ctdb/server/ctdb_ltdb_server.c

   1 /*
   2    ctdb ltdb code - server side
   3
   4    Copyright (C) Andrew Tridgell  2007
   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 "tdb.h"
  22 #include "system/network.h"
  23 #include "system/filesys.h"
  24 #include "system/dir.h"
  25 #include "system/time.h"
  26 #include "../include/ctdb_private.h"
  27 #include "../common/rb_tree.h"
  28 #include "db_wrap.h"
  29 #include "lib/util/dlinklist.h"
  30 #include <ctype.h>
  31
  32 #define PERSISTENT_HEALTH_TDB "persistent_health.tdb"
  33
  34 /**
  35  * write a record to a normal database
  36  *
  37  * This is the server-variant of the ctdb_ltdb_store function.
  38  * It contains logic to determine whether a record should be
  39  * stored or deleted. It also sends SCHEDULE_FOR_DELETION
  40  * controls to the local ctdb daemon if apporpriate.
  41  */
  42 static int ctdb_ltdb_store_server(struct ctdb_db_context *ctdb_db,
  43                                   TDB_DATA key,
  44                                   struct ctdb_ltdb_header *header,
  45                                   TDB_DATA data)
  46 {
  47         struct ctdb_context *ctdb = ctdb_db->ctdb;
  48         TDB_DATA rec;
  49         int ret;
  50         bool seqnum_suppressed = false;
  51         bool keep = false;
  52         bool schedule_for_deletion = false;
  53         bool remove_from_delete_queue = false;
  54         uint32_t lmaster;
  55
  56         if (ctdb->flags & CTDB_FLAG_TORTURE) {
  57                 struct ctdb_ltdb_header *h2;
  58                 rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
  59                 h2 = (struct ctdb_ltdb_header *)rec.dptr;
  60                 if (rec.dptr && rec.dsize >= sizeof(h2) && h2->rsn > header->rsn) {
  61                         DEBUG(DEBUG_CRIT,("RSN regression! %llu %llu\n",
  62                                  (unsigned long long)h2->rsn, (unsigned long long)header->rsn));
  63                 }
  64                 if (rec.dptr) free(rec.dptr);
  65         }
  66
  67         if (ctdb->vnn_map == NULL) {
  68                 /*
  69                  * Called from a client: always store the record
  70                  * Also don't call ctdb_lmaster since it uses the vnn_map!
  71                  */
  72                 keep = true;
  73                 goto store;
  74         }
  75
  76         lmaster = ctdb_lmaster(ctdb_db->ctdb, &key);
  77
  78         /*
  79          * If we migrate an empty record off to another node
  80          * and the record has not been migrated with data,
  81          * delete the record instead of storing the empty record.
  82          */
  83         if (data.dsize != 0) {
  84                 keep = true;
  85         } else if (header->flags & CTDB_REC_RO_FLAGS) {
  86                 keep = true;
  87         } else if (ctdb_db->persistent) {
  88                 keep = true;
  89         } else if (header->flags & CTDB_REC_FLAG_AUTOMATIC) {
  90                 /*
  91                  * The record is not created by the client but
  92                  * automatically by the ctdb_ltdb_fetch logic that
  93                  * creates a record with an initial header in the
  94                  * ltdb before trying to migrate the record from
  95                  * the current lmaster. Keep it instead of trying
  96                  * to delete the non-existing record...
  97                  */
  98                 keep = true;
  99                 schedule_for_deletion = true;
 100         } else if (header->flags & CTDB_REC_FLAG_MIGRATED_WITH_DATA) {
 101                 keep = true;
 102         } else if (ctdb_db->ctdb->pnn == lmaster) {
 103                 /*
 104                  * If we are lmaster, then we usually keep the record.
 105                  * But if we retrieve the dmaster role by a VACUUM_MIGRATE
 106                  * and the record is empty and has never been migrated
 107                  * with data, then we should delete it instead of storing it.
 108                  * This is part of the vacuuming process.
 109                  *
 110                  * The reason that we usually need to store even empty records
 111                  * on the lmaster is that a client operating directly on the
 112                  * lmaster (== dmaster) expects the local copy of the record to
 113                  * exist after successful ctdb migrate call. If the record does
 114                  * not exist, the client goes into a migrate loop and eventually
 115                  * fails. So storing the empty record makes sure that we do not
 116                  * need to change the client code.
 117                  */
 118                 if (!(header->flags & CTDB_REC_FLAG_VACUUM_MIGRATED)) {
 119                         keep = true;
 120                 } else if (ctdb_db->ctdb->pnn != header->dmaster) {
 121                         keep = true;
 122                 }
 123         } else if (ctdb_db->ctdb->pnn == header->dmaster) {
 124                 keep = true;
 125         }
 126
 127         if (keep) {
 128                 if (!ctdb_db->persistent &&
 129                     (ctdb_db->ctdb->pnn == header->dmaster) &&
 130                     !(header->flags & CTDB_REC_RO_FLAGS))
 131                 {
 132                         header->rsn++;
 133
 134                         if (data.dsize == 0) {
 135                                 schedule_for_deletion = true;
 136                         }
 137                 }
 138                 remove_from_delete_queue = !schedule_for_deletion;
 139         }
 140
 141 store:
 142         /*
 143          * The VACUUM_MIGRATED flag is only set temporarily for
 144          * the above logic when the record was retrieved by a
 145          * VACUUM_MIGRATE call and should not be stored in the
 146          * database.
 147          *
 148          * The VACUUM_MIGRATE call is triggered by a vacuum fetch,
 149          * and there are two cases in which the corresponding record
 150          * is stored in the local database:
 151          * 1. The record has been migrated with data in the past
 152          *    (the MIGRATED_WITH_DATA record flag is set).
 153          * 2. The record has been filled with data again since it
 154          *    had been submitted in the VACUUM_FETCH message to the
 155          *    lmaster.
 156          * For such records it is important to not store the
 157          * VACUUM_MIGRATED flag in the database.
 158          */
 159         header->flags &= ~CTDB_REC_FLAG_VACUUM_MIGRATED;
 160
 161         /*
 162          * Similarly, clear the AUTOMATIC flag which should not enter
 163          * the local database copy since this would require client
 164          * modifications to clear the flag when the client stores
 165          * the record.
