source3/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 #include "smbd/smbd.h"
  25 #include "smbd/globals.h"
  26 #include "messages.h"
  27 #include "../librpc/gen_ndr/open_files.h"
  28
  29 /*
  30  * helper function used by the kernel oplock backends to post the break message
  31  */
  32 void break_kernel_oplock(struct messaging_context *msg_ctx, files_struct *fsp)
  33 {
  34         uint8_t msg[MSG_SMB_KERNEL_BREAK_SIZE];
  35
  36         /* Put the kernel break info into the message. */
  37         push_file_id_24((char *)msg, &fsp->file_id);
  38         SIVAL(msg,24,fsp->fh->gen_id);
  39
  40         /* Don't need to be root here as we're only ever
  41            sending to ourselves. */
  42
  43         messaging_send_buf(msg_ctx, messaging_server_id(msg_ctx),
  44                            MSG_SMB_KERNEL_BREAK,
  45                            msg, MSG_SMB_KERNEL_BREAK_SIZE);
  46 }
  47
  48 /****************************************************************************
  49  Attempt to set an oplock on a file. Succeeds if kernel oplocks are
  50  disabled (just sets flags).
  51 ****************************************************************************/
  52
  53 NTSTATUS set_file_oplock(files_struct *fsp, int oplock_type)
  54 {
  55         struct smbd_server_connection *sconn = fsp->conn->sconn;
  56         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
  57         bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
  58
  59         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
  60                 if (use_kernel &&
  61                     !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
  62                         DEBUG(10, ("Refusing level2 oplock, kernel oplocks "
  63                                    "don't support them\n"));
  64                         return NT_STATUS_NOT_SUPPORTED;
  65                 }
  66         }
  67
  68         if ((fsp->oplock_type != NO_OPLOCK) &&
  69             use_kernel &&
  70             !koplocks->ops->set_oplock(koplocks, fsp, oplock_type))
  71         {
  72                 return map_nt_error_from_unix(errno);
  73         }
  74
  75         fsp->oplock_type = oplock_type;
  76         fsp->sent_oplock_break = NO_BREAK_SENT;
  77         if (oplock_type == LEVEL_II_OPLOCK) {
  78                 sconn->oplocks.level_II_open++;
  79         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
  80                 sconn->oplocks.exclusive_open++;
  81         }
  82
  83         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
  84                     "tv_sec = %x, tv_usec = %x\n",
  85                  fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
  86                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
  87                  (int)fsp->open_time.tv_usec ));
  88
  89         return NT_STATUS_OK;
  90 }
  91
  92 /****************************************************************************
  93  Attempt to release an oplock on a file. Decrements oplock count.
  94 ****************************************************************************/
  95
  96 void release_file_oplock(files_struct *fsp)
  97 {
  98         struct smbd_server_connection *sconn = fsp->conn->sconn;
  99         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 100
 101         if ((fsp->oplock_type != NO_OPLOCK) &&
 102             koplocks) {
 103                 koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
 104         }
 105
 106         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 107                 sconn->oplocks.level_II_open--;
 108         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 109                 sconn->oplocks.exclusive_open--;
 110         }
 111
 112         SMB_ASSERT(sconn->oplocks.exclusive_open>=0);
 113         SMB_ASSERT(sconn->oplocks.level_II_open>=0);
 114
 115         fsp->oplock_type = NO_OPLOCK;
 116         fsp->sent_oplock_break = NO_BREAK_SENT;
 117
 118         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 119         delete_write_cache(fsp);
 120
 121         TALLOC_FREE(fsp->oplock_timeout);
 122 }
 123
 124 /****************************************************************************
 125  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 126 ****************************************************************************/
 127
 128 static void downgrade_file_oplock(files_struct *fsp)
 129 {
 130         struct smbd_server_connection *sconn = fsp->conn->sconn;
 131         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 132
 133         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 134                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 135                 return;
 136         }
 137
 138         if (koplocks) {
 139                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 140         }
 141         fsp->oplock_type = LEVEL_II_OPLOCK;
 142         sconn->oplocks.exclusive_open--;
 143         sconn->oplocks.level_II_open++;
 144         fsp->sent_oplock_break = NO_BREAK_SENT;
 145
 146         TALLOC_FREE(fsp->oplock_timeout);
 147 }
 148
 149 /****************************************************************************
 150  Remove a file oplock. Copes with level II and exclusive.
 151  Locks then unlocks the share mode lock. Client can decide to go directly
 152  to none even if a "break-to-level II" was sent.
