source3/smbd/oplock.c

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