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         TALLOC_FREE(fsp->oplock_timeout);
 155 }
 156
 157 /****************************************************************************
 158  Remove a file oplock. Copes with level II and exclusive.
 159  Locks then unlocks the share mode lock. Client can decide to go directly
 160  to none even if a "break-to-level II" was sent.
 161 ****************************************************************************/
 162
 163 bool remove_oplock(files_struct *fsp)
 164 {
 165         bool ret;
 166         struct share_mode_lock *lck;
 167
 168         /* Remove the oplock flag from the sharemode. */
 169         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 170         if (lck == NULL) {
 171                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 172                          "file %s\n", fsp_str_dbg(fsp)));
 173                 return False;
 174         }
 175         ret = remove_share_oplock(lck, fsp);
 176         if (!ret) {
 177                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 178                          "file %s, %s, %s\n",
 179                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 180                          file_id_string_tos(&fsp->file_id)));
 181         }
 182         release_file_oplock(fsp);
 183         TALLOC_FREE(lck);
 184         return ret;
 185 }
 186
 187 /*
 188  * Deal with a reply when a break-to-level II was sent.
 189  */
 190 bool downgrade_oplock(files_struct *fsp)
 191 {
 192         bool ret;
 193         struct share_mode_lock *lck;
 194
 195         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 196         if (lck == NULL) {
 197                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 198                          "file %s\n", fsp_str_dbg(fsp)));
 199                 return False;
 200         }
 201         ret = downgrade_share_oplock(lck, fsp);
 202         if (!ret) {
 203                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 204                          "for file %s, %s, file_id %s\n",
 205                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 206                          file_id_string_tos(&fsp->file_id)));
 207         }
 208
 209         downgrade_file_oplock(fsp);
 210         TALLOC_FREE(lck);
 211         return ret;
 212 }
 213
 214 /*
 215  * Some kernel oplock implementations handle the notification themselves.
 216  */
 217 bool should_notify_deferred_opens(struct smbd_server_connection *sconn)
 218 {
 219         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 220         return !(koplocks &&
 221                 (koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
 222 }
 223
 224 /****************************************************************************
 225  Set up an oplock break message.
 226 ****************************************************************************/
 227
 228 #define SMB1_BREAK_MESSAGE_LENGTH (smb_size + 8*2)
 229
 230 static void new_break_message_smb1(files_struct *fsp, int cmd,
 231                                    char result[SMB1_BREAK_MESSAGE_LENGTH])
 232 {
 233         memset(result,'\0',smb_size);
 234         srv_set_message(result,8,0,true);
 235         SCVAL(result,smb_com,SMBlockingX);
 236         SSVAL(result,smb_tid,fsp->conn->cnum);
 237         SSVAL(result,smb_pid,0xFFFF);
 238         SSVAL(result,smb_uid,0);
 239         SSVAL(result,smb_mid,0xFFFF);
 240         SCVAL(result,smb_vwv0,0xFF);
 241         SSVAL(result,smb_vwv2,fsp->fnum);
 242         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 243         SCVAL(result,smb_vwv3+1,cmd);
 244 }
 245
 246 /****************************************************************************
 247  Function to do the waiting before sending a local break.
 248 ****************************************************************************/
 249
 250 static void wait_before_sending_break(void)
 251 {
 252         long wait_time = (long)lp_oplock_break_wait_time();
 253
 254         if (wait_time) {
 255                 smb_msleep(wait_time);
 256         }
 257 }
 258
 259 /****************************************************************************
 260  Ensure that we have a valid oplock.
 261 ****************************************************************************/
 262
 263 static files_struct *initial_break_processing(
 264         struct smbd_server_connection *sconn, struct file_id id,
 265         unsigned long file_id)
 266 {
 267         files_struct *fsp = NULL;
 268
 269         if( DEBUGLVL( 3 ) ) {
 270                 dbgtext( "initial_break_processing: called for %s/%u\n",
 271                          file_id_string_tos(&id), (int)file_id);
 272                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 273                         sconn->oplocks.exclusive_open,
 274                         sconn->oplocks.level_II_open);
 275         }
 276
 277         /*
 278          * We need to search the file open table for the
 279          * entry containing this dev and inode, and ensure
 280          * we have an oplock on it.
 281          */
 282
 283         fsp = file_find_dif(sconn, id, file_id);
 284
 285         if(fsp == NULL) {
 286                 /* The file could have been closed in the meantime - return success. */
 287                 if( DEBUGLVL( 3 ) ) {
 288                         dbgtext( "initial_break_processing: cannot find open file with " );
 289                         dbgtext( "file_id %s gen_id = %lu, ", file_id_string_tos(&id), file_id);
 290                         dbgtext( "allowing break to succeed.\n" );
 291                 }
 292                 return NULL;
 293         }
 294
 295         /* Ensure we have an oplock on the file */
 296
 297         /*
 298          * There is a potential race condition in that an oplock could
 299          * have been broken due to another udp request, and yet there are
 300          * still oplock break messages being sent in the udp message
 301          * queue for this file. So return true if we don't have an oplock,
 302          * as we may have just freed it.
