source3/smbd/oplock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    oplock processing
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 1998 - 2001
   6    Copyright (C) Volker Lendecke 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #define DBGC_CLASS DBGC_LOCKING
  23 #include "includes.h"
  24 #include "smbd/smbd.h"
  25 #include "smbd/globals.h"
  26 #include "messages.h"
  27 #include "../librpc/gen_ndr/open_files.h"
  28
  29 /*
  30  * helper function used by the kernel oplock backends to post the break message
  31  */
  32 void break_kernel_oplock(struct messaging_context *msg_ctx, files_struct *fsp)
  33 {
  34         uint8_t msg[MSG_SMB_KERNEL_BREAK_SIZE];
  35
  36         /* Put the kernel break info into the message. */
  37         push_file_id_24((char *)msg, &fsp->file_id);
  38         SIVAL(msg,24,fsp->fh->gen_id);
  39
  40         /* Don't need to be root here as we're only ever
  41            sending to ourselves. */
  42
  43         messaging_send_buf(msg_ctx, messaging_server_id(msg_ctx),
  44                            MSG_SMB_KERNEL_BREAK,
  45                            msg, MSG_SMB_KERNEL_BREAK_SIZE);
  46 }
  47
  48 /****************************************************************************
  49  Attempt to set an oplock on a file. Succeeds if kernel oplocks are
  50  disabled (just sets flags).
  51 ****************************************************************************/
  52
  53 NTSTATUS set_file_oplock(files_struct *fsp, int oplock_type)
  54 {
  55         struct smbd_server_connection *sconn = fsp->conn->sconn;
  56         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
  57         bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
  58
  59         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
  60                 if (use_kernel &&
  61                     !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
  62                         DEBUG(10, ("Refusing level2 oplock, kernel oplocks "
  63                                    "don't support them\n"));
  64                         return NT_STATUS_NOT_SUPPORTED;
  65                 }
  66         }
  67
  68         if ((fsp->oplock_type != NO_OPLOCK) &&
  69             use_kernel &&
  70             !koplocks->ops->set_oplock(koplocks, fsp, oplock_type))
  71         {
  72                 return map_nt_error_from_unix(errno);
  73         }
  74
  75         fsp->oplock_type = oplock_type;
  76         fsp->sent_oplock_break = NO_BREAK_SENT;
  77         if (oplock_type == LEVEL_II_OPLOCK) {
  78                 sconn->oplocks.level_II_open++;
  79         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
  80                 sconn->oplocks.exclusive_open++;
  81         }
  82
  83         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
  84                     "tv_sec = %x, tv_usec = %x\n",
  85                  fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
  86                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
  87                  (int)fsp->open_time.tv_usec ));
  88
  89         return NT_STATUS_OK;
  90 }
  91
  92 /****************************************************************************
  93  Attempt to release an oplock on a file. Decrements oplock count.
  94 ****************************************************************************/
  95
  96 void release_file_oplock(files_struct *fsp)
  97 {
  98         struct smbd_server_connection *sconn = fsp->conn->sconn;
  99         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 100
 101         if ((fsp->oplock_type != NO_OPLOCK) &&
 102             koplocks) {
 103                 koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
 104         }
 105
 106         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 107                 sconn->oplocks.level_II_open--;
 108         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 109                 sconn->oplocks.exclusive_open--;
 110         }
 111
 112         SMB_ASSERT(sconn->oplocks.exclusive_open>=0);
 113         SMB_ASSERT(sconn->oplocks.level_II_open>=0);
 114
 115         fsp->oplock_type = NO_OPLOCK;
 116         fsp->sent_oplock_break = NO_BREAK_SENT;
 117
 118         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 119         delete_write_cache(fsp);
 120
 121         TALLOC_FREE(fsp->oplock_timeout);
 122 }
 123
 124 /****************************************************************************
 125  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 126 ****************************************************************************/
 127
 128 static void downgrade_file_oplock(files_struct *fsp)
 129 {
 130         struct smbd_server_connection *sconn = fsp->conn->sconn;
 131         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 132
 133         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 134                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 135                 return;
 136         }
 137
 138         if (koplocks) {
 139                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 140         }
 141         fsp->oplock_type = LEVEL_II_OPLOCK;
 142         sconn->oplocks.exclusive_open--;
 143         sconn->oplocks.level_II_open++;
 144         fsp->sent_oplock_break = NO_BREAK_SENT;
 145
 146         TALLOC_FREE(fsp->oplock_timeout);
 147 }
 148
 149 /****************************************************************************
