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/globals.h"
  25
  26 /****************************************************************************
  27  Get the number of current exclusive oplocks.
  28 ****************************************************************************/
  29
  30 int32 get_number_of_exclusive_open_oplocks(void)
  31 {
  32   return exclusive_oplocks_open;
  33 }
  34
  35 /*
  36  * helper function used by the kernel oplock backends to post the break message
  37  */
  38 void break_kernel_oplock(struct messaging_context *msg_ctx, files_struct *fsp)
  39 {
  40         uint8_t msg[MSG_SMB_KERNEL_BREAK_SIZE];
  41
  42         /* Put the kernel break info into the message. */
  43         push_file_id_24((char *)msg, &fsp->file_id);
  44         SIVAL(msg,24,fsp->fh->gen_id);
  45
  46         /* Don't need to be root here as we're only ever
  47            sending to ourselves. */
  48
  49         messaging_send_buf(msg_ctx, procid_self(),
  50                            MSG_SMB_KERNEL_BREAK,
  51                            msg, MSG_SMB_KERNEL_BREAK_SIZE);
  52 }
  53
  54 /****************************************************************************
  55  Attempt to set an oplock on a file. Always succeeds if kernel oplocks are
  56  disabled (just sets flags). Returns True if oplock set.
  57 ****************************************************************************/
  58
  59 bool set_file_oplock(files_struct *fsp, int oplock_type)
  60 {
  61         if ((fsp->oplock_type == LEVEL_II_OPLOCK)
  62             && koplocks && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
  63                 DEBUG(10, ("Refusing level2 oplock, kernel oplocks don't "
  64                            "support them\n"));
  65                 return false;
  66         }
  67         if ((fsp->oplock_type != NO_OPLOCK) &&
  68             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
  69             koplocks &&
  70             !koplocks->ops->set_oplock(koplocks, fsp, oplock_type)) {
  71                 return False;
  72         }
  73
  74         fsp->oplock_type = oplock_type;
  75         fsp->sent_oplock_break = NO_BREAK_SENT;
  76         if (oplock_type == LEVEL_II_OPLOCK) {
  77                 level_II_oplocks_open++;
  78         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
  79                 exclusive_oplocks_open++;
  80         }
  81
  82         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
  83                     "tv_sec = %x, tv_usec = %x\n",
  84                  fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
  85                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
  86                  (int)fsp->open_time.tv_usec ));
  87
  88         return True;
  89 }
  90
  91 /****************************************************************************
  92  Attempt to release an oplock on a file. Decrements oplock count.
  93 ****************************************************************************/
  94
  95 void release_file_oplock(files_struct *fsp)
  96 {
  97         if ((fsp->oplock_type != NO_OPLOCK) &&
  98             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
  99             koplocks) {
 100                 koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
 101         }
 102
 103         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 104                 level_II_oplocks_open--;
 105         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 106                 exclusive_oplocks_open--;
 107         }
 108
 109         SMB_ASSERT(exclusive_oplocks_open>=0);
 110         SMB_ASSERT(level_II_oplocks_open>=0);
 111
 112         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 113                 /* This doesn't matter for close. */
 114                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 115         } else {
 116                 fsp->oplock_type = NO_OPLOCK;
 117         }
 118         fsp->sent_oplock_break = NO_BREAK_SENT;
 119
 120         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 121
 122         TALLOC_FREE(fsp->oplock_timeout);
 123 }
 124
 125 /****************************************************************************
 126  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 127 ****************************************************************************/
 128
 129 static void downgrade_file_oplock(files_struct *fsp)
 130 {
 131         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 132                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 133                 return;
 134         }
 135
 136         if (koplocks) {
 137                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 138         }
 139         fsp->oplock_type = LEVEL_II_OPLOCK;
 140         exclusive_oplocks_open--;
 141         level_II_oplocks_open++;
 142         fsp->sent_oplock_break = NO_BREAK_SENT;
 143 }
 144
 145 /****************************************************************************
 146  Remove a file oplock. Copes with level II and exclusive.
 147  Locks then unlocks the share mode lock. Client can decide to go directly
 148  to none even if a "break-to-level II" was sent.
