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