source3/smbd/oplock.c

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