source3/lib/dbwrap_ctdb.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Database interface wrapper around ctdbd
   4    Copyright (C) Volker Lendecke 2007-2009
   5    Copyright (C) Michael Adam 2009
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #ifdef CLUSTER_SUPPORT
  23 #include "ctdb.h"
  24 #include "ctdb_private.h"
  25 #include "ctdbd_conn.h"
  26 #include "g_lock.h"
  27
  28 struct db_ctdb_transaction_handle {
  29         struct db_ctdb_ctx *ctx;
  30         /*
  31          * we store the reads and writes done under a transaction:
  32          * - one list stores both reads and writes (m_all),
  33          * - the other just writes (m_write)
  34          */
  35         struct ctdb_marshall_buffer *m_all;
  36         struct ctdb_marshall_buffer *m_write;
  37         uint32_t nesting;
  38         bool nested_cancel;
  39         char *lock_name;
  40 };
  41
  42 struct db_ctdb_ctx {
  43         struct db_context *db;
  44         struct tdb_wrap *wtdb;
  45         uint32 db_id;
  46         struct db_ctdb_transaction_handle *transaction;
  47         struct g_lock_ctx *lock_ctx;
  48 };
  49
  50 struct db_ctdb_rec {
  51         struct db_ctdb_ctx *ctdb_ctx;
  52         struct ctdb_ltdb_header header;
  53 };
  54
  55 static struct db_record *fetch_locked_internal(struct db_ctdb_ctx *ctx,
  56                                                TALLOC_CTX *mem_ctx,
  57                                                TDB_DATA key,
  58                                                bool persistent);
  59
  60 static NTSTATUS tdb_error_to_ntstatus(struct tdb_context *tdb)
  61 {
  62         NTSTATUS status;
  63         enum TDB_ERROR tret = tdb_error(tdb);
  64
  65         switch (tret) {
  66         case TDB_ERR_EXISTS:
  67                 status = NT_STATUS_OBJECT_NAME_COLLISION;
  68                 break;
  69         case TDB_ERR_NOEXIST:
  70                 status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
  71                 break;
  72         default:
  73                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
  74                 break;
  75         }
  76
  77         return status;
  78 }
  79
  80
  81 /**
  82  * fetch a record from the tdb, separating out the header
  83  * information and returning the body of the record.
  84  */
  85 static NTSTATUS db_ctdb_ltdb_fetch(struct db_ctdb_ctx *db,
  86                                    TDB_DATA key,
  87                                    struct ctdb_ltdb_header *header,
  88                                    TALLOC_CTX *mem_ctx,
  89                                    TDB_DATA *data)
  90 {
  91         TDB_DATA rec;
  92         NTSTATUS status;
  93
  94         rec = tdb_fetch(db->wtdb->tdb, key);
  95         if (rec.dsize < sizeof(struct ctdb_ltdb_header)) {
  96                 status = NT_STATUS_NOT_FOUND;
  97                 if (data) {
  98                         ZERO_STRUCTP(data);
  99                 }
 100                 if (header) {
 101                         header->dmaster = (uint32_t)-1;
 102                         header->rsn = 0;
 103                 }
 104                 goto done;
 105         }
 106
 107         if (header) {
 108                 *header = *(struct ctdb_ltdb_header *)rec.dptr;
 109         }
 110
 111         if (data) {
 112                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 113                 if (data->dsize == 0) {
 114                         data->dptr = NULL;
 115                 } else {
 116                         data->dptr = (unsigned char *)talloc_memdup(mem_ctx,
 117                                         rec.dptr
 118                                          + sizeof(struct ctdb_ltdb_header),
 119                                         data->dsize);
 120                         if (data->dptr == NULL) {
 121                                 status = NT_STATUS_NO_MEMORY;
 122                                 goto done;
 123                         }
 124                 }
 125         }
 126
 127         status = NT_STATUS_OK;
 128
 129 done:
 130         SAFE_FREE(rec.dptr);
 131         return status;
 132 }
 133
 134 /*
 135  * Store a record together with the ctdb record header
 136  * in the local copy of the database.
 137  */
 138 static NTSTATUS db_ctdb_ltdb_store(struct db_ctdb_ctx *db,
 139                                    TDB_DATA key,
 140                                    struct ctdb_ltdb_header *header,
 141                                    TDB_DATA data)
 142 {
 143         TALLOC_CTX *tmp_ctx = talloc_stackframe();
 144         TDB_DATA rec;
 145         int ret;
 146
 147         rec.dsize = data.dsize + sizeof(struct ctdb_ltdb_header);
 148         rec.dptr = (uint8_t *)talloc_size(tmp_ctx, rec.dsize);
 149
 150         if (rec.dptr == NULL) {
 151                 talloc_free(tmp_ctx);
 152                 return NT_STATUS_NO_MEMORY;
 153         }
 154
 155         memcpy(rec.dptr, header, sizeof(struct ctdb_ltdb_header));
 156         memcpy(sizeof(struct ctdb_ltdb_header) + (uint8_t *)rec.dptr, data.dptr, data.dsize);
 157
 158         ret = tdb_store(db->wtdb->tdb, key, rec, TDB_REPLACE);
 159
 160         talloc_free(tmp_ctx);
 161
 162         return (ret == 0) ? NT_STATUS_OK
 163                           : tdb_error_to_ntstatus(db->wtdb->tdb);
 164
 165 }
 166
 167 /*
 168   form a ctdb_rec_data record from a key/data pair
 169
 170   note that header may be NULL. If not NULL then it is included in the data portion
 171   of the record
 172  */
 173 static struct ctdb_rec_data *db_ctdb_marshall_record(TALLOC_CTX *mem_ctx, uint32_t reqid,
 174                                                   TDB_DATA key,
 175                                                   struct ctdb_ltdb_header *header,
 176                                                   TDB_DATA data)
 177 {
 178         size_t length;
 179         struct ctdb_rec_data *d;
 180
 181         length = offsetof(struct ctdb_rec_data, data) + key.dsize +
 182                 data.dsize + (header?sizeof(*header):0);
 183         d = (struct ctdb_rec_data *)talloc_size(mem_ctx, length);
 184         if (d == NULL) {
 185                 return NULL;
