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  Set up an oplock break message.
 216 ****************************************************************************/
 217
 218 #define SMB1_BREAK_MESSAGE_LENGTH (smb_size + 8*2)
 219
 220 static void new_break_message_smb1(files_struct *fsp, int cmd,
 221                                    char result[SMB1_BREAK_MESSAGE_LENGTH])
 222 {
 223         memset(result,'\0',smb_size);
 224         srv_set_message(result,8,0,true);
 225         SCVAL(result,smb_com,SMBlockingX);
 226         SSVAL(result,smb_tid,fsp->conn->cnum);
 227         SSVAL(result,smb_pid,0xFFFF);
 228         SSVAL(result,smb_uid,0);
 229         SSVAL(result,smb_mid,0xFFFF);
 230         SCVAL(result,smb_vwv0,0xFF);
 231         SSVAL(result,smb_vwv2,fsp->fnum);
 232         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 233         SCVAL(result,smb_vwv3+1,cmd);
 234 }
 235
 236 /****************************************************************************
 237  Function to do the waiting before sending a local break.
 238 ****************************************************************************/
 239
 240 static void wait_before_sending_break(void)
 241 {
 242         long wait_time = (long)lp_oplock_break_wait_time();
 243
 244         if (wait_time) {
 245                 smb_msleep(wait_time);
 246         }
 247 }
 248
 249 /****************************************************************************
 250  Ensure that we have a valid oplock.
 251 ****************************************************************************/
 252
 253 static files_struct *initial_break_processing(
 254         struct smbd_server_connection *sconn, struct file_id id,
 255         unsigned long file_id)
 256 {
 257         files_struct *fsp = NULL;
 258
 259         if( DEBUGLVL( 3 ) ) {
 260                 dbgtext( "initial_break_processing: called for %s/%u\n",
 261                          file_id_string_tos(&id), (int)file_id);
 262                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 263                         sconn->oplocks.exclusive_open,
 264                         sconn->oplocks.level_II_open);
 265         }
 266
 267         /*
 268          * We need to search the file open table for the
 269          * entry containing this dev and inode, and ensure
 270          * we have an oplock on it.
 271          */
 272
 273         fsp = file_find_dif(sconn, id, file_id);
 274
 275         if(fsp == NULL) {
 276                 /* The file could have been closed in the meantime - return success. */
 277                 if( DEBUGLVL( 3 ) ) {
 278                         dbgtext( "initial_break_processing: cannot find open file with " );
 279                         dbgtext( "file_id %s gen_id = %lu, ", file_id_string_tos(&id), file_id);
 280                         dbgtext( "allowing break to succeed.\n" );
 281                 }
 282                 return NULL;
 283         }
 284
 285         /* Ensure we have an oplock on the file */
 286
 287         /*
 288          * There is a potential race condition in that an oplock could
 289          * have been broken due to another udp request, and yet there are
 290          * still oplock break messages being sent in the udp message
 291          * queue for this file. So return true if we don't have an oplock,
 292          * as we may have just freed it.
 293          */
 294
 295         if(fsp->oplock_type == NO_OPLOCK) {
 296                 if( DEBUGLVL( 3 ) ) {
 297                         dbgtext( "initial_break_processing: file %s ",
 298                                  fsp_str_dbg(fsp));
 299                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 300                                  file_id_string_tos(&id), fsp->fh->gen_id );
 301                         dbgtext( "Allowing break to succeed regardless.\n" );
 302                 }
 303                 return NULL;
 304         }
 305
 306         return fsp;
 307 }
 308
 309 static void oplock_timeout_handler(struct tevent_context *ctx,
 310                                    struct tevent_timer *te,
 311                                    struct timeval now,
 312                                    void *private_data)
 313 {
 314         files_struct *fsp = (files_struct *)private_data;
 315
 316         SMB_ASSERT(fsp->sent_oplock_break != NO_BREAK_SENT);
 317
 318         /* Remove the timed event handler. */
 319         TALLOC_FREE(fsp->oplock_timeout);
 320         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 321                   fsp_str_dbg(fsp)));
 322         remove_oplock(fsp);
 323 }
 324
 325 /*******************************************************************
 326  Add a timeout handler waiting for the client reply.
 327 *******************************************************************/
 328
 329 static void add_oplock_timeout_handler(files_struct *fsp)
 330 {
 331         struct smbd_server_connection *sconn = fsp->conn->sconn;
 332         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 333
 334         /*
 335          * If kernel oplocks already notifies smbds when an oplock break times
 336          * out, just return.