 149 ****************************************************************************/
 150
 151 bool remove_oplock(files_struct *fsp)
 152 {
 153         bool ret;
 154         struct share_mode_lock *lck;
 155
 156         /* Remove the oplock flag from the sharemode. */
 157         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 158                                   NULL);
 159         if (lck == NULL) {
 160                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 161                          "file %s\n", fsp_str_dbg(fsp)));
 162                 return False;
 163         }
 164         ret = remove_share_oplock(lck, fsp);
 165         if (!ret) {
 166                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 167                          "file %s fnum %d, %s\n",
 168                          fsp_str_dbg(fsp), fsp->fnum,
 169                          file_id_string_tos(&fsp->file_id)));
 170         }
 171         release_file_oplock(fsp);
 172         TALLOC_FREE(lck);
 173         return ret;
 174 }
 175
 176 /*
 177  * Deal with a reply when a break-to-level II was sent.
 178  */
 179 bool downgrade_oplock(files_struct *fsp)
 180 {
 181         bool ret;
 182         struct share_mode_lock *lck;
 183
 184         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 185                                   NULL);
 186         if (lck == NULL) {
 187                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 188                          "file %s\n", fsp_str_dbg(fsp)));
 189                 return False;
 190         }
 191         ret = downgrade_share_oplock(lck, fsp);
 192         if (!ret) {
 193                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 194                          "for file %s fnum %d, file_id %s\n",
 195                          fsp_str_dbg(fsp), fsp->fnum,
 196                          file_id_string_tos(&fsp->file_id)));
 197         }
 198
 199         downgrade_file_oplock(fsp);
 200         TALLOC_FREE(lck);
 201         return ret;
 202 }
 203
 204 /*
 205  * Some kernel oplock implementations handle the notification themselves.
 206  */
 207 bool should_notify_deferred_opens()
 208 {
 209         return !(koplocks &&
 210                 (koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
 211 }
 212
 213 /****************************************************************************
 214  Set up an oplock break message.
 215 ****************************************************************************/
 216
 217 static char *new_break_smb_message(TALLOC_CTX *mem_ctx,
 218                                    files_struct *fsp, uint8 cmd)
 219 {
 220         char *result = TALLOC_ARRAY(mem_ctx, char, smb_size + 8*2 + 0);
 221
 222         if (result == NULL) {
 223                 DEBUG(0, ("talloc failed\n"));
 224                 return NULL;
 225         }
 226
 227         memset(result,'\0',smb_size);
 228         srv_set_message(result,8,0,true);
 229         SCVAL(result,smb_com,SMBlockingX);
 230         SSVAL(result,smb_tid,fsp->conn->cnum);
 231         SSVAL(result,smb_pid,0xFFFF);
 232         SSVAL(result,smb_uid,0);
 233         SSVAL(result,smb_mid,0xFFFF);
 234         SCVAL(result,smb_vwv0,0xFF);
 235         SSVAL(result,smb_vwv2,fsp->fnum);
 236         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 237         SCVAL(result,smb_vwv3+1,cmd);
 238         return result;
 239 }
 240
 241 /****************************************************************************
 242  Function to do the waiting before sending a local break.
 243 ****************************************************************************/
 244
 245 static void wait_before_sending_break(void)
 246 {
 247         long wait_time = (long)lp_oplock_break_wait_time();
 248
 249         if (wait_time) {
 250                 smb_msleep(wait_time);
 251         }
 252 }
 253
 254 /****************************************************************************
 255  Ensure that we have a valid oplock.
 256 ****************************************************************************/
 257
 258 static files_struct *initial_break_processing(struct file_id id, unsigned long file_id)
 259 {
 260         files_struct *fsp = NULL;
 261
 262         if( DEBUGLVL( 3 ) ) {
 263                 dbgtext( "initial_break_processing: called for %s/%u\n",
 264                          file_id_string_tos(&id), (int)file_id);
 265                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 266                         exclusive_oplocks_open, level_II_oplocks_open );
 267         }
 268
 269         /*
 270          * We need to search the file open table for the
 271          * entry containing this dev and inode, and ensure
 272          * we have an oplock on it.