 186         }
 187         d->length = length;
 188         d->reqid = reqid;
 189         d->keylen = key.dsize;
 190         memcpy(&d->data[0], key.dptr, key.dsize);
 191         if (header) {
 192                 d->datalen = data.dsize + sizeof(*header);
 193                 memcpy(&d->data[key.dsize], header, sizeof(*header));
 194                 memcpy(&d->data[key.dsize+sizeof(*header)], data.dptr, data.dsize);
 195         } else {
 196                 d->datalen = data.dsize;
 197                 memcpy(&d->data[key.dsize], data.dptr, data.dsize);
 198         }
 199         return d;
 200 }
 201
 202
 203 /* helper function for marshalling multiple records */
 204 static struct ctdb_marshall_buffer *db_ctdb_marshall_add(TALLOC_CTX *mem_ctx,
 205                                                struct ctdb_marshall_buffer *m,
 206                                                uint64_t db_id,
 207                                                uint32_t reqid,
 208                                                TDB_DATA key,
 209                                                struct ctdb_ltdb_header *header,
 210                                                TDB_DATA data)
 211 {
 212         struct ctdb_rec_data *r;
 213         size_t m_size, r_size;
 214         struct ctdb_marshall_buffer *m2 = NULL;
 215
 216         r = db_ctdb_marshall_record(talloc_tos(), reqid, key, header, data);
 217         if (r == NULL) {
 218                 talloc_free(m);
 219                 return NULL;
 220         }
 221
 222         if (m == NULL) {
 223                 m = (struct ctdb_marshall_buffer *)talloc_zero_size(
 224                         mem_ctx, offsetof(struct ctdb_marshall_buffer, data));
 225                 if (m == NULL) {
 226                         goto done;
 227                 }
 228                 m->db_id = db_id;
 229         }
 230
 231         m_size = talloc_get_size(m);
 232         r_size = talloc_get_size(r);
 233
 234         m2 = (struct ctdb_marshall_buffer *)talloc_realloc_size(
 235                 mem_ctx, m,  m_size + r_size);
 236         if (m2 == NULL) {
 237                 talloc_free(m);
 238                 goto done;
 239         }
 240
 241         memcpy(m_size + (uint8_t *)m2, r, r_size);
 242
 243         m2->count++;
 244
 245 done:
 246         talloc_free(r);
 247         return m2;
 248 }
 249
 250 /* we've finished marshalling, return a data blob with the marshalled records */
 251 static TDB_DATA db_ctdb_marshall_finish(struct ctdb_marshall_buffer *m)
 252 {
 253         TDB_DATA data;
 254         data.dptr = (uint8_t *)m;
 255         data.dsize = talloc_get_size(m);
 256         return data;
 257 }
 258
 259 /*
 260    loop over a marshalling buffer
 261
 262      - pass r==NULL to start
 263      - loop the number of times indicated by m->count
 264 */
 265 static struct ctdb_rec_data *db_ctdb_marshall_loop_next(struct ctdb_marshall_buffer *m, struct ctdb_rec_data *r,
 266                                                      uint32_t *reqid,
 267                                                      struct ctdb_ltdb_header *header,
 268                                                      TDB_DATA *key, TDB_DATA *data)
 269 {
 270         if (r == NULL) {
 271                 r = (struct ctdb_rec_data *)&m->data[0];
 272         } else {
 273                 r = (struct ctdb_rec_data *)(r->length + (uint8_t *)r);
 274         }
 275
 276         if (reqid != NULL) {
 277                 *reqid = r->reqid;
 278         }
 279
 280         if (key != NULL) {
 281                 key->dptr   = &r->data[0];
 282                 key->dsize  = r->keylen;
 283         }
 284         if (data != NULL) {
 285                 data->dptr  = &r->data[r->keylen];
 286                 data->dsize = r->datalen;
 287                 if (header != NULL) {
 288                         data->dptr += sizeof(*header);
 289                         data->dsize -= sizeof(*header);
 290                 }
 291         }
 292
 293         if (header != NULL) {
 294                 if (r->datalen < sizeof(*header)) {
 295                         return NULL;
 296                 }
 297                 *header = *(struct ctdb_ltdb_header *)&r->data[r->keylen];
 298         }
 299
 300         return r;
 301 }
 302
 303 /**
 304  * CTDB transaction destructor
 305  */
 306 static int db_ctdb_transaction_destructor(struct db_ctdb_transaction_handle *h)
 307 {
 308         NTSTATUS status;
 309
 310         status = g_lock_unlock(h->ctx->lock_ctx, h->lock_name);
 311         if (!NT_STATUS_IS_OK(status)) {
 312                 DEBUG(0, ("g_lock_unlock failed: %s\n", nt_errstr(status)));
 313                 return -1;
 314         }
 315         return 0;
 316 }
 317
 318 /**
 319  * CTDB dbwrap API: transaction_start function
 320  * starts a transaction on a persistent database
 321  */
 322 static int db_ctdb_transaction_start(struct db_context *db)
 323 {
 324         struct db_ctdb_transaction_handle *h;
 325         NTSTATUS status;
 326         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
 327                                                         struct db_ctdb_ctx);
 328
 329         if (!db->persistent) {
 330                 DEBUG(0,("transactions not supported on non-persistent database 0x%08x\n",
 331                          ctx->db_id));
 332                 return -1;
 333         }
 334
 335         if (ctx->transaction) {
 336                 ctx->transaction->nesting++;
 337                 return 0;
 338         }
 339
 340         h = talloc_zero(db, struct db_ctdb_transaction_handle);
 341         if (h == NULL) {
 342                 DEBUG(0,(__location__ " oom for transaction handle\n"));
 343                 return -1;
 344         }
 345
 346         h->ctx = ctx;
 347
 348         h->lock_name = talloc_asprintf(h, "transaction_db_0x%08x",
 349                                        (unsigned int)ctx->db_id);
 350         if (h->lock_name == NULL) {
 351                 DEBUG(0, ("talloc_asprintf failed\n"));
 352                 TALLOC_FREE(h);
 353                 return -1;
 354         }
 355
 356         /*
 357          * Wait a day, i.e. forever...
