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) and no byte-range locks in the file. Returns True
  51  if oplock set.
  52 ****************************************************************************/
  53
  54 NTSTATUS set_file_oplock(files_struct *fsp, int oplock_type)
  55 {
  56         struct smbd_server_connection *sconn = fsp->conn->sconn;
  57         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
  58         bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
  59
  60         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
  61                 if (use_kernel &&
  62                     !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
  63                         DEBUG(10, ("Refusing level2 oplock, kernel oplocks "
  64                                    "don't support them\n"));
  65                         return NT_STATUS_NOT_SUPPORTED;
  66                 }
  67         }
  68
  69         if ((fsp->oplock_type != NO_OPLOCK) &&
  70             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
  71             use_kernel &&
  72             !koplocks->ops->set_oplock(koplocks, fsp, oplock_type))
  73         {
  74                 return map_nt_error_from_unix(errno);
  75         }
  76
  77         fsp->oplock_type = oplock_type;
  78         fsp->sent_oplock_break = NO_BREAK_SENT;
  79         if (oplock_type == LEVEL_II_OPLOCK) {
  80                 sconn->oplocks.level_II_open++;
  81         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
  82                 sconn->oplocks.exclusive_open++;
  83         }
  84
  85         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
  86                     "tv_sec = %x, tv_usec = %x\n",
  87                  fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
  88                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
  89                  (int)fsp->open_time.tv_usec ));
  90
  91         return NT_STATUS_OK;
  92 }
  93
  94 /****************************************************************************
  95  Attempt to release an oplock on a file. Decrements oplock count.
  96 ****************************************************************************/
  97
  98 void release_file_oplock(files_struct *fsp)
  99 {
 100         struct smbd_server_connection *sconn = fsp->conn->sconn;
 101         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 102
 103         if ((fsp->oplock_type != NO_OPLOCK) &&
 104             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 105             koplocks) {
 106                 koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
 107         }
 108
 109         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 110                 sconn->oplocks.level_II_open--;
 111         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 112                 sconn->oplocks.exclusive_open--;
 113         }
 114
 115         SMB_ASSERT(sconn->oplocks.exclusive_open>=0);
 116         SMB_ASSERT(sconn->oplocks.level_II_open>=0);
 117
 118         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 119                 /* This doesn't matter for close. */
 120                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 121         } else {
 122                 fsp->oplock_type = NO_OPLOCK;
 123         }
 124         fsp->sent_oplock_break = NO_BREAK_SENT;
 125
 126         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 127         delete_write_cache(fsp);
 128
 129         TALLOC_FREE(fsp->oplock_timeout);
 130 }
 131
 132 /****************************************************************************
 133  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 134 ****************************************************************************/
 135
 136 static void downgrade_file_oplock(files_struct *fsp)
 137 {
 138         struct smbd_server_connection *sconn = fsp->conn->sconn;
 139         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 140
 141         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 142                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 143                 return;
 144         }
 145
 146         if (koplocks) {
 147                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 148         }
 149         fsp->oplock_type = LEVEL_II_OPLOCK;
 150         sconn->oplocks.exclusive_open--;
 151         sconn->oplocks.level_II_open++;
 152         fsp->sent_oplock_break = NO_BREAK_SENT;
 153 }
 154
 155 /****************************************************************************
 156  Remove a file oplock. Copes with level II and exclusive.
 157  Locks then unlocks the share mode lock. Client can decide to go directly
 158  to none even if a "break-to-level II" was sent.
 159 ****************************************************************************/
 160
 161 bool remove_oplock(files_struct *fsp)
 162 {
 163         bool ret;
 164         struct share_mode_lock *lck;
 165
 166         /* Remove the oplock flag from the sharemode. */
 167         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 168         if (lck == NULL) {
 169                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 170                          "file %s\n", fsp_str_dbg(fsp)));
 171                 return False;
 172         }
 173         ret = remove_share_oplock(lck, fsp);
 174         if (!ret) {
 175                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 176                          "file %s, %s, %s\n",
 177                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 178                          file_id_string_tos(&fsp->file_id)));
 179         }
 180         release_file_oplock(fsp);
 181         TALLOC_FREE(lck);
 182         return ret;
 183 }
 184
 185 /*
 186  * Deal with a reply when a break-to-level II was sent.