 166          */
 167         header->flags &= ~CTDB_REC_FLAG_AUTOMATIC;
 168
 169         rec.dsize = sizeof(*header) + data.dsize;
 170         rec.dptr = talloc_size(ctdb, rec.dsize);
 171         CTDB_NO_MEMORY(ctdb, rec.dptr);
 172
 173         memcpy(rec.dptr, header, sizeof(*header));
 174         memcpy(rec.dptr + sizeof(*header), data.dptr, data.dsize);
 175
 176         /* Databases with seqnum updates enabled only get their seqnum
 177            changes when/if we modify the data */
 178         if (ctdb_db->seqnum_update != NULL) {
 179                 TDB_DATA old;
 180                 old = tdb_fetch(ctdb_db->ltdb->tdb, key);
 181
 182                 if ( (old.dsize == rec.dsize)
 183                 && !memcmp(old.dptr+sizeof(struct ctdb_ltdb_header),
 184                           rec.dptr+sizeof(struct ctdb_ltdb_header),
 185                           rec.dsize-sizeof(struct ctdb_ltdb_header)) ) {
 186                         tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 187                         seqnum_suppressed = true;
 188                 }
 189                 if (old.dptr) free(old.dptr);
 190         }
 191
 192         DEBUG(DEBUG_DEBUG, (__location__ " db[%s]: %s record: hash[0x%08x]\n",
 193                             ctdb_db->db_name,
 194                             keep?"storing":"deleting",
 195                             ctdb_hash(&key)));
 196
 197         if (keep) {
 198                 ret = tdb_store(ctdb_db->ltdb->tdb, key, rec, TDB_REPLACE);
 199         } else {
 200                 ret = tdb_delete(ctdb_db->ltdb->tdb, key);
 201         }
 202
 203         if (ret != 0) {
 204                 int lvl = DEBUG_ERR;
 205
 206                 if (keep == false &&
 207                     tdb_error(ctdb_db->ltdb->tdb) == TDB_ERR_NOEXIST)
 208                 {
 209                         lvl = DEBUG_DEBUG;
 210                 }
 211
 212                 DEBUG(lvl, (__location__ " db[%s]: Failed to %s record: "
 213                             "%d - %s\n",
 214                             ctdb_db->db_name,
 215                             keep?"store":"delete", ret,
 216                             tdb_errorstr(ctdb_db->ltdb->tdb)));
 217
 218                 schedule_for_deletion = false;
 219                 remove_from_delete_queue = false;
 220         }
 221         if (seqnum_suppressed) {
 222                 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 223         }
 224
 225         talloc_free(rec.dptr);
 226
 227         if (schedule_for_deletion) {
 228                 int ret2;
 229                 ret2 = ctdb_local_schedule_for_deletion(ctdb_db, header, key);
 230                 if (ret2 != 0) {
 231                         DEBUG(DEBUG_ERR, (__location__ " ctdb_local_schedule_for_deletion failed.\n"));
 232                 }
 233         }
 234
 235         if (remove_from_delete_queue) {
 236                 ctdb_local_remove_from_delete_queue(ctdb_db, header, key);
 237         }
 238
 239         return ret;
 240 }
 241
 242 struct lock_fetch_state {
 243         struct ctdb_context *ctdb;
 244         void (*recv_pkt)(void *, struct ctdb_req_header *);
 245         void *recv_context;
 246         struct ctdb_req_header *hdr;
 247         uint32_t generation;
 248         bool ignore_generation;
 249 };
 250
 251 /*
 252   called when we should retry the operation
 253  */
 254 static void lock_fetch_callback(void *p, bool locked)
 255 {
 256         struct lock_fetch_state *state = talloc_get_type(p, struct lock_fetch_state);
 257         if (!state->ignore_generation &&
 258             state->generation != state->ctdb->vnn_map->generation) {
 259                 DEBUG(DEBUG_NOTICE,("Discarding previous generation lockwait packet\n"));
 260                 talloc_free(state->hdr);
 261                 return;
 262         }
 263         state->recv_pkt(state->recv_context, state->hdr);
 264         DEBUG(DEBUG_INFO,(__location__ " PACKET REQUEUED\n"));
 265 }
 266
 267
 268 /*
 269   do a non-blocking ltdb_lock, deferring this ctdb request until we
 270   have the chainlock
 271
 272   It does the following:
 273
 274    1) tries to get the chainlock. If it succeeds, then it returns 0
 275
 276    2) if it fails to get a chainlock immediately then it sets up a
 277    non-blocking chainlock via ctdb_lock_record, and when it gets the
 278    chainlock it re-submits this ctdb request to the main packet
 279    receive function.
 280
 281    This effectively queues all ctdb requests that cannot be
 282    immediately satisfied until it can get the lock. This means that
 283    the main ctdb daemon will not block waiting for a chainlock held by
 284    a client
 285
 286    There are 3 possible return values:
 287
 288        0:    means that it got the lock immediately.
 289       -1:    means that it failed to get the lock, and won't retry
 290       -2:    means that it failed to get the lock immediately, but will retry
 291  */
 292 int ctdb_ltdb_lock_requeue(struct ctdb_db_context *ctdb_db,
 293                            TDB_DATA key, struct ctdb_req_header *hdr,
 294                            void (*recv_pkt)(void *, struct ctdb_req_header *),
 295                            void *recv_context, bool ignore_generation)
 296 {
 297         int ret;
 298         struct tdb_context *tdb = ctdb_db->ltdb->tdb;
 299         struct lock_request *lreq;
 300         struct lock_fetch_state *state;
 301
 302         ret = tdb_chainlock_nonblock(tdb, key);
 303
 304         if (ret != 0 &&
 305             !(errno == EACCES || errno == EAGAIN || errno == EDEADLK)) {
 306                 /* a hard failure - don't try again */
 307                 return -1;
 308         }
 309
 310         /* when torturing, ensure we test the contended path */
 311         if ((ctdb_db->ctdb->flags & CTDB_FLAG_TORTURE) &&
 312             random() % 5 == 0) {
 313                 ret = -1;
 314                 tdb_chainunlock(tdb, key);
 315         }
 316
 317         /* first the non-contended path */
 318         if (ret == 0) {
 319                 return 0;
 320         }
 321
 322         state = talloc(hdr, struct lock_fetch_state);
 323         state->ctdb = ctdb_db->ctdb;
 324         state->hdr = hdr;
 325         state->recv_pkt = recv_pkt;
 326         state->recv_context = recv_context;
 327         state->generation = ctdb_db->ctdb->vnn_map->generation;
 328         state->ignore_generation = ignore_generation;
 329
 330         /* now the contended path */
 331         lreq = ctdb_lock_record(state, ctdb_db, key, true, lock_fetch_callback, state);
 332         if (lreq == NULL) {
 333                 return -1;
 334         }
 335
 336         /* we need to move the packet off the temporary context in ctdb_input_pkt(),
 337            so it won't be freed yet */
 338         talloc_steal(state, hdr);
 339
 340         /* now tell the caller than we will retry asynchronously */
 341         return -2;
 342 }
 343
 344 /*
 345   a varient of ctdb_ltdb_lock_requeue that also fetches the record
 346  */
 347 int ctdb_ltdb_lock_fetch_requeue(struct ctdb_db_context *ctdb_db,
 348                                  TDB_DATA key, struct ctdb_ltdb_header *header,
 349                                  struct ctdb_req_header *hdr, TDB_DATA *data,
 350                                  void (*recv_pkt)(void *, struct ctdb_req_header *),
 351                                  void *recv_context, bool ignore_generation)
 352 {
 353         int ret;
 354
 355         ret = ctdb_ltdb_lock_requeue(ctdb_db, key, hdr, recv_pkt,
 356                                      recv_context, ignore_generation);
 357         if (ret == 0) {
 358                 ret = ctdb_ltdb_fetch(ctdb_db, key, header, hdr, data);
 359                 if (ret != 0) {
 360                         int uret;
 361                         uret = ctdb_ltdb_unlock(ctdb_db, key);
 362                         if (uret != 0) {
 363                                 DEBUG(DEBUG_ERR,(__location__ " ctdb_ltdb_unlock() failed with error %d\n", uret));
 364                         }
 365                 }
 366         }
 367         return ret;
 368 }
 369
 370
 371 /*
 372   paraoid check to see if the db is empty
 373  */
 374 static void ctdb_check_db_empty(struct ctdb_db_context *ctdb_db)
 375 {
 376         struct tdb_context *tdb = ctdb_db->ltdb->tdb;
 377         int count = tdb_traverse_read(tdb, NULL, NULL);
 378         if (count != 0) {
 379                 DEBUG(DEBUG_ALERT,(__location__ " tdb '%s' not empty on attach! aborting\n",
 380                          ctdb_db->db_path));
 381                 ctdb_fatal(ctdb_db->ctdb, "database not empty on attach");
 382         }
 383 }
 384
 385 int ctdb_load_persistent_health(struct ctdb_context *ctdb,
 386                                 struct ctdb_db_context *ctdb_db)
 387 {
 388         struct tdb_context *tdb = ctdb->db_persistent_health->tdb;
 389         char *old;
 390         char *reason = NULL;
 391         TDB_DATA key;
 392         TDB_DATA val;
 393
 394         key.dptr = discard_const_p(uint8_t, ctdb_db->db_name);
 395         key.dsize = strlen(ctdb_db->db_name);
 396
 397         old = ctdb_db->unhealthy_reason;
 398         ctdb_db->unhealthy_reason = NULL;
 399
 400         val = tdb_fetch(tdb, key);