 153 ****************************************************************************/
 154
 155 bool remove_oplock(files_struct *fsp)
 156 {
 157         bool ret;
 158         struct share_mode_lock *lck;
 159
 160         DEBUG(10, ("remove_oplock called for %s\n",
 161                    fsp_str_dbg(fsp)));
 162
 163         /* Remove the oplock flag from the sharemode. */
 164         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 165         if (lck == NULL) {
 166                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 167                          "file %s\n", fsp_str_dbg(fsp)));
 168                 return False;
 169         }
 170
 171         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 172
 173                 /*
 174                  * If we're the only LEVEL_II holder, we have to remove the
 175                  * have_read_oplocks from the brlock entry
 176                  */
 177
 178                 struct share_mode_data *data = lck->data;
 179                 uint32_t i, num_level2;
 180
 181                 num_level2 = 0;
 182                 for (i=0; i<data->num_share_modes; i++) {
 183                         if (data->share_modes[i].op_type == LEVEL_II_OPLOCK) {
 184                                 num_level2 += 1;
 185                         }
 186                         if (num_level2 > 1) {
 187                                 /*
 188                                  * No need to count them all...
 189                                  */
 190                                 break;
 191                         }
 192                 }
 193
 194                 if (num_level2 == 1) {
 195                         /*
 196                          * That's only us. We are dropping that level2 oplock,
 197                          * so remove the brlock flag.
 198                          */
 199                         struct byte_range_lock *brl;
 200
 201                         brl = brl_get_locks(talloc_tos(), fsp);
 202                         if (brl) {
 203                                 brl_set_have_read_oplocks(brl, false);
 204                                 TALLOC_FREE(brl);
 205                         }
 206                 }
 207         }
 208
 209         ret = remove_share_oplock(lck, fsp);
 210         if (!ret) {
 211                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 212                          "file %s, %s, %s\n",
 213                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 214                          file_id_string_tos(&fsp->file_id)));
 215         }
 216         release_file_oplock(fsp);
 217         TALLOC_FREE(lck);
 218         return ret;
 219 }
 220
 221 /*
 222  * Deal with a reply when a break-to-level II was sent.
 223  */
 224 bool downgrade_oplock(files_struct *fsp)
 225 {
 226         bool ret;
 227         struct share_mode_lock *lck;
 228         struct byte_range_lock *brl;
 229
 230         DEBUG(10, ("downgrade_oplock called for %s\n",
 231                    fsp_str_dbg(fsp)));
 232
 233         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 234         if (lck == NULL) {
 235                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 236                          "file %s\n", fsp_str_dbg(fsp)));
 237                 return False;
 238         }
 239         ret = downgrade_share_oplock(lck, fsp);
 240         if (!ret) {
 241                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 242                          "for file %s, %s, file_id %s\n",
 243                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 244                          file_id_string_tos(&fsp->file_id)));
 245         }
 246
 247         downgrade_file_oplock(fsp);
 248
 249         brl = brl_get_locks(talloc_tos(), fsp);
 250         if (brl != NULL) {
 251                 brl_set_have_read_oplocks(brl, true);
 252                 TALLOC_FREE(brl);
 253         }
 254
 255         TALLOC_FREE(lck);
 256         return ret;
 257 }
 258
 259 /****************************************************************************
 260  Set up an oplock break message.
 261 ****************************************************************************/
 262
 263 #define SMB1_BREAK_MESSAGE_LENGTH (smb_size + 8*2)
 264
 265 static void new_break_message_smb1(files_struct *fsp, int cmd,
 266                                    char result[SMB1_BREAK_MESSAGE_LENGTH])
 267 {
 268         memset(result,'\0',smb_size);
 269         srv_set_message(result,8,0,true);
 270         SCVAL(result,smb_com,SMBlockingX);
 271         SSVAL(result,smb_tid,fsp->conn->cnum);
 272         SSVAL(result,smb_pid,0xFFFF);
 273         SSVAL(result,smb_uid,0);
 274         SSVAL(result,smb_mid,0xFFFF);
 275         SCVAL(result,smb_vwv0,0xFF);
 276         SSVAL(result,smb_vwv2,fsp->fnum);
 277         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 278         SCVAL(result,smb_vwv3+1,cmd);
 279 }
 280
 281 /****************************************************************************