 187  */
 188 bool downgrade_oplock(files_struct *fsp)
 189 {
 190         bool ret;
 191         struct share_mode_lock *lck;
 192
 193         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 194         if (lck == NULL) {
 195                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 196                          "file %s\n", fsp_str_dbg(fsp)));
 197                 return False;
 198         }
 199         ret = downgrade_share_oplock(lck, fsp);
 200         if (!ret) {
 201                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 202                          "for file %s, %s, file_id %s\n",
 203                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 204                          file_id_string_tos(&fsp->file_id)));
 205         }
 206
 207         downgrade_file_oplock(fsp);
 208         TALLOC_FREE(lck);
 209         return ret;
 210 }
 211
 212 /*
 213  * Some kernel oplock implementations handle the notification themselves.
 214  */
 215 bool should_notify_deferred_opens(struct smbd_server_connection *sconn)
 216 {
 217         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 218         return !(koplocks &&
 219                 (koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
 220 }
 221
 222 /****************************************************************************
 223  Set up an oplock break message.
 224 ****************************************************************************/
 225
 226 static char *new_break_message_smb1(TALLOC_CTX *mem_ctx,
 227                                    files_struct *fsp, int cmd)
 228 {
 229         char *result = talloc_array(mem_ctx, char, smb_size + 8*2 + 0);
 230
 231         if (result == NULL) {
 232                 DEBUG(0, ("talloc failed\n"));
 233                 return NULL;
 234         }
 235
 236         memset(result,'\0',smb_size);
 237         srv_set_message(result,8,0,true);
 238         SCVAL(result,smb_com,SMBlockingX);
 239         SSVAL(result,smb_tid,fsp->conn->cnum);
 240         SSVAL(result,smb_pid,0xFFFF);
 241         SSVAL(result,smb_uid,0);
 242         SSVAL(result,smb_mid,0xFFFF);
 243         SCVAL(result,smb_vwv0,0xFF);
 244         SSVAL(result,smb_vwv2,fsp->fnum);
 245         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 246         SCVAL(result,smb_vwv3+1,cmd);
 247         return result;
 248 }
 249
 250 /****************************************************************************
 251  Function to do the waiting before sending a local break.
 252 ****************************************************************************/
 253
 254 static void wait_before_sending_break(void)
 255 {
 256         long wait_time = (long)lp_oplock_break_wait_time();
 257
 258         if (wait_time) {
 259                 smb_msleep(wait_time);
 260         }
 261 }
 262
 263 /****************************************************************************
 264  Ensure that we have a valid oplock.
 265 ****************************************************************************/
 266
 267 static files_struct *initial_break_processing(
 268         struct smbd_server_connection *sconn, struct file_id id,
 269         unsigned long file_id)
 270 {
 271         files_struct *fsp = NULL;
 272
 273         if( DEBUGLVL( 3 ) ) {
 274                 dbgtext( "initial_break_processing: called for %s/%u\n",
 275                          file_id_string_tos(&id), (int)file_id);
 276                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 277                         sconn->oplocks.exclusive_open,
 278                         sconn->oplocks.level_II_open);
 279         }
 280
 281         /*
 282          * We need to search the file open table for the
 283          * entry containing this dev and inode, and ensure
 284          * we have an oplock on it.
 285          */
 286
 287         fsp = file_find_dif(sconn, id, file_id);
 288
 289         if(fsp == NULL) {
 290                 /* The file could have been closed in the meantime - return success. */
 291                 if( DEBUGLVL( 3 ) ) {
 292                         dbgtext( "initial_break_processing: cannot find open file with " );
 293                         dbgtext( "file_id %s gen_id = %lu, ", file_id_string_tos(&id), file_id);
 294                         dbgtext( "allowing break to succeed.\n" );
 295                 }
 296                 return NULL;
 297         }
 298
 299         /* Ensure we have an oplock on the file */
 300
 301         /*
 302          * There is a potential race condition in that an oplock could
 303          * have been broken due to another udp request, and yet there are
 304          * still oplock break messages being sent in the udp message
 305          * queue for this file. So return true if we don't have an oplock,
 306          * as we may have just freed it.
