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 bool set_file_oplock(files_struct *fsp, int oplock_type)
  55 {
  56         struct smbd_server_connection *sconn = fsp->conn->sconn;
  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 false;
  65                 }
  66         }
  67
  68         if ((fsp->oplock_type != NO_OPLOCK) &&
  69             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
  70             use_kernel &&
  71             !koplocks->ops->set_oplock(koplocks, fsp, oplock_type)) {
  72                 return False;
  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 True;
  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
 100         if ((fsp->oplock_type != NO_OPLOCK) &&
 101             (fsp->oplock_type != FAKE_LEVEL_II_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         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 116                 /* This doesn't matter for close. */
 117                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 118         } else {
 119                 fsp->oplock_type = NO_OPLOCK;
 120         }
 121         fsp->sent_oplock_break = NO_BREAK_SENT;
 122
 123         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 124         delete_write_cache(fsp);
 125
 126         TALLOC_FREE(fsp->oplock_timeout);
 127 }
 128
 129 /****************************************************************************
 130  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 131 ****************************************************************************/
 132
 133 static void downgrade_file_oplock(files_struct *fsp)
 134 {
 135         struct smbd_server_connection *sconn = fsp->conn->sconn;
 136
 137         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 138                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 139                 return;
 140         }
 141
 142         if (koplocks) {
 143                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 144         }
 145         fsp->oplock_type = LEVEL_II_OPLOCK;
 146         sconn->oplocks.exclusive_open--;
 147         sconn->oplocks.level_II_open++;
 148         fsp->sent_oplock_break = NO_BREAK_SENT;
 149 }
 150
 151 /****************************************************************************
 152  Remove a file oplock. Copes with level II and exclusive.
 153  Locks then unlocks the share mode lock. Client can decide to go directly
 154  to none even if a "break-to-level II" was sent.
 155 ****************************************************************************/
 156
 157 bool remove_oplock(files_struct *fsp)
 158 {
 159         bool ret;
 160         struct share_mode_lock *lck;
 161
 162         /* Remove the oplock flag from the sharemode. */
 163         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 164         if (lck == NULL) {
 165                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 166                          "file %s\n", fsp_str_dbg(fsp)));
 167                 return False;
 168         }
 169         ret = remove_share_oplock(lck, fsp);
 170         if (!ret) {
 171                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 172                          "file %s fnum %d, %s\n",
 173                          fsp_str_dbg(fsp), fsp->fnum,
 174                          file_id_string_tos(&fsp->file_id)));
 175         }
 176         release_file_oplock(fsp);
 177         TALLOC_FREE(lck);
 178         return ret;
 179 }
 180
 181 /*
 182  * Deal with a reply when a break-to-level II was sent.
 183  */
 184 bool downgrade_oplock(files_struct *fsp)
 185 {
 186         bool ret;
 187         struct share_mode_lock *lck;
 188
 189         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 190         if (lck == NULL) {
 191                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 192                          "file %s\n", fsp_str_dbg(fsp)));
 193                 return False;
 194         }
 195         ret = downgrade_share_oplock(lck, fsp);
 196         if (!ret) {
 197                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 198                          "for file %s fnum %d, file_id %s\n",
 199                          fsp_str_dbg(fsp), fsp->fnum,
 200                          file_id_string_tos(&fsp->file_id)));
 201         }
 202
 203         downgrade_file_oplock(fsp);
 204         TALLOC_FREE(lck);
 205         return ret;
 206 }
 207
 208 /*
 209  * Some kernel oplock implementations handle the notification themselves.