 401         if (val.dsize > 0) {
 402                 reason = talloc_strndup(ctdb_db,
 403                                         (const char *)val.dptr,
 404                                         val.dsize);
 405                 if (reason == NULL) {
 406                         DEBUG(DEBUG_ALERT,(__location__ " talloc_strndup(%d) failed\n",
 407                                            (int)val.dsize));
 408                         ctdb_db->unhealthy_reason = old;
 409                         free(val.dptr);
 410                         return -1;
 411                 }
 412         }
 413
 414         if (val.dptr) {
 415                 free(val.dptr);
 416         }
 417
 418         talloc_free(old);
 419         ctdb_db->unhealthy_reason = reason;
 420         return 0;
 421 }
 422
 423 int ctdb_update_persistent_health(struct ctdb_context *ctdb,
 424                                   struct ctdb_db_context *ctdb_db,
 425                                   const char *given_reason,/* NULL means healthy */
 426                                   int num_healthy_nodes)
 427 {
 428         struct tdb_context *tdb = ctdb->db_persistent_health->tdb;
 429         int ret;
 430         TDB_DATA key;
 431         TDB_DATA val;
 432         char *new_reason = NULL;
 433         char *old_reason = NULL;
 434
 435         ret = tdb_transaction_start(tdb);
 436         if (ret != 0) {
 437                 DEBUG(DEBUG_ALERT,(__location__ " tdb_transaction_start('%s') failed: %d - %s\n",
 438                                    tdb_name(tdb), ret, tdb_errorstr(tdb)));
 439                 return -1;
 440         }
 441
 442         ret = ctdb_load_persistent_health(ctdb, ctdb_db);
 443         if (ret != 0) {
 444                 DEBUG(DEBUG_ALERT,(__location__ " ctdb_load_persistent_health('%s') failed: %d\n",
 445                                    ctdb_db->db_name, ret));
 446                 return -1;
 447         }
 448         old_reason = ctdb_db->unhealthy_reason;
 449
 450         key.dptr = discard_const_p(uint8_t, ctdb_db->db_name);
 451         key.dsize = strlen(ctdb_db->db_name);
 452
 453         if (given_reason) {
 454                 new_reason = talloc_strdup(ctdb_db, given_reason);
 455                 if (new_reason == NULL) {
 456                         DEBUG(DEBUG_ALERT,(__location__ " talloc_strdup(%s) failed\n",
 457                                           given_reason));
 458                         return -1;
 459                 }
 460         } else if (old_reason && num_healthy_nodes == 0) {
 461                 /*
 462                  * If the reason indicates ok, but there where no healthy nodes
 463                  * available, that it means, we have not recovered valid content
 464                  * of the db. So if there's an old reason, prefix it with
 465                  * "NO-HEALTHY-NODES - "
 466                  */
 467                 const char *prefix;
 468
 469 #define _TMP_PREFIX "NO-HEALTHY-NODES - "
 470                 ret = strncmp(_TMP_PREFIX, old_reason, strlen(_TMP_PREFIX));
 471                 if (ret != 0) {
 472                         prefix = _TMP_PREFIX;
 473                 } else {
 474                         prefix = "";
 475                 }
 476                 new_reason = talloc_asprintf(ctdb_db, "%s%s",
 477                                          prefix, old_reason);
 478                 if (new_reason == NULL) {
 479                         DEBUG(DEBUG_ALERT,(__location__ " talloc_asprintf(%s%s) failed\n",
 480                                           prefix, old_reason));
 481                         return -1;
 482                 }
 483 #undef _TMP_PREFIX
 484         }
 485
 486         if (new_reason) {
 487                 val.dptr = discard_const_p(uint8_t, new_reason);
 488                 val.dsize = strlen(new_reason);
 489
 490                 ret = tdb_store(tdb, key, val, TDB_REPLACE);
 491                 if (ret != 0) {
 492                         tdb_transaction_cancel(tdb);
 493                         DEBUG(DEBUG_ALERT,(__location__ " tdb_store('%s', %s, %s) failed: %d - %s\n",
 494                                            tdb_name(tdb), ctdb_db->db_name, new_reason,
 495                                            ret, tdb_errorstr(tdb)));
 496                         talloc_free(new_reason);
 497                         return -1;
 498                 }
 499                 DEBUG(DEBUG_ALERT,("Updated db health for db(%s) to: %s\n",
 500                                    ctdb_db->db_name, new_reason));
 501         } else if (old_reason) {
 502                 ret = tdb_delete(tdb, key);
 503                 if (ret != 0) {
 504                         tdb_transaction_cancel(tdb);
 505                         DEBUG(DEBUG_ALERT,(__location__ " tdb_delete('%s', %s) failed: %d - %s\n",
 506                                            tdb_name(tdb), ctdb_db->db_name,
 507                                            ret, tdb_errorstr(tdb)));
 508                         talloc_free(new_reason);
 509                         return -1;
 510                 }
 511                 DEBUG(DEBUG_NOTICE,("Updated db health for db(%s): OK\n",
 512                                    ctdb_db->db_name));
 513         }
 514
 515         ret = tdb_transaction_commit(tdb);
 516         if (ret != TDB_SUCCESS) {
 517                 DEBUG(DEBUG_ALERT,(__location__ " tdb_transaction_commit('%s') failed: %d - %s\n",
 518                                    tdb_name(tdb), ret, tdb_errorstr(tdb)));
 519                 talloc_free(new_reason);
 520                 return -1;
 521         }
 522
 523         talloc_free(old_reason);
 524         ctdb_db->unhealthy_reason = new_reason;
 525
 526         return 0;
 527 }
 528
 529 static int ctdb_backup_corrupted_tdb(struct ctdb_context *ctdb,
 530                                      struct ctdb_db_context *ctdb_db)
 531 {
 532         time_t now = time(NULL);
 533         char *new_path;
 534         char *new_reason;
 535         int ret;
 536         struct tm *tm;
 537
 538         tm = gmtime(&now);
 539
 540         /* formatted like: foo.tdb.0.corrupted.20091204160825.0Z */
 541         new_path = talloc_asprintf(ctdb_db, "%s.corrupted."
 542                                    "%04u%02u%02u%02u%02u%02u.0Z",
 543                                    ctdb_db->db_path,
 544                                    tm->tm_year+1900, tm->tm_mon+1,
 545                                    tm->tm_mday, tm->tm_hour, tm->tm_min,
 546                                    tm->tm_sec);
 547         if (new_path == NULL) {
 548                 DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
 549                 return -1;
 550         }
 551
 552         new_reason = talloc_asprintf(ctdb_db,
 553                                      "ERROR - Backup of corrupted TDB in '%s'",
 554                                      new_path);
 555         if (new_reason == NULL) {
 556                 DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
 557                 return -1;
 558         }
 559         ret = ctdb_update_persistent_health(ctdb, ctdb_db, new_reason, 0);
 560         talloc_free(new_reason);
 561         if (ret != 0) {
 562                 DEBUG(DEBUG_CRIT,(__location__
 563                                  ": ctdb_backup_corrupted_tdb(%s) not implemented yet\n",
 564                                  ctdb_db->db_path));
 565                 return -1;
 566         }
 567
 568         ret = rename(ctdb_db->db_path, new_path);
 569         if (ret != 0) {
 570                 DEBUG(DEBUG_CRIT,(__location__
 571                                   ": ctdb_backup_corrupted_tdb(%s) rename to %s failed: %d - %s\n",
 572                                   ctdb_db->db_path, new_path,
 573                                   errno, strerror(errno)));
 574                 talloc_free(new_path);
 575                 return -1;
 576         }
 577
 578         DEBUG(DEBUG_CRIT,(__location__
 579                          ": ctdb_backup_corrupted_tdb(%s) renamed to %s\n",
 580                          ctdb_db->db_path, new_path));
 581         talloc_free(new_path);
 582         return 0;
 583 }
 584
 585 int ctdb_recheck_persistent_health(struct ctdb_context *ctdb)
 586 {
 587         struct ctdb_db_context *ctdb_db;
 588         int ret;
 589         int ok = 0;
 590         int fail = 0;
 591
 592         for (ctdb_db = ctdb->db_list; ctdb_db; ctdb_db = ctdb_db->next) {
 593                 if (!ctdb_db->persistent) {
 594                         continue;
 595                 }
 596
 597                 ret = ctdb_load_persistent_health(ctdb, ctdb_db);
 598                 if (ret != 0) {
 599                         DEBUG(DEBUG_ALERT,(__location__
 600                                            " load persistent health for '%s' failed\n",
 601                                            ctdb_db->db_path));
 602                         return -1;
 603                 }
 604
 605                 if (ctdb_db->unhealthy_reason == NULL) {
 606                         ok++;
 607                         DEBUG(DEBUG_INFO,(__location__
 608                                    " persistent db '%s' healthy\n",
 609                                    ctdb_db->db_path));