 358          */
 359         status = g_lock_lock(ctx->lock_ctx, h->lock_name, G_LOCK_WRITE,
 360                              timeval_set(86400, 0));
 361         if (!NT_STATUS_IS_OK(status)) {
 362                 DEBUG(0, ("g_lock_lock failed: %s\n", nt_errstr(status)));
 363                 TALLOC_FREE(h);
 364                 return -1;
 365         }
 366
 367         talloc_set_destructor(h, db_ctdb_transaction_destructor);
 368
 369         ctx->transaction = h;
 370
 371         DEBUG(5,(__location__ " Started transaction on db 0x%08x\n", ctx->db_id));
 372
 373         return 0;
 374 }
 375
 376 static bool pull_newest_from_marshall_buffer(struct ctdb_marshall_buffer *buf,
 377                                              TDB_DATA key,
 378                                              struct ctdb_ltdb_header *pheader,
 379                                              TALLOC_CTX *mem_ctx,
 380                                              TDB_DATA *pdata)
 381 {
 382         struct ctdb_rec_data *rec = NULL;
 383         struct ctdb_ltdb_header h;
 384         bool found = false;
 385         TDB_DATA data;
 386         int i;
 387
 388         if (buf == NULL) {
 389                 return false;
 390         }
 391
 392         ZERO_STRUCT(h);
 393         ZERO_STRUCT(data);
 394
 395         /*
 396          * Walk the list of records written during this
 397          * transaction. If we want to read one we have already
 398          * written, return the last written sample. Thus we do not do
 399          * a "break;" for the first hit, this record might have been
 400          * overwritten later.
 401          */
 402
 403         for (i=0; i<buf->count; i++) {
 404                 TDB_DATA tkey, tdata;
 405                 uint32_t reqid;
 406                 struct ctdb_ltdb_header hdr;
 407
 408                 ZERO_STRUCT(hdr);
 409
 410                 rec = db_ctdb_marshall_loop_next(buf, rec, &reqid, &hdr, &tkey,
 411                                                  &tdata);
 412                 if (rec == NULL) {
 413                         return false;
 414                 }
 415
 416                 if (tdb_data_equal(key, tkey)) {
 417                         found = true;
 418                         data = tdata;
 419                         h = hdr;
 420                 }
 421         }
 422
 423         if (!found) {
 424                 return false;
 425         }
 426
 427         if (pdata != NULL) {
 428                 data.dptr = (uint8_t *)talloc_memdup(mem_ctx, data.dptr,
 429                                                      data.dsize);
 430                 if ((data.dsize != 0) && (data.dptr == NULL)) {
 431                         return false;
 432                 }
 433                 *pdata = data;
 434         }
 435
 436         if (pheader != NULL) {
 437                 *pheader = h;
 438         }
 439
 440         return true;
 441 }
 442
 443 /*
 444   fetch a record inside a transaction
 445  */
 446 static int db_ctdb_transaction_fetch(struct db_ctdb_ctx *db,
 447                                      TALLOC_CTX *mem_ctx,
 448                                      TDB_DATA key, TDB_DATA *data)
 449 {
 450         struct db_ctdb_transaction_handle *h = db->transaction;
 451         NTSTATUS status;
 452         bool found;
 453
 454         found = pull_newest_from_marshall_buffer(h->m_write, key, NULL,
 455                                                  mem_ctx, data);
 456         if (found) {
 457                 return 0;
 458         }
 459
 460         status = db_ctdb_ltdb_fetch(h->ctx, key, NULL, mem_ctx, data);
 461
 462         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 463                 *data = tdb_null;
 464         } else if (!NT_STATUS_IS_OK(status)) {
 465                 return -1;
 466         }
 467
 468         h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 1, key,
 469                                         NULL, *data);
 470         if (h->m_all == NULL) {
 471                 DEBUG(0,(__location__ " Failed to add to marshalling "
 472                          "record\n"));
 473                 data->dsize = 0;
 474                 talloc_free(data->dptr);
 475                 return -1;
 476         }
 477
 478         return 0;
 479 }
 480
 481
 482 static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag);
 483 static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec);
 484
 485 static struct db_record *db_ctdb_fetch_locked_transaction(struct db_ctdb_ctx *ctx,
 486                                                           TALLOC_CTX *mem_ctx,
 487                                                           TDB_DATA key)
 488 {
 489         struct db_record *result;
 490         TDB_DATA ctdb_data;
 491
 492         if (!(result = talloc(mem_ctx, struct db_record))) {
 493                 DEBUG(0, ("talloc failed\n"));
 494                 return NULL;
 495         }
 496
 497         result->private_data = ctx->transaction;
 498
 499         result->key.dsize = key.dsize;
 500         result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
 501         if (result->key.dptr == NULL) {
 502                 DEBUG(0, ("talloc failed\n"));
 503                 TALLOC_FREE(result);
 504                 return NULL;
 505         }
 506
 507         result->store = db_ctdb_store_transaction;
 508         result->delete_rec = db_ctdb_delete_transaction;
 509
 510         if (pull_newest_from_marshall_buffer(ctx->transaction->m_write, key,
 511                                              NULL, result, &result->value)) {
 512                 return result;
 513         }
 514
 515         ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
 516         if (ctdb_data.dptr == NULL) {
 517                 /* create the record */
 518                 result->value = tdb_null;
 519                 return result;
 520         }
 521
 522         result->value.dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
 523         result->value.dptr = NULL;
 524
 525         if ((result->value.dsize != 0)
 526             && !(result->value.dptr = (uint8 *)talloc_memdup(
 527                          result, ctdb_data.dptr + sizeof(struct ctdb_ltdb_header),
 528                          result->value.dsize))) {
 529                 DEBUG(0, ("talloc failed\n"));
 530                 TALLOC_FREE(result);
 531         }
 532
 533         SAFE_FREE(ctdb_data.dptr);
 534
 535         return result;
 536 }
 537