 210  */
 211 bool should_notify_deferred_opens(struct smbd_server_connection *sconn)
 212 {
 213         return !(koplocks &&
 214                 (koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
 215 }
 216
 217 /****************************************************************************
 218  Set up an oplock break message.
 219 ****************************************************************************/
 220
 221 static char *new_break_message_smb1(TALLOC_CTX *mem_ctx,
 222                                    files_struct *fsp, int cmd)
 223 {
 224         char *result = talloc_array(mem_ctx, char, smb_size + 8*2 + 0);
 225
 226         if (result == NULL) {
 227                 DEBUG(0, ("talloc failed\n"));
 228                 return NULL;
 229         }
 230
 231         memset(result,'\0',smb_size);
 232         srv_set_message(result,8,0,true);
 233         SCVAL(result,smb_com,SMBlockingX);
 234         SSVAL(result,smb_tid,fsp->conn->cnum);
 235         SSVAL(result,smb_pid,0xFFFF);
 236         SSVAL(result,smb_uid,0);
 237         SSVAL(result,smb_mid,0xFFFF);
 238         SCVAL(result,smb_vwv0,0xFF);
 239         SSVAL(result,smb_vwv2,fsp->fnum);
 240         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 241         SCVAL(result,smb_vwv3+1,cmd);
 242         return result;
 243 }
 244
 245 /****************************************************************************
 246  Function to do the waiting before sending a local break.
 247 ****************************************************************************/
 248
 249 static void wait_before_sending_break(void)
 250 {
 251         long wait_time = (long)lp_oplock_break_wait_time();
 252
 253         if (wait_time) {
 254                 smb_msleep(wait_time);
 255         }
 256 }
 257
 258 /****************************************************************************
 259  Ensure that we have a valid oplock.
 260 ****************************************************************************/
 261
 262 static files_struct *initial_break_processing(
 263         struct smbd_server_connection *sconn, struct file_id id,
 264         unsigned long file_id)
 265 {
 266         files_struct *fsp = NULL;
 267
 268         if( DEBUGLVL( 3 ) ) {
 269                 dbgtext( "initial_break_processing: called for %s/%u\n",
 270                          file_id_string_tos(&id), (int)file_id);
 271                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 272                         sconn->oplocks.exclusive_open,
 273                         sconn->oplocks.level_II_open);
 274         }
 275
 276         /*
 277          * We need to search the file open table for the
 278          * entry containing this dev and inode, and ensure
 279          * we have an oplock on it.
 280          */
 281
 282         fsp = file_find_dif(sconn, id, file_id);
 283
 284         if(fsp == NULL) {
 285                 /* The file could have been closed in the meantime - return success. */
 286                 if( DEBUGLVL( 3 ) ) {
 287                         dbgtext( "initial_break_processing: cannot find open file with " );
 288                         dbgtext( "file_id %s gen_id = %lu", file_id_string_tos(&id), file_id);
 289                         dbgtext( "allowing break to succeed.\n" );
 290                 }
 291                 return NULL;
 292         }
 293
 294         /* Ensure we have an oplock on the file */
 295
 296         /*
 297          * There is a potential race condition in that an oplock could
 298          * have been broken due to another udp request, and yet there are
 299          * still oplock break messages being sent in the udp message
 300          * queue for this file. So return true if we don't have an oplock,
 301          * as we may have just freed it.
 302          */
 303
 304         if(fsp->oplock_type == NO_OPLOCK) {
 305                 if( DEBUGLVL( 3 ) ) {
 306                         dbgtext( "initial_break_processing: file %s ",
 307                                  fsp_str_dbg(fsp));
 308                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 309                                  file_id_string_tos(&id), fsp->fh->gen_id );
 310                         dbgtext( "Allowing break to succeed regardless.\n" );
 311                 }
 312                 return NULL;
 313         }
 314
 315         return fsp;
 316 }
 317
 318 static void oplock_timeout_handler(struct event_context *ctx,
 319                                    struct timed_event *te,
 320                                    struct timeval now,
 321                                    void *private_data)
 322 {
 323         files_struct *fsp = (files_struct *)private_data;
 324
 325         /* Remove the timed event handler. */
 326         TALLOC_FREE(fsp->oplock_timeout);
 327         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 328                   fsp_str_dbg(fsp)));
 329         remove_oplock(fsp);
 330         reply_to_oplock_break_requests(fsp);
 331 }
 332
 333 /*******************************************************************
 334  Add a timeout handler waiting for the client reply.
 335 *******************************************************************/
 336
 337 static void add_oplock_timeout_handler(files_struct *fsp)
 338 {
 339         /*
 340          * If kernel oplocks already notifies smbds when an oplock break times
 341          * out, just return.