 303          */
 304
 305         if(fsp->oplock_type == NO_OPLOCK) {
 306                 if( DEBUGLVL( 3 ) ) {
 307                         dbgtext( "initial_break_processing: file %s ",
 308                                  fsp_str_dbg(fsp));
 309                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 310                                  file_id_string_tos(&id), fsp->fh->gen_id );
 311                         dbgtext( "Allowing break to succeed regardless.\n" );
 312                 }
 313                 return NULL;
 314         }
 315
 316         return fsp;
 317 }
 318
 319 static void oplock_timeout_handler(struct tevent_context *ctx,
 320                                    struct tevent_timer *te,
 321                                    struct timeval now,
 322                                    void *private_data)
 323 {
 324         files_struct *fsp = (files_struct *)private_data;
 325
 326         SMB_ASSERT(fsp->sent_oplock_break != NO_BREAK_SENT);
 327
 328         /* Remove the timed event handler. */
 329         TALLOC_FREE(fsp->oplock_timeout);
 330         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 331                   fsp_str_dbg(fsp)));
 332         remove_oplock(fsp);
 333 }
 334
 335 /*******************************************************************
 336  Add a timeout handler waiting for the client reply.
 337 *******************************************************************/
 338
 339 static void add_oplock_timeout_handler(files_struct *fsp)
 340 {
 341         struct smbd_server_connection *sconn = fsp->conn->sconn;
 342         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 343
 344         /*
 345          * If kernel oplocks already notifies smbds when an oplock break times
 346          * out, just return.
 347          */
 348         if (koplocks &&
 349             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 350                 return;
 351         }
 352
 353         if (fsp->oplock_timeout != NULL) {
 354                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 355                           "around\n"));
 356         }
 357
 358         fsp->oplock_timeout =
 359                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 360                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 361                                  oplock_timeout_handler, fsp);
 362
 363         if (fsp->oplock_timeout == NULL) {
 364                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 365         }
 366 }
 367
 368 static void send_break_message_smb1(files_struct *fsp, int level)
 369 {
 370         char break_msg[SMB1_BREAK_MESSAGE_LENGTH];
 371
 372         new_break_message_smb1(fsp, level, break_msg);
 373
 374         show_msg(break_msg);
 375         if (!srv_send_smb(fsp->conn->sconn,
 376                         break_msg, false, 0,
 377                         IS_CONN_ENCRYPTED(fsp->conn),
 378                         NULL)) {
 379                 exit_server_cleanly("send_break_message_smb1: "
 380                         "srv_send_smb failed.");
 381         }
 382 }
 383
 384 static 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 %s, file %s\n", fsp_fnum_dbg(fsp),
 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         struct server_id self = messaging_server_id(sconn->msg_ctx);
 491         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 492
 493         if (data->data == NULL) {
 494                 DEBUG(0, ("Got NULL buffer\n"));
 495                 return;
 496         }
 497
 498         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 499                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 500                 return;
 501         }
 502
 503         /* De-linearize incoming message. */
 504         message_to_share_mode_entry(&msg, (char *)data->data);
 505
 506         DEBUG(10, ("Got oplock break message from pid %s: %s/%llu\n",
 507                    server_id_str(talloc_tos(), &src),
 508                    file_id_string_tos(&msg.id),
 509                    (unsigned long long)msg.share_file_id));
 510
 511         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 512
 513         if (fsp == NULL) {
 514                 /* We hit a race here. Break messages are sent, and before we
 515                  * get to process this message, we have closed the file. */
 516                 DEBUG(3, ("Did not find fsp\n"));
 517                 return;
 518         }
 519
 520         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 521                 /*
 522                  * Nothing to do anymore
 523                  */
 524                 return;
 525         }
 526
 527         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 528             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 529                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 530                           file_id_string_tos(&fsp->file_id),
 531                           fsp_str_dbg(fsp)));
 532                 return;
 533         }
 534
 535         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 536
 537         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 538             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 539             lp_level2_oplocks(SNUM(fsp->conn))) {
 540                 break_to_level2 = True;
 541         }
 542
 543         /* Need to wait before sending a break
 544            message if we sent ourselves this message. */
 545         if (serverid_equal(&self, &src)) {
 546                 wait_before_sending_break();
 547         }
 548
 549         if (sconn->using_smb2) {
 550                 send_break_message_smb2(fsp, break_to_level2 ?