 538 static int db_ctdb_record_destructor(struct db_record **recp)
 539 {
 540         struct db_record *rec = talloc_get_type_abort(*recp, struct db_record);
 541         struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
 542                 rec->private_data, struct db_ctdb_transaction_handle);
 543         int ret = h->ctx->db->transaction_commit(h->ctx->db);
 544         if (ret != 0) {
 545                 DEBUG(0,(__location__ " transaction_commit failed\n"));
 546         }
 547         return 0;
 548 }
 549
 550 /*
 551   auto-create a transaction for persistent databases
 552  */
 553 static struct db_record *db_ctdb_fetch_locked_persistent(struct db_ctdb_ctx *ctx,
 554                                                          TALLOC_CTX *mem_ctx,
 555                                                          TDB_DATA key)
 556 {
 557         int res;
 558         struct db_record *rec, **recp;
 559
 560         res = db_ctdb_transaction_start(ctx->db);
 561         if (res == -1) {
 562                 return NULL;
 563         }
 564
 565         rec = db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
 566         if (rec == NULL) {
 567                 ctx->db->transaction_cancel(ctx->db);
 568                 return NULL;
 569         }
 570
 571         /* destroy this transaction when we release the lock */
 572         recp = talloc(rec, struct db_record *);
 573         if (recp == NULL) {
 574                 ctx->db->transaction_cancel(ctx->db);
 575                 talloc_free(rec);
 576                 return NULL;
 577         }
 578         *recp = rec;
 579         talloc_set_destructor(recp, db_ctdb_record_destructor);
 580         return rec;
 581 }
 582
 583
 584 /*
 585   stores a record inside a transaction
 586  */
 587 static NTSTATUS db_ctdb_transaction_store(struct db_ctdb_transaction_handle *h,
 588                                           TDB_DATA key, TDB_DATA data)
 589 {
 590         TALLOC_CTX *tmp_ctx = talloc_new(h);
 591         TDB_DATA rec;
 592         struct ctdb_ltdb_header header;
 593
 594         ZERO_STRUCT(header);
 595
 596         /* we need the header so we can update the RSN */
 597
 598         if (!pull_newest_from_marshall_buffer(h->m_write, key, &header,
 599                                               NULL, NULL)) {
 600
 601                 rec = tdb_fetch(h->ctx->wtdb->tdb, key);
 602
 603                 if (rec.dptr != NULL) {
 604                         memcpy(&header, rec.dptr,
 605                                sizeof(struct ctdb_ltdb_header));
 606                         rec.dsize -= sizeof(struct ctdb_ltdb_header);
 607
 608                         /*
 609                          * a special case, we are writing the same
 610                          * data that is there now
 611                          */
 612                         if (data.dsize == rec.dsize &&
 613                             memcmp(data.dptr,
 614                                    rec.dptr + sizeof(struct ctdb_ltdb_header),
 615                                    data.dsize) == 0) {
 616                                 SAFE_FREE(rec.dptr);
 617                                 talloc_free(tmp_ctx);
 618                                 return NT_STATUS_OK;
 619                         }
 620                 }
 621                 SAFE_FREE(rec.dptr);
 622         }
 623
 624         header.dmaster = get_my_vnn();
 625         header.rsn++;
 626
 627         h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 0, key,
 628                                         NULL, data);
 629         if (h->m_all == NULL) {
 630                 DEBUG(0,(__location__ " Failed to add to marshalling "
 631                          "record\n"));
 632                 talloc_free(tmp_ctx);
 633                 return NT_STATUS_NO_MEMORY;
 634         }
 635
 636         h->m_write = db_ctdb_marshall_add(h, h->m_write, h->ctx->db_id, 0, key, &header, data);
 637         if (h->m_write == NULL) {
 638                 DEBUG(0,(__location__ " Failed to add to marshalling record\n"));
 639                 talloc_free(tmp_ctx);
 640                 return NT_STATUS_NO_MEMORY;
 641         }
 642
 643         talloc_free(tmp_ctx);
 644         return NT_STATUS_OK;
 645 }
 646
 647
 648 /*
 649    a record store inside a transaction
 650  */
 651 static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag)
 652 {
 653         struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
 654                 rec->private_data, struct db_ctdb_transaction_handle);
 655         NTSTATUS status;
 656
 657         status = db_ctdb_transaction_store(h, rec->key, data);
 658         return status;
 659 }
 660
 661 /*
 662    a record delete inside a transaction
 663  */
 664 static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec)
 665 {
 666         struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
 667                 rec->private_data, struct db_ctdb_transaction_handle);
 668         NTSTATUS status;
 669
 670         status =  db_ctdb_transaction_store(h, rec->key, tdb_null);
 671         return status;
 672 }
 673
 674 /**
 675  * Fetch the db sequence number of a persistent db directly from the db.
 676  */
 677 static NTSTATUS db_ctdb_fetch_db_seqnum_from_db(struct db_ctdb_ctx *db,
 678                                                 uint64_t *seqnum)
 679 {
 680         NTSTATUS status;
 681         const char *keyname = CTDB_DB_SEQNUM_KEY;
 682         TDB_DATA key;
 683         TDB_DATA data;
 684         struct ctdb_ltdb_header header;
 685         TALLOC_CTX *mem_ctx = talloc_stackframe();
 686
 687         if (seqnum == NULL) {
 688                 return NT_STATUS_INVALID_PARAMETER;
 689         }
 690
 691         key.dptr = (uint8_t *)discard_const(keyname);
 692         key.dsize = strlen(keyname) + 1;
 693
 694         status = db_ctdb_ltdb_fetch(db, key, &header, mem_ctx, &data);
 695         if (!NT_STATUS_IS_OK(status) &&
 696             !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND))
 697         {
 698                 goto done;
 699         }
 700
 701         status = NT_STATUS_OK;
 702
 703         if (data.dsize != sizeof(uint64_t)) {
 704                 *seqnum = 0;
 705                 goto done;
 706         }
 707
 708         *seqnum = *(uint64_t *)data.dptr;
 709
 710 done:
 711         TALLOC_FREE(mem_ctx);
 712         return status;
 713 }
 714
 715 /**
 716  * Store the database sequence number inside a transaction.