 337          */
 338         if (koplocks &&
 339             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 340                 return;
 341         }
 342
 343         if (fsp->oplock_timeout != NULL) {
 344                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 345                           "around\n"));
 346         }
 347
 348         fsp->oplock_timeout =
 349                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 350                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 351                                  oplock_timeout_handler, fsp);
 352
 353         if (fsp->oplock_timeout == NULL) {
 354                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 355         }
 356 }
 357
 358 static void send_break_message_smb1(files_struct *fsp, int level)
 359 {
 360         char break_msg[SMB1_BREAK_MESSAGE_LENGTH];
 361
 362         new_break_message_smb1(fsp, level, break_msg);
 363
 364         show_msg(break_msg);
 365         if (!srv_send_smb(fsp->conn->sconn,
 366                         break_msg, false, 0,
 367                         IS_CONN_ENCRYPTED(fsp->conn),
 368                         NULL)) {
 369                 exit_server_cleanly("send_break_message_smb1: "
 370                         "srv_send_smb failed.");
 371         }
 372 }
 373
 374 static void break_level2_to_none_async(files_struct *fsp)
 375 {
 376         struct smbd_server_connection *sconn = fsp->conn->sconn;
 377
 378         if (fsp->oplock_type == NO_OPLOCK) {
 379                 /* We already got a "break to none" message and we've handled
 380                  * it.  just ignore. */
 381                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 382                           "broken to none, ignoring.\n"));
 383                 return;
 384         }
 385
 386         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 387                 /* Don't tell the client, just downgrade. */
 388                 DEBUG(3, ("process_oplock_async_level2_break_message: "
 389                           "downgrading fake level 2 oplock.\n"));
 390                 remove_oplock(fsp);
 391                 return;
 392         }
 393
 394         /* Ensure we're really at level2 state. */
 395         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 396
 397         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 398                   "to none message for %s, file %s\n", fsp_fnum_dbg(fsp),
 399                   fsp_str_dbg(fsp)));
 400
 401         /* Now send a break to none message to our client. */
 402         if (sconn->using_smb2) {
 403                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 404         } else {
 405                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 406         }
 407
 408         /* Async level2 request, don't send a reply, just remove the oplock. */
 409         remove_oplock(fsp);
 410 }
 411
 412 /*******************************************************************
 413  This handles the case of a write triggering a break to none
 414  message on a level2 oplock.
 415  When we get this message we may be in any of three states :
 416  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 417  the client for LEVEL2.
 418 *******************************************************************/
 419
 420 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 421                                                       void *private_data,
 422                                                       uint32_t msg_type,
 423                                                       struct server_id src,
 424                                                       DATA_BLOB *data)
 425 {
 426         struct share_mode_entry msg;
 427         files_struct *fsp;
 428         struct smbd_server_connection *sconn =
 429                 talloc_get_type_abort(private_data,
 430                 struct smbd_server_connection);
 431
 432         if (data->data == NULL) {
 433                 DEBUG(0, ("Got NULL buffer\n"));
 434                 return;
 435         }
 436
 437         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 438                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 439                 return;
 440         }
 441
 442         /* De-linearize incoming message. */
 443         message_to_share_mode_entry(&msg, (char *)data->data);
 444
 445         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 446                    "%s/%llu\n", server_id_str(talloc_tos(), &src),
 447                    file_id_string_tos(&msg.id),
 448                    (unsigned long long)msg.share_file_id));
 449
 450         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 451
 452         if (fsp == NULL) {
 453                 /* We hit a race here. Break messages are sent, and before we
 454                  * get to process this message, we have closed the file.