 342          */
 343         if (koplocks &&
 344             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 345                 return;
 346         }
 347
 348         if (fsp->oplock_timeout != NULL) {
 349                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 350                           "around\n"));
 351         }
 352
 353         fsp->oplock_timeout =
 354                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 355                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 356                                  oplock_timeout_handler, fsp);
 357
 358         if (fsp->oplock_timeout == NULL) {
 359                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 360         }
 361 }
 362
 363 static void send_break_message_smb1(files_struct *fsp, int level)
 364 {
 365         char *break_msg = new_break_message_smb1(talloc_tos(),
 366                                         fsp,
 367                                         level);
 368         if (break_msg == NULL) {
 369                 exit_server("Could not talloc break_msg\n");
 370         }
 371
 372         show_msg(break_msg);
 373         if (!srv_send_smb(fsp->conn->sconn,
 374                         break_msg, false, 0,
 375                         IS_CONN_ENCRYPTED(fsp->conn),
 376                         NULL)) {
 377                 exit_server_cleanly("send_break_message_smb1: "
 378                         "srv_send_smb failed.");
 379         }
 380
 381         TALLOC_FREE(break_msg);
 382 }
 383
 384 void break_level2_to_none_async(files_struct *fsp)
 385 {
 386         struct smbd_server_connection *sconn = fsp->conn->sconn;
 387
 388         if (fsp->oplock_type == NO_OPLOCK) {
 389                 /* We already got a "break to none" message and we've handled
 390                  * it.  just ignore. */
 391                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 392                           "broken to none, ignoring.\n"));
 393                 return;
 394         }
 395
 396         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 397                 /* Don't tell the client, just downgrade. */
 398                 DEBUG(3, ("process_oplock_async_level2_break_message: "
 399                           "downgrading fake level 2 oplock.\n"));
 400                 remove_oplock(fsp);
 401                 return;
 402         }
 403
 404         /* Ensure we're really at level2 state. */
 405         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 406
 407         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 408                   "to none message for fid %d, file %s\n", fsp->fnum,
 409                   fsp_str_dbg(fsp)));
 410
 411         /* Now send a break to none message to our client. */
 412         if (sconn->using_smb2) {
 413                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 414         } else {
 415                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 416         }
 417
 418         /* Async level2 request, don't send a reply, just remove the oplock. */
 419         remove_oplock(fsp);
 420 }
 421
 422 /*******************************************************************
 423  This handles the case of a write triggering a break to none
 424  message on a level2 oplock.
 425  When we get this message we may be in any of three states :
 426  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 427  the client for LEVEL2.
 428 *******************************************************************/
 429
 430 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 431                                                       void *private_data,
 432                                                       uint32_t msg_type,
 433                                                       struct server_id src,
 434                                                       DATA_BLOB *data)
 435 {
 436         struct share_mode_entry msg;
 437         files_struct *fsp;
 438         struct smbd_server_connection *sconn =
 439                 talloc_get_type_abort(private_data,
 440                 struct smbd_server_connection);
 441
 442         if (data->data == NULL) {
 443                 DEBUG(0, ("Got NULL buffer\n"));
 444                 return;
 445         }
 446
 447         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 448                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 449                 return;
 450         }
 451
 452         /* De-linearize incoming message. */
 453         message_to_share_mode_entry(&msg, (char *)data->data);
 454
 455         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 456                    "%s/%llu\n", server_id_str(talloc_tos(), &src),
 457                    file_id_string_tos(&msg.id),
 458                    (unsigned long long)msg.share_file_id));
 459
 460         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 461
 462         if (fsp == NULL) {
 463                 /* We hit a race here. Break messages are sent, and before we
 464                  * get to process this message, we have closed the file.