 307          */
 308
 309         if(fsp->oplock_type == NO_OPLOCK) {
 310                 if( DEBUGLVL( 3 ) ) {
 311                         dbgtext( "initial_break_processing: file %s ",
 312                                  fsp_str_dbg(fsp));
 313                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 314                                  file_id_string_tos(&id), fsp->fh->gen_id );
 315                         dbgtext( "Allowing break to succeed regardless.\n" );
 316                 }
 317                 return NULL;
 318         }
 319
 320         return fsp;
 321 }
 322
 323 static void oplock_timeout_handler(struct tevent_context *ctx,
 324                                    struct tevent_timer *te,
 325                                    struct timeval now,
 326                                    void *private_data)
 327 {
 328         files_struct *fsp = (files_struct *)private_data;
 329
 330         /* Remove the timed event handler. */
 331         TALLOC_FREE(fsp->oplock_timeout);
 332         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 333                   fsp_str_dbg(fsp)));
 334         remove_oplock(fsp);
 335 }
 336
 337 /*******************************************************************
 338  Add a timeout handler waiting for the client reply.
 339 *******************************************************************/
 340
 341 static void add_oplock_timeout_handler(files_struct *fsp)
 342 {
 343         struct smbd_server_connection *sconn = fsp->conn->sconn;
 344         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 345
 346         /*
 347          * If kernel oplocks already notifies smbds when an oplock break times
 348          * out, just return.
 349          */
 350         if (koplocks &&
 351             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 352                 return;
 353         }
 354
 355         if (fsp->oplock_timeout != NULL) {
 356                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 357                           "around\n"));
 358         }
 359
 360         fsp->oplock_timeout =
 361                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 362                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 363                                  oplock_timeout_handler, fsp);
 364
 365         if (fsp->oplock_timeout == NULL) {
 366                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 367         }
 368 }
 369
 370 static void send_break_message_smb1(files_struct *fsp, int level)
 371 {
 372         char *break_msg = new_break_message_smb1(talloc_tos(),
 373                                         fsp,
 374                                         level);
 375         if (break_msg == NULL) {
 376                 exit_server("Could not talloc break_msg\n");
 377         }
 378
 379         show_msg(break_msg);
 380         if (!srv_send_smb(fsp->conn->sconn,
 381                         break_msg, false, 0,
 382                         IS_CONN_ENCRYPTED(fsp->conn),
 383                         NULL)) {
 384                 exit_server_cleanly("send_break_message_smb1: "
 385                         "srv_send_smb failed.");
 386         }
 387
 388         TALLOC_FREE(break_msg);
 389 }
 390
 391 void break_level2_to_none_async(files_struct *fsp)
 392 {
 393         struct smbd_server_connection *sconn = fsp->conn->sconn;
 394
 395         if (fsp->oplock_type == NO_OPLOCK) {
 396                 /* We already got a "break to none" message and we've handled
 397                  * it.  just ignore. */
 398                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 399                           "broken to none, ignoring.\n"));
 400                 return;
 401         }
 402
 403         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 404                 /* Don't tell the client, just downgrade. */
 405                 DEBUG(3, ("process_oplock_async_level2_break_message: "
 406                           "downgrading fake level 2 oplock.\n"));
 407                 remove_oplock(fsp);
 408                 return;
 409         }
 410
 411         /* Ensure we're really at level2 state. */
 412         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 413
 414         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 415                   "to none message for %s, file %s\n", fsp_fnum_dbg(fsp),
 416                   fsp_str_dbg(fsp)));
 417
 418         /* Now send a break to none message to our client. */
 419         if (sconn->using_smb2) {
 420                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 421         } else {
 422                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 423         }
 424
 425         /* Async level2 request, don't send a reply, just remove the oplock. */
 426         remove_oplock(fsp);
 427 }
 428
 429 /*******************************************************************
 430  This handles the case of a write triggering a break to none
 431  message on a level2 oplock.
 432  When we get this message we may be in any of three states :
 433  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 434  the client for LEVEL2.