 455                  * No need to reply as this is an async message. */
 456                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 457                 return;
 458         }
 459
 460         break_level2_to_none_async(fsp);
 461 }
 462
 463 /*******************************************************************
 464  This handles the generic oplock break message from another smbd.
 465 *******************************************************************/
 466
 467 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 468                                          void *private_data,
 469                                          uint32_t msg_type,
 470                                          struct server_id src,
 471                                          DATA_BLOB *data)
 472 {
 473         struct share_mode_entry msg;
 474         files_struct *fsp;
 475         bool break_to_level2 = False;
 476         bool use_kernel;
 477         struct smbd_server_connection *sconn =
 478                 talloc_get_type_abort(private_data,
 479                 struct smbd_server_connection);
 480         struct server_id self = messaging_server_id(sconn->msg_ctx);
 481         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 482
 483         if (data->data == NULL) {
 484                 DEBUG(0, ("Got NULL buffer\n"));
 485                 return;
 486         }
 487
 488         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 489                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 490                 return;
 491         }
 492
 493         /* De-linearize incoming message. */
 494         message_to_share_mode_entry(&msg, (char *)data->data);
 495
 496         DEBUG(10, ("Got oplock break message from pid %s: %s/%llu\n",
 497                    server_id_str(talloc_tos(), &src),
 498                    file_id_string_tos(&msg.id),
 499                    (unsigned long long)msg.share_file_id));
 500
 501         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 502
 503         if (fsp == NULL) {
 504                 /* We hit a race here. Break messages are sent, and before we
 505                  * get to process this message, we have closed the file. */
 506                 DEBUG(3, ("Did not find fsp\n"));
 507                 return;
 508         }
 509
 510         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 511                 /*
 512                  * Nothing to do anymore
 513                  */
 514                 return;
 515         }
 516
 517         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 518             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 519                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 520                           file_id_string_tos(&fsp->file_id),
 521                           fsp_str_dbg(fsp)));
 522                 return;
 523         }
 524
 525         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 526
 527         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 528             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 529             lp_level2_oplocks(SNUM(fsp->conn))) {
 530                 break_to_level2 = True;
 531         }
 532
 533         /* Need to wait before sending a break
 534            message if we sent ourselves this message. */
 535         if (serverid_equal(&self, &src)) {
 536                 wait_before_sending_break();
 537         }
 538
 539         if (sconn->using_smb2) {
 540                 send_break_message_smb2(fsp, break_to_level2 ?
 541                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 542         } else {
 543                 send_break_message_smb1(fsp, break_to_level2 ?
 544                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 545         }
 546
 547         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 548
 549         add_oplock_timeout_handler(fsp);
 550 }
 551
 552 /*******************************************************************
 553  This handles the kernel oplock break message.
 554 *******************************************************************/
 555
 556 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 557                                         void *private_data,
 558                                         uint32_t msg_type,
 559                                         struct server_id src,
 560                                         DATA_BLOB *data)
 561 {
 562         struct file_id id;
 563         unsigned long file_id;
 564         files_struct *fsp;
 565         struct smbd_server_connection *sconn =
 566                 talloc_get_type_abort(private_data,
 567                 struct smbd_server_connection);
 568
 569         if (data->data == NULL) {
 570                 DEBUG(0, ("Got NULL buffer\n"));
 571                 return;
 572         }
 573
 574         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 575                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 576                 return;
 577         }
 578
 579         /* Pull the data from the message. */
 580         pull_file_id_24((char *)data->data, &id);
 581         file_id = (unsigned long)IVAL(data->data, 24);
 582
 583         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 584                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 585                    (unsigned int)file_id));
 586
 587         fsp = initial_break_processing(sconn, id, file_id);
 588
 589         if (fsp == NULL) {
 590                 DEBUG(3, ("Got a kernel oplock break message for a file "
 591                           "I don't know about\n"));
 592                 return;
 593         }
 594
 595         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 596                 /* This is ok, kernel oplocks come in completely async */
 597                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 598                           "break reply\n"));
 599                 return;
 600         }
 601
 602         if (sconn->using_smb2) {
 603                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 604         } else {
 605                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 606         }
 607
 608         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 609
 610         add_oplock_timeout_handler(fsp);
 611 }
 612
 613 struct break_to_none_state {
 614         struct smbd_server_connection *sconn;
 615         struct file_id id;
 616 };
 617 static void do_break_to_none(struct tevent_context *ctx,
 618                              struct tevent_immediate *im,
 619                              void *private_data);
 620
 621 /****************************************************************************
 622  This function is called on any file modification or lock request. If a file
 623  is level 2 oplocked then it must tell all other level 2 holders to break to
 624  none.