 150  Remove a file oplock. Copes with level II and exclusive.
 151  Locks then unlocks the share mode lock. Client can decide to go directly
 152  to none even if a "break-to-level II" was sent.
 153 ****************************************************************************/
 154
 155 bool remove_oplock(files_struct *fsp)
 156 {
 157         bool ret;
 158         struct share_mode_lock *lck;
 159
 160         /* Remove the oplock flag from the sharemode. */
 161         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 162         if (lck == NULL) {
 163                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 164                          "file %s\n", fsp_str_dbg(fsp)));
 165                 return False;
 166         }
 167
 168         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 169
 170                 /*
 171                  * If we're the only LEVEL_II holder, we have to remove the
 172                  * have_read_oplocks from the brlock entry
 173                  */
 174
 175                 struct share_mode_data *data = lck->data;
 176                 uint32_t i, num_level2;
 177
 178                 num_level2 = 0;
 179                 for (i=0; i<data->num_share_modes; i++) {
 180                         if (data->share_modes[i].op_type == LEVEL_II_OPLOCK) {
 181                                 num_level2 += 1;
 182                         }
 183                         if (num_level2 > 1) {
 184                                 /*
 185                                  * No need to count them all...
 186                                  */
 187                                 break;
 188                         }
 189                 }
 190
 191                 if (num_level2 == 1) {
 192                         /*
 193                          * That's only us. We are dropping that level2 oplock,
 194                          * so remove the brlock flag.
 195                          */
 196                         struct byte_range_lock *brl;
 197
 198                         brl = brl_get_locks(talloc_tos(), fsp);
 199                         if (brl) {
 200                                 brl_set_have_read_oplocks(brl, false);
 201                                 TALLOC_FREE(brl);
 202                         }
 203                 }
 204         }
 205
 206         ret = remove_share_oplock(lck, fsp);
 207         if (!ret) {
 208                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 209                          "file %s, %s, %s\n",
 210                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 211                          file_id_string_tos(&fsp->file_id)));
 212         }
 213         release_file_oplock(fsp);
 214         TALLOC_FREE(lck);
 215         return ret;
 216 }
 217
 218 /*
 219  * Deal with a reply when a break-to-level II was sent.
 220  */
 221 bool downgrade_oplock(files_struct *fsp)
 222 {
 223         bool ret;
 224         struct share_mode_lock *lck;
 225         struct byte_range_lock *brl;
 226
 227         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 228         if (lck == NULL) {
 229                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 230                          "file %s\n", fsp_str_dbg(fsp)));
 231                 return False;
 232         }
 233         ret = downgrade_share_oplock(lck, fsp);
 234         if (!ret) {
 235                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 236                          "for file %s, %s, file_id %s\n",
 237                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 238                          file_id_string_tos(&fsp->file_id)));
 239         }
 240
 241         downgrade_file_oplock(fsp);
 242
 243         brl = brl_get_locks(talloc_tos(), fsp);
 244         if (brl != NULL) {
 245                 brl_set_have_read_oplocks(brl, true);
 246                 TALLOC_FREE(brl);
 247         }
 248
 249         TALLOC_FREE(lck);
 250         return ret;
 251 }
 252
 253 /****************************************************************************
