source3/lib/g_lock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    global locks based on dbwrap and messaging
   4    Copyright (C) 2009 by Volker Lendecke
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "system/filesys.h"
  22 #include "lib/util/server_id.h"
  23 #include "dbwrap/dbwrap.h"
  24 #include "dbwrap/dbwrap_open.h"
  25 #include "dbwrap/dbwrap_watch.h"
  26 #include "g_lock.h"
  27 #include "util_tdb.h"
  28 #include "../lib/util/tevent_ntstatus.h"
  29 #include "messages.h"
  30 #include "serverid.h"
  31
  32 struct g_lock_ctx {
  33         struct db_context *db;
  34         struct messaging_context *msg;
  35 };
  36
  37 /*
  38  * The "g_lock.tdb" file contains records, indexed by the 0-terminated
  39  * lockname. The record contains an array of "struct g_lock_rec"
  40  * structures.
  41  */
  42
  43 #define G_LOCK_REC_LENGTH (SERVER_ID_BUF_LENGTH+1)
  44
  45 static void g_lock_rec_put(uint8_t buf[G_LOCK_REC_LENGTH],
  46                            const struct g_lock_rec rec)
  47 {
  48         SCVAL(buf, 0, rec.lock_type);
  49         server_id_put(buf+1, rec.pid);
  50 }
  51
  52 static void g_lock_rec_get(struct g_lock_rec *rec,
  53                            const uint8_t buf[G_LOCK_REC_LENGTH])
  54 {
  55         rec->lock_type = CVAL(buf, 0);
  56         server_id_get(&rec->pid, buf+1);
  57 }
  58
  59 struct g_lock {
  60         uint8_t *recsbuf;
  61         size_t num_recs;
  62         uint8_t *data;
  63         size_t datalen;
  64 };
  65
  66 static bool g_lock_parse(uint8_t *buf, size_t buflen, struct g_lock *lck)
  67 {
  68         size_t found_recs, data_ofs;
  69
  70         if (buflen < sizeof(uint32_t)) {
  71                 *lck = (struct g_lock) {0};
  72                 return true;
  73         }
  74
  75         found_recs = IVAL(buf, 0);
  76
  77         buf += sizeof(uint32_t);
  78         buflen -= sizeof(uint32_t);
  79         if (found_recs > buflen/G_LOCK_REC_LENGTH) {
  80                 return false;
  81         }
  82
  83         data_ofs = found_recs * G_LOCK_REC_LENGTH;
  84
  85         *lck = (struct g_lock) {
  86                 .recsbuf = buf, .num_recs = found_recs,
  87                 .data = buf+data_ofs, .datalen = buflen-data_ofs
  88         };
  89
  90         return true;
  91 }
  92
  93 static void g_lock_get_rec(struct g_lock *lck, size_t i,
  94                            struct g_lock_rec *rec)
  95 {
  96         if (i >= lck->num_recs) {
  97                 abort();
  98         }
  99         g_lock_rec_get(rec, lck->recsbuf + i*G_LOCK_REC_LENGTH);
 100 }
 101
 102 static void g_lock_rec_del(struct g_lock *lck, size_t i)
 103 {
 104         if (i >= lck->num_recs) {
 105                 abort();
 106         }
 107         lck->num_recs -= 1;
 108         if (i < lck->num_recs) {
 109                 uint8_t *recptr = lck->recsbuf + i*G_LOCK_REC_LENGTH;
 110                 memcpy(recptr, lck->recsbuf + lck->num_recs*G_LOCK_REC_LENGTH,
 111                        G_LOCK_REC_LENGTH);
 112         }
 113 }
 114
 115 static NTSTATUS g_lock_store(struct db_record *rec, struct g_lock *lck,
 116                              struct g_lock_rec *add)
 117 {
 118         uint8_t sizebuf[4];
 119         uint8_t addbuf[G_LOCK_REC_LENGTH];
 120
 121         struct TDB_DATA dbufs[] = {
 122                 { .dptr = sizebuf, .dsize = sizeof(sizebuf) },
 123                 { .dptr = lck->recsbuf,
 124                   .dsize = lck->num_recs * G_LOCK_REC_LENGTH },
 125                 { 0 },
 126                 { .dptr = lck->data, .dsize = lck->datalen }
 127         };
 128
 129         if (add != NULL) {
 130                 g_lock_rec_put(addbuf, *add);
 131
 132                 dbufs[2] = (TDB_DATA) {
 133                         .dptr = addbuf, .dsize = G_LOCK_REC_LENGTH
 134                 };
 135
 136                 lck->num_recs += 1;
 137         }
 138
 139         SIVAL(sizebuf, 0, lck->num_recs);
 140
 141         return dbwrap_record_storev(rec, dbufs, ARRAY_SIZE(dbufs), 0);
 142 }
 143
 144 struct g_lock_ctx *g_lock_ctx_init(TALLOC_CTX *mem_ctx,