 273          */
 274
 275         fsp = file_find_dif(id, file_id);
 276
 277         if(fsp == NULL) {
 278                 /* The file could have been closed in the meantime - return success. */
 279                 if( DEBUGLVL( 3 ) ) {
 280                         dbgtext( "initial_break_processing: cannot find open file with " );
 281                         dbgtext( "file_id %s gen_id = %lu", file_id_string_tos(&id), file_id);
 282                         dbgtext( "allowing break to succeed.\n" );
 283                 }
 284                 return NULL;
 285         }
 286
 287         /* Ensure we have an oplock on the file */
 288
 289         /*
 290          * There is a potential race condition in that an oplock could
 291          * have been broken due to another udp request, and yet there are
 292          * still oplock break messages being sent in the udp message
 293          * queue for this file. So return true if we don't have an oplock,
 294          * as we may have just freed it.
 295          */
 296
 297         if(fsp->oplock_type == NO_OPLOCK) {
 298                 if( DEBUGLVL( 3 ) ) {
 299                         dbgtext( "initial_break_processing: file %s ",
 300                                  fsp_str_dbg(fsp));
 301                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 302                                  file_id_string_tos(&id), fsp->fh->gen_id );
 303                         dbgtext( "Allowing break to succeed regardless.\n" );
 304                 }
 305                 return NULL;
 306         }
 307
 308         return fsp;
 309 }
 310
 311 static void oplock_timeout_handler(struct event_context *ctx,
 312                                    struct timed_event *te,
 313                                    struct timeval now,
 314                                    void *private_data)
 315 {
 316         files_struct *fsp = (files_struct *)private_data;
 317
 318         /* Remove the timed event handler. */
 319         TALLOC_FREE(fsp->oplock_timeout);
 320         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 321                   fsp_str_dbg(fsp)));
 322         global_client_failed_oplock_break = True;
 323         remove_oplock(fsp);
 324         reply_to_oplock_break_requests(fsp);
 325 }
 326
 327 /*******************************************************************
 328  Add a timeout handler waiting for the client reply.
 329 *******************************************************************/
 330
 331 static void add_oplock_timeout_handler(files_struct *fsp)
 332 {
 333         /*
 334          * If kernel oplocks already notifies smbds when an oplock break times
 335          * out, just return.
 336          */
 337         if (koplocks &&
 338             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 339                 return;
 340         }
 341
 342         if (fsp->oplock_timeout != NULL) {
 343                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 344                           "around\n"));
 345         }
 346
 347         fsp->oplock_timeout =
 348                 event_add_timed(smbd_event_context(), NULL,
 349                                 timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 350                                 oplock_timeout_handler, fsp);
 351
 352         if (fsp->oplock_timeout == NULL) {
 353                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 354         }
 355 }
 356
 357 void break_level2_to_none_async(files_struct *fsp)
 358 {
 359         char *break_msg;
 360
 361         if (fsp->oplock_type == NO_OPLOCK) {
 362                 /* We already got a "break to none" message and we've handled
 363                  * it.  just ignore. */
 364                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 365                           "broken to none, ignoring.\n"));
 366                 return;
 367         }
 368
 369         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 370                 /* Don't tell the client, just downgrade. */
 371                 DEBUG(3, ("process_oplock_async_level2_break_message: "
 372                           "downgrading fake level 2 oplock.\n"));
 373                 remove_oplock(fsp);
 374                 return;
 375         }
 376
 377         /* Ensure we're really at level2 state. */
 378         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 379
 380         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 381                   "to none message for fid %d, file %s\n", fsp->fnum,
 382                   fsp_str_dbg(fsp)));
 383
 384         /* Now send a break to none message to our client. */
 385         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 386         if (break_msg == NULL) {
 387                 exit_server("Could not talloc break_msg\n");
 388         }
 389
 390         show_msg(break_msg);
 391         if (!srv_send_smb(smbd_server_fd(),
 392                         break_msg, false, 0,
 393                         IS_CONN_ENCRYPTED(fsp->conn),
 394                         NULL)) {
 395                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 396         }
 397
 398         TALLOC_FREE(break_msg);
 399
 400         /* Async level2 request, don't send a reply, just remove the oplock. */
 401         remove_oplock(fsp);
 402
 403 }
 404
 405 /*******************************************************************
 406  This handles the case of a write triggering a break to none
 407  message on a level2 oplock.