 254  Set up an oplock break message.
 255 ****************************************************************************/
 256
 257 #define SMB1_BREAK_MESSAGE_LENGTH (smb_size + 8*2)
 258
 259 static void new_break_message_smb1(files_struct *fsp, int cmd,
 260                                    char result[SMB1_BREAK_MESSAGE_LENGTH])
 261 {
 262         memset(result,'\0',smb_size);
 263         srv_set_message(result,8,0,true);
 264         SCVAL(result,smb_com,SMBlockingX);
 265         SSVAL(result,smb_tid,fsp->conn->cnum);
 266         SSVAL(result,smb_pid,0xFFFF);
 267         SSVAL(result,smb_uid,0);
 268         SSVAL(result,smb_mid,0xFFFF);
 269         SCVAL(result,smb_vwv0,0xFF);
 270         SSVAL(result,smb_vwv2,fsp->fnum);
 271         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 272         SCVAL(result,smb_vwv3+1,cmd);
 273 }
 274
 275 /****************************************************************************
 276  Function to do the waiting before sending a local break.
 277 ****************************************************************************/
 278
 279 static void wait_before_sending_break(void)
 280 {
 281         long wait_time = (long)lp_oplock_break_wait_time();
 282
 283         if (wait_time) {
 284                 smb_msleep(wait_time);
 285         }
 286 }
 287
 288 /****************************************************************************
 289  Ensure that we have a valid oplock.
 290 ****************************************************************************/
 291
 292 static files_struct *initial_break_processing(
 293         struct smbd_server_connection *sconn, struct file_id id,
 294         unsigned long file_id)
 295 {
 296         files_struct *fsp = NULL;
 297
 298         DEBUG(3, ("initial_break_processing: called for %s/%u\n"
 299                   "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 300                   file_id_string_tos(&id), (int)file_id,
 301                   sconn->oplocks.exclusive_open,
 302                   sconn->oplocks.level_II_open));
 303
 304         /*
 305          * We need to search the file open table for the
 306          * entry containing this dev and inode, and ensure
 307          * we have an oplock on it.
 308          */
 309
 310         fsp = file_find_dif(sconn, id, file_id);
 311
 312         if(fsp == NULL) {
 313                 /* The file could have been closed in the meantime - return success. */
 314                 DEBUG(3, ("initial_break_processing: cannot find open file "
 315                           "with file_id %s gen_id = %lu, allowing break to "
 316                           "succeed.\n", file_id_string_tos(&id), file_id));
 317                 return NULL;
 318         }
 319
 320         /* Ensure we have an oplock on the file */
 321
 322         /*
 323          * There is a potential race condition in that an oplock could
 324          * have been broken due to another udp request, and yet there are
 325          * still oplock break messages being sent in the udp message
 326          * queue for this file. So return true if we don't have an oplock,
 327          * as we may have just freed it.
 328          */
 329
 330         if(fsp->oplock_type == NO_OPLOCK) {
 331                 DEBUG(3, ("initial_break_processing: file %s (file_id = %s "
 332                           "gen_id = %lu) has no oplock. Allowing break to "
 333                           "succeed regardless.\n", fsp_str_dbg(fsp),
 334                           file_id_string_tos(&id), fsp->fh->gen_id));
 335                 return NULL;
 336         }
 337
 338         return fsp;
 339 }
 340
 341 static void oplock_timeout_handler(struct tevent_context *ctx,
 342                                    struct tevent_timer *te,
 343                                    struct timeval now,
 344                                    void *private_data)
 345 {
 346         files_struct *fsp = (files_struct *)private_data;
 347
 348         SMB_ASSERT(fsp->sent_oplock_break != NO_BREAK_SENT);
 349
 350         /* Remove the timed event handler. */
 351         TALLOC_FREE(fsp->oplock_timeout);
 352         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 353                   fsp_str_dbg(fsp)));
 354         remove_oplock(fsp);
 355 }
 356
 357 /*******************************************************************
 358  Add a timeout handler waiting for the client reply.
 359 *******************************************************************/
 360
 361 static void add_oplock_timeout_handler(files_struct *fsp)
 362 {
 363         struct smbd_server_connection *sconn = fsp->conn->sconn;
 364         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 365
 366         /*
 367          * If kernel oplocks already notifies smbds when an oplock break times
 368          * out, just return.