 717  */
 718 static NTSTATUS db_ctdb_store_db_seqnum(struct db_ctdb_transaction_handle *h,
 719                                         uint64_t seqnum)
 720 {
 721         NTSTATUS status;
 722         const char *keyname = CTDB_DB_SEQNUM_KEY;
 723         TDB_DATA key;
 724         TDB_DATA data;
 725
 726         key.dptr = (uint8_t *)discard_const(keyname);
 727         key.dsize = strlen(keyname);
 728
 729         data.dptr = (uint8_t *)&seqnum;
 730         data.dsize = sizeof(uint64_t);
 731
 732         status = db_ctdb_transaction_store(h, key, data);
 733
 734         return status;
 735 }
 736
 737 /*
 738   commit a transaction
 739  */
 740 static int db_ctdb_transaction_commit(struct db_context *db)
 741 {
 742         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
 743                                                         struct db_ctdb_ctx);
 744         NTSTATUS rets;
 745         int status;
 746         struct db_ctdb_transaction_handle *h = ctx->transaction;
 747         uint64_t old_seqnum, new_seqnum;
 748         int ret;
 749
 750         if (h == NULL) {
 751                 DEBUG(0,(__location__ " transaction commit with no open transaction on db 0x%08x\n", ctx->db_id));
 752                 return -1;
 753         }
 754
 755         if (h->nested_cancel) {
 756                 db->transaction_cancel(db);
 757                 DEBUG(5,(__location__ " Failed transaction commit after nested cancel\n"));
 758                 return -1;
 759         }
 760
 761         if (h->nesting != 0) {
 762                 h->nesting--;
 763                 return 0;
 764         }
 765
 766         if (h->m_write == NULL) {
 767                 /*
 768                  * No changes were made, so don't change the seqnum,
 769                  * don't push to other node, just exit with success.
 770                  */
 771                 ret = 0;
 772                 goto done;
 773         }
 774
 775         DEBUG(5,(__location__ " Commit transaction on db 0x%08x\n", ctx->db_id));
 776
 777         /*
 778          * As the last db action before committing, bump the database sequence
 779          * number. Note that this undoes all changes to the seqnum records
 780          * performed under the transaction. This record is not meant to be
 781          * modified by user interaction. It is for internal use only...
 782          */
 783         rets = db_ctdb_fetch_db_seqnum_from_db(ctx, &old_seqnum);
 784         if (!NT_STATUS_IS_OK(rets)) {
 785                 DEBUG(1, (__location__ " failed to fetch the db sequence number "
 786                           "in transaction commit on db 0x%08x\n", ctx->db_id));
 787                 ret = -1;
 788                 goto done;
 789         }
 790
 791         new_seqnum = old_seqnum + 1;
 792
 793         rets = db_ctdb_store_db_seqnum(h, new_seqnum);
 794         if (!NT_STATUS_IS_OK(rets)) {
 795                 DEBUG(1, (__location__ "failed to store the db sequence number "
 796                           " in transaction commit on db 0x%08x\n", ctx->db_id));
 797                 ret = -1;
 798                 goto done;
 799         }
 800
 801 again:
 802         /* tell ctdbd to commit to the other nodes */
 803         rets = ctdbd_control_local(messaging_ctdbd_connection(),
 804                                    CTDB_CONTROL_TRANS3_COMMIT,
 805                                    h->ctx->db_id, 0,
 806                                    db_ctdb_marshall_finish(h->m_write),
 807                                    NULL, NULL, &status);
 808         if (!NT_STATUS_IS_OK(rets) || status != 0) {
 809                 /*
 810                  * The TRANS3_COMMIT control should only possibly fail when a
 811                  * recovery has been running concurrently. In any case, the db
 812                  * will be the same on all nodes, either the new copy or the
 813                  * old copy.  This can be detected by comparing the old and new
 814                  * local sequence numbers.
 815                  */
 816                 rets = db_ctdb_fetch_db_seqnum_from_db(ctx, &new_seqnum);
 817                 if (!NT_STATUS_IS_OK(rets)) {
 818                         DEBUG(1, (__location__ " failed to refetch db sequence "
 819                                   "number after failed TRANS3_COMMIT\n"));
 820                         ret = -1;
 821                         goto done;
 822                 }
 823
 824                 if (new_seqnum == old_seqnum) {
 825                         /* Recovery prevented all our changes: retry. */
 826                         goto again;
 827                 } else if (new_seqnum != (old_seqnum + 1)) {
 828                         DEBUG(0, (__location__ " ERROR: new_seqnum[%lu] != "
 829                                   "old_seqnum[%lu] + (0 or 1) after failed "
 830                                   "TRANS3_COMMIT - this should not happen!\n",
 831                                   (unsigned long)new_seqnum,
 832                                   (unsigned long)old_seqnum));
 833                         ret = -1;
 834                         goto done;
 835                 }
 836                 /*
 837                  * Recovery propagated our changes to all nodes, completing
 838                  * our commit for us - succeed.