 282  Function to do the waiting before sending a local break.
 283 ****************************************************************************/
 284
 285 static void wait_before_sending_break(void)
 286 {
 287         long wait_time = (long)lp_oplock_break_wait_time();
 288
 289         if (wait_time) {
 290                 smb_msleep(wait_time);
 291         }
 292 }
 293
 294 /****************************************************************************
 295  Ensure that we have a valid oplock.
 296 ****************************************************************************/
 297
 298 static files_struct *initial_break_processing(
 299         struct smbd_server_connection *sconn, struct file_id id,
 300         unsigned long file_id)
 301 {
 302         files_struct *fsp = NULL;
 303
 304         DEBUG(3, ("initial_break_processing: called for %s/%u\n"
 305                   "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 306                   file_id_string_tos(&id), (int)file_id,
 307                   sconn->oplocks.exclusive_open,
 308                   sconn->oplocks.level_II_open));
 309
 310         /*
 311          * We need to search the file open table for the
 312          * entry containing this dev and inode, and ensure
 313          * we have an oplock on it.
 314          */
 315
 316         fsp = file_find_dif(sconn, id, file_id);
 317
 318         if(fsp == NULL) {
 319                 /* The file could have been closed in the meantime - return success. */
 320                 DEBUG(3, ("initial_break_processing: cannot find open file "
 321                           "with file_id %s gen_id = %lu, allowing break to "
 322                           "succeed.\n", file_id_string_tos(&id), file_id));
 323                 return NULL;
 324         }
 325
 326         /* Ensure we have an oplock on the file */
 327
 328         /*
 329          * There is a potential race condition in that an oplock could
 330          * have been broken due to another udp request, and yet there are
 331          * still oplock break messages being sent in the udp message
 332          * queue for this file. So return true if we don't have an oplock,
 333          * as we may have just freed it.
 334          */
 335
 336         if(fsp->oplock_type == NO_OPLOCK) {
 337                 DEBUG(3, ("initial_break_processing: file %s (file_id = %s "
 338                           "gen_id = %lu) has no oplock. Allowing break to "
 339                           "succeed regardless.\n", fsp_str_dbg(fsp),
 340                           file_id_string_tos(&id), fsp->fh->gen_id));
 341                 return NULL;
 342         }
 343
 344         return fsp;
 345 }
 346
 347 static void oplock_timeout_handler(struct tevent_context *ctx,
 348                                    struct tevent_timer *te,
 349                                    struct timeval now,
 350                                    void *private_data)
 351 {
 352         files_struct *fsp = (files_struct *)private_data;
 353
 354         SMB_ASSERT(fsp->sent_oplock_break != NO_BREAK_SENT);
 355
 356         /* Remove the timed event handler. */
 357         TALLOC_FREE(fsp->oplock_timeout);
 358         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 359                   fsp_str_dbg(fsp)));
 360         remove_oplock(fsp);
 361 }
 362
 363 /*******************************************************************
 364  Add a timeout handler waiting for the client reply.
 365 *******************************************************************/
 366
 367 static void add_oplock_timeout_handler(files_struct *fsp)
 368 {
 369         struct smbd_server_connection *sconn = fsp->conn->sconn;
 370         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 371
 372         /*
 373          * If kernel oplocks already notifies smbds when an oplock break times
 374          * out, just return.
 375          */
 376         if (koplocks &&
 377             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 378                 return;
 379         }
 380
 381         if (fsp->oplock_timeout != NULL) {
 382                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 383                           "around\n"));
 384         }
 385
 386         fsp->oplock_timeout =
 387                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 388                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 389                                  oplock_timeout_handler, fsp);
 390
 391         if (fsp->oplock_timeout == NULL) {
 392                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 393         }
 394 }
 395
 396 static void send_break_message_smb1(files_struct *fsp, int level)
 397 {
 398         char break_msg[SMB1_BREAK_MESSAGE_LENGTH];
 399
 400         new_break_message_smb1(fsp, level, break_msg);
 401
 402         show_msg(break_msg);
 403         if (!srv_send_smb(fsp->conn->sconn,
 404                         break_msg, false, 0,
 405                         IS_CONN_ENCRYPTED(fsp->conn),
 406                         NULL)) {
 407                 exit_server_cleanly("send_break_message_smb1: "
 408                         "srv_send_smb failed.");
 409         }
 410 }
 411
 412 static void break_level2_to_none_async(struct server_id src, files_struct *fsp)
 413 {
 414         struct smbd_server_connection *sconn = fsp->conn->sconn;
 415         struct server_id self = messaging_server_id(sconn->msg_ctx);
 416
 417         if (fsp->oplock_type == NO_OPLOCK) {
 418                 /* We already got a "break to none" message and we've handled
 419                  * it.  just ignore. */
 420                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 421                           "broken to none, ignoring.\n"));
 422                 return;
 423         }
 424
 425         /* Ensure we're really at level2 state. */
 426         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 427
 428         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 429                   "to none message for %s, file %s\n", fsp_fnum_dbg(fsp),
 430                   fsp_str_dbg(fsp)));
 431
 432         /* Need to wait before sending a break
 433            message if we sent ourselves this message. */
 434         if (serverid_equal(&self, &src)) {
 435                 wait_before_sending_break();
 436         }
 437
 438         /* Now send a break to none message to our client. */
 439         if (sconn->using_smb2) {
 440                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 441         } else {
 442                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 443         }
 444
 445         /* Async level2 request, don't send a reply, just remove the oplock. */
 446         remove_oplock(fsp);
 447 }
 448
 449 /*******************************************************************
 450  This handles the case of a write triggering a break to none
 451  message on a level2 oplock.
