source3/smbd/oplock.c

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