 465                  * No need to reply as this is an async message. */
 466                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 467                 return;
 468         }
 469
 470         break_level2_to_none_async(fsp);
 471 }
 472
 473 /*******************************************************************
 474  This handles the generic oplock break message from another smbd.
 475 *******************************************************************/
 476
 477 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 478                                          void *private_data,
 479                                          uint32_t msg_type,
 480                                          struct server_id src,
 481                                          DATA_BLOB *data)
 482 {
 483         struct share_mode_entry msg;
 484         files_struct *fsp;
 485         bool break_to_level2 = False;
 486         bool use_kernel;
 487         struct smbd_server_connection *sconn =
 488                 talloc_get_type_abort(private_data,
 489                 struct smbd_server_connection);
 490
 491         if (data->data == NULL) {
 492                 DEBUG(0, ("Got NULL buffer\n"));
 493                 return;
 494         }
 495
 496         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 497                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 498                 return;
 499         }
 500
 501         /* De-linearize incoming message. */
 502         message_to_share_mode_entry(&msg, (char *)data->data);
 503
 504         DEBUG(10, ("Got oplock break message from pid %s: %s/%llu\n",
 505                    server_id_str(talloc_tos(), &src),
 506                    file_id_string_tos(&msg.id),
 507                    (unsigned long long)msg.share_file_id));
 508
 509         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 510
 511         if (fsp == NULL) {
 512                 /* We hit a race here. Break messages are sent, and before we
 513                  * get to process this message, we have closed the file. Reply
 514                  * with 'ok, oplock broken' */
 515                 DEBUG(3, ("Did not find fsp\n"));
 516
 517                 /* We just send the same message back. */
 518                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 519                                    (uint8 *)data->data,
 520                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 521                 return;
 522         }
 523
 524         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 525                 /* Remember we have to inform the requesting PID when the
 526                  * client replies */
 527                 msg.pid = src;
 528                 ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 529                              &fsp->pending_break_messages,
 530                              &fsp->num_pending_break_messages);
 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                 /* We just send the same message back. */
 540                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 541                                    (uint8 *)data->data,
 542                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 543                 return;
 544         }
 545
 546         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 547
 548         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 549             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 550             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 551             lp_level2_oplocks(SNUM(fsp->conn))) {
 552                 break_to_level2 = True;
 553         }
 554
 555         /* Need to wait before sending a break
 556            message if we sent ourselves this message. */
 557         if (procid_is_me(&src)) {
 558                 wait_before_sending_break();
 559         }
 560
 561         if (sconn->using_smb2) {
 562                 send_break_message_smb2(fsp, break_to_level2 ?
 563                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 564         } else {
 565                 send_break_message_smb1(fsp, break_to_level2 ?
 566                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 567         }
 568
 569         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 570
 571         msg.pid = src;
 572         ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 573                      &fsp->pending_break_messages,
 574                      &fsp->num_pending_break_messages);
 575
 576         add_oplock_timeout_handler(fsp);