 369          */
 370         if (koplocks &&
 371             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 372                 return;
 373         }
 374
 375         if (fsp->oplock_timeout != NULL) {
 376                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 377                           "around\n"));
 378         }
 379
 380         fsp->oplock_timeout =
 381                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 382                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 383                                  oplock_timeout_handler, fsp);
 384
 385         if (fsp->oplock_timeout == NULL) {
 386                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 387         }
 388 }
 389
 390 static void send_break_message_smb1(files_struct *fsp, int level)
 391 {
 392         char break_msg[SMB1_BREAK_MESSAGE_LENGTH];
 393
 394         new_break_message_smb1(fsp, level, break_msg);
 395
 396         show_msg(break_msg);
 397         if (!srv_send_smb(fsp->conn->sconn,
 398                         break_msg, false, 0,
 399                         IS_CONN_ENCRYPTED(fsp->conn),
 400                         NULL)) {
 401                 exit_server_cleanly("send_break_message_smb1: "
 402                         "srv_send_smb failed.");
 403         }
 404 }
 405
 406 static void break_level2_to_none_async(files_struct *fsp)
 407 {
 408         struct smbd_server_connection *sconn = fsp->conn->sconn;
 409
 410         if (fsp->oplock_type == NO_OPLOCK) {
 411                 /* We already got a "break to none" message and we've handled
 412                  * it.  just ignore. */
 413                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 414                           "broken to none, ignoring.\n"));
 415                 return;
 416         }
 417
 418         /* Ensure we're really at level2 state. */
 419         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 420
 421         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 422                   "to none message for %s, file %s\n", fsp_fnum_dbg(fsp),
 423                   fsp_str_dbg(fsp)));
 424
 425         /* Now send a break to none message to our client. */
 426         if (sconn->using_smb2) {
 427                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 428         } else {
 429                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 430         }
 431
 432         /* Async level2 request, don't send a reply, just remove the oplock. */
 433         remove_oplock(fsp);
 434 }
 435
 436 /*******************************************************************
 437  This handles the case of a write triggering a break to none
 438  message on a level2 oplock.
 439  When we get this message we may be in any of three states :
 440  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 441  the client for LEVEL2.
 442 *******************************************************************/
 443
 444 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 445                                                       void *private_data,
 446                                                       uint32_t msg_type,
 447                                                       struct server_id src,
 448                                                       DATA_BLOB *data)
 449 {
 450         struct share_mode_entry msg;
 451         files_struct *fsp;
 452         struct smbd_server_connection *sconn =
 453                 talloc_get_type_abort(private_data,
 454                 struct smbd_server_connection);
 455
 456         if (data->data == NULL) {
 457                 DEBUG(0, ("Got NULL buffer\n"));
 458                 return;
 459         }
 460
 461         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 462                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 463                 return;
 464         }
 465
 466         /* De-linearize incoming message. */
 467         message_to_share_mode_entry(&msg, (char *)data->data);
 468
 469         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 470                    "%s/%llu\n", server_id_str(talloc_tos(), &src),
 471                    file_id_string_tos(&msg.id),
 472                    (unsigned long long)msg.share_file_id));
 473
 474         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 475
 476         if (fsp == NULL) {
 477                 /* We hit a race here. Break messages are sent, and before we
 478                  * get to process this message, we have closed the file.