 452  When we get this message we may be in any of two states :
 453  NO_OPLOCK, LEVEL_II. We only send a message to
 454  the client for LEVEL2.
 455 *******************************************************************/
 456
 457 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 458                                                       void *private_data,
 459                                                       uint32_t msg_type,
 460                                                       struct server_id src,
 461                                                       DATA_BLOB *data)
 462 {
 463         struct share_mode_entry msg;
 464         files_struct *fsp;
 465         struct smbd_server_connection *sconn =
 466                 talloc_get_type_abort(private_data,
 467                 struct smbd_server_connection);
 468
 469         if (data->data == NULL) {
 470                 DEBUG(0, ("Got NULL buffer\n"));
 471                 return;
 472         }
 473
 474         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 475                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 476                 return;
 477         }
 478
 479         /* De-linearize incoming message. */
 480         message_to_share_mode_entry(&msg, (char *)data->data);
 481
 482         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 483                    "%s/%llu\n", server_id_str(talloc_tos(), &src),
 484                    file_id_string_tos(&msg.id),
 485                    (unsigned long long)msg.share_file_id));
 486
 487         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 488
 489         if (fsp == NULL) {
 490                 /* We hit a race here. Break messages are sent, and before we
 491                  * get to process this message, we have closed the file.
 492                  * No need to reply as this is an async message. */
 493                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 494                 return;
 495         }
 496
 497         break_level2_to_none_async(src, fsp);
 498 }
 499
 500 /*******************************************************************
 501  This handles the generic oplock break message from another smbd.
 502 *******************************************************************/
 503
 504 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 505                                          void *private_data,
 506                                          uint32_t msg_type,
 507                                          struct server_id src,
 508                                          DATA_BLOB *data)
 509 {
 510         struct share_mode_entry msg;
 511         files_struct *fsp;
 512         bool break_to_level2 = False;
 513         bool use_kernel;
 514         struct smbd_server_connection *sconn =
 515                 talloc_get_type_abort(private_data,
 516                 struct smbd_server_connection);
 517         struct server_id self = messaging_server_id(sconn->msg_ctx);
 518         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 519
 520         if (data->data == NULL) {
 521                 DEBUG(0, ("Got NULL buffer\n"));
 522                 return;
 523         }
 524
 525         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 526                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 527                 return;
 528         }
 529
 530         /* De-linearize incoming message. */
 531         message_to_share_mode_entry(&msg, (char *)data->data);
 532
 533         DEBUG(10, ("Got oplock break message from pid %s: %s/%llu\n",
 534                    server_id_str(talloc_tos(), &src),
 535                    file_id_string_tos(&msg.id),
 536                    (unsigned long long)msg.share_file_id));
 537
 538         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 539
 540         if (fsp == NULL) {
 541                 /* We hit a race here. Break messages are sent, and before we
 542                  * get to process this message, we have closed the file. */
 543                 DEBUG(3, ("Did not find fsp\n"));
 544                 return;
 545         }
 546
 547         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 548                 /*
 549                  * Nothing to do anymore
 550                  */
 551                 return;
 552         }
 553
 554         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 555             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 556                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 557                           file_id_string_tos(&fsp->file_id),
 558                           fsp_str_dbg(fsp)));
 559                 return;
 560         }
 561
 562         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 563
 564         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 565             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 566             lp_level2_oplocks(SNUM(fsp->conn))) {
 567                 break_to_level2 = True;
 568         }
 569
 570         /* Need to wait before sending a break
 571            message if we sent ourselves this message. */
 572         if (serverid_equal(&self, &src)) {
 573                 wait_before_sending_break();
 574         }
 575
 576         if (sconn->using_smb2) {
 577                 send_break_message_smb2(fsp, break_to_level2 ?