 408  When we get this message we may be in any of three states :
 409  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 410  the client for LEVEL2.
 411 *******************************************************************/
 412
 413 void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 414                                                       void *private_data,
 415                                                       uint32_t msg_type,
 416                                                       struct server_id src,
 417                                                       DATA_BLOB *data)
 418 {
 419         struct share_mode_entry msg;
 420         files_struct *fsp;
 421
 422         if (data->data == NULL) {
 423                 DEBUG(0, ("Got NULL buffer\n"));
 424                 return;
 425         }
 426
 427         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 428                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 429                 return;
 430         }
 431
 432         /* De-linearize incoming message. */
 433         message_to_share_mode_entry(&msg, (char *)data->data);
 434
 435         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 436                    "%s/%lu\n", procid_str(debug_ctx(), &src),
 437                    file_id_string_tos(&msg.id), msg.share_file_id));
 438
 439         fsp = initial_break_processing(msg.id, msg.share_file_id);
 440
 441         if (fsp == NULL) {
 442                 /* We hit a race here. Break messages are sent, and before we
 443                  * get to process this message, we have closed the file.
 444                  * No need to reply as this is an async message. */
 445                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 446                 return;
 447         }
 448
 449         break_level2_to_none_async(fsp);
 450 }
 451
 452 /*******************************************************************
 453  This handles the generic oplock break message from another smbd.
 454 *******************************************************************/
 455
 456 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 457                                          void *private_data,
 458                                          uint32_t msg_type,
 459                                          struct server_id src,
 460                                          DATA_BLOB *data)
 461 {
 462         struct share_mode_entry msg;
 463         files_struct *fsp;
 464         char *break_msg;
 465         bool break_to_level2 = False;
 466
 467         if (data->data == NULL) {
 468                 DEBUG(0, ("Got NULL buffer\n"));
 469                 return;
 470         }
 471
 472         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 473                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 474                 return;
 475         }
 476
 477         /* De-linearize incoming message. */
 478         message_to_share_mode_entry(&msg, (char *)data->data);
 479
 480         DEBUG(10, ("Got oplock break message from pid %s: %s/%lu\n",
 481                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 482                    msg.share_file_id));
 483
 484         fsp = initial_break_processing(msg.id, msg.share_file_id);
 485
 486         if (fsp == NULL) {
 487                 /* a We hit race here. Break messages are sent, and before we
 488                  * get to process this message, we have closed the file. Reply
 489                  * with 'ok, oplock broken' */
 490                 DEBUG(3, ("Did not find fsp\n"));
 491
 492                 /* We just send the same message back. */
 493                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 494                                    (uint8 *)data->data,
 495                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 496                 return;
 497         }
 498
 499         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 500                 /* Remember we have to inform the requesting PID when the
 501                  * client replies */
 502                 msg.pid = src;
 503                 ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 504                              &fsp->pending_break_messages,
 505                              &fsp->num_pending_break_messages);
 506                 return;
 507         }
 508
 509         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 510             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 511                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 512                           file_id_string_tos(&fsp->file_id),
 513                           fsp_str_dbg(fsp)));
 514                 /* We just send the same message back. */
 515                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 516                                    (uint8 *)data->data,
 517                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 518                 return;
 519         }
 520
 521         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 522             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 523             !(koplocks && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 524             lp_level2_oplocks(SNUM(fsp->conn))) {
 525                 break_to_level2 = True;
 526         }
 527
 528         break_msg = new_break_smb_message(NULL, fsp, break_to_level2 ?