 551                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 552         } else {
 553                 send_break_message_smb1(fsp, break_to_level2 ?
 554                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 555         }
 556
 557         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 558
 559         add_oplock_timeout_handler(fsp);
 560 }
 561
 562 /*******************************************************************
 563  This handles the kernel oplock break message.
 564 *******************************************************************/
 565
 566 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 567                                         void *private_data,
 568                                         uint32_t msg_type,
 569                                         struct server_id src,
 570                                         DATA_BLOB *data)
 571 {
 572         struct file_id id;
 573         unsigned long file_id;
 574         files_struct *fsp;
 575         struct smbd_server_connection *sconn =
 576                 talloc_get_type_abort(private_data,
 577                 struct smbd_server_connection);
 578
 579         if (data->data == NULL) {
 580                 DEBUG(0, ("Got NULL buffer\n"));
 581                 return;
 582         }
 583
 584         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 585                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 586                 return;
 587         }
 588
 589         /* Pull the data from the message. */
 590         pull_file_id_24((char *)data->data, &id);
 591         file_id = (unsigned long)IVAL(data->data, 24);
 592
 593         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 594                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 595                    (unsigned int)file_id));
 596
 597         fsp = initial_break_processing(sconn, id, file_id);
 598
 599         if (fsp == NULL) {
 600                 DEBUG(3, ("Got a kernel oplock break message for a file "
 601                           "I don't know about\n"));
 602                 return;
 603         }
 604
 605         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 606                 /* This is ok, kernel oplocks come in completely async */
 607                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 608                           "break reply\n"));
 609                 return;
 610         }
 611
 612         if (sconn->using_smb2) {
 613                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 614         } else {
 615                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 616         }
 617
 618         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 619
 620         add_oplock_timeout_handler(fsp);
 621 }
 622
 623 struct break_to_none_state {
 624         struct smbd_server_connection *sconn;
 625         struct file_id id;
 626 };
 627 static void do_break_to_none(struct tevent_context *ctx,
 628                              struct tevent_immediate *im,
 629                              void *private_data);
 630
 631 /****************************************************************************
 632  This function is called on any file modification or lock request. If a file
 633  is level 2 oplocked then it must tell all other level 2 holders to break to
 634  none.
 635 ****************************************************************************/
 636
 637 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 638                                               enum level2_contention_type type)
 639 {
 640         struct smbd_server_connection *sconn = fsp->conn->sconn;
 641         struct tevent_immediate *im;
 642         struct break_to_none_state *state;
 643
 644         /*
 645          * If this file is level II oplocked then we need
 646          * to grab the shared memory lock and inform all
 647          * other files with a level II lock that they need
 648          * to flush their read caches. We keep the lock over
 649          * the shared memory area whilst doing this.
 650          */
 651
 652         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 653                 return;
 654
 655         /*
 656          * When we get here we might have a brlock entry locked. Also
 657          * locking the share mode entry would violate the locking
 658          * order. Breaking level2 oplocks to none is asynchronous
 659          * anyway, so we postpone this into an immediate timed event.
 660          */
 661
 662         state = talloc(sconn, struct break_to_none_state);
 663         if (state == NULL) {
 664                 DEBUG(1, ("talloc failed\n"));
 665                 return;
 666         }
 667         state->sconn = sconn;
 668         state->id = fsp->file_id;
 669
 670         im = tevent_create_immediate(state);
 671         if (im == NULL) {
 672                 DEBUG(1, ("tevent_create_immediate failed\n"));
 673                 TALLOC_FREE(state);
 674                 return;
 675         }
 676         tevent_schedule_immediate(im, sconn->ev_ctx, do_break_to_none, state);
 677 }
 678
 679 static void do_break_to_none(struct tevent_context *ctx,
 680                              struct tevent_immediate *im,
 681                              void *private_data)
 682 {
 683         struct break_to_none_state *state = talloc_get_type_abort(
 684                 private_data, struct break_to_none_state);
 685         struct server_id self = messaging_server_id(state->sconn->msg_ctx);
 686         int i;
 687         struct share_mode_lock *lck;
 688
 689         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 690         if (lck == NULL) {
 691                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 692                           "share mode entry for file %s.\n",
 693                           file_id_string_tos(&state->id)));
 694                 goto done;
 695         }
 696
 697         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 698                   lck->data->num_share_modes ));
 699
 700         for(i = 0; i < lck->data->num_share_modes; i++) {
 701                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 702                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 703
 704                 if (!is_valid_share_mode_entry(share_entry)) {
 705                         continue;
 706                 }
 707
 708                 /*
 709                  * As there could have been multiple writes waiting at the
 710                  * lock_share_entry gate we may not be the first to
 711                  * enter. Hence the state of the op_types in the share mode
 712                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 713                  * oplock. It will do no harm to re-send break messages to
 714                  * those smbd's that are still waiting their turn to remove
 715                  * their LEVEL_II state, and also no harm to ignore existing
 716                  * NO_OPLOCK states. JRA.