 435 *******************************************************************/
 436
 437 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 438                                                       void *private_data,
 439                                                       uint32_t msg_type,
 440                                                       struct server_id src,
 441                                                       DATA_BLOB *data)
 442 {
 443         struct share_mode_entry msg;
 444         files_struct *fsp;
 445         struct smbd_server_connection *sconn =
 446                 talloc_get_type_abort(private_data,
 447                 struct smbd_server_connection);
 448
 449         if (data->data == NULL) {
 450                 DEBUG(0, ("Got NULL buffer\n"));
 451                 return;
 452         }
 453
 454         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 455                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 456                 return;
 457         }
 458
 459         /* De-linearize incoming message. */
 460         message_to_share_mode_entry(&msg, (char *)data->data);
 461
 462         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 463                    "%s/%llu\n", server_id_str(talloc_tos(), &src),
 464                    file_id_string_tos(&msg.id),
 465                    (unsigned long long)msg.share_file_id));
 466
 467         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 468
 469         if (fsp == NULL) {
 470                 /* We hit a race here. Break messages are sent, and before we
 471                  * get to process this message, we have closed the file.
 472                  * No need to reply as this is an async message. */
 473                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 474                 return;
 475         }
 476
 477         break_level2_to_none_async(fsp);
 478 }
 479
 480 /*******************************************************************
 481  This handles the generic oplock break message from another smbd.
 482 *******************************************************************/
 483
 484 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 485                                          void *private_data,
 486                                          uint32_t msg_type,
 487                                          struct server_id src,
 488                                          DATA_BLOB *data)
 489 {
 490         struct share_mode_entry msg;
 491         files_struct *fsp;
 492         bool break_to_level2 = False;
 493         bool use_kernel;
 494         struct smbd_server_connection *sconn =
 495                 talloc_get_type_abort(private_data,
 496                 struct smbd_server_connection);
 497         struct server_id self = messaging_server_id(sconn->msg_ctx);
 498         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 499
 500         if (data->data == NULL) {
 501                 DEBUG(0, ("Got NULL buffer\n"));
 502                 return;
 503         }
 504
 505         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 506                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 507                 return;
 508         }
 509
 510         /* De-linearize incoming message. */
 511         message_to_share_mode_entry(&msg, (char *)data->data);
 512
 513         DEBUG(10, ("Got oplock break message from pid %s: %s/%llu\n",
 514                    server_id_str(talloc_tos(), &src),
 515                    file_id_string_tos(&msg.id),
 516                    (unsigned long long)msg.share_file_id));
 517
 518         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 519
 520         if (fsp == NULL) {
 521                 /* We hit a race here. Break messages are sent, and before we
 522                  * get to process this message, we have closed the file. */
 523                 DEBUG(3, ("Did not find fsp\n"));
 524                 return;
 525         }
 526
 527         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 528                 /*
 529                  * Nothing to do anymore
 530                  */
 531                 return;
 532         }
 533
 534         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 535             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 536                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 537                           file_id_string_tos(&fsp->file_id),
 538                           fsp_str_dbg(fsp)));
 539                 return;
 540         }
 541
 542         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 543
 544         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 545             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 546             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 547             lp_level2_oplocks(SNUM(fsp->conn))) {
 548                 break_to_level2 = True;
 549         }
 550
 551         /* Need to wait before sending a break
 552            message if we sent ourselves this message. */
 553         if (serverid_equal(&self, &src)) {
 554                 wait_before_sending_break();
 555         }
 556
 557         if (sconn->using_smb2) {
 558                 send_break_message_smb2(fsp, break_to_level2 ?
 559                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 560         } else {
 561                 send_break_message_smb1(fsp, break_to_level2 ?
 562                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 563         }
 564
 565         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 566
 567         add_oplock_timeout_handler(fsp);