 529                                           OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 530         if (break_msg == NULL) {
 531                 exit_server("Could not talloc break_msg\n");
 532         }
 533
 534         /* Need to wait before sending a break message if we sent ourselves this message. */
 535         if (procid_is_me(&src)) {
 536                 wait_before_sending_break();
 537         }
 538
 539         show_msg(break_msg);
 540         if (!srv_send_smb(smbd_server_fd(),
 541                         break_msg, false, 0,
 542                         IS_CONN_ENCRYPTED(fsp->conn),
 543                         NULL)) {
 544                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 545         }
 546
 547         TALLOC_FREE(break_msg);
 548
 549         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 550
 551         msg.pid = src;
 552         ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 553                      &fsp->pending_break_messages,
 554                      &fsp->num_pending_break_messages);
 555
 556         add_oplock_timeout_handler(fsp);
 557 }
 558
 559 /*******************************************************************
 560  This handles the kernel oplock break message.
 561 *******************************************************************/
 562
 563 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 564                                         void *private_data,
 565                                         uint32_t msg_type,
 566                                         struct server_id src,
 567                                         DATA_BLOB *data)
 568 {
 569         struct file_id id;
 570         unsigned long file_id;
 571         files_struct *fsp;
 572         char *break_msg;
 573
 574         if (data->data == NULL) {
 575                 DEBUG(0, ("Got NULL buffer\n"));
 576                 return;
 577         }
 578
 579         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 580                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 581                 return;
 582         }
 583
 584         /* Pull the data from the message. */
 585         pull_file_id_24((char *)data->data, &id);
 586         file_id = (unsigned long)IVAL(data->data, 24);
 587
 588         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 589                    procid_str(debug_ctx(), &src), file_id_string_tos(&id),
 590                    (unsigned int)file_id));
 591
 592         fsp = initial_break_processing(id, file_id);
 593
 594         if (fsp == NULL) {
 595                 DEBUG(3, ("Got a kernel oplock break message for a file "
 596                           "I don't know about\n"));
 597                 return;
 598         }
 599
 600         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 601                 /* This is ok, kernel oplocks come in completely async */
 602                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 603                           "break reply\n"));
 604                 return;
 605         }
 606
 607         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 608         if (break_msg == NULL) {
 609                 exit_server("Could not talloc break_msg\n");
 610         }
 611
 612         show_msg(break_msg);
 613         if (!srv_send_smb(smbd_server_fd(),
 614                         break_msg, false, 0,
 615                         IS_CONN_ENCRYPTED(fsp->conn),
 616                         NULL)) {
 617                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 618         }
 619
 620         TALLOC_FREE(break_msg);
 621
 622         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 623
 624         add_oplock_timeout_handler(fsp);
 625 }
 626
 627 void reply_to_oplock_break_requests(files_struct *fsp)
 628 {
 629         int i;
 630
 631         /*
 632          * If kernel oplocks already notifies smbds when oplocks are
 633          * broken/removed, just return.
 634          */
 635         if (koplocks &&
 636             (koplocks->flags & KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION)) {
 637                 return;
 638         }
 639
 640         for (i=0; i<fsp->num_pending_break_messages; i++) {
 641                 struct share_mode_entry *e = &fsp->pending_break_messages[i];
 642                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 643
 644                 share_mode_entry_to_message(msg, e);
 645
 646                 messaging_send_buf(smbd_messaging_context(), e->pid,
 647                                    MSG_SMB_BREAK_RESPONSE,
 648                                    (uint8 *)msg,
 649                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 650         }
 651
 652         SAFE_FREE(fsp->pending_break_messages);
 653         fsp->num_pending_break_messages = 0;
 654         if (fsp->oplock_timeout != NULL) {
 655                 /* Remove the timed event handler. */
 656                 TALLOC_FREE(fsp->oplock_timeout);
 657                 fsp->oplock_timeout = NULL;
 658         }
 659         return;
 660 }
 661
 662 static void process_oplock_break_response(struct messaging_context *msg_ctx,
 663                                           void *private_data,
 664                                           uint32_t msg_type,
 665                                           struct server_id src,
 666                                           DATA_BLOB *data)
 667 {
 668         struct share_mode_entry msg;
 669
 670         if (data->data == NULL) {
 671                 DEBUG(0, ("Got NULL buffer\n"));
 672                 return;
 673         }
 674
 675         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 676                 DEBUG(0, ("Got invalid msg len %u\n",
 677                           (unsigned int)data->length));
 678                 return;
 679         }
 680
 681         /* De-linearize incoming message. */
 682         message_to_share_mode_entry(&msg, (char *)data->data);
 683
 684         DEBUG(10, ("Got oplock break response from pid %s: %s/%lu mid %u\n",
 685                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 686                    msg.share_file_id, (unsigned int)msg.op_mid));
 687
 688         /* Here's the hack from open.c, store the mid in the 'port' field */
 689         schedule_deferred_open_smb_message(msg.op_mid);
 690 }
 691
 692 static void process_open_retry_message(struct messaging_context *msg_ctx,
 693                                        void *private_data,
 694                                        uint32_t msg_type,
 695                                        struct server_id src,
 696                                        DATA_BLOB *data)
 697 {
 698         struct share_mode_entry msg;
 699
 700         if (data->data == NULL) {
 701                 DEBUG(0, ("Got NULL buffer\n"));
 702                 return;
 703         }
 704
 705         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 706                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 707                 return;
 708         }
 709
 710         /* De-linearize incoming message. */
 711         message_to_share_mode_entry(&msg, (char *)data->data);
 712
 713         DEBUG(10, ("Got open retry msg from pid %s: %s mid %u\n",
 714                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 715                    (unsigned int)msg.op_mid));
 716
 717         schedule_deferred_open_smb_message(msg.op_mid);
 718 }
 719
 720 /****************************************************************************
 721  This function is called on any file modification or lock request. If a file
 722  is level 2 oplocked then it must tell all other level 2 holders to break to
 723  none.