 610                         continue;
 611                 }
 612
 613                 fail++;
 614                 DEBUG(DEBUG_ALERT,(__location__
 615                                    " persistent db '%s' unhealthy: %s\n",
 616                                    ctdb_db->db_path,
 617                                    ctdb_db->unhealthy_reason));
 618         }
 619         DEBUG((fail!=0)?DEBUG_ALERT:DEBUG_NOTICE,
 620               ("ctdb_recheck_presistent_health: OK[%d] FAIL[%d]\n",
 621                ok, fail));
 622
 623         if (fail != 0) {
 624                 return -1;
 625         }
 626
 627         return 0;
 628 }
 629
 630
 631 /*
 632   mark a database - as healthy
 633  */
 634 int32_t ctdb_control_db_set_healthy(struct ctdb_context *ctdb, TDB_DATA indata)
 635 {
 636         uint32_t db_id = *(uint32_t *)indata.dptr;
 637         struct ctdb_db_context *ctdb_db;
 638         int ret;
 639         bool may_recover = false;
 640
 641         ctdb_db = find_ctdb_db(ctdb, db_id);
 642         if (!ctdb_db) {
 643                 DEBUG(DEBUG_ERR,(__location__ " Unknown db 0x%x\n", db_id));
 644                 return -1;
 645         }
 646
 647         if (ctdb_db->unhealthy_reason) {
 648                 may_recover = true;
 649         }
 650
 651         ret = ctdb_update_persistent_health(ctdb, ctdb_db, NULL, 1);
 652         if (ret != 0) {
 653                 DEBUG(DEBUG_ERR,(__location__
 654                                  " ctdb_update_persistent_health(%s) failed\n",
 655                                  ctdb_db->db_name));
 656                 return -1;
 657         }
 658
 659         if (may_recover && ctdb->runstate == CTDB_RUNSTATE_STARTUP) {
 660                 DEBUG(DEBUG_ERR, (__location__ " db %s become healthy  - force recovery for startup\n",
 661                                   ctdb_db->db_name));
 662                 ctdb->recovery_mode = CTDB_RECOVERY_ACTIVE;
 663         }
 664
 665         return 0;
 666 }
 667
 668 int32_t ctdb_control_db_get_health(struct ctdb_context *ctdb,
 669                                    TDB_DATA indata,
 670                                    TDB_DATA *outdata)
 671 {
 672         uint32_t db_id = *(uint32_t *)indata.dptr;
 673         struct ctdb_db_context *ctdb_db;
 674         int ret;
 675
 676         ctdb_db = find_ctdb_db(ctdb, db_id);
 677         if (!ctdb_db) {
 678                 DEBUG(DEBUG_ERR,(__location__ " Unknown db 0x%x\n", db_id));
 679                 return -1;
 680         }
 681
 682         ret = ctdb_load_persistent_health(ctdb, ctdb_db);
 683         if (ret != 0) {
 684                 DEBUG(DEBUG_ERR,(__location__
 685                                  " ctdb_load_persistent_health(%s) failed\n",
 686                                  ctdb_db->db_name));
 687                 return -1;
 688         }
 689
 690         *outdata = tdb_null;
 691         if (ctdb_db->unhealthy_reason) {
 692                 outdata->dptr = (uint8_t *)ctdb_db->unhealthy_reason;
 693                 outdata->dsize = strlen(ctdb_db->unhealthy_reason)+1;
 694         }
 695
 696         return 0;
 697 }
 698
 699
 700 int ctdb_set_db_readonly(struct ctdb_context *ctdb, struct ctdb_db_context *ctdb_db)
 701 {
 702         char *ropath;
 703
 704         if (ctdb_db->readonly) {
 705                 return 0;
 706         }
 707
 708         if (ctdb_db->persistent) {
 709                 DEBUG(DEBUG_ERR,("Persistent databases do not support readonly property\n"));
 710                 return -1;
 711         }
 712
 713         ropath = talloc_asprintf(ctdb_db, "%s.RO", ctdb_db->db_path);
 714         if (ropath == NULL) {
 715                 DEBUG(DEBUG_CRIT,("Failed to asprintf the tracking database\n"));
 716                 return -1;
 717         }
 718         ctdb_db->rottdb = tdb_open(ropath,
 719                               ctdb->tunable.database_hash_size,
 720                               TDB_NOLOCK|TDB_CLEAR_IF_FIRST|TDB_NOSYNC,
 721                               O_CREAT|O_RDWR, 0);
 722         if (ctdb_db->rottdb == NULL) {
 723                 DEBUG(DEBUG_CRIT,("Failed to open/create the tracking database '%s'\n", ropath));
 724                 talloc_free(ropath);
 725                 return -1;
 726         }
 727
 728         DEBUG(DEBUG_NOTICE,("OPENED tracking database : '%s'\n", ropath));
 729
 730         ctdb_db->readonly = true;
 731
 732         DEBUG(DEBUG_NOTICE, ("Readonly property set on DB %s\n", ctdb_db->db_name));
 733
 734         talloc_free(ropath);
 735         return 0;
 736 }
 737
 738 /*
 739   attach to a database, handling both persistent and non-persistent databases
 740   return 0 on success, -1 on failure
 741  */
 742 static int ctdb_local_attach(struct ctdb_context *ctdb, const char *db_name,
 743                              bool persistent, const char *unhealthy_reason,
 744                              bool jenkinshash, bool mutexes)
 745 {
 746         struct ctdb_db_context *ctdb_db, *tmp_db;
 747         int ret;
 748         struct TDB_DATA key;
 749         unsigned tdb_flags;
 750         int mode = 0600;
 751         int remaining_tries = 0;
 752
 753         ctdb_db = talloc_zero(ctdb, struct ctdb_db_context);
 754         CTDB_NO_MEMORY(ctdb, ctdb_db);
 755
 756         ctdb_db->priority = 1;
 757         ctdb_db->ctdb = ctdb;
 758         ctdb_db->db_name = talloc_strdup(ctdb_db, db_name);
 759         CTDB_NO_MEMORY(ctdb, ctdb_db->db_name);
 760
 761         key.dsize = strlen(db_name)+1;
 762         key.dptr  = discard_const(db_name);
 763         ctdb_db->db_id = ctdb_hash(&key);
 764         ctdb_db->persistent = persistent;
 765
 766         if (!ctdb_db->persistent) {
 767                 ctdb_db->delete_queue = trbt_create(ctdb_db, 0);
 768                 if (ctdb_db->delete_queue == NULL) {
 769                         CTDB_NO_MEMORY(ctdb, ctdb_db->delete_queue);
 770                 }
 771
 772                 ctdb_db->ctdb_ltdb_store_fn = ctdb_ltdb_store_server;
 773         }
 774
 775         /* check for hash collisions */
 776         for (tmp_db=ctdb->db_list;tmp_db;tmp_db=tmp_db->next) {
 777                 if (tmp_db->db_id == ctdb_db->db_id) {
 778                         DEBUG(DEBUG_CRIT,("db_id 0x%x hash collision. name1='%s' name2='%s'\n",
 779                                  tmp_db->db_id, db_name, tmp_db->db_name));
 780                         talloc_free(ctdb_db);
 781                         return -1;
 782                 }
 783         }
 784
 785         if (persistent) {
 786                 if (unhealthy_reason) {
 787                         ret = ctdb_update_persistent_health(ctdb, ctdb_db,
 788                                                             unhealthy_reason, 0);
 789                         if (ret != 0) {
 790                                 DEBUG(DEBUG_ALERT,(__location__ " ctdb_update_persistent_health('%s','%s') failed: %d\n",
 791                                                    ctdb_db->db_name, unhealthy_reason, ret));
 792                                 talloc_free(ctdb_db);
 793                                 return -1;
 794                         }
 795                 }
 796
 797                 if (ctdb->max_persistent_check_errors > 0) {
 798                         remaining_tries = 1;
 799                 }
 800                 if (ctdb->runstate == CTDB_RUNSTATE_RUNNING) {
 801                         remaining_tries = 0;
 802                 }
 803
 804                 ret = ctdb_load_persistent_health(ctdb, ctdb_db);
 805                 if (ret != 0) {
 806                         DEBUG(DEBUG_ALERT,(__location__ " ctdb_load_persistent_health('%s') failed: %d\n",
 807                                    ctdb_db->db_name, ret));
 808                         talloc_free(ctdb_db);
 809                         return -1;
 810                 }
 811         }
 812
 813         if (ctdb_db->unhealthy_reason && remaining_tries == 0) {
 814                 DEBUG(DEBUG_ALERT,(__location__ "ERROR: tdb %s is marked as unhealthy: %s\n",
 815                                    ctdb_db->db_name, ctdb_db->unhealthy_reason));
 816                 talloc_free(ctdb_db);
 817                 return -1;
 818         }
 819
 820         if (ctdb_db->unhealthy_reason) {
 821                 /* this is just a warning, but we want that in the log file! */
 822                 DEBUG(DEBUG_ALERT,(__location__ "Warning: tdb %s is marked as unhealthy: %s\n",
 823                                    ctdb_db->db_name, ctdb_db->unhealthy_reason));
 824         }
 825
 826         /* open the database */
 827         ctdb_db->db_path = talloc_asprintf(ctdb_db, "%s/%s.%u",
 828                                            persistent?ctdb->db_directory_persistent:ctdb->db_directory,
 829                                            db_name, ctdb->pnn);
 830
 831         tdb_flags = persistent? TDB_DEFAULT : TDB_CLEAR_IF_FIRST | TDB_NOSYNC;
 832         if (ctdb->valgrinding) {
 833                 tdb_flags |= TDB_NOMMAP;
 834         }
 835         tdb_flags |= TDB_DISALLOW_NESTING;
 836         if (jenkinshash) {
 837                 tdb_flags |= TDB_INCOMPATIBLE_HASH;
 838         }
 839 #ifdef TDB_MUTEX_LOCKING
 840         if (ctdb->tunable.mutex_enabled && mutexes &&