 145                                    struct messaging_context *msg)
 146 {
 147         struct g_lock_ctx *result;
 148         struct db_context *backend;
 149         char *db_path;
 150
 151         result = talloc(mem_ctx, struct g_lock_ctx);
 152         if (result == NULL) {
 153                 return NULL;
 154         }
 155         result->msg = msg;
 156
 157         db_path = lock_path("g_lock.tdb");
 158         if (db_path == NULL) {
 159                 TALLOC_FREE(result);
 160                 return NULL;
 161         }
 162
 163         backend = db_open(result, db_path, 0,
 164                           TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 165                           O_RDWR|O_CREAT, 0600,
 166                           DBWRAP_LOCK_ORDER_3,
 167                           DBWRAP_FLAG_NONE);
 168         TALLOC_FREE(db_path);
 169         if (backend == NULL) {
 170                 DEBUG(1, ("g_lock_init: Could not open g_lock.tdb\n"));
 171                 TALLOC_FREE(result);
 172                 return NULL;
 173         }
 174
 175         result->db = db_open_watched(result, backend, msg);
 176         if (result->db == NULL) {
 177                 DBG_WARNING("g_lock_init: db_open_watched failed\n");
 178                 TALLOC_FREE(result);
 179                 return NULL;
 180         }
 181         return result;
 182 }
 183
 184 static bool g_lock_conflicts(enum g_lock_type l1, enum g_lock_type l2)
 185 {
 186         /*
 187          * Only tested write locks so far. Very likely this routine
 188          * needs to be fixed for read locks....
 189          */
 190         if ((l1 == G_LOCK_READ) && (l2 == G_LOCK_READ)) {
 191                 return false;
 192         }
 193         return true;
 194 }
 195
 196 static NTSTATUS g_lock_trylock(struct db_record *rec, struct server_id self,
 197                                enum g_lock_type type,
 198                                struct server_id *blocker)
 199 {
 200         TDB_DATA data;
 201         size_t i;
 202         struct g_lock lck;
 203         struct g_lock_rec _mylock;
 204         struct g_lock_rec *mylock = NULL;
 205         NTSTATUS status;
 206         bool modified = false;
 207         bool ok;
 208
 209         data = dbwrap_record_get_value(rec);
 210
 211         ok = g_lock_parse(data.dptr, data.dsize, &lck);
 212         if (!ok) {
 213                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 214         }
 215
 216         if ((type == G_LOCK_READ) && (lck.num_recs > 0)) {
 217                 struct g_lock_rec check_rec;
 218
 219                 /*
 220                  * Read locks can stay around forever if the process
 221                  * dies. Do a heuristic check for process existence:
 222                  * Check one random process for existence. Hopefully
 223                  * this will keep runaway read locks under control.
 224                  */
 225                 i = generate_random() % lck.num_recs;
 226
 227                 g_lock_get_rec(&lck, i, &check_rec);
 228
 229                 if (!serverid_exists(&check_rec.pid)) {
 230                         g_lock_rec_del(&lck, i);
 231                         modified = true;
 232                 }
 233         }
 234
 235         i = 0;
 236
 237         while (i < lck.num_recs) {
 238                 struct g_lock_rec lock;
 239
 240                 g_lock_get_rec(&lck, i, &lock);
 241
 242                 if (serverid_equal(&self, &lock.pid)) {
 243                         if (lock.lock_type == type) {
 244                                 status = NT_STATUS_WAS_LOCKED;
 245                                 goto done;
 246                         }
 247                         if (mylock != NULL) {
 248                                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 249                                 goto done;
 250                         }
 251                         _mylock = lock;
 252                         mylock = &_mylock;
 253                         /*
 254                          * Remove "our" lock entry. Re-add it later
 255                          * with our new lock type.