 578                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 579         } else {
 580                 send_break_message_smb1(fsp, break_to_level2 ?
 581                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 582         }
 583
 584         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 585
 586         add_oplock_timeout_handler(fsp);
 587 }
 588
 589 /*******************************************************************
 590  This handles the kernel oplock break message.
 591 *******************************************************************/
 592
 593 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 594                                         void *private_data,
 595                                         uint32_t msg_type,
 596                                         struct server_id src,
 597                                         DATA_BLOB *data)
 598 {
 599         struct file_id id;
 600         unsigned long file_id;
 601         files_struct *fsp;
 602         struct smbd_server_connection *sconn =
 603                 talloc_get_type_abort(private_data,
 604                 struct smbd_server_connection);
 605
 606         if (data->data == NULL) {
 607                 DEBUG(0, ("Got NULL buffer\n"));
 608                 return;
 609         }
 610
 611         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 612                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 613                 return;
 614         }
 615
 616         /* Pull the data from the message. */
 617         pull_file_id_24((char *)data->data, &id);
 618         file_id = (unsigned long)IVAL(data->data, 24);
 619
 620         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 621                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 622                    (unsigned int)file_id));
 623
 624         fsp = initial_break_processing(sconn, id, file_id);
 625
 626         if (fsp == NULL) {
 627                 DEBUG(3, ("Got a kernel oplock break message for a file "
 628                           "I don't know about\n"));
 629                 return;
 630         }
 631
 632         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 633                 /* This is ok, kernel oplocks come in completely async */
 634                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 635                           "break reply\n"));
 636                 return;
 637         }
 638
 639         if (sconn->using_smb2) {
 640                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 641         } else {
 642                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 643         }
 644
 645         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 646
 647         add_oplock_timeout_handler(fsp);
 648 }
 649
 650 struct break_to_none_state {
 651         struct smbd_server_connection *sconn;
 652         struct file_id id;
 653 };
 654 static void do_break_to_none(struct tevent_context *ctx,
 655                              struct tevent_immediate *im,
 656                              void *private_data);
 657
 658 /****************************************************************************
 659  This function is called on any file modification or lock request. If a file
 660  is level 2 oplocked then it must tell all other level 2 holders to break to
 661  none.
 662 ****************************************************************************/
 663
 664 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 665                                               enum level2_contention_type type)
 666 {
 667         struct smbd_server_connection *sconn = fsp->conn->sconn;
 668         struct tevent_immediate *im;
 669         struct break_to_none_state *state;
 670         struct byte_range_lock *brl;
 671
 672         /*
 673          * If this file is level II oplocked then we need
 674          * to grab the shared memory lock and inform all
 675          * other files with a level II lock that they need
 676          * to flush their read caches. We keep the lock over
 677          * the shared memory area whilst doing this.
 678          */
 679
 680         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 681                 /*
 682                  * There can't be any level2 oplocks, we're alone.
 683                  */
 684                 return;
 685         }
 686
 687         brl = brl_get_locks_readonly(fsp);
 688         if ((brl != NULL) && !brl_have_read_oplocks(brl)) {
 689                 DEBUG(10, ("No read oplocks around\n"));
 690                 return;
 691         }
 692
 693         /*
 694          * When we get here we might have a brlock entry locked. Also
 695          * locking the share mode entry would violate the locking
 696          * order. Breaking level2 oplocks to none is asynchronous
 697          * anyway, so we postpone this into an immediate event.