 724 ****************************************************************************/
 725
 726 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 727                                               enum level2_contention_type type)
 728 {
 729         int i;
 730         struct share_mode_lock *lck;
 731
 732         /*
 733          * If this file is level II oplocked then we need
 734          * to grab the shared memory lock and inform all
 735          * other files with a level II lock that they need
 736          * to flush their read caches. We keep the lock over
 737          * the shared memory area whilst doing this.
 738          */
 739
 740         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 741                 return;
 742
 743         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 744                                   NULL);
 745         if (lck == NULL) {
 746                 DEBUG(0,("release_level_2_oplocks_on_change: failed to lock "
 747                          "share mode entry for file %s.\n", fsp_str_dbg(fsp)));
 748                 return;
 749         }
 750
 751         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 752                   lck->num_share_modes ));
 753
 754         for(i = 0; i < lck->num_share_modes; i++) {
 755                 struct share_mode_entry *share_entry = &lck->share_modes[i];
 756                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 757
 758                 if (!is_valid_share_mode_entry(share_entry)) {
 759                         continue;
 760                 }
 761
 762                 /*
 763                  * As there could have been multiple writes waiting at the
 764                  * lock_share_entry gate we may not be the first to
 765                  * enter. Hence the state of the op_types in the share mode
 766                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 767                  * oplock. It will do no harm to re-send break messages to
 768                  * those smbd's that are still waiting their turn to remove
 769                  * their LEVEL_II state, and also no harm to ignore existing
 770                  * NO_OPLOCK states. JRA.
 771                  */
 772
 773                 DEBUG(10,("release_level_2_oplocks_on_change: "
 774                           "share_entry[%i]->op_type == %d\n",
 775                           i, share_entry->op_type ));
 776
 777                 if (share_entry->op_type == NO_OPLOCK) {
 778                         continue;
 779                 }
 780
 781                 /* Paranoia .... */
 782                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 783                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 784                                  "share mode entry %d is an exlusive "
 785                                  "oplock !\n", i ));
 786                         TALLOC_FREE(lck);
 787                         abort();
 788                 }
 789
 790                 share_mode_entry_to_message(msg, share_entry);
 791
 792                 /*
 793                  * Deal with a race condition when breaking level2
 794                  * oplocks. Don't send all the messages and release
 795                  * the lock, this allows someone else to come in and
 796                  * get a level2 lock before any of the messages are
 797                  * processed, and thus miss getting a break message.
 798                  * Ensure at least one entry (the one we're breaking)
 799                  * is processed immediately under the lock and becomes
 800                  * set as NO_OPLOCK to stop any waiter getting a level2.
 801                  * Bugid #5980.