 256                          */
 257                         g_lock_rec_del(&lck, i);
 258                         modified = true;
 259                         continue;
 260                 }
 261
 262                 if (g_lock_conflicts(type, lock.lock_type)) {
 263                         struct server_id pid = lock.pid;
 264
 265                         /*
 266                          * As the serverid_exists might recurse into
 267                          * the g_lock code, we use
 268                          * SERVERID_UNIQUE_ID_NOT_TO_VERIFY to avoid the loop
 269                          */
 270                         pid.unique_id = SERVERID_UNIQUE_ID_NOT_TO_VERIFY;
 271
 272                         if (serverid_exists(&pid)) {
 273                                 status = NT_STATUS_LOCK_NOT_GRANTED;
 274                                 *blocker = lock.pid;
 275                                 goto done;
 276                         }
 277
 278                         /*
 279                          * Delete stale conflicting entry
 280                          */
 281                         g_lock_rec_del(&lck, i);
 282                         modified = true;
 283                         continue;
 284                 }
 285                 i++;
 286         }
 287
 288         modified = true;
 289
 290         _mylock = (struct g_lock_rec) {
 291                 .pid = self,
 292                 .lock_type = type
 293         };
 294         mylock = &_mylock;
 295
 296         status = NT_STATUS_OK;
 297 done:
 298         if (modified) {
 299                 NTSTATUS store_status;
 300
 301                 store_status = g_lock_store(rec, &lck, mylock);
 302                 if (!NT_STATUS_IS_OK(store_status)) {
 303                         DBG_WARNING("g_lock_record_store failed: %s\n",
 304                                     nt_errstr(store_status));
 305                         status = store_status;
 306                 }
 307         }
 308         return status;
 309 }
 310
 311 struct g_lock_lock_state {
 312         struct tevent_context *ev;
 313         struct g_lock_ctx *ctx;
 314         TDB_DATA key;
 315         enum g_lock_type type;
 316 };
 317
 318 static void g_lock_lock_retry(struct tevent_req *subreq);
 319
 320 struct g_lock_lock_fn_state {
 321         struct g_lock_lock_state *state;
 322         struct server_id self;
 323
 324         struct tevent_req *watch_req;
 325         NTSTATUS status;
 326 };
 327
 328 static void g_lock_lock_fn(struct db_record *rec, void *private_data)
 329 {
 330         struct g_lock_lock_fn_state *state = private_data;
 331         struct server_id blocker;
 332
 333         state->status = g_lock_trylock(rec, state->self, state->state->type,
 334                                        &blocker);
 335         if (!NT_STATUS_EQUAL(state->status, NT_STATUS_LOCK_NOT_GRANTED)) {
 336                 return;
 337         }
 338
 339         state->watch_req = dbwrap_watched_watch_send(
 340                 state->state, state->state->ev, rec, blocker);
 341 }
 342
 343 struct tevent_req *g_lock_lock_send(TALLOC_CTX *mem_ctx,
 344                                     struct tevent_context *ev,
 345                                     struct g_lock_ctx *ctx,
 346                                     TDB_DATA key,
 347                                     enum g_lock_type type)
 348 {
 349         struct tevent_req *req;
 350         struct g_lock_lock_state *state;
 351         struct g_lock_lock_fn_state fn_state;
 352         NTSTATUS status;
 353
 354         req = tevent_req_create(mem_ctx, &state, struct g_lock_lock_state);
 355         if (req == NULL) {
 356                 return NULL;
 357         }
 358         state->ev = ev;
 359         state->ctx = ctx;
 360         state->key = key;
 361         state->type = type;
 362
 363         fn_state = (struct g_lock_lock_fn_state) {
 364                 .state = state, .self = messaging_server_id(ctx->msg)
