716
 717         DEBUG(10, ("Got oplock break response from pid %d: %s/%lu mid %u\n",
 718                    (int)procid_to_pid(&src), file_id_string_tos(&msg.id), msg.share_file_id,
 719                    (unsigned int)msg.op_mid));
 720
 721         /* Here's the hack from open.c, store the mid in the 'port' field */
 722         schedule_deferred_open_smb_message(msg.op_mid);
 723 }
 724
 725 static void process_open_retry_message(struct messaging_context *msg_ctx,
 726                                        void *private_data,
 727                                        uint32_t msg_type,
 728                                        struct server_id src,
 729                                        DATA_BLOB *data)
 730 {
 731         struct share_mode_entry msg;
 732
 733         if (data->data == NULL) {
 734                 DEBUG(0, ("Got NULL buffer\n"));
 735                 return;
 736         }
 737
 738         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 739                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 740                 return;
 741         }
 742
 743         /* De-linearize incoming message. */
 744         message_to_share_mode_entry(&msg, (char *)data->data);
 745
 746         DEBUG(10, ("Got open retry msg from pid %d: %s mid %u\n",
 747                    (int)procid_to_pid(&src), file_id_string_tos(&msg.id),
 748                    (unsigned int)msg.op_mid));
 749
 750         schedule_deferred_open_smb_message(msg.op_mid);
 751 }
 752
 753 /****************************************************************************
 754  This function is called on any file modification or lock request. If a file
 755  is level 2 oplocked then it must tell all other level 2 holders to break to
 756  none.
 757 ****************************************************************************/
 758
 759 void release_level_2_oplocks_on_change(files_struct *fsp)
 760 {
 761         int i;
 762         struct share_mode_lock *lck;
 763
 764         /*
 765          * If this file is level II oplocked then we need
 766          * to grab the shared memory lock and inform all
 767          * other files with a level II lock that they need
 768          * to flush their read caches. We keep the lock over
 769          * the shared memory area whilst doing this.
 770          */
 771
 772         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 773                 return;
 774
 775         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 776                                   NULL);
 777         if (lck == NULL) {
 778                 DEBUG(0,("release_level_2_oplocks_on_change: failed to lock "
 779                          "share mode entry for file %s.\n", fsp->fsp_name ));
 780                 return;
 781         }
 782
 783         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 784                   lck->num_share_modes ));
 785
 786         for(i = 0; i < lck->num_share_modes; i++) {
 787                 struct share_mode_entry *share_entry = &lck->share_modes[i];
 788                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 789
 790                 if (!is_valid_share_mode_entry(share_entry)) {
 791                         continue;
 792                 }
 793
 794                 /*
 795                  * As there could have been multiple writes waiting at the
 796                  * lock_share_entry gate we may not be the first to
 797                  * enter. Hence the state of the op_types in the share mode
 798                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 799                  * oplock. It will do no harm to re-send break messages to
 800                  * those smbd's that are still waiting their turn to remove
 801                  * their LEVEL_II state, and also no harm to ignore existing
 802                  * NO_OPLOCK states. JRA.
 803                  */
 804
 805                 DEBUG(10,("release_level_2_oplocks_on_change: "
 806                           "share_entry[%i]->op_type == %d\n",
 807                           i, share_entry->op_type ));
 808
 809                 if (share_entry->op_type == NO_OPLOCK) {
 810                         continue;
 811                 }
 812
 813                 /* Paranoia .... */
 814                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 815                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 816                                  "share mode entry %d is an exlusive "
 817                                  "oplock !\n", i ));
 818                         TALLOC_FREE(lck);
 819                         abort();
 820                 }
 821
 822                 share_mode_entry_to_message(msg, share_entry);
 823
 824                 /*
 825                  * Deal with a race condition when breaking level2
 826                  * oplocks. Don't send all the messages and release
 827                  * the lock, this allows someone else to come in and
 828                  * get a level2 lock before any of the messages are
 829                  * processed, and thus miss getting a break message.
 830                  * Ensure at least one entry (the one we're breaking)
 831                  * is processed immediately under the lock and becomes
 832                  * set as NO_OPLOCK to stop any waiter getting a level2.