 479                  * No need to reply as this is an async message. */
 480                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 481                 return;
 482         }
 483
 484         break_level2_to_none_async(fsp);
 485 }
 486
 487 /*******************************************************************
 488  This handles the generic oplock break message from another smbd.
 489 *******************************************************************/
 490
 491 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 492                                          void *private_data,
 493                                          uint32_t msg_type,
 494                                          struct server_id src,
 495                                          DATA_BLOB *data)
 496 {
 497         struct share_mode_entry msg;
 498         files_struct *fsp;
 499         bool break_to_level2 = False;
 500         bool use_kernel;
 501         struct smbd_server_connection *sconn =
 502                 talloc_get_type_abort(private_data,
 503                 struct smbd_server_connection);
 504         struct server_id self = messaging_server_id(sconn->msg_ctx);
 505         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 506
 507         if (data->data == NULL) {
 508                 DEBUG(0, ("Got NULL buffer\n"));
 509                 return;
 510         }
 511
 512         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 513                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 514                 return;
 515         }
 516
 517         /* De-linearize incoming message. */
 518         message_to_share_mode_entry(&msg, (char *)data->data);
 519
 520         DEBUG(10, ("Got oplock break message from pid %s: %s/%llu\n",
 521                    server_id_str(talloc_tos(), &src),
 522                    file_id_string_tos(&msg.id),
 523                    (unsigned long long)msg.share_file_id));
 524
 525         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 526
 527         if (fsp == NULL) {
 528                 /* We hit a race here. Break messages are sent, and before we
 529                  * get to process this message, we have closed the file. */
 530                 DEBUG(3, ("Did not find fsp\n"));
 531                 return;
 532         }
 533
 534         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 535                 /*
 536                  * Nothing to do anymore
 537                  */
 538                 return;
 539         }
 540
 541         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 542             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 543                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 544                           file_id_string_tos(&fsp->file_id),
 545                           fsp_str_dbg(fsp)));
 546                 return;
 547         }
 548
 549         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 550
 551         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 552             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 553             lp_level2_oplocks(SNUM(fsp->conn))) {
 554                 break_to_level2 = True;
 555         }
 556
 557         /* Need to wait before sending a break
 558            message if we sent ourselves this message. */
 559         if (serverid_equal(&self, &src)) {
 560                 wait_before_sending_break();
 561         }
 562
 563         if (sconn->using_smb2) {
 564                 send_break_message_smb2(fsp, break_to_level2 ?
 565                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 566         } else {
 567                 send_break_message_smb1(fsp, break_to_level2 ?
 568                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 569         }
 570
 571         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 572
 573         add_oplock_timeout_handler(fsp);
 574 }
 575
 576 /*******************************************************************
 577  This handles the kernel oplock break message.
 578 *******************************************************************/
 579
 580 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 581                                         void *private_data,
 582                                         uint32_t msg_type,
 583                                         struct server_id src,
 584                                         DATA_BLOB *data)
 585 {
 586         struct file_id id;
 587         unsigned long file_id;
 588         files_struct *fsp;
 589         struct smbd_server_connection *sconn =
 590                 talloc_get_type_abort(private_data,
 591                 struct smbd_server_connection);
 592
 593         if (data->data == NULL) {
 594                 DEBUG(0, ("Got NULL buffer\n"));
 595                 return;
 596         }
 597
 598         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 599                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 600                 return;
 601         }
 602
 603         /* Pull the data from the message. */
 604         pull_file_id_24((char *)data->data, &id);
 605         file_id = (unsigned long)IVAL(data->data, 24);
 606
 607         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 608                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 609                    (unsigned int)file_id));
 610
 611         fsp = initial_break_processing(sconn, id, file_id);
 612
 613         if (fsp == NULL) {
 614                 DEBUG(3, ("Got a kernel oplock break message for a file "
 615                           "I don't know about\n"));
 616                 return;
 617         }
 618
 619         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 620                 /* This is ok, kernel oplocks come in completely async */
 621                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 622                           "break reply\n"));
 623                 return;
 624         }
 625
 626         if (sconn->using_smb2) {
 627                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 628         } else {
 629                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 630         }
 631
 632         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 633
 634         add_oplock_timeout_handler(fsp);
 635 }
 636
 637 struct break_to_none_state {
 638         struct smbd_server_connection *sconn;
 639         struct file_id id;
 640 };
 641 static void do_break_to_none(struct tevent_context *ctx,
 642                              struct tevent_immediate *im,
 643                              void *private_data);
 644
 645 /****************************************************************************
 646  This function is called on any file modification or lock request. If a file
 647  is level 2 oplocked then it must tell all other level 2 holders to break to
 648  none.