 839                  */
 840         }
 841
 842         ret = 0;
 843
 844 done:
 845         h->ctx->transaction = NULL;
 846         talloc_free(h);
 847         return ret;
 848 }
 849
 850
 851 /*
 852   cancel a transaction
 853  */
 854 static int db_ctdb_transaction_cancel(struct db_context *db)
 855 {
 856         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
 857                                                         struct db_ctdb_ctx);
 858         struct db_ctdb_transaction_handle *h = ctx->transaction;
 859
 860         if (h == NULL) {
 861                 DEBUG(0,(__location__ " transaction cancel with no open transaction on db 0x%08x\n", ctx->db_id));
 862                 return -1;
 863         }
 864
 865         if (h->nesting != 0) {
 866                 h->nesting--;
 867                 h->nested_cancel = true;
 868                 return 0;
 869         }
 870
 871         DEBUG(5,(__location__ " Cancel transaction on db 0x%08x\n", ctx->db_id));
 872
 873         ctx->transaction = NULL;
 874         talloc_free(h);
 875         return 0;
 876 }
 877
 878
 879 static NTSTATUS db_ctdb_store(struct db_record *rec, TDB_DATA data, int flag)
 880 {
 881         struct db_ctdb_rec *crec = talloc_get_type_abort(
 882                 rec->private_data, struct db_ctdb_rec);
 883
 884         return db_ctdb_ltdb_store(crec->ctdb_ctx, rec->key, &(crec->header), data);
 885 }
 886
 887
 888
 889 static NTSTATUS db_ctdb_delete(struct db_record *rec)
 890 {
 891         TDB_DATA data;
 892
 893         /*
 894          * We have to store the header with empty data. TODO: Fix the
 895          * tdb-level cleanup
 896          */
 897
 898         ZERO_STRUCT(data);
 899
 900         return db_ctdb_store(rec, data, 0);
 901
 902 }
 903
 904 static int db_ctdb_record_destr(struct db_record* data)
 905 {
 906         struct db_ctdb_rec *crec = talloc_get_type_abort(
 907                 data->private_data, struct db_ctdb_rec);
 908
 909         DEBUG(10, (DEBUGLEVEL > 10
 910                    ? "Unlocking db %u key %s\n"
 911                    : "Unlocking db %u key %.20s\n",
 912                    (int)crec->ctdb_ctx->db_id,
 913                    hex_encode_talloc(data, (unsigned char *)data->key.dptr,
 914                               data->key.dsize)));
 915
 916         if (tdb_chainunlock(crec->ctdb_ctx->wtdb->tdb, data->key) != 0) {
 917                 DEBUG(0, ("tdb_chainunlock failed\n"));
 918                 return -1;
 919         }
 920
 921         return 0;
 922 }
 923
 924 static struct db_record *fetch_locked_internal(struct db_ctdb_ctx *ctx,
 925                                                TALLOC_CTX *mem_ctx,
 926                                                TDB_DATA key,
 927                                                bool persistent)
 928 {
 929         struct db_record *result;
 930         struct db_ctdb_rec *crec;
 931         NTSTATUS status;
 932         TDB_DATA ctdb_data;
 933         int migrate_attempts = 0;
 934
 935         if (!(result = talloc(mem_ctx, struct db_record))) {
 936                 DEBUG(0, ("talloc failed\n"));
 937                 return NULL;
 938         }
 939
 940         if (!(crec = TALLOC_ZERO_P(result, struct db_ctdb_rec))) {
 941                 DEBUG(0, ("talloc failed\n"));
 942                 TALLOC_FREE(result);
 943                 return NULL;
 944         }
 945
 946         result->private_data = (void *)crec;
 947         crec->ctdb_ctx = ctx;
 948
 949         result->key.dsize = key.dsize;
 950         result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
 951         if (result->key.dptr == NULL) {
 952                 DEBUG(0, ("talloc failed\n"));
 953                 TALLOC_FREE(result);
 954                 return NULL;
 955         }
 956
 957         /*
 958          * Do a blocking lock on the record
 959          */
 960 again:
 961
 962         if (DEBUGLEVEL >= 10) {
 963                 char *keystr = hex_encode_talloc(result, key.dptr, key.dsize);
 964                 DEBUG(10, (DEBUGLEVEL > 10
 965                            ? "Locking db %u key %s\n"
 966                            : "Locking db %u key %.20s\n",
 967                            (int)crec->ctdb_ctx->db_id, keystr));
 968                 TALLOC_FREE(keystr);
 969         }
 970
 971         if (tdb_chainlock(ctx->wtdb->tdb, key) != 0) {
 972                 DEBUG(3, ("tdb_chainlock failed\n"));
 973                 TALLOC_FREE(result);
 974                 return NULL;
 975         }
 976
 977         result->store = db_ctdb_store;
 978         result->delete_rec = db_ctdb_delete;
 979         talloc_set_destructor(result, db_ctdb_record_destr);
 980
 981         ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
 982
 983         /*
 984          * See if we have a valid record and we are the dmaster. If so, we can
 985          * take the shortcut and just return it.
 986          */
 987
 988         if ((ctdb_data.dptr == NULL) ||
 989             (ctdb_data.dsize < sizeof(struct ctdb_ltdb_header)) ||
 990             ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster != get_my_vnn()
 991 #if 0
 992             || (random() % 2 != 0)
 993 #endif
 994 ) {
 995                 SAFE_FREE(ctdb_data.dptr);
 996                 tdb_chainunlock(ctx->wtdb->tdb, key);
 997                 talloc_set_destructor(result, NULL);
 998
 999                 migrate_attempts += 1;
1000
1001                 DEBUG(10, ("ctdb_data.dptr = %p, dmaster = %u (%u)\n",
1002                            ctdb_data.dptr, ctdb_data.dptr ?