 698          */
 699
 700         state = talloc(sconn, struct break_to_none_state);
 701         if (state == NULL) {
 702                 DEBUG(1, ("talloc failed\n"));
 703                 return;
 704         }
 705         state->sconn = sconn;
 706         state->id = fsp->file_id;
 707
 708         im = tevent_create_immediate(state);
 709         if (im == NULL) {
 710                 DEBUG(1, ("tevent_create_immediate failed\n"));
 711                 TALLOC_FREE(state);
 712                 return;
 713         }
 714         tevent_schedule_immediate(im, sconn->ev_ctx, do_break_to_none, state);
 715 }
 716
 717 static void do_break_to_none(struct tevent_context *ctx,
 718                              struct tevent_immediate *im,
 719                              void *private_data)
 720 {
 721         struct break_to_none_state *state = talloc_get_type_abort(
 722                 private_data, struct break_to_none_state);
 723         int i;
 724         struct share_mode_lock *lck;
 725
 726         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 727         if (lck == NULL) {
 728                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 729                           "share mode entry for file %s.\n",
 730                           file_id_string_tos(&state->id)));
 731                 goto done;
 732         }
 733
 734         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 735                   lck->data->num_share_modes ));
 736
 737         for(i = 0; i < lck->data->num_share_modes; i++) {
 738                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 739                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 740
 741                 if (!is_valid_share_mode_entry(share_entry)) {
 742                         continue;
 743                 }
 744
 745                 /*
 746                  * As there could have been multiple writes waiting at the
 747                  * lock_share_entry gate we may not be the first to
 748                  * enter. Hence the state of the op_types in the share mode
 749                  * entries may be partly NO_OPLOCK and partly LEVEL_II
 750                  * oplock. It will do no harm to re-send break messages to
 751                  * those smbd's that are still waiting their turn to remove
 752                  * their LEVEL_II state, and also no harm to ignore existing
 753                  * NO_OPLOCK states. JRA.
 754                  */
 755
 756                 DEBUG(10,("release_level_2_oplocks_on_change: "
 757                           "share_entry[%i]->op_type == %d\n",
 758                           i, share_entry->op_type ));
 759
 760                 if (share_entry->op_type == NO_OPLOCK) {
 761                         continue;
 762                 }
 763
 764                 /* Paranoia .... */
 765                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 766                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 767                                  "share mode entry %d is an exlusive "
 768                                  "oplock !\n", i ));
 769                         TALLOC_FREE(lck);
 770                         abort();
 771                 }
 772
 773                 share_mode_entry_to_message(msg, share_entry);
 774
 775                 messaging_send_buf(state->sconn->msg_ctx, share_entry->pid,
 776                                    MSG_SMB_ASYNC_LEVEL2_BREAK,
 777                                    (uint8 *)msg, sizeof(msg));
 778         }
 779
 780         /* We let the message receivers handle removing the oplock state
 781            in the share mode lock db. */
 782
 783         TALLOC_FREE(lck);
 784 done:
 785         TALLOC_FREE(state);
 786         return;
 787 }
 788
 789 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 790                                   enum level2_contention_type type)
 791 {
 792         struct smbd_server_connection *sconn = fsp->conn->sconn;
 793         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 794
 795         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 796                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 797                 return;
 798         }
 799
 800         contend_level2_oplocks_begin_default(fsp, type);
 801 }
 802
 803 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 804                                 enum level2_contention_type type)
 805 {
 806         struct smbd_server_connection *sconn = fsp->conn->sconn;
 807         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 808
 809         /* Only kernel oplocks implement this so far */
 810         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 811                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 812         }
 813 }
 814
 815 /****************************************************************************
 816  Linearize a share mode entry struct to an internal oplock break message.
 817 ****************************************************************************/
 818
 819 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 820 {
 821         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 822         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 823         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 824         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 825         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 826         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 827         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 828         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 829         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 830         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 831         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 832         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 833         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 834         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 835 }
 836
 837 /****************************************************************************
 838  De-linearize an internal oplock break message to a share mode entry struct.
 839 ****************************************************************************/
 840
 841 void message_to_share_mode_entry(struct share_mode_entry *e, const char *msg)
 842 {
 843         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 844         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 845         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 846         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 847         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 848         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 849         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 850         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 851         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 852         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 853         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 854         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 855         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 856         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 857 }
 858
 859 /****************************************************************************
 860  Setup oplocks for this process.
 861 ****************************************************************************/
 862
 863 bool init_oplocks(struct smbd_server_connection *sconn)
 864 {
 865         DEBUG(3,("init_oplocks: initializing messages.\n"));
 866
 867         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 868                            process_oplock_break_message);
 869         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 870                            process_oplock_async_level2_break_message);
 871         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 872                            process_kernel_oplock_break);
 873         return true;
 874 }
 875
 876 void init_kernel_oplocks(struct smbd_server_connection *sconn)
 877 {
 878         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 879
 880         /* only initialize once */
 881         if (koplocks == NULL) {
 882 #if HAVE_KERNEL_OPLOCKS_IRIX
 883                 koplocks = irix_init_kernel_oplocks(sconn);
 884 #elif HAVE_KERNEL_OPLOCKS_LINUX
 885                 koplocks = linux_init_kernel_oplocks(sconn);
 886 #endif
 887                 sconn->oplocks.kernel_ops = koplocks;
 888         }
 889 }