 841             tdb_runtime_check_for_robust_mutexes()) {
 842                 tdb_flags |= TDB_MUTEX_LOCKING;
 843         }
 844 #endif
 845
 846 again:
 847         ctdb_db->ltdb = tdb_wrap_open(ctdb_db, ctdb_db->db_path,
 848                                       ctdb->tunable.database_hash_size,
 849                                       tdb_flags,
 850                                       O_CREAT|O_RDWR, mode);
 851         if (ctdb_db->ltdb == NULL) {
 852                 struct stat st;
 853                 int saved_errno = errno;
 854
 855                 if (!persistent) {
 856                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s': %d - %s\n",
 857                                           ctdb_db->db_path,
 858                                           saved_errno,
 859                                           strerror(saved_errno)));
 860                         talloc_free(ctdb_db);
 861                         return -1;
 862                 }
 863
 864                 if (remaining_tries == 0) {
 865                         DEBUG(DEBUG_CRIT,(__location__
 866                                           "Failed to open persistent tdb '%s': %d - %s\n",
 867                                           ctdb_db->db_path,
 868                                           saved_errno,
 869                                           strerror(saved_errno)));
 870                         talloc_free(ctdb_db);
 871                         return -1;
 872                 }
 873
 874                 ret = stat(ctdb_db->db_path, &st);
 875                 if (ret != 0) {
 876                         DEBUG(DEBUG_CRIT,(__location__
 877                                           "Failed to open persistent tdb '%s': %d - %s\n",
 878                                           ctdb_db->db_path,
 879                                           saved_errno,
 880                                           strerror(saved_errno)));
 881                         talloc_free(ctdb_db);
 882                         return -1;
 883                 }
 884
 885                 ret = ctdb_backup_corrupted_tdb(ctdb, ctdb_db);
 886                 if (ret != 0) {
 887                         DEBUG(DEBUG_CRIT,(__location__
 888                                           "Failed to open persistent tdb '%s': %d - %s\n",
 889                                           ctdb_db->db_path,
 890                                           saved_errno,
 891                                           strerror(saved_errno)));
 892                         talloc_free(ctdb_db);
 893                         return -1;
 894                 }
 895
 896                 remaining_tries--;
 897                 mode = st.st_mode;
 898                 goto again;
 899         }
 900
 901         if (!persistent) {
 902                 ctdb_check_db_empty(ctdb_db);
 903         } else {
 904                 ret = tdb_check(ctdb_db->ltdb->tdb, NULL, NULL);
 905                 if (ret != 0) {
 906                         int fd;
 907                         struct stat st;
 908
 909                         DEBUG(DEBUG_CRIT,("tdb_check(%s) failed: %d - %s\n",
 910                                           ctdb_db->db_path, ret,
 911                                           tdb_errorstr(ctdb_db->ltdb->tdb)));
 912                         if (remaining_tries == 0) {
 913                                 talloc_free(ctdb_db);
 914                                 return -1;
 915                         }
 916
 917                         fd = tdb_fd(ctdb_db->ltdb->tdb);
 918                         ret = fstat(fd, &st);
 919                         if (ret != 0) {
 920                                 DEBUG(DEBUG_CRIT,(__location__
 921                                                   "Failed to fstat() persistent tdb '%s': %d - %s\n",
 922                                                   ctdb_db->db_path,
 923                                                   errno,
 924                                                   strerror(errno)));
 925                                 talloc_free(ctdb_db);
 926                                 return -1;
 927                         }
 928
 929                         /* close the TDB */
 930                         talloc_free(ctdb_db->ltdb);
 931                         ctdb_db->ltdb = NULL;
 932
 933                         ret = ctdb_backup_corrupted_tdb(ctdb, ctdb_db);
 934                         if (ret != 0) {
 935                                 DEBUG(DEBUG_CRIT,("Failed to backup corrupted tdb '%s'\n",
 936                                                   ctdb_db->db_path));
 937                                 talloc_free(ctdb_db);
 938                                 return -1;
 939                         }
 940
 941                         remaining_tries--;
 942                         mode = st.st_mode;
 943                         goto again;
 944                 }
 945         }
 946
 947         /* set up a rb tree we can use to track which records we have a
 948            fetch-lock in-flight for so we can defer any additional calls
 949            for the same record.
 950          */
 951         ctdb_db->deferred_fetch = trbt_create(ctdb_db, 0);
 952         if (ctdb_db->deferred_fetch == NULL) {
 953                 DEBUG(DEBUG_ERR,("Failed to create deferred fetch rb tree for ctdb database\n"));
 954                 talloc_free(ctdb_db);
 955                 return -1;
 956         }
 957
 958         DLIST_ADD(ctdb->db_list, ctdb_db);
 959
 960         /* setting this can help some high churn databases */
 961         tdb_set_max_dead(ctdb_db->ltdb->tdb, ctdb->tunable.database_max_dead);
 962
 963         /*
 964            all databases support the "null" function. we need this in
 965            order to do forced migration of records
 966         */
 967         ret = ctdb_daemon_set_call(ctdb, ctdb_db->db_id, ctdb_null_func, CTDB_NULL_FUNC);
 968         if (ret != 0) {
 969                 DEBUG(DEBUG_CRIT,("Failed to setup null function for '%s'\n", ctdb_db->db_name));
 970                 talloc_free(ctdb_db);
 971                 return -1;
 972         }
 973
 974         /*
 975            all databases support the "fetch" function. we need this
 976            for efficient Samba3 ctdb fetch
 977         */
 978         ret = ctdb_daemon_set_call(ctdb, ctdb_db->db_id, ctdb_fetch_func, CTDB_FETCH_FUNC);
 979         if (ret != 0) {
 980                 DEBUG(DEBUG_CRIT,("Failed to setup fetch function for '%s'\n", ctdb_db->db_name));
 981                 talloc_free(ctdb_db);
 982                 return -1;
 983         }
 984
 985         /*
 986            all databases support the "fetch_with_header" function. we need this
 987            for efficient readonly record fetches
 988         */
 989         ret = ctdb_daemon_set_call(ctdb, ctdb_db->db_id, ctdb_fetch_with_header_func, CTDB_FETCH_WITH_HEADER_FUNC);
 990         if (ret != 0) {
 991                 DEBUG(DEBUG_CRIT,("Failed to setup fetch function for '%s'\n", ctdb_db->db_name));
 992                 talloc_free(ctdb_db);
 993                 return -1;
 994         }
 995
 996         ret = ctdb_vacuum_init(ctdb_db);
 997         if (ret != 0) {
 998                 DEBUG(DEBUG_CRIT,("Failed to setup vacuuming for "
 999                                   "database '%s'\n", ctdb_db->db_name));
1000                 talloc_free(ctdb_db);
1001                 return -1;
1002         }
1003
1004
1005         DEBUG(DEBUG_NOTICE,("Attached to database '%s' with flags 0x%x\n",
1006                             ctdb_db->db_path, tdb_flags));
1007
1008         /* success */
1009         return 0;
1010 }
1011
1012
1013 struct ctdb_deferred_attach_context {
1014         struct ctdb_deferred_attach_context *next, *prev;
1015         struct ctdb_context *ctdb;
1016         struct ctdb_req_control *c;
1017 };
1018
1019
1020 static int ctdb_deferred_attach_destructor(struct ctdb_deferred_attach_context *da_ctx)
1021 {
1022         DLIST_REMOVE(da_ctx->ctdb->deferred_attach, da_ctx);
1023
1024         return 0;
1025 }
1026
1027 static void ctdb_deferred_attach_timeout(struct event_context *ev, struct timed_event *te, struct timeval t, void *private_data)
1028 {
1029         struct ctdb_deferred_attach_context *da_ctx = talloc_get_type(private_data, struct ctdb_deferred_attach_context);
1030         struct ctdb_context *ctdb = da_ctx->ctdb;
1031
1032         ctdb_request_control_reply(ctdb, da_ctx->c, NULL, -1, NULL);
1033         talloc_free(da_ctx);
1034 }
1035
1036 static void ctdb_deferred_attach_callback(struct event_context *ev, struct timed_event *te, struct timeval t, void *private_data)
1037 {
1038         struct ctdb_deferred_attach_context *da_ctx = talloc_get_type(private_data, struct ctdb_deferred_attach_context);
1039         struct ctdb_context *ctdb = da_ctx->ctdb;
1040
1041         /* This talloc-steals the packet ->c */
1042         ctdb_input_pkt(ctdb, (struct ctdb_req_header *)da_ctx->c);
1043         talloc_free(da_ctx);
1044 }
1045
1046 int ctdb_process_deferred_attach(struct ctdb_context *ctdb)
1047 {
1048         struct ctdb_deferred_attach_context *da_ctx;
1049
1050         /* call it from the main event loop as soon as the current event
1051            finishes.