1003                            ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster : -1,
1004                            get_my_vnn()));
1005
1006                 status = ctdbd_migrate(messaging_ctdbd_connection(),ctx->db_id, key);
1007                 if (!NT_STATUS_IS_OK(status)) {
1008                         DEBUG(5, ("ctdb_migrate failed: %s\n",
1009                                   nt_errstr(status)));
1010                         TALLOC_FREE(result);
1011                         return NULL;
1012                 }
1013                 /* now its migrated, try again */
1014                 goto again;
1015         }
1016
1017         if (migrate_attempts > 10) {
1018                 DEBUG(0, ("db_ctdb_fetch_locked needed %d attempts\n",
1019                           migrate_attempts));
1020         }
1021
1022         memcpy(&crec->header, ctdb_data.dptr, sizeof(crec->header));
1023
1024         result->value.dsize = ctdb_data.dsize - sizeof(crec->header);
1025         result->value.dptr = NULL;
1026
1027         if ((result->value.dsize != 0)
1028             && !(result->value.dptr = (uint8 *)talloc_memdup(
1029                          result, ctdb_data.dptr + sizeof(crec->header),
1030                          result->value.dsize))) {
1031                 DEBUG(0, ("talloc failed\n"));
1032                 TALLOC_FREE(result);
1033         }
1034
1035         SAFE_FREE(ctdb_data.dptr);
1036
1037         return result;
1038 }
1039
1040 static struct db_record *db_ctdb_fetch_locked(struct db_context *db,
1041                                               TALLOC_CTX *mem_ctx,
1042                                               TDB_DATA key)
1043 {
1044         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1045                                                         struct db_ctdb_ctx);
1046
1047         if (ctx->transaction != NULL) {
1048                 return db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
1049         }
1050
1051         if (db->persistent) {
1052                 return db_ctdb_fetch_locked_persistent(ctx, mem_ctx, key);
1053         }
1054
1055         return fetch_locked_internal(ctx, mem_ctx, key, db->persistent);
1056 }
1057
1058 /*
1059   fetch (unlocked, no migration) operation on ctdb
1060  */
1061 static int db_ctdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
1062                          TDB_DATA key, TDB_DATA *data)
1063 {
1064         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1065                                                         struct db_ctdb_ctx);
1066         NTSTATUS status;
1067         TDB_DATA ctdb_data;
1068
1069         if (ctx->transaction) {
1070                 return db_ctdb_transaction_fetch(ctx, mem_ctx, key, data);
1071         }
1072
1073         /* try a direct fetch */
1074         ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
1075
1076         /*
1077          * See if we have a valid record and we are the dmaster. If so, we can
1078          * take the shortcut and just return it.
1079          * we bypass the dmaster check for persistent databases
1080          */
1081         if ((ctdb_data.dptr != NULL) &&
1082             (ctdb_data.dsize >= sizeof(struct ctdb_ltdb_header)) &&
1083             (db->persistent ||
1084              ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster == get_my_vnn())) {
1085                 /* we are the dmaster - avoid the ctdb protocol op */
1086
1087                 data->dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
1088                 if (data->dsize == 0) {
1089                         SAFE_FREE(ctdb_data.dptr);
1090                         data->dptr = NULL;
1091                         return 0;
1092                 }
1093
1094                 data->dptr = (uint8 *)talloc_memdup(
1095                         mem_ctx, ctdb_data.dptr+sizeof(struct ctdb_ltdb_header),
1096                         data->dsize);
1097
1098                 SAFE_FREE(ctdb_data.dptr);
1099
1100                 if (data->dptr == NULL) {
1101                         return -1;
1102                 }
1103                 return 0;
1104         }
1105
1106         SAFE_FREE(ctdb_data.dptr);
1107
1108         /* we weren't able to get it locally - ask ctdb to fetch it for us */
1109         status = ctdbd_fetch(messaging_ctdbd_connection(),ctx->db_id, key, mem_ctx, data);
1110         if (!NT_STATUS_IS_OK(status)) {
1111                 DEBUG(5, ("ctdbd_fetch failed: %s\n", nt_errstr(status)));
1112                 return -1;
1113         }
1114
1115         return 0;
1116 }
1117
1118 struct traverse_state {
1119         struct db_context *db;
1120         int (*fn)(struct db_record *rec, void *private_data);
1121         void *private_data;
1122 };
1123
1124 static void traverse_callback(TDB_DATA key, TDB_DATA data, void *private_data)
1125 {
1126         struct traverse_state *state = (struct traverse_state *)private_data;
1127         struct db_record *rec;
1128         TALLOC_CTX *tmp_ctx = talloc_new(state->db);
1129         /* we have to give them a locked record to prevent races */
1130         rec = db_ctdb_fetch_locked(state->db, tmp_ctx, key);
1131         if (rec && rec->value.dsize > 0) {
1132                 state->fn(rec, state->private_data);
1133         }
1134         talloc_free(tmp_ctx);
1135 }
1136
1137 static int traverse_persistent_callback(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
1138                                         void *private_data)
1139 {
1140         struct traverse_state *state = (struct traverse_state *)private_data;
1141         struct db_record *rec;
1142         TALLOC_CTX *tmp_ctx = talloc_new(state->db);
1143         int ret = 0;
1144         /* we have to give them a locked record to prevent races */
1145         rec = db_ctdb_fetch_locked(state->db, tmp_ctx, kbuf);
1146         if (rec && rec->value.dsize > 0) {
1147                 ret = state->fn(rec, state->private_data);
1148         }
1149         talloc_free(tmp_ctx);
1150         return ret;
1151 }
1152
1153 static int db_ctdb_traverse(struct db_context *db,
1154                             int (*fn)(struct db_record *rec,
1155                                       void *private_data),
1156                             void *private_data)
1157 {
1158         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1159                                                         struct db_ctdb_ctx);
1160         struct traverse_state state;
1161
1162         state.db = db;
1163         state.fn = fn;
1164         state.private_data = private_data;
1165
1166         if (db->persistent) {
1167                 /* for persistent databases we don't need to do a ctdb traverse,
1168                    we can do a faster local traverse */