 365         };
 366
 367         status = dbwrap_do_locked(ctx->db, key, g_lock_lock_fn, &fn_state);
 368         if (tevent_req_nterror(req, status)) {
 369                 DBG_DEBUG("dbwrap_do_locked failed: %s\n",
 370                           nt_errstr(status));
 371                 return tevent_req_post(req, ev);
 372         }
 373
 374         if (NT_STATUS_IS_OK(fn_state.status)) {
 375                 tevent_req_done(req);
 376                 return tevent_req_post(req, ev);
 377         }
 378         if (!NT_STATUS_EQUAL(fn_state.status, NT_STATUS_LOCK_NOT_GRANTED)) {
 379                 tevent_req_nterror(req, fn_state.status);
 380                 return tevent_req_post(req, ev);
 381         }
 382
 383         if (tevent_req_nomem(fn_state.watch_req, req)) {
 384                 return tevent_req_post(req, ev);
 385         }
 386
 387         if (!tevent_req_set_endtime(
 388                     fn_state.watch_req, state->ev,
 389                     timeval_current_ofs(5 + sys_random() % 5, 0))) {
 390                 return tevent_req_post(req, ev);
 391         }
 392         tevent_req_set_callback(fn_state.watch_req, g_lock_lock_retry, req);
 393         return req;
 394 }
 395
 396 static void g_lock_lock_retry(struct tevent_req *subreq)
 397 {
 398         struct tevent_req *req = tevent_req_callback_data(
 399                 subreq, struct tevent_req);
 400         struct g_lock_lock_state *state = tevent_req_data(
 401                 req, struct g_lock_lock_state);
 402         struct g_lock_lock_fn_state fn_state;
 403         NTSTATUS status;
 404
 405         status = dbwrap_watched_watch_recv(subreq, NULL, NULL);
 406         DBG_DEBUG("watch_recv returned %s\n", nt_errstr(status));
 407         TALLOC_FREE(subreq);
 408
 409         if (!NT_STATUS_IS_OK(status) &&
 410             !NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
 411                 tevent_req_nterror(req, status);
 412                 return;
 413         }
 414
 415         fn_state = (struct g_lock_lock_fn_state) {
 416                 .state = state, .self = messaging_server_id(state->ctx->msg)
 417         };
 418
 419         status = dbwrap_do_locked(state->ctx->db, state->key,
 420                                   g_lock_lock_fn, &fn_state);
 421         if (tevent_req_nterror(req, status)) {
 422                 DBG_DEBUG("dbwrap_do_locked failed: %s\n",
 423                           nt_errstr(status));
 424                 return;
 425         }
 426
 427         if (NT_STATUS_IS_OK(fn_state.status)) {
 428                 tevent_req_done(req);
 429                 return;
 430         }
 431         if (!NT_STATUS_EQUAL(fn_state.status, NT_STATUS_LOCK_NOT_GRANTED)) {
 432                 tevent_req_nterror(req, fn_state.status);
 433                 return;
 434         }
 435
 436         if (tevent_req_nomem(fn_state.watch_req, req)) {
 437                 return;
 438         }
 439
 440         if (!tevent_req_set_endtime(
 441                     fn_state.watch_req, state->ev,
 442                     timeval_current_ofs(5 + sys_random() % 5, 0))) {
 443                 return;
 444         }
 445         tevent_req_set_callback(fn_state.watch_req, g_lock_lock_retry, req);
 446 }
 447
 448 NTSTATUS g_lock_lock_recv(struct tevent_req *req)
 449 {
 450         return tevent_req_simple_recv_ntstatus(req);
 451 }
 452
 453 NTSTATUS g_lock_lock(struct g_lock_ctx *ctx, TDB_DATA key,
 454                      enum g_lock_type type, struct timeval timeout)
 455 {
 456         TALLOC_CTX *frame = talloc_stackframe();
 457         struct tevent_context *ev;
 458         struct tevent_req *req;
 459         struct timeval end;
 460         NTSTATUS status = NT_STATUS_NO_MEMORY;
 461
 462         ev = samba_tevent_context_init(frame);
 463         if (ev == NULL) {
 464                 goto fail;
 465         }
 466         req = g_lock_lock_send(frame, ev, ctx, key, type);
 467         if (req == NULL) {