1052          */
1053         while ((da_ctx = ctdb->deferred_attach) != NULL) {
1054                 DLIST_REMOVE(ctdb->deferred_attach, da_ctx);
1055                 event_add_timed(ctdb->ev, da_ctx, timeval_current_ofs(1,0), ctdb_deferred_attach_callback, da_ctx);
1056         }
1057
1058         return 0;
1059 }
1060
1061 /*
1062   a client has asked to attach a new database
1063  */
1064 int32_t ctdb_control_db_attach(struct ctdb_context *ctdb, TDB_DATA indata,
1065                                TDB_DATA *outdata, uint64_t tdb_flags,
1066                                bool persistent, uint32_t client_id,
1067                                struct ctdb_req_control *c,
1068                                bool *async_reply)
1069 {
1070         const char *db_name = (const char *)indata.dptr;
1071         struct ctdb_db_context *db;
1072         struct ctdb_node *node = ctdb->nodes[ctdb->pnn];
1073         struct ctdb_client *client = NULL;
1074         bool with_jenkinshash, with_mutexes;
1075
1076         if (ctdb->tunable.allow_client_db_attach == 0) {
1077                 DEBUG(DEBUG_ERR, ("DB Attach to database %s denied by tunable "
1078                                   "AllowClientDBAccess == 0\n", db_name));
1079                 return -1;
1080         }
1081
1082         /* dont allow any local clients to attach while we are in recovery mode
1083          * except for the recovery daemon.
1084          * allow all attach from the network since these are always from remote
1085          * recovery daemons.
1086          */
1087         if (client_id != 0) {
1088                 client = ctdb_reqid_find(ctdb, client_id, struct ctdb_client);
1089         }
1090         if (client != NULL) {
1091                 /* If the node is inactive it is not part of the cluster
1092                    and we should not allow clients to attach to any
1093                    databases
1094                 */
1095                 if (node->flags & NODE_FLAGS_INACTIVE) {
1096                         DEBUG(DEBUG_ERR,("DB Attach to database %s refused since node is inactive (flags=0x%x)\n", db_name, node->flags));
1097                         return -1;
1098                 }
1099
1100                 if (ctdb->recovery_mode == CTDB_RECOVERY_ACTIVE &&
1101                     client->pid != ctdb->recoverd_pid &&
1102                     ctdb->runstate < CTDB_RUNSTATE_RUNNING) {
1103                         struct ctdb_deferred_attach_context *da_ctx = talloc(client, struct ctdb_deferred_attach_context);
1104
1105                         if (da_ctx == NULL) {
1106                                 DEBUG(DEBUG_ERR,("DB Attach to database %s deferral for client with pid:%d failed due to OOM.\n", db_name, client->pid));
1107                                 return -1;
1108                         }
1109
1110                         da_ctx->ctdb = ctdb;
1111                         da_ctx->c = talloc_steal(da_ctx, c);
1112                         talloc_set_destructor(da_ctx, ctdb_deferred_attach_destructor);
1113                         DLIST_ADD(ctdb->deferred_attach, da_ctx);
1114
1115                         event_add_timed(ctdb->ev, da_ctx, timeval_current_ofs(ctdb->tunable.deferred_attach_timeout, 0), ctdb_deferred_attach_timeout, da_ctx);
1116
1117                         DEBUG(DEBUG_ERR,("DB Attach to database %s deferred for client with pid:%d since node is in recovery mode.\n", db_name, client->pid));
1118                         *async_reply = true;
1119                         return 0;
1120                 }
1121         }
1122
1123         /* the client can optionally pass additional tdb flags, but we
1124            only allow a subset of those on the database in ctdb. Note
1125            that tdb_flags is passed in via the (otherwise unused)
1126            srvid to the attach control */
1127 #ifdef TDB_MUTEX_LOCKING
1128         tdb_flags &= (TDB_NOSYNC|TDB_INCOMPATIBLE_HASH|TDB_MUTEX_LOCKING);
1129 #else
1130         tdb_flags &= (TDB_NOSYNC|TDB_INCOMPATIBLE_HASH);
1131 #endif
1132
1133         /* see if we already have this name */
1134         db = ctdb_db_handle(ctdb, db_name);
1135         if (db) {
1136                 if (db->persistent != persistent) {
1137                         DEBUG(DEBUG_ERR, ("ERROR: DB Attach %spersistent to %spersistent "
1138                                           "database %s\n", persistent ? "" : "non-",
1139                                           db-> persistent ? "" : "non-", db_name));
1140                         return -1;
1141                 }
1142                 outdata->dptr  = (uint8_t *)&db->db_id;
1143                 outdata->dsize = sizeof(db->db_id);
1144                 tdb_add_flags(db->ltdb->tdb, tdb_flags);
1145                 return 0;
1146         }
1147
1148         with_jenkinshash = (tdb_flags & TDB_INCOMPATIBLE_HASH) ? true : false;
1149 #ifdef TDB_MUTEX_LOCKING
1150         with_mutexes = (tdb_flags & TDB_MUTEX_LOCKING) ? true : false;
1151 #else
1152         with_mutexes = false;
1153 #endif
1154
1155         if (ctdb_local_attach(ctdb, db_name, persistent, NULL,
1156                               with_jenkinshash, with_mutexes) != 0) {
1157                 return -1;
1158         }
1159
1160         db = ctdb_db_handle(ctdb, db_name);
1161         if (!db) {
1162                 DEBUG(DEBUG_ERR,("Failed to find db handle for name '%s'\n", db_name));
1163                 return -1;
1164         }
1165
1166         /* remember the flags the client has specified */
1167         tdb_add_flags(db->ltdb->tdb, tdb_flags);
1168
1169         outdata->dptr  = (uint8_t *)&db->db_id;
1170         outdata->dsize = sizeof(db->db_id);
1171
1172         /* Try to ensure it's locked in mem */
1173         lockdown_memory(ctdb->valgrinding);
1174
1175         /* tell all the other nodes about this database */
1176         ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_ALL, tdb_flags,
1177                                  persistent?CTDB_CONTROL_DB_ATTACH_PERSISTENT:
1178                                                 CTDB_CONTROL_DB_ATTACH,
1179                                  0, CTDB_CTRL_FLAG_NOREPLY,
1180                                  indata, NULL, NULL);
1181
1182         /* success */
1183         return 0;
1184 }
1185
1186 /*
1187  * a client has asked to detach from a database
1188  */
1189 int32_t ctdb_control_db_detach(struct ctdb_context *ctdb, TDB_DATA indata,
1190                                uint32_t client_id)
1191 {
1192         uint32_t db_id;
1193         struct ctdb_db_context *ctdb_db;
1194         struct ctdb_client *client = NULL;
1195
1196         db_id = *(uint32_t *)indata.dptr;
1197         ctdb_db = find_ctdb_db(ctdb, db_id);
1198         if (ctdb_db == NULL) {
1199                 DEBUG(DEBUG_ERR, ("Invalid dbid 0x%08x in DB detach\n",
1200                                   db_id));
1201                 return -1;
1202         }
1203
1204         if (ctdb->tunable.allow_client_db_attach == 1) {
1205                 DEBUG(DEBUG_ERR, ("DB detach from database %s denied. "
1206                                   "Clients are allowed access to databases "
1207                                   "(AllowClientDBAccess == 1)\n",
1208                                   ctdb_db->db_name));
1209                 return -1;
1210         }
1211
1212         if (ctdb_db->persistent) {
1213                 DEBUG(DEBUG_ERR, ("DB detach from persistent database %s "
1214                                   "denied\n", ctdb_db->db_name));
1215                 return -1;
1216         }
1217
1218         /* Cannot detach from database when in recovery */
1219         if (ctdb->recovery_mode == CTDB_RECOVERY_ACTIVE) {
1220                 DEBUG(DEBUG_ERR, ("DB detach denied while in recovery\n"));
1221                 return -1;
1222         }
1223
1224         /* If a control comes from a client, then broadcast it to all nodes.