 625 ****************************************************************************/
 626
 627 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 628                                               enum level2_contention_type type)
 629 {
 630         struct smbd_server_connection *sconn = fsp->conn->sconn;
 631         struct tevent_immediate *im;
 632         struct break_to_none_state *state;
 633
 634         /*
 635          * If this file is level II oplocked then we need
 636          * to grab the shared memory lock and inform all
 637          * other files with a level II lock that they need
 638          * to flush their read caches. We keep the lock over
 639          * the shared memory area whilst doing this.
 640          */
 641
 642         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 643                 return;
 644
 645         /*
 646          * When we get here we might have a brlock entry locked. Also
 647          * locking the share mode entry would violate the locking
 648          * order. Breaking level2 oplocks to none is asynchronous
 649          * anyway, so we postpone this into an immediate timed event.
 650          */
 651
 652         state = talloc(sconn, struct break_to_none_state);
 653         if (state == NULL) {
 654                 DEBUG(1, ("talloc failed\n"));
 655                 return;
 656         }
 657         state->sconn = sconn;
 658         state->id = fsp->file_id;
 659
 660         im = tevent_create_immediate(state);
 661         if (im == NULL) {
 662                 DEBUG(1, ("tevent_create_immediate failed\n"));
 663                 TALLOC_FREE(state);
 664                 return;
 665         }
 666         tevent_schedule_immediate(im, sconn->ev_ctx, do_break_to_none, state);
 667 }
 668
 669 static void do_break_to_none(struct tevent_context *ctx,
 670                              struct tevent_immediate *im,
 671                              void *private_data)
 672 {
 673         struct break_to_none_state *state = talloc_get_type_abort(
 674                 private_data, struct break_to_none_state);
 675         struct server_id self = messaging_server_id(state->sconn->msg_ctx);
 676         int i;
 677         struct share_mode_lock *lck;
 678
 679         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 680         if (lck == NULL) {
 681                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 682                           "share mode entry for file %s.\n",
 683                           file_id_string_tos(&state->id)));
 684                 goto done;
 685         }
 686
 687         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 688                   lck->data->num_share_modes ));
 689
 690         for(i = 0; i < lck->data->num_share_modes; i++) {
 691                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 692                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 693
 694                 if (!is_valid_share_mode_entry(share_entry)) {
 695                         continue;
 696                 }
 697
 698                 /*
 699                  * As there could have been multiple writes waiting at the
 700                  * lock_share_entry gate we may not be the first to
 701                  * enter. Hence the state of the op_types in the share mode
 702                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 703                  * oplock. It will do no harm to re-send break messages to
 704                  * those smbd's that are still waiting their turn to remove
 705                  * their LEVEL_II state, and also no harm to ignore existing
 706                  * NO_OPLOCK states. JRA.
 707                  */
 708
 709                 DEBUG(10,("release_level_2_oplocks_on_change: "
 710                           "share_entry[%i]->op_type == %d\n",
 711                           i, share_entry->op_type ));
 712
 713                 if (share_entry->op_type == NO_OPLOCK) {
 714                         continue;
 715                 }
 716
 717                 /* Paranoia .... */
 718                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 719                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 720                                  "share mode entry %d is an exlusive "
 721                                  "oplock !\n", i ));
 722                         TALLOC_FREE(lck);
 723                         abort();
 724                 }
 725
 726                 share_mode_entry_to_message(msg, share_entry);
 727
 728                 /*
 729                  * Deal with a race condition when breaking level2
 730                  * oplocks. Don't send all the messages and release
 731                  * the lock, this allows someone else to come in and
 732                  * get a level2 lock before any of the messages are
 733                  * processed, and thus miss getting a break message.