 568 }
 569
 570 /*******************************************************************
 571  This handles the kernel oplock break message.
 572 *******************************************************************/
 573
 574 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 575                                         void *private_data,
 576                                         uint32_t msg_type,
 577                                         struct server_id src,
 578                                         DATA_BLOB *data)
 579 {
 580         struct file_id id;
 581         unsigned long file_id;
 582         files_struct *fsp;
 583         struct smbd_server_connection *sconn =
 584                 talloc_get_type_abort(private_data,
 585                 struct smbd_server_connection);
 586
 587         if (data->data == NULL) {
 588                 DEBUG(0, ("Got NULL buffer\n"));
 589                 return;
 590         }
 591
 592         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 593                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 594                 return;
 595         }
 596
 597         /* Pull the data from the message. */
 598         pull_file_id_24((char *)data->data, &id);
 599         file_id = (unsigned long)IVAL(data->data, 24);
 600
 601         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 602                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 603                    (unsigned int)file_id));
 604
 605         fsp = initial_break_processing(sconn, id, file_id);
 606
 607         if (fsp == NULL) {
 608                 DEBUG(3, ("Got a kernel oplock break message for a file "
 609                           "I don't know about\n"));
 610                 return;
 611         }
 612
 613         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 614                 /* This is ok, kernel oplocks come in completely async */
 615                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 616                           "break reply\n"));
 617                 return;
 618         }
 619
 620         if (sconn->using_smb2) {
 621                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 622         } else {
 623                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 624         }
 625
 626         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 627
 628         add_oplock_timeout_handler(fsp);
 629 }
 630
 631 struct break_to_none_state {
 632         struct smbd_server_connection *sconn;
 633         struct file_id id;
 634 };
 635 static void do_break_to_none(struct tevent_req *req);
 636
 637 /****************************************************************************
 638  This function is called on any file modification or lock request. If a file
 639  is level 2 oplocked then it must tell all other level 2 holders to break to
 640  none.
 641 ****************************************************************************/
 642
 643 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 644                                               enum level2_contention_type type)
 645 {
 646         struct smbd_server_connection *sconn = fsp->conn->sconn;
 647         struct tevent_req *req;
 648         struct break_to_none_state *state;
 649
 650         /*
 651          * If this file is level II oplocked then we need
 652          * to grab the shared memory lock and inform all
 653          * other files with a level II lock that they need
 654          * to flush their read caches. We keep the lock over
 655          * the shared memory area whilst doing this.
 656          */
 657
 658         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 659                 return;
 660
 661         /*
 662          * When we get here we might have a brlock entry locked. Also
 663          * locking the share mode entry would violate the locking
 664          * order. Breaking level2 oplocks to none is asynchronous
 665          * anyway, so we postpone this into an immediate timed event.
 666          */
 667
 668         state = talloc(sconn, struct break_to_none_state);
 669         if (state == NULL) {
 670                 DEBUG(1, ("talloc failed\n"));
 671                 return;
 672         }
 673         state->sconn = sconn;
 674         state->id = fsp->file_id;
 675
 676         req = tevent_wakeup_send(state, sconn->ev_ctx, timeval_set(0, 0));
 677         if (req == NULL) {
 678                 DEBUG(1, ("tevent_wakeup_send failed\n"));
 679                 TALLOC_FREE(state);
 680                 return;
 681         }
 682         tevent_req_set_callback(req, do_break_to_none, state);
 683         return;
 684 }
 685
 686 static void do_break_to_none(struct tevent_req *req)
 687 {
 688         struct break_to_none_state *state = tevent_req_callback_data(
 689                 req, struct break_to_none_state);
 690         struct server_id self = messaging_server_id(state->sconn->msg_ctx);
 691         bool ret;
 692         int i;
 693         struct share_mode_lock *lck;
 694
 695         ret = tevent_wakeup_recv(req);
 696         TALLOC_FREE(req);
 697         if (!ret) {
 698                 DEBUG(1, ("tevent_wakeup_recv failed\n"));
 699                 goto done;
 700         }
 701         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 702         if (lck == NULL) {
 703                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 704                           "share mode entry for file %s.\n",
 705                           file_id_string_tos(&state->id)));
 706                 goto done;
 707         }
 708
 709         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 710                   lck->data->num_share_modes ));
 711
 712         for(i = 0; i < lck->data->num_share_modes; i++) {
 713                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 714                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 715
 716                 if (!is_valid_share_mode_entry(share_entry)) {
 717                         continue;
 718                 }
 719
 720                 /*
 721                  * As there could have been multiple writes waiting at the
 722                  * lock_share_entry gate we may not be the first to
 723                  * enter. Hence the state of the op_types in the share mode
 724                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 725                  * oplock. It will do no harm to re-send break messages to
 726                  * those smbd's that are still waiting their turn to remove
 727                  * their LEVEL_II state, and also no harm to ignore existing
 728                  * NO_OPLOCK states. JRA.