 717                  */
 718
 719                 DEBUG(10,("release_level_2_oplocks_on_change: "
 720                           "share_entry[%i]->op_type == %d\n",
 721                           i, share_entry->op_type ));
 722
 723                 if (share_entry->op_type == NO_OPLOCK) {
 724                         continue;
 725                 }
 726
 727                 /* Paranoia .... */
 728                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 729                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 730                                  "share mode entry %d is an exlusive "
 731                                  "oplock !\n", i ));
 732                         TALLOC_FREE(lck);
 733                         abort();
 734                 }
 735
 736                 share_mode_entry_to_message(msg, share_entry);
 737
 738                 /*
 739                  * Deal with a race condition when breaking level2
 740                  * oplocks. Don't send all the messages and release
 741                  * the lock, this allows someone else to come in and
 742                  * get a level2 lock before any of the messages are
 743                  * processed, and thus miss getting a break message.
 744                  * Ensure at least one entry (the one we're breaking)
 745                  * is processed immediately under the lock and becomes
 746                  * set as NO_OPLOCK to stop any waiter getting a level2.
 747                  * Bugid #5980.
 748                  */
 749
 750                 if (serverid_equal(&self, &share_entry->pid)) {
 751                         struct files_struct *cur_fsp =
 752                                 initial_break_processing(state->sconn,
 753                                         share_entry->id,
 754                                         share_entry->share_file_id);
 755                         if (cur_fsp != NULL) {
 756                                 wait_before_sending_break();
 757                                 break_level2_to_none_async(cur_fsp);
 758                         } else {
 759                                 DEBUG(3, ("release_level_2_oplocks_on_change: "
 760                                 "Did not find fsp, ignoring\n"));
 761                         }
 762                 } else {
 763                         messaging_send_buf(state->sconn->msg_ctx,
 764                                         share_entry->pid,
 765                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 766                                         (uint8 *)msg,
 767                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 768                 }
 769         }
 770
 771         /* We let the message receivers handle removing the oplock state
 772            in the share mode lock db. */
 773
 774         TALLOC_FREE(lck);
 775 done:
 776         TALLOC_FREE(state);
 777         return;
 778 }
 779
 780 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 781                                   enum level2_contention_type type)
 782 {
 783         struct smbd_server_connection *sconn = fsp->conn->sconn;
 784         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 785
 786         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 787                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 788                 return;
 789         }
 790
 791         contend_level2_oplocks_begin_default(fsp, type);
 792 }
 793
 794 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 795                                 enum level2_contention_type type)
 796 {
 797         struct smbd_server_connection *sconn = fsp->conn->sconn;
 798         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 799
 800         /* Only kernel oplocks implement this so far */
 801         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 802                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 803         }
 804 }
 805
 806 /****************************************************************************
 807  Linearize a share mode entry struct to an internal oplock break message.
 808 ****************************************************************************/
 809
 810 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 811 {
 812         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 813         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 814         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 815         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 816         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 817         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 818         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 819         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 820         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 821         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 822         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 823         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 824         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 825         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 826 }
 827
 828 /****************************************************************************
 829  De-linearize an internal oplock break message to a share mode entry struct.
 830 ****************************************************************************/
 831
 832 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 833 {
 834         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 835         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 836         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 837         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 838         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 839         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 840         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 841         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 842         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 843         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 844         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 845         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 846         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 847         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 848 }
 849
 850 /****************************************************************************
 851  Setup oplocks for this process.
 852 ****************************************************************************/
 853
 854 bool init_oplocks(struct smbd_server_connection *sconn)
 855 {
 856         DEBUG(3,("init_oplocks: initializing messages.\n"));
 857
 858         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 859                            process_oplock_break_message);
 860         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 861                            process_oplock_async_level2_break_message);
 862         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 863                            process_kernel_oplock_break);
 864         return true;
 865 }
 866
 867 void init_kernel_oplocks(struct smbd_server_connection *sconn)
 868 {
 869         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 870
 871         /* only initialize once */
 872         if (koplocks == NULL) {
 873 #if HAVE_KERNEL_OPLOCKS_IRIX
 874                 koplocks = irix_init_kernel_oplocks(sconn);
 875 #elif HAVE_KERNEL_OPLOCKS_LINUX
 876                 koplocks = linux_init_kernel_oplocks(sconn);
 877 #endif
 878                 sconn->oplocks.kernel_ops = koplocks;
 879         }
 880 }