1225          * Do the actual detach only if the control comes from other daemons.
1226          */
1227         if (client_id != 0) {
1228                 client = ctdb_reqid_find(ctdb, client_id, struct ctdb_client);
1229                 if (client != NULL) {
1230                         /* forward the control to all the nodes */
1231                         ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_ALL, 0,
1232                                                  CTDB_CONTROL_DB_DETACH, 0,
1233                                                  CTDB_CTRL_FLAG_NOREPLY,
1234                                                  indata, NULL, NULL);
1235                         return 0;
1236                 }
1237                 DEBUG(DEBUG_ERR, ("Client has gone away. Failing DB detach "
1238                                   "for database '%s'\n", ctdb_db->db_name));
1239                 return -1;
1240         }
1241
1242         /* Detach database from recoverd */
1243         if (ctdb_daemon_send_message(ctdb, ctdb->pnn,
1244                                      CTDB_SRVID_DETACH_DATABASE,
1245                                      indata) != 0) {
1246                 DEBUG(DEBUG_ERR, ("Unable to detach DB from recoverd\n"));
1247                 return -1;
1248         }
1249
1250         /* Disable vacuuming and drop all vacuuming data */
1251         talloc_free(ctdb_db->vacuum_handle);
1252         talloc_free(ctdb_db->delete_queue);
1253
1254         /* Terminate any deferred fetch */
1255         talloc_free(ctdb_db->deferred_fetch);
1256
1257         /* Terminate any traverses */
1258         while (ctdb_db->traverse) {
1259                 talloc_free(ctdb_db->traverse);
1260         }
1261
1262         /* Terminate any revokes */
1263         while (ctdb_db->revokechild_active) {
1264                 talloc_free(ctdb_db->revokechild_active);
1265         }
1266
1267         /* Free readonly tracking database */
1268         if (ctdb_db->readonly) {
1269                 talloc_free(ctdb_db->rottdb);
1270         }
1271
1272         DLIST_REMOVE(ctdb->db_list, ctdb_db);
1273
1274         DEBUG(DEBUG_NOTICE, ("Detached from database '%s'\n",
1275                              ctdb_db->db_name));
1276         talloc_free(ctdb_db);
1277
1278         return 0;
1279 }
1280
1281 /*
1282   attach to all existing persistent databases
1283  */
1284 static int ctdb_attach_persistent(struct ctdb_context *ctdb,
1285                                   const char *unhealthy_reason)
1286 {
1287         DIR *d;
1288         struct dirent *de;
1289
1290         /* open the persistent db directory and scan it for files */
1291         d = opendir(ctdb->db_directory_persistent);
1292         if (d == NULL) {
1293                 return 0;
1294         }
1295
1296         while ((de=readdir(d))) {
1297                 char *p, *s, *q;
1298                 size_t len = strlen(de->d_name);
1299                 uint32_t node;
1300                 int invalid_name = 0;
1301
1302                 s = talloc_strdup(ctdb, de->d_name);
1303                 if (s == NULL) {
1304                         closedir(d);
1305                         CTDB_NO_MEMORY(ctdb, s);
1306                 }
1307
1308                 /* only accept names ending in .tdb */
1309                 p = strstr(s, ".tdb.");
1310                 if (len < 7 || p == NULL) {
1311                         talloc_free(s);
1312                         continue;
1313                 }
1314
1315                 /* only accept names ending with .tdb. and any number of digits */
1316                 q = p+5;
1317                 while (*q != 0 && invalid_name == 0) {
1318                         if (!isdigit(*q++)) {
1319                                 invalid_name = 1;
1320                         }
1321                 }
1322                 if (invalid_name == 1 || sscanf(p+5, "%u", &node) != 1 || node != ctdb->pnn) {
1323                         DEBUG(DEBUG_ERR,("Ignoring persistent database '%s'\n", de->d_name));
1324                         talloc_free(s);
1325                         continue;
1326                 }
1327                 p[4] = 0;
1328
1329                 if (ctdb_local_attach(ctdb, s, true, unhealthy_reason, false, false) != 0) {
1330                         DEBUG(DEBUG_ERR,("Failed to attach to persistent database '%s'\n", de->d_name));
1331                         closedir(d);
1332                         talloc_free(s);
1333                         return -1;
1334                 }
1335
1336                 DEBUG(DEBUG_INFO,("Attached to persistent database %s\n", s));
1337
1338                 talloc_free(s);
1339         }
1340         closedir(d);
1341         return 0;
1342 }
1343
1344 int ctdb_attach_databases(struct ctdb_context *ctdb)
1345 {
1346         int ret;
1347         char *persistent_health_path = NULL;
1348         char *unhealthy_reason = NULL;
1349         bool first_try = true;
1350
1351         persistent_health_path = talloc_asprintf(ctdb, "%s/%s.%u",
1352                                                  ctdb->db_directory_state,
1353                                                  PERSISTENT_HEALTH_TDB,
1354                                                  ctdb->pnn);
1355         if (persistent_health_path == NULL) {
1356                 DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
1357                 return -1;
1358         }
1359
1360 again:
1361
1362         ctdb->db_persistent_health = tdb_wrap_open(ctdb, persistent_health_path,
1363                                                    0, TDB_DISALLOW_NESTING,
1364                                                    O_CREAT | O_RDWR, 0600);
1365         if (ctdb->db_persistent_health == NULL) {
1366                 struct tdb_wrap *tdb;
1367
1368                 if (!first_try) {
1369                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s': %d - %s\n",
1370                                           persistent_health_path,
1371                                           errno,
1372                                           strerror(errno)));
1373                         talloc_free(persistent_health_path);
1374                         talloc_free(unhealthy_reason);
1375                         return -1;
1376                 }
1377                 first_try = false;
1378
1379                 unhealthy_reason = talloc_asprintf(ctdb, "WARNING - '%s' %s - %s",
1380                                                    persistent_health_path,
1381                                                    "was cleared after a failure",
1382                                                    "manual verification needed");
1383                 if (unhealthy_reason == NULL) {
1384                         DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
1385                         talloc_free(persistent_health_path);
1386                         return -1;
1387                 }
1388
1389                 DEBUG(DEBUG_CRIT,("Failed to open tdb '%s' - retrying after CLEAR_IF_FIRST\n",
1390                                   persistent_health_path));
1391                 tdb = tdb_wrap_open(ctdb, persistent_health_path,
1392                                     0, TDB_CLEAR_IF_FIRST | TDB_DISALLOW_NESTING,
1393                                     O_CREAT | O_RDWR, 0600);
1394                 if (tdb) {
1395                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s' - with CLEAR_IF_FIRST: %d - %s\n",
1396                                           persistent_health_path,
1397                                           errno,
1398                                           strerror(errno)));
1399                         talloc_free(persistent_health_path);
1400                         talloc_free(unhealthy_reason);
1401                         return -1;
1402                 }
1403
1404                 talloc_free(tdb);
1405                 goto again;
1406         }
1407         ret = tdb_check(ctdb->db_persistent_health->tdb, NULL, NULL);
1408         if (ret != 0) {
1409                 struct tdb_wrap *tdb;
1410
1411                 talloc_free(ctdb->db_persistent_health);
1412                 ctdb->db_persistent_health = NULL;
1413
1414                 if (!first_try) {
1415                         DEBUG(DEBUG_CRIT,("tdb_check('%s') failed\n",