 649 ****************************************************************************/
 650
 651 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 652                                               enum level2_contention_type type)
 653 {
 654         struct smbd_server_connection *sconn = fsp->conn->sconn;
 655         struct tevent_immediate *im;
 656         struct break_to_none_state *state;
 657         struct byte_range_lock *brl;
 658
 659         /*
 660          * If this file is level II oplocked then we need
 661          * to grab the shared memory lock and inform all
 662          * other files with a level II lock that they need
 663          * to flush their read caches. We keep the lock over
 664          * the shared memory area whilst doing this.
 665          */
 666
 667         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 668                 /*
 669                  * There can't be any level2 oplocks, we're alone.
 670                  */
 671                 return;
 672         }
 673
 674         brl = brl_get_locks_readonly(fsp);
 675         if ((brl != NULL) && !brl_have_read_oplocks(brl)) {
 676                 DEBUG(10, ("No read oplocks around\n"));
 677                 return;
 678         }
 679
 680         /*
 681          * When we get here we might have a brlock entry locked. Also
 682          * locking the share mode entry would violate the locking
 683          * order. Breaking level2 oplocks to none is asynchronous
 684          * anyway, so we postpone this into an immediate event.
 685          */
 686
 687         state = talloc(sconn, struct break_to_none_state);
 688         if (state == NULL) {
 689                 DEBUG(1, ("talloc failed\n"));
 690                 return;
 691         }
 692         state->sconn = sconn;
 693         state->id = fsp->file_id;
 694
 695         im = tevent_create_immediate(state);
 696         if (im == NULL) {
 697                 DEBUG(1, ("tevent_create_immediate failed\n"));
 698                 TALLOC_FREE(state);
 699                 return;
 700         }
 701         tevent_schedule_immediate(im, sconn->ev_ctx, do_break_to_none, state);
 702 }
 703
 704 static void do_break_to_none(struct tevent_context *ctx,
 705                              struct tevent_immediate *im,
 706                              void *private_data)
 707 {
 708         struct break_to_none_state *state = talloc_get_type_abort(
 709                 private_data, struct break_to_none_state);
 710         struct server_id self = messaging_server_id(state->sconn->msg_ctx);
 711         int i;
 712         struct share_mode_lock *lck;
 713
 714         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 715         if (lck == NULL) {
 716                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 717                           "share mode entry for file %s.\n",
 718                           file_id_string_tos(&state->id)));
 719                 goto done;
 720         }
 721
 722         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 723                   lck->data->num_share_modes ));
 724
 725         for(i = 0; i < lck->data->num_share_modes; i++) {
 726                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 727                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 728
 729                 if (!is_valid_share_mode_entry(share_entry)) {
 730                         continue;
 731                 }
 732
 733                 /*
 734                  * As there could have been multiple writes waiting at the
 735                  * lock_share_entry gate we may not be the first to
 736                  * enter. Hence the state of the op_types in the share mode
 737                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 738                  * oplock. It will do no harm to re-send break messages to
 739                  * those smbd's that are still waiting their turn to remove
 740                  * their LEVEL_II state, and also no harm to ignore existing
 741                  * NO_OPLOCK states. JRA.
 742                  */
 743
 744                 DEBUG(10,("release_level_2_oplocks_on_change: "
 745                           "share_entry[%i]->op_type == %d\n",
 746                           i, share_entry->op_type ));
 747
 748                 if (share_entry->op_type == NO_OPLOCK) {
 749                         continue;
 750                 }
 751
 752                 /* Paranoia .... */
 753                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 754                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 755                                  "share mode entry %d is an exlusive "
 756                                  "oplock !\n", i ));
 757                         TALLOC_FREE(lck);
 758                         abort();
 759                 }
 760
 761                 share_mode_entry_to_message(msg, share_entry);
 762
 763                 /*
 764                  * Deal with a race condition when breaking level2
 765                  * oplocks. Don't send all the messages and release
 766                  * the lock, this allows someone else to come in and
 767                  * get a level2 lock before any of the messages are
 768                  * processed, and thus miss getting a break message.