 729                  */
 730
 731                 DEBUG(10,("release_level_2_oplocks_on_change: "
 732                           "share_entry[%i]->op_type == %d\n",
 733                           i, share_entry->op_type ));
 734
 735                 if (share_entry->op_type == NO_OPLOCK) {
 736                         continue;
 737                 }
 738
 739                 /* Paranoia .... */
 740                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 741                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 742                                  "share mode entry %d is an exlusive "
 743                                  "oplock !\n", i ));
 744                         TALLOC_FREE(lck);
 745                         abort();
 746                 }
 747
 748                 share_mode_entry_to_message(msg, share_entry);
 749
 750                 /*
 751                  * Deal with a race condition when breaking level2
 752                  * oplocks. Don't send all the messages and release
 753                  * the lock, this allows someone else to come in and
 754                  * get a level2 lock before any of the messages are
 755                  * processed, and thus miss getting a break message.
 756                  * Ensure at least one entry (the one we're breaking)
 757                  * is processed immediately under the lock and becomes
 758                  * set as NO_OPLOCK to stop any waiter getting a level2.
 759                  * Bugid #5980.
 760                  */
 761
 762                 if (serverid_equal(&self, &share_entry->pid)) {
 763                         struct files_struct *cur_fsp =
 764                                 initial_break_processing(state->sconn,
 765                                         share_entry->id,
 766                                         share_entry->share_file_id);
 767                         wait_before_sending_break();
 768                         if (cur_fsp != NULL) {
 769                                 break_level2_to_none_async(cur_fsp);
 770                         } else {
 771                                 DEBUG(3, ("release_level_2_oplocks_on_change: "
 772                                 "Did not find fsp, ignoring\n"));
 773                         }
 774                 } else {
 775                         messaging_send_buf(state->sconn->msg_ctx,
 776                                         share_entry->pid,
 777                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 778                                         (uint8 *)msg,
 779                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 780                 }
 781         }
 782
 783         /* We let the message receivers handle removing the oplock state
 784            in the share mode lock db. */
 785
 786         TALLOC_FREE(lck);
 787 done:
 788         TALLOC_FREE(state);
 789         return;
 790 }
 791
 792 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 793                                   enum level2_contention_type type)
 794 {
 795         struct smbd_server_connection *sconn = fsp->conn->sconn;
 796         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 797
 798         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 799                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 800                 return;
 801         }
 802
 803         contend_level2_oplocks_begin_default(fsp, type);
 804 }
 805
 806 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 807                                 enum level2_contention_type type)
 808 {
 809         struct smbd_server_connection *sconn = fsp->conn->sconn;
 810         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 811
 812         /* Only kernel oplocks implement this so far */
 813         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 814                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 815         }
 816 }
 817
 818 /****************************************************************************
 819  Linearize a share mode entry struct to an internal oplock break message.
 820 ****************************************************************************/
 821
 822 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 823 {
 824         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 825         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 826         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 827         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 828         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 829         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 830         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 831         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 832         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 833         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 834         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 835         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 836         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 837         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 838 }
 839
 840 /****************************************************************************
 841  De-linearize an internal oplock break message to a share mode entry struct.
 842 ****************************************************************************/
 843
 844 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 845 {
 846         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 847         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 848         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 849         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 850         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 851         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 852         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 853         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 854         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 855         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 856         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 857         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 858         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 859         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 860 }
 861
 862 /****************************************************************************
 863  Setup oplocks for this process.
 864 ****************************************************************************/
 865
 866 bool init_oplocks(struct smbd_server_connection *sconn)
 867 {
 868         DEBUG(3,("init_oplocks: initializing messages.\n"));
 869
 870         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 871                            process_oplock_break_message);
 872         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 873                            process_oplock_async_level2_break_message);
 874         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 875                            process_kernel_oplock_break);
 876         return true;
 877 }
 878
 879 void init_kernel_oplocks(struct smbd_server_connection *sconn)
 880 {
 881         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 882
 883         /* only initialize once */
 884         if (koplocks == NULL) {
 885 #if HAVE_KERNEL_OPLOCKS_IRIX
 886                 koplocks = irix_init_kernel_oplocks(sconn);
 887 #elif HAVE_KERNEL_OPLOCKS_LINUX
 888                 koplocks = linux_init_kernel_oplocks(sconn);
 889 #endif
 890                 sconn->oplocks.kernel_ops = koplocks;
 891         }
 892 }