 802                  */
 803
 804                 if (procid_is_me(&share_entry->pid)) {
 805                         wait_before_sending_break();
 806                         break_level2_to_none_async(fsp);
 807                 } else {
 808                         messaging_send_buf(smbd_messaging_context(),
 809                                         share_entry->pid,
 810                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 811                                         (uint8 *)msg,
 812                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 813                 }
 814         }
 815
 816         /* We let the message receivers handle removing the oplock state
 817            in the share mode lock db. */
 818
 819         TALLOC_FREE(lck);
 820 }
 821
 822 void contend_level2_oplocks_begin(files_struct *fsp,
 823                                   enum level2_contention_type type)
 824 {
 825         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 826                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 827                 return;
 828         }
 829
 830         contend_level2_oplocks_begin_default(fsp, type);
 831 }
 832
 833 void contend_level2_oplocks_end(files_struct *fsp,
 834                                 enum level2_contention_type type)
 835 {
 836         /* Only kernel oplocks implement this so far */
 837         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 838                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 839         }
 840 }
 841
 842 /****************************************************************************
 843  Linearize a share mode entry struct to an internal oplock break message.
 844 ****************************************************************************/
 845
 846 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 847 {
 848         SIVAL(msg,0,(uint32)e->pid.pid);
 849         SSVAL(msg,4,e->op_mid);
 850         SSVAL(msg,6,e->op_type);
 851         SIVAL(msg,8,e->access_mask);
 852         SIVAL(msg,12,e->share_access);
 853         SIVAL(msg,16,e->private_options);
 854         SIVAL(msg,20,(uint32)e->time.tv_sec);
 855         SIVAL(msg,24,(uint32)e->time.tv_usec);
 856         push_file_id_24(msg+28, &e->id);
 857         SIVAL(msg,52,e->share_file_id);
 858         SIVAL(msg,56,e->uid);
 859         SSVAL(msg,60,e->flags);
 860 #ifdef CLUSTER_SUPPORT
 861         SIVAL(msg,62,e->pid.vnn);
 862 #endif
 863 }
 864
 865 /****************************************************************************
 866  De-linearize an internal oplock break message to a share mode entry struct.
 867 ****************************************************************************/
 868
 869 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 870 {
 871         e->pid.pid = (pid_t)IVAL(msg,0);
 872         e->op_mid = SVAL(msg,4);
 873         e->op_type = SVAL(msg,6);
 874         e->access_mask = IVAL(msg,8);
 875         e->share_access = IVAL(msg,12);
 876         e->private_options = IVAL(msg,16);
 877         e->time.tv_sec = (time_t)IVAL(msg,20);
 878         e->time.tv_usec = (int)IVAL(msg,24);
 879         pull_file_id_24(msg+28, &e->id);
 880         e->share_file_id = (unsigned long)IVAL(msg,52);
 881         e->uid = (uint32)IVAL(msg,56);
 882         e->flags = (uint16)SVAL(msg,60);
 883 #ifdef CLUSTER_SUPPORT
 884         e->pid.vnn = IVAL(msg,62);
 885 #endif
 886 }
 887
 888 /****************************************************************************
 889  Setup oplocks for this process.
 890 ****************************************************************************/
 891
 892 bool init_oplocks(struct messaging_context *msg_ctx)
 893 {
 894         DEBUG(3,("init_oplocks: initializing messages.\n"));
 895
 896         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_REQUEST,
 897                            process_oplock_break_message);
 898         messaging_register(msg_ctx, NULL, MSG_SMB_ASYNC_LEVEL2_BREAK,
 899                            process_oplock_async_level2_break_message);
 900         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_RESPONSE,
 901                            process_oplock_break_response);
 902         messaging_register(msg_ctx, NULL, MSG_SMB_KERNEL_BREAK,
 903                            process_kernel_oplock_break);
 904         messaging_register(msg_ctx, NULL, MSG_SMB_OPEN_RETRY,
 905                            process_open_retry_message);
 906
 907         if (lp_kernel_oplocks()) {
 908 #if HAVE_KERNEL_OPLOCKS_IRIX
 909                 koplocks = irix_init_kernel_oplocks(talloc_autofree_context());
 910 #elif HAVE_KERNEL_OPLOCKS_LINUX
 911                 koplocks = linux_init_kernel_oplocks(talloc_autofree_context());
 912 #elif HAVE_ONEFS
 913                 koplocks = onefs_init_kernel_oplocks(talloc_autofree_context());
 914 #endif
 915         }
 916
 917         return True;
 918 }