 468                 goto fail;
 469         }
 470         end = timeval_current_ofs(timeout.tv_sec, timeout.tv_usec);
 471         if (!tevent_req_set_endtime(req, ev, end)) {
 472                 goto fail;
 473         }
 474         if (!tevent_req_poll_ntstatus(req, ev, &status)) {
 475                 goto fail;
 476         }
 477         status = g_lock_lock_recv(req);
 478  fail:
 479         TALLOC_FREE(frame);
 480         return status;
 481 }
 482
 483 struct g_lock_unlock_state {
 484         TDB_DATA key;
 485         struct server_id self;
 486         NTSTATUS status;
 487 };
 488
 489 static void g_lock_unlock_fn(struct db_record *rec,
 490                              void *private_data)
 491 {
 492         struct g_lock_unlock_state *state = private_data;
 493         TDB_DATA value;
 494         struct g_lock lck;
 495         size_t i;
 496         bool ok;
 497
 498         value = dbwrap_record_get_value(rec);
 499
 500         ok = g_lock_parse(value.dptr, value.dsize, &lck);
 501         if (!ok) {
 502                 DBG_DEBUG("g_lock_get for %s failed\n",
 503                           hex_encode_talloc(talloc_tos(),
 504                                             state->key.dptr,
 505                                             state->key.dsize));
 506                 state->status = NT_STATUS_FILE_INVALID;
 507                 return;
 508         }
 509         for (i=0; i<lck.num_recs; i++) {
 510                 struct g_lock_rec lockrec;
 511                 g_lock_get_rec(&lck, i, &lockrec);
 512                 if (serverid_equal(&state->self, &lockrec.pid)) {
 513                         break;
 514                 }
 515         }
 516         if (i == lck.num_recs) {
 517                 DBG_DEBUG("Lock not found, num_rec=%zu\n", lck.num_recs);
 518                 state->status = NT_STATUS_NOT_FOUND;
 519                 return;
 520         }
 521
 522         g_lock_rec_del(&lck, i);
 523
 524         if ((lck.num_recs == 0) && (lck.datalen == 0)) {
 525                 state->status = dbwrap_record_delete(rec);
 526                 return;
 527         }
 528         state->status = g_lock_store(rec, &lck, NULL);
 529 }
 530
 531 NTSTATUS g_lock_unlock(struct g_lock_ctx *ctx, TDB_DATA key)
 532 {
 533         struct g_lock_unlock_state state = {
 534                 .self = messaging_server_id(ctx->msg), .key = key
 535         };
 536         NTSTATUS status;
 537
 538         status = dbwrap_do_locked(ctx->db, key, g_lock_unlock_fn, &state);
 539         if (!NT_STATUS_IS_OK(status)) {
 540                 DBG_WARNING("dbwrap_do_locked failed: %s\n",
 541                             nt_errstr(status));
 542                 return status;
 543         }
 544         if (!NT_STATUS_IS_OK(state.status)) {
 545                 DBG_WARNING("g_lock_unlock_fn failed: %s\n",
 546                             nt_errstr(state.status));
 547                 return state.status;
 548         }
 549
 550         return NT_STATUS_OK;
 551 }
 552
 553 struct g_lock_write_data_state {
 554         TDB_DATA key;
 555         struct server_id self;
 556         const uint8_t *data;
 557         size_t datalen;
 558         NTSTATUS status;
 559 };
 560
 561 static void g_lock_write_data_fn(struct db_record *rec,
 562                                  void *private_data)
 563 {
 564         struct g_lock_write_data_state *state = private_data;
 565         TDB_DATA value;
 566         struct g_lock lck;
 567         size_t i;
 568         bool ok;
 569
 570         value = dbwrap_record_get_value(rec);
 571
 572         ok = g_lock_parse(value.dptr, value.dsize, &lck);
 573         if (!ok) {
 574                 DBG_DEBUG("g_lock_parse for %s failed\n",
 575                           hex_encode_talloc(talloc_tos(),
 576                                             state->key.dptr,
 577                                             state->key.dsize));