 577 }
 578
 579 /*******************************************************************
 580  This handles the kernel oplock break message.
 581 *******************************************************************/
 582
 583 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 584                                         void *private_data,
 585                                         uint32_t msg_type,
 586                                         struct server_id src,
 587                                         DATA_BLOB *data)
 588 {
 589         struct file_id id;
 590         unsigned long file_id;
 591         files_struct *fsp;
 592         struct smbd_server_connection *sconn =
 593                 talloc_get_type_abort(private_data,
 594                 struct smbd_server_connection);
 595
 596         if (data->data == NULL) {
 597                 DEBUG(0, ("Got NULL buffer\n"));
 598                 return;
 599         }
 600
 601         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 602                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 603                 return;
 604         }
 605
 606         /* Pull the data from the message. */
 607         pull_file_id_24((char *)data->data, &id);
 608         file_id = (unsigned long)IVAL(data->data, 24);
 609
 610         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 611                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 612                    (unsigned int)file_id));
 613
 614         fsp = initial_break_processing(sconn, id, file_id);
 615
 616         if (fsp == NULL) {
 617                 DEBUG(3, ("Got a kernel oplock break message for a file "
 618                           "I don't know about\n"));
 619                 return;
 620         }
 621
 622         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 623                 /* This is ok, kernel oplocks come in completely async */
 624                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 625                           "break reply\n"));
 626                 return;
 627         }
 628
 629         if (sconn->using_smb2) {
 630                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 631         } else {
 632                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 633         }
 634
 635         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 636
 637         add_oplock_timeout_handler(fsp);
 638 }
 639
 640 void reply_to_oplock_break_requests(files_struct *fsp)
 641 {
 642         int i;
 643
 644         /*
 645          * If kernel oplocks already notifies smbds when oplocks are
 646          * broken/removed, just return.
 647          */
 648         if (koplocks &&
 649             (koplocks->flags & KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION)) {
 650                 return;
 651         }
 652
 653         for (i=0; i<fsp->num_pending_break_messages; i++) {
 654                 struct share_mode_entry *e = &fsp->pending_break_messages[i];
 655                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 656
 657                 share_mode_entry_to_message(msg, e);
 658
 659                 messaging_send_buf(fsp->conn->sconn->msg_ctx, e->pid,
 660                                    MSG_SMB_BREAK_RESPONSE,
 661                                    (uint8 *)msg,
 662                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 663         }
 664
 665         SAFE_FREE(fsp->pending_break_messages);
 666         fsp->num_pending_break_messages = 0;
 667         TALLOC_FREE(fsp->oplock_timeout);
 668         return;
 669 }
 670
 671 static void process_oplock_break_response(struct messaging_context *msg_ctx,
 672                                           void *private_data,
 673                                           uint32_t msg_type,
 674                                           struct server_id src,
 675                                           DATA_BLOB *data)
 676 {
 677         struct share_mode_entry msg;
 678         struct smbd_server_connection *sconn =
 679                 talloc_get_type_abort(private_data,
 680                 struct smbd_server_connection);
 681
 682         if (data->data == NULL) {
 683                 DEBUG(0, ("Got NULL buffer\n"));
 684                 return;
 685         }
 686
 687         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 688                 DEBUG(0, ("Got invalid msg len %u\n",
 689                           (unsigned int)data->length));
 690                 return;
 691         }
 692
 693         /* De-linearize incoming message. */
 694         message_to_share_mode_entry(&msg, (char *)data->data);
 695
 696         DEBUG(10, ("Got oplock break response from pid %s: %s/%llu mid %llu\n",
 697                    server_id_str(talloc_tos(), &src),
 698                    file_id_string_tos(&msg.id),
 699                    (unsigned long long)msg.share_file_id,
 700                    (unsigned long long)msg.op_mid));
 701
 702         schedule_deferred_open_message_smb(sconn, msg.op_mid);
 703 }
 704
 705 static void process_open_retry_message(struct messaging_context *msg_ctx,
 706                                        void *private_data,
 707                                        uint32_t msg_type,
 708                                        struct server_id src,
 709                                        DATA_BLOB *data)
 710 {
 711         struct share_mode_entry msg;
 712         struct smbd_server_connection *sconn =
 713                 talloc_get_type_abort(private_data,
 714                 struct smbd_server_connection);
 715
 716         if (data->data == NULL) {
 717                 DEBUG(0, ("Got NULL buffer\n"));
 718                 return;
 719         }
 720
 721         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 722                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 723                 return;
 724         }
 725
 726         /* De-linearize incoming message. */
 727         message_to_share_mode_entry(&msg, (char *)data->data);
 728
 729         DEBUG(10, ("Got open retry msg from pid %s: %s mid %llu\n",
 730                    server_id_str(talloc_tos(), &src), file_id_string_tos(&msg.id),
 731                    (unsigned long long)msg.op_mid));
 732
 733         schedule_deferred_open_message_smb(sconn, msg.op_mid);
 734 }
 735
 736 struct break_to_none_state {
 737         struct smbd_server_connection *sconn;
 738         struct file_id id;
 739 };
 740 static void do_break_to_none(struct tevent_req *req);
 741
 742 /****************************************************************************
 743  This function is called on any file modification or lock request. If a file
 744  is level 2 oplocked then it must tell all other level 2 holders to break to
 745  none.