 833                  * Bugid #5980.
 834                  */
 835
 836                 if (procid_is_me(&share_entry->pid)) {
 837                         DATA_BLOB blob = data_blob_const(msg,
 838                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 839                         process_oplock_async_level2_break_message(smbd_messaging_context(),
 840                                                 NULL,
 841                                                 MSG_SMB_ASYNC_LEVEL2_BREAK,
 842                                                 share_entry->pid,
 843                                                 &blob);
 844                 } else {
 845                         messaging_send_buf(smbd_messaging_context(),
 846                                         share_entry->pid,
 847                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 848                                         (uint8 *)msg,
 849                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 850                 }
 851         }
 852
 853         /* We let the message receivers handle removing the oplock state
 854            in the share mode lock db. */
 855
 856         TALLOC_FREE(lck);
 857 }
 858
 859 /****************************************************************************
 860  Linearize a share mode entry struct to an internal oplock break message.
 861 ****************************************************************************/
 862
 863 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 864 {
 865         SIVAL(msg,0,(uint32)e->pid.pid);
 866         SSVAL(msg,4,e->op_mid);
 867         SSVAL(msg,6,e->op_type);
 868         SIVAL(msg,8,e->access_mask);
 869         SIVAL(msg,12,e->share_access);
 870         SIVAL(msg,16,e->private_options);
 871         SIVAL(msg,20,(uint32)e->time.tv_sec);
 872         SIVAL(msg,24,(uint32)e->time.tv_usec);
 873         push_file_id_16(msg+28, &e->id);
 874         SIVAL(msg,44,e->share_file_id);
 875         SIVAL(msg,48,e->uid);
 876         SSVAL(msg,52,e->flags);
 877 #ifdef CLUSTER_SUPPORT
 878         SIVAL(msg,54,e->pid.vnn);
 879 #endif
 880 }
 881
 882 /****************************************************************************
 883  De-linearize an internal oplock break message to a share mode entry struct.
 884 ****************************************************************************/
 885
 886 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 887 {
 888         e->pid.pid = (pid_t)IVAL(msg,0);
 889         e->op_mid = SVAL(msg,4);
 890         e->op_type = SVAL(msg,6);
 891         e->access_mask = IVAL(msg,8);
 892         e->share_access = IVAL(msg,12);
 893         e->private_options = IVAL(msg,16);
 894         e->time.tv_sec = (time_t)IVAL(msg,20);
 895         e->time.tv_usec = (int)IVAL(msg,24);
 896         pull_file_id_16(msg+28, &e->id);
 897         e->share_file_id = (unsigned long)IVAL(msg,44);
 898         e->uid = (uint32)IVAL(msg,48);
 899         e->flags = (uint16)SVAL(msg,52);
 900 #ifdef CLUSTER_SUPPORT
 901         e->pid.vnn = IVAL(msg,54);
 902 #endif
 903 }
 904
 905 /****************************************************************************
 906  Setup oplocks for this process.
 907 ****************************************************************************/
 908
 909 bool init_oplocks(struct messaging_context *msg_ctx)
 910 {
 911         DEBUG(3,("init_oplocks: initializing messages.\n"));
 912
 913         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_REQUEST,
 914                            process_oplock_break_message);
 915         messaging_register(msg_ctx, NULL, MSG_SMB_ASYNC_LEVEL2_BREAK,
 916                            process_oplock_async_level2_break_message);
 917         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_RESPONSE,
 918                            process_oplock_break_response);
 919         messaging_register(msg_ctx, NULL, MSG_SMB_KERNEL_BREAK,
 920                            process_kernel_oplock_break);
 921         messaging_register(msg_ctx, NULL, MSG_SMB_OPEN_RETRY,
 922                            process_open_retry_message);
 923
 924         if (lp_kernel_oplocks()) {
 925 #if HAVE_KERNEL_OPLOCKS_IRIX
 926                 koplocks = irix_init_kernel_oplocks();
 927 #elif HAVE_KERNEL_OPLOCKS_LINUX
 928                 koplocks = linux_init_kernel_oplocks();
 929 #endif
 930         }
 931
 932         return True;
 933 }