 769                  * Ensure at least one entry (the one we're breaking)
 770                  * is processed immediately under the lock and becomes
 771                  * set as NO_OPLOCK to stop any waiter getting a level2.
 772                  * Bugid #5980.
 773                  */
 774
 775                 if (serverid_equal(&self, &share_entry->pid)) {
 776                         struct files_struct *cur_fsp =
 777                                 initial_break_processing(state->sconn,
 778                                         share_entry->id,
 779                                         share_entry->share_file_id);
 780                         if (cur_fsp != NULL) {
 781                                 wait_before_sending_break();
 782                                 break_level2_to_none_async(cur_fsp);
 783                         } else {
 784                                 DEBUG(3, ("release_level_2_oplocks_on_change: "
 785                                 "Did not find fsp, ignoring\n"));
 786                         }
 787                 } else {
 788                         messaging_send_buf(state->sconn->msg_ctx,
 789                                         share_entry->pid,
 790                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 791                                         (uint8 *)msg, sizeof(msg));
 792                 }
 793         }
 794
 795         /* We let the message receivers handle removing the oplock state
 796            in the share mode lock db. */
 797
 798         TALLOC_FREE(lck);
 799 done:
 800         TALLOC_FREE(state);
 801         return;
 802 }
 803
 804 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 805                                   enum level2_contention_type type)
 806 {
 807         struct smbd_server_connection *sconn = fsp->conn->sconn;
 808         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 809
 810         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 811                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 812                 return;
 813         }
 814
 815         contend_level2_oplocks_begin_default(fsp, type);
 816 }
 817
 818 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 819                                 enum level2_contention_type type)
 820 {
 821         struct smbd_server_connection *sconn = fsp->conn->sconn;
 822         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 823
 824         /* Only kernel oplocks implement this so far */
 825         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 826                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 827         }
 828 }
 829
 830 /****************************************************************************
 831  Linearize a share mode entry struct to an internal oplock break message.
 832 ****************************************************************************/
 833
 834 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 835 {
 836         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 837         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 838         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 839         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 840         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 841         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 842         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 843         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 844         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 845         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 846         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 847         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 848         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 849         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 850 }
 851
 852 /****************************************************************************
 853  De-linearize an internal oplock break message to a share mode entry struct.
 854 ****************************************************************************/
 855
 856 void message_to_share_mode_entry(struct share_mode_entry *e, const char *msg)
 857 {
 858         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 859         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 860         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 861         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 862         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 863         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 864         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 865         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 866         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 867         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 868         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 869         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 870         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 871         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 872 }
 873
 874 /****************************************************************************
 875  Setup oplocks for this process.
 876 ****************************************************************************/
 877
 878 bool init_oplocks(struct smbd_server_connection *sconn)
 879 {
 880         DEBUG(3,("init_oplocks: initializing messages.\n"));
 881
 882         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 883                            process_oplock_break_message);
 884         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 885                            process_oplock_async_level2_break_message);
 886         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 887                            process_kernel_oplock_break);
 888         return true;
 889 }
 890
 891 void init_kernel_oplocks(struct smbd_server_connection *sconn)
 892 {
 893         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 894
 895         /* only initialize once */
 896         if (koplocks == NULL) {
 897 #if HAVE_KERNEL_OPLOCKS_IRIX
 898                 koplocks = irix_init_kernel_oplocks(sconn);
 899 #elif HAVE_KERNEL_OPLOCKS_LINUX
 900                 koplocks = linux_init_kernel_oplocks(sconn);
 901 #endif
 902                 sconn->oplocks.kernel_ops = koplocks;
 903         }
 904 }