 734                  * Ensure at least one entry (the one we're breaking)
 735                  * is processed immediately under the lock and becomes
 736                  * set as NO_OPLOCK to stop any waiter getting a level2.
 737                  * Bugid #5980.
 738                  */
 739
 740                 if (serverid_equal(&self, &share_entry->pid)) {
 741                         struct files_struct *cur_fsp =
 742                                 initial_break_processing(state->sconn,
 743                                         share_entry->id,
 744                                         share_entry->share_file_id);
 745                         if (cur_fsp != NULL) {
 746                                 wait_before_sending_break();
 747                                 break_level2_to_none_async(cur_fsp);
 748                         } else {
 749                                 DEBUG(3, ("release_level_2_oplocks_on_change: "
 750                                 "Did not find fsp, ignoring\n"));
 751                         }
 752                 } else {
 753                         messaging_send_buf(state->sconn->msg_ctx,
 754                                         share_entry->pid,
 755                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 756                                         (uint8 *)msg, sizeof(msg));
 757                 }
 758         }
 759
 760         /* We let the message receivers handle removing the oplock state
 761            in the share mode lock db. */
 762
 763         TALLOC_FREE(lck);
 764 done:
 765         TALLOC_FREE(state);
 766         return;
 767 }
 768
 769 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 770                                   enum level2_contention_type type)
 771 {
 772         struct smbd_server_connection *sconn = fsp->conn->sconn;
 773         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 774
 775         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 776                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 777                 return;
 778         }
 779
 780         contend_level2_oplocks_begin_default(fsp, type);
 781 }
 782
 783 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 784                                 enum level2_contention_type type)
 785 {
 786         struct smbd_server_connection *sconn = fsp->conn->sconn;
 787         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 788
 789         /* Only kernel oplocks implement this so far */
 790         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 791                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 792         }
 793 }
 794
 795 /****************************************************************************
 796  Linearize a share mode entry struct to an internal oplock break message.
 797 ****************************************************************************/
 798
 799 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 800 {
 801         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 802         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 803         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 804         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 805         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 806         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 807         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 808         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 809         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 810         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 811         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 812         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 813         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 814         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 815 }
 816
 817 /****************************************************************************
 818  De-linearize an internal oplock break message to a share mode entry struct.
 819 ****************************************************************************/
 820
 821 void message_to_share_mode_entry(struct share_mode_entry *e, const char *msg)
 822 {
 823         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 824         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 825         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 826         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 827         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 828         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 829         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 830         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 831         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 832         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 833         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 834         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 835         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 836         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 837 }
 838
 839 /****************************************************************************
 840  Setup oplocks for this process.
 841 ****************************************************************************/
 842
 843 bool init_oplocks(struct smbd_server_connection *sconn)
 844 {
 845         DEBUG(3,("init_oplocks: initializing messages.\n"));
 846
 847         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 848                            process_oplock_break_message);
 849         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 850                            process_oplock_async_level2_break_message);
 851         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 852                            process_kernel_oplock_break);
 853         return true;
 854 }
 855
 856 void init_kernel_oplocks(struct smbd_server_connection *sconn)
 857 {
 858         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 859
 860         /* only initialize once */
 861         if (koplocks == NULL) {
 862 #if HAVE_KERNEL_OPLOCKS_IRIX
 863                 koplocks = irix_init_kernel_oplocks(sconn);
 864 #elif HAVE_KERNEL_OPLOCKS_LINUX
 865                 koplocks = linux_init_kernel_oplocks(sconn);
 866 #endif
 867                 sconn->oplocks.kernel_ops = koplocks;
 868         }
 869 }