 746 ****************************************************************************/
 747
 748 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 749                                               enum level2_contention_type type)
 750 {
 751         struct smbd_server_connection *sconn = fsp->conn->sconn;
 752         struct tevent_req *req;
 753         struct break_to_none_state *state;
 754
 755         /*
 756          * If this file is level II oplocked then we need
 757          * to grab the shared memory lock and inform all
 758          * other files with a level II lock that they need
 759          * to flush their read caches. We keep the lock over
 760          * the shared memory area whilst doing this.
 761          */
 762
 763         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 764                 return;
 765
 766         /*
 767          * When we get here we might have a brlock entry locked. Also
 768          * locking the share mode entry would violate the locking
 769          * order. Breaking level2 oplocks to none is asynchronous
 770          * anyway, so we postpone this into an immediate timed event.
 771          */
 772
 773         state = talloc(sconn, struct break_to_none_state);
 774         if (state == NULL) {
 775                 DEBUG(1, ("talloc failed\n"));
 776                 return;
 777         }
 778         state->sconn = sconn;
 779         state->id = fsp->file_id;
 780
 781         req = tevent_wakeup_send(state, sconn->ev_ctx, timeval_set(0, 0));
 782         if (req == NULL) {
 783                 DEBUG(1, ("tevent_wakeup_send failed\n"));
 784                 TALLOC_FREE(state);
 785                 return;
 786         }
 787         tevent_req_set_callback(req, do_break_to_none, state);
 788         return;
 789 }
 790
 791 static void do_break_to_none(struct tevent_req *req)
 792 {
 793         struct break_to_none_state *state = tevent_req_callback_data(
 794                 req, struct break_to_none_state);
 795         bool ret;
 796         int i;
 797         struct share_mode_lock *lck;
 798
 799         ret = tevent_wakeup_recv(req);
 800         TALLOC_FREE(req);
 801         if (!ret) {
 802                 DEBUG(1, ("tevent_wakeup_recv failed\n"));
 803                 goto done;
 804         }
 805         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 806         if (lck == NULL) {
 807                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 808                           "share mode entry for file %s.\n",
 809                           file_id_string_tos(&state->id)));
 810                 goto done;
 811         }
 812
 813         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 814                   lck->data->num_share_modes ));
 815
 816         for(i = 0; i < lck->data->num_share_modes; i++) {
 817                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 818                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 819
 820                 if (!is_valid_share_mode_entry(share_entry)) {
 821                         continue;
 822                 }
 823
 824                 /*
 825                  * As there could have been multiple writes waiting at the
 826                  * lock_share_entry gate we may not be the first to
 827                  * enter. Hence the state of the op_types in the share mode
 828                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 829                  * oplock. It will do no harm to re-send break messages to
 830                  * those smbd's that are still waiting their turn to remove
 831                  * their LEVEL_II state, and also no harm to ignore existing
 832                  * NO_OPLOCK states. JRA.