 578                 state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 579                 return;
 580         }
 581         for (i=0; i<lck.num_recs; i++) {
 582                 struct g_lock_rec lockrec;
 583                 g_lock_get_rec(&lck, i, &lockrec);
 584                 if ((lockrec.lock_type == G_LOCK_WRITE) &&
 585                     serverid_equal(&state->self, &lockrec.pid)) {
 586                         break;
 587                 }
 588         }
 589         if (i == lck.num_recs) {
 590                 DBG_DEBUG("Not locked by us\n");
 591                 state->status = NT_STATUS_NOT_LOCKED;
 592                 return;
 593         }
 594
 595         lck.data = discard_const_p(uint8_t, state->data);
 596         lck.datalen = state->datalen;
 597         state->status = g_lock_store(rec, &lck, NULL);
 598 }
 599
 600 NTSTATUS g_lock_write_data(struct g_lock_ctx *ctx, TDB_DATA key,
 601                            const uint8_t *buf, size_t buflen)
 602 {
 603         struct g_lock_write_data_state state = {
 604                 .key = key, .self = messaging_server_id(ctx->msg),
 605                 .data = buf, .datalen = buflen
 606         };
 607         NTSTATUS status;
 608
 609         status = dbwrap_do_locked(ctx->db, key,
 610                                   g_lock_write_data_fn, &state);
 611         if (!NT_STATUS_IS_OK(status)) {
 612                 DBG_WARNING("dbwrap_do_locked failed: %s\n",
 613                             nt_errstr(status));
 614                 return status;
 615         }
 616         if (!NT_STATUS_IS_OK(state.status)) {
 617                 DBG_WARNING("g_lock_write_data_fn failed: %s\n",
 618                             nt_errstr(state.status));
 619                 return state.status;
 620         }
 621
 622         return NT_STATUS_OK;
 623 }
 624
 625 struct g_lock_locks_state {
 626         int (*fn)(TDB_DATA key, void *private_data);
 627         void *private_data;
 628 };
 629
 630 static int g_lock_locks_fn(struct db_record *rec, void *priv)
 631 {
 632         TDB_DATA key;
 633         struct g_lock_locks_state *state = (struct g_lock_locks_state *)priv;
 634
 635         key = dbwrap_record_get_key(rec);
 636         return state->fn(key, state->private_data);
 637 }
 638
 639 int g_lock_locks(struct g_lock_ctx *ctx,
 640                  int (*fn)(TDB_DATA key, void *private_data),
 641                  void *private_data)
 642 {
 643         struct g_lock_locks_state state;
 644         NTSTATUS status;
 645         int count;
 646
 647         state.fn = fn;
 648         state.private_data = private_data;
 649
 650         status = dbwrap_traverse_read(ctx->db, g_lock_locks_fn, &state, &count);
 651         if (!NT_STATUS_IS_OK(status)) {
 652                 return -1;
 653         }
 654         return count;
 655 }
 656
 657 struct g_lock_dump_state {
 658         TALLOC_CTX *mem_ctx;
 659         TDB_DATA key;
 660         void (*fn)(const struct g_lock_rec *locks,
 661                    size_t num_locks,
 662                    const uint8_t *data,
 663                    size_t datalen,
 664                    void *private_data);
 665         void *private_data;
 666         NTSTATUS status;
 667 };
 668
 669 static void g_lock_dump_fn(TDB_DATA key, TDB_DATA data,
 670                            void *private_data)
 671 {
 672         struct g_lock_dump_state *state = private_data;
 673         struct g_lock_rec *recs;
 674         struct g_lock lck;
 675         size_t i;
 676         bool ok;
 677
 678         ok = g_lock_parse(data.dptr, data.dsize, &lck);
 679         if (!ok) {
 680                 DBG_DEBUG("g_lock_parse failed for %s\n",
 681                           hex_encode_talloc(talloc_tos(),
 682                                             state->key.dptr,
 683                                             state->key.dsize));
 684                 state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 685                 return;
 686         }
 687