1169                 return tdb_traverse(ctx->wtdb->tdb, traverse_persistent_callback, &state);
1170         }
1171
1172
1173         ctdbd_traverse(ctx->db_id, traverse_callback, &state);
1174         return 0;
1175 }
1176
1177 static NTSTATUS db_ctdb_store_deny(struct db_record *rec, TDB_DATA data, int flag)
1178 {
1179         return NT_STATUS_MEDIA_WRITE_PROTECTED;
1180 }
1181
1182 static NTSTATUS db_ctdb_delete_deny(struct db_record *rec)
1183 {
1184         return NT_STATUS_MEDIA_WRITE_PROTECTED;
1185 }
1186
1187 static void traverse_read_callback(TDB_DATA key, TDB_DATA data, void *private_data)
1188 {
1189         struct traverse_state *state = (struct traverse_state *)private_data;
1190         struct db_record rec;
1191         rec.key = key;
1192         rec.value = data;
1193         rec.store = db_ctdb_store_deny;
1194         rec.delete_rec = db_ctdb_delete_deny;
1195         rec.private_data = state->db;
1196         state->fn(&rec, state->private_data);
1197 }
1198
1199 static int traverse_persistent_callback_read(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
1200                                         void *private_data)
1201 {
1202         struct traverse_state *state = (struct traverse_state *)private_data;
1203         struct db_record rec;
1204         rec.key = kbuf;
1205         rec.value = dbuf;
1206         rec.store = db_ctdb_store_deny;
1207         rec.delete_rec = db_ctdb_delete_deny;
1208         rec.private_data = state->db;
1209
1210         if (rec.value.dsize <= sizeof(struct ctdb_ltdb_header)) {
1211                 /* a deleted record */
1212                 return 0;
1213         }
1214         rec.value.dsize -= sizeof(struct ctdb_ltdb_header);
1215         rec.value.dptr += sizeof(struct ctdb_ltdb_header);
1216
1217         return state->fn(&rec, state->private_data);
1218 }
1219
1220 static int db_ctdb_traverse_read(struct db_context *db,
1221                                  int (*fn)(struct db_record *rec,
1222                                            void *private_data),
1223                                  void *private_data)
1224 {
1225         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1226                                                         struct db_ctdb_ctx);
1227         struct traverse_state state;
1228
1229         state.db = db;
1230         state.fn = fn;
1231         state.private_data = private_data;
1232
1233         if (db->persistent) {
1234                 /* for persistent databases we don't need to do a ctdb traverse,
1235                    we can do a faster local traverse */
1236                 return tdb_traverse_read(ctx->wtdb->tdb, traverse_persistent_callback_read, &state);
1237         }
1238
1239         ctdbd_traverse(ctx->db_id, traverse_read_callback, &state);
1240         return 0;
1241 }
1242
1243 static int db_ctdb_get_seqnum(struct db_context *db)
1244 {
1245         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1246                                                         struct db_ctdb_ctx);
1247         return tdb_get_seqnum(ctx->wtdb->tdb);
1248 }
1249
1250 static int db_ctdb_get_flags(struct db_context *db)
1251 {
1252         struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1253                                                         struct db_ctdb_ctx);
1254         return tdb_get_flags(ctx->wtdb->tdb);
1255 }
1256
1257 struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
1258                                 const char *name,
1259                                 int hash_size, int tdb_flags,
1260                                 int open_flags, mode_t mode)
1261 {
1262         struct db_context *result;
1263         struct db_ctdb_ctx *db_ctdb;
1264         char *db_path;
1265         struct ctdbd_connection *conn;
1266
1267         if (!lp_clustering()) {
1268                 DEBUG(10, ("Clustering disabled -- no ctdb\n"));
1269                 return NULL;
1270         }
1271
1272         if (!(result = TALLOC_ZERO_P(mem_ctx, struct db_context))) {
1273                 DEBUG(0, ("talloc failed\n"));
1274                 TALLOC_FREE(result);
1275                 return NULL;
1276         }
1277
1278         if (!(db_ctdb = TALLOC_P(result, struct db_ctdb_ctx))) {
1279                 DEBUG(0, ("talloc failed\n"));
1280                 TALLOC_FREE(result);
1281                 return NULL;
1282         }
1283
1284         db_ctdb->transaction = NULL;
1285         db_ctdb->db = result;
1286
1287         conn = messaging_ctdbd_connection();
1288
1289         if (!NT_STATUS_IS_OK(ctdbd_db_attach(conn, name, &db_ctdb->db_id, tdb_flags))) {
1290                 DEBUG(0, ("ctdbd_db_attach failed for %s\n", name));
1291                 TALLOC_FREE(result);
1292                 return NULL;
1293         }
1294
1295         db_path = ctdbd_dbpath(conn, db_ctdb, db_ctdb->db_id);
1296
1297         result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
1298
1299         /* only pass through specific flags */
1300         tdb_flags &= TDB_SEQNUM;
1301
1302         /* honor permissions if user has specified O_CREAT */
1303         if (open_flags & O_CREAT) {
1304                 chmod(db_path, mode);
1305         }
1306
1307         db_ctdb->wtdb = tdb_wrap_open(db_ctdb, db_path, hash_size, tdb_flags, O_RDWR, 0);
1308         if (db_ctdb->wtdb == NULL) {
1309                 DEBUG(0, ("Could not open tdb %s: %s\n", db_path, strerror(errno)));
1310                 TALLOC_FREE(result);
1311                 return NULL;
1312         }
1313         talloc_free(db_path);
1314
1315         if (result->persistent) {
1316                 db_ctdb->lock_ctx = g_lock_ctx_init(db_ctdb,
1317                                                     ctdb_conn_msg_ctx(conn));
1318                 if (db_ctdb->lock_ctx == NULL) {
1319                         DEBUG(0, ("g_lock_ctx_init failed\n"));
1320                         TALLOC_FREE(result);
1321                         return NULL;
1322                 }
1323         }
1324
1325         result->private_data = (void *)db_ctdb;
1326         result->fetch_locked = db_ctdb_fetch_locked;
1327         result->fetch = db_ctdb_fetch;
1328         result->traverse = db_ctdb_traverse;
1329         result->traverse_read = db_ctdb_traverse_read;
1330         result->get_seqnum = db_ctdb_get_seqnum;
1331         result->get_flags = db_ctdb_get_flags;
1332         result->transaction_start = db_ctdb_transaction_start;
1333         result->transaction_commit = db_ctdb_transaction_commit;
1334         result->transaction_cancel = db_ctdb_transaction_cancel;
1335
1336         DEBUG(3,("db_open_ctdb: opened database '%s' with dbid 0x%x\n",
1337                  name, db_ctdb->db_id));
1338
1339         return result;
1340 }
1341 #endif