 833                  */
 834
 835                 DEBUG(10,("release_level_2_oplocks_on_change: "
 836                           "share_entry[%i]->op_type == %d\n",
 837                           i, share_entry->op_type ));
 838
 839                 if (share_entry->op_type == NO_OPLOCK) {
 840                         continue;
 841                 }
 842
 843                 /* Paranoia .... */
 844                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 845                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 846                                  "share mode entry %d is an exlusive "
 847                                  "oplock !\n", i ));
 848                         TALLOC_FREE(lck);
 849                         abort();
 850                 }
 851
 852                 share_mode_entry_to_message(msg, share_entry);
 853
 854                 /*
 855                  * Deal with a race condition when breaking level2
 856                  * oplocks. Don't send all the messages and release
 857                  * the lock, this allows someone else to come in and
 858                  * get a level2 lock before any of the messages are
 859                  * processed, and thus miss getting a break message.
 860                  * Ensure at least one entry (the one we're breaking)
 861                  * is processed immediately under the lock and becomes
 862                  * set as NO_OPLOCK to stop any waiter getting a level2.
 863                  * Bugid #5980.
 864                  */
 865
 866                 if (procid_is_me(&share_entry->pid)) {
 867                         struct files_struct *cur_fsp =
 868                                 initial_break_processing(state->sconn,
 869                                         share_entry->id,
 870                                         share_entry->share_file_id);
 871                         wait_before_sending_break();
 872                         if (cur_fsp != NULL) {
 873                                 break_level2_to_none_async(cur_fsp);
 874                         } else {
 875                                 DEBUG(3, ("release_level_2_oplocks_on_change: "
 876                                 "Did not find fsp, ignoring\n"));
 877                         }
 878                 } else {
 879                         messaging_send_buf(state->sconn->msg_ctx,
 880                                         share_entry->pid,
 881                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 882                                         (uint8 *)msg,
 883                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 884                 }
 885         }
 886
 887         /* We let the message receivers handle removing the oplock state
 888            in the share mode lock db. */
 889
 890         TALLOC_FREE(lck);
 891 done:
 892         TALLOC_FREE(state);
 893         return;
 894 }
 895
 896 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 897                                   enum level2_contention_type type)
 898 {
 899         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 900                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 901                 return;
 902         }
 903
 904         contend_level2_oplocks_begin_default(fsp, type);
 905 }
 906
 907 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 908                                 enum level2_contention_type type)
 909 {
 910         /* Only kernel oplocks implement this so far */
 911         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 912                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 913         }
 914 }
 915
 916 /****************************************************************************
 917  Linearize a share mode entry struct to an internal oplock break message.
 918 ****************************************************************************/
 919
 920 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 921 {
 922         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 923         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 924         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 925         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 926         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 927         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 928         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 929         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 930         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 931         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 932         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 933         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 934         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 935         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 936 }
 937
 938 /****************************************************************************
 939  De-linearize an internal oplock break message to a share mode entry struct.
 940 ****************************************************************************/
 941
 942 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 943 {
 944         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 945         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 946         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 947         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 948         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 949         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 950         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 951         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 952         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 953         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 954         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 955         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 956         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 957         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 958 }
 959
 960 /****************************************************************************
 961  Setup oplocks for this process.
 962 ****************************************************************************/
 963
 964 bool init_oplocks(struct smbd_server_connection *sconn)
 965 {
 966         DEBUG(3,("init_oplocks: initializing messages.\n"));
 967
 968         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 969                            process_oplock_break_message);
 970         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 971                            process_oplock_async_level2_break_message);
 972         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_RESPONSE,
 973                            process_oplock_break_response);
 974         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 975                            process_kernel_oplock_break);
 976         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_OPEN_RETRY,
 977                            process_open_retry_message);
 978
 979         return true;
 980 }
 981
 982 void init_kernel_oplocks(struct smbd_server_connection *sconn)
 983 {
 984         /* only initialize once */
 985         if (koplocks == NULL) {
 986 #if HAVE_KERNEL_OPLOCKS_IRIX
 987                 koplocks = irix_init_kernel_oplocks(sconn);
 988 #elif HAVE_KERNEL_OPLOCKS_LINUX
 989                 koplocks = linux_init_kernel_oplocks(sconn);
 990 #endif
 991         }
 992 }