 688         recs = talloc_array(state->mem_ctx, struct g_lock_rec, lck.num_recs);
 689         if (recs == NULL) {
 690                 DBG_DEBUG("talloc failed\n");
 691                 state->status = NT_STATUS_NO_MEMORY;
 692                 return;
 693         }
 694
 695         for (i=0; i<lck.num_recs; i++) {
 696                 g_lock_get_rec(&lck, i, &recs[i]);
 697         }
 698
 699         state->fn(recs, lck.num_recs, lck.data, lck.datalen,
 700                   state->private_data);
 701
 702         TALLOC_FREE(recs);
 703
 704         state->status = NT_STATUS_OK;
 705 }
 706
 707 NTSTATUS g_lock_dump(struct g_lock_ctx *ctx, TDB_DATA key,
 708                      void (*fn)(const struct g_lock_rec *locks,
 709                                 size_t num_locks,
 710                                 const uint8_t *data,
 711                                 size_t datalen,
 712                                 void *private_data),
 713                      void *private_data)
 714 {
 715         struct g_lock_dump_state state = {
 716                 .mem_ctx = ctx, .key = key,
 717                 .fn = fn, .private_data = private_data
 718         };
 719         NTSTATUS status;
 720
 721         status = dbwrap_parse_record(ctx->db, key, g_lock_dump_fn, &state);
 722         if (!NT_STATUS_IS_OK(status)) {
 723                 DBG_DEBUG("dbwrap_parse_record returned %s\n",
 724                           nt_errstr(status));
 725                 return status;
 726         }
 727         if (!NT_STATUS_IS_OK(state.status)) {
 728                 DBG_DEBUG("g_lock_dump_fn returned %s\n",
 729                           nt_errstr(state.status));
 730                 return state.status;
 731         }
 732         return NT_STATUS_OK;
 733 }
 734
 735 static bool g_lock_init_all(TALLOC_CTX *mem_ctx,
 736                             struct tevent_context **pev,
 737                             struct messaging_context **pmsg,
 738                             struct g_lock_ctx **pg_ctx)
 739 {
 740         struct tevent_context *ev = NULL;
 741         struct messaging_context *msg = NULL;
 742         struct g_lock_ctx *g_ctx = NULL;
 743
 744         ev = samba_tevent_context_init(mem_ctx);
 745         if (ev == NULL) {
 746                 d_fprintf(stderr, "ERROR: could not init event context\n");
 747                 goto fail;
 748         }
 749         msg = messaging_init(mem_ctx, ev);
 750         if (msg == NULL) {
 751                 d_fprintf(stderr, "ERROR: could not init messaging context\n");
 752                 goto fail;
 753         }
 754         g_ctx = g_lock_ctx_init(mem_ctx, msg);
 755         if (g_ctx == NULL) {
 756                 d_fprintf(stderr, "ERROR: could not init g_lock context\n");
 757                 goto fail;
 758         }
 759
 760         *pev = ev;
 761         *pmsg = msg;
 762         *pg_ctx = g_ctx;
 763         return true;
 764 fail:
 765         TALLOC_FREE(g_ctx);
 766         TALLOC_FREE(msg);
 767         TALLOC_FREE(ev);
 768         return false;
 769 }
 770
 771 NTSTATUS g_lock_do(TDB_DATA key, enum g_lock_type lock_type,
 772                    struct timeval timeout,
 773                    void (*fn)(void *private_data), void *private_data)
 774 {
 775         struct tevent_context *ev = NULL;
 776         struct messaging_context *msg = NULL;
 777         struct g_lock_ctx *g_ctx = NULL;
 778         NTSTATUS status;
 779
 780         if (!g_lock_init_all(talloc_tos(), &ev, &msg, &g_ctx)) {
 781                 status = NT_STATUS_ACCESS_DENIED;
 782                 goto done;
 783         }
 784
 785         status = g_lock_lock(g_ctx, key, lock_type, timeout);
 786         if (!NT_STATUS_IS_OK(status)) {
 787                 goto done;
 788         }
 789         fn(private_data);
 790         g_lock_unlock(g_ctx, key);
 791
 792 done:
 793         TALLOC_FREE(g_ctx);
 794         TALLOC_FREE(msg);
 795         TALLOC_FREE(ev);
 796         return status;
 797 }