1416                                           persistent_health_path));
1417                         talloc_free(persistent_health_path);
1418                         talloc_free(unhealthy_reason);
1419                         return -1;
1420                 }
1421                 first_try = false;
1422
1423                 unhealthy_reason = talloc_asprintf(ctdb, "WARNING - '%s' %s - %s",
1424                                                    persistent_health_path,
1425                                                    "was cleared after a failure",
1426                                                    "manual verification needed");
1427                 if (unhealthy_reason == NULL) {
1428                         DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
1429                         talloc_free(persistent_health_path);
1430                         return -1;
1431                 }
1432
1433                 DEBUG(DEBUG_CRIT,("tdb_check('%s') failed - retrying after CLEAR_IF_FIRST\n",
1434                                   persistent_health_path));
1435                 tdb = tdb_wrap_open(ctdb, persistent_health_path,
1436                                     0, TDB_CLEAR_IF_FIRST | TDB_DISALLOW_NESTING,
1437                                     O_CREAT | O_RDWR, 0600);
1438                 if (tdb) {
1439                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s' - with CLEAR_IF_FIRST: %d - %s\n",
1440                                           persistent_health_path,
1441                                           errno,
1442                                           strerror(errno)));
1443                         talloc_free(persistent_health_path);
1444                         talloc_free(unhealthy_reason);
1445                         return -1;
1446                 }
1447
1448                 talloc_free(tdb);
1449                 goto again;
1450         }
1451         talloc_free(persistent_health_path);
1452
1453         ret = ctdb_attach_persistent(ctdb, unhealthy_reason);
1454         talloc_free(unhealthy_reason);
1455         if (ret != 0) {
1456                 return ret;
1457         }
1458
1459         return 0;
1460 }
1461
1462 /*
1463   called when a broadcast seqnum update comes in
1464  */
1465 int32_t ctdb_ltdb_update_seqnum(struct ctdb_context *ctdb, uint32_t db_id, uint32_t srcnode)
1466 {
1467         struct ctdb_db_context *ctdb_db;
1468         if (srcnode == ctdb->pnn) {
1469                 /* don't update ourselves! */
1470                 return 0;
1471         }
1472
1473         ctdb_db = find_ctdb_db(ctdb, db_id);
1474         if (!ctdb_db) {
1475                 DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in ctdb_ltdb_update_seqnum\n", db_id));
1476                 return -1;
1477         }
1478
1479         if (ctdb_db->unhealthy_reason) {
1480                 DEBUG(DEBUG_ERR,("db(%s) unhealty in ctdb_ltdb_update_seqnum: %s\n",
1481                                  ctdb_db->db_name, ctdb_db->unhealthy_reason));
1482                 return -1;
1483         }
1484
1485         tdb_increment_seqnum_nonblock(ctdb_db->ltdb->tdb);
1486         ctdb_db->seqnum = tdb_get_seqnum(ctdb_db->ltdb->tdb);
1487         return 0;
1488 }
1489
1490 /*
1491   timer to check for seqnum changes in a ltdb and propogate them
1492  */
1493 static void ctdb_ltdb_seqnum_check(struct event_context *ev, struct timed_event *te,
1494                                    struct timeval t, void *p)
1495 {
1496         struct ctdb_db_context *ctdb_db = talloc_get_type(p, struct ctdb_db_context);
1497         struct ctdb_context *ctdb = ctdb_db->ctdb;
1498         uint32_t new_seqnum = tdb_get_seqnum(ctdb_db->ltdb->tdb);
1499         if (new_seqnum != ctdb_db->seqnum) {
1500                 /* something has changed - propogate it */
1501                 TDB_DATA data;
1502                 data.dptr = (uint8_t *)&ctdb_db->db_id;
1503                 data.dsize = sizeof(uint32_t);
1504                 ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_VNNMAP, 0,
1505                                          CTDB_CONTROL_UPDATE_SEQNUM, 0, CTDB_CTRL_FLAG_NOREPLY,
1506                                          data, NULL, NULL);
1507         }
1508         ctdb_db->seqnum = new_seqnum;
1509
1510         /* setup a new timer */
1511         ctdb_db->seqnum_update =
1512                 event_add_timed(ctdb->ev, ctdb_db,
1513                                 timeval_current_ofs(ctdb->tunable.seqnum_interval/1000, (ctdb->tunable.seqnum_interval%1000)*1000),
1514                                 ctdb_ltdb_seqnum_check, ctdb_db);
1515 }
1516
1517 /*
1518   enable seqnum handling on this db
1519  */
1520 int32_t ctdb_ltdb_enable_seqnum(struct ctdb_context *ctdb, uint32_t db_id)
1521 {
1522         struct ctdb_db_context *ctdb_db;
1523         ctdb_db = find_ctdb_db(ctdb, db_id);
1524         if (!ctdb_db) {
1525                 DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in ctdb_ltdb_enable_seqnum\n", db_id));
1526                 return -1;
1527         }
1528
1529         if (ctdb_db->seqnum_update == NULL) {
1530                 ctdb_db->seqnum_update =
1531                         event_add_timed(ctdb->ev, ctdb_db,
1532                                         timeval_current_ofs(ctdb->tunable.seqnum_interval/1000, (ctdb->tunable.seqnum_interval%1000)*1000),
1533                                         ctdb_ltdb_seqnum_check, ctdb_db);
1534         }
1535
1536         tdb_enable_seqnum(ctdb_db->ltdb->tdb);
1537         ctdb_db->seqnum = tdb_get_seqnum(ctdb_db->ltdb->tdb);
1538         return 0;
1539 }
1540
1541 int32_t ctdb_control_set_db_priority(struct ctdb_context *ctdb, TDB_DATA indata,
1542                                      uint32_t client_id)
1543 {
1544         struct ctdb_db_priority *db_prio = (struct ctdb_db_priority *)indata.dptr;
1545         struct ctdb_db_context *ctdb_db;
1546
1547         ctdb_db = find_ctdb_db(ctdb, db_prio->db_id);
1548         if (!ctdb_db) {
1549                 if (!(ctdb->nodes[ctdb->pnn]->flags & NODE_FLAGS_INACTIVE)) {
1550                         DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in ctdb_set_db_priority\n",
1551                                          db_prio->db_id));
1552                 }
1553                 return 0;
1554         }
1555
1556         if ((db_prio->priority<1) || (db_prio->priority>NUM_DB_PRIORITIES)) {
1557                 DEBUG(DEBUG_ERR,("Trying to set invalid priority : %u\n", db_prio->priority));
1558                 return 0;
1559         }
1560
1561         ctdb_db->priority = db_prio->priority;
1562         DEBUG(DEBUG_INFO,("Setting DB priority to %u for db 0x%08x\n", db_prio->priority, db_prio->db_id));
1563
1564         if (client_id != 0) {
1565                 /* Broadcast the update to the rest of the cluster */
1566                 ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_ALL, 0,
1567                                          CTDB_CONTROL_SET_DB_PRIORITY, 0,
1568                                          CTDB_CTRL_FLAG_NOREPLY, indata,
1569                                          NULL, NULL);
1570         }
1571         return 0;
1572 }
1573
1574
1575 int ctdb_set_db_sticky(struct ctdb_context *ctdb, struct ctdb_db_context *ctdb_db)
1576 {
1577         if (ctdb_db->sticky) {
1578                 return 0;
1579         }
1580
1581         if (ctdb_db->persistent) {
1582                 DEBUG(DEBUG_ERR,("Trying to set persistent database with sticky property\n"));
1583                 return -1;
1584         }
1585
1586         ctdb_db->sticky_records = trbt_create(ctdb_db, 0);
1587
1588         ctdb_db->sticky = true;
1589
1590         DEBUG(DEBUG_NOTICE,("set db sticky %s\n", ctdb_db->db_name));
1591
1592         return 0;
1593 }
1594
1595 int32_t ctdb_control_get_db_statistics(struct ctdb_context *ctdb,
1596                                 uint32_t db_id,
1597                                 TDB_DATA *outdata)
1598 {
1599         struct ctdb_db_context *ctdb_db;
1600         struct ctdb_db_statistics *stats;
1601         int i;
1602         int len;
1603         char *ptr;
1604
1605         ctdb_db = find_ctdb_db(ctdb, db_id);
1606         if (!ctdb_db) {
1607                 DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in get_db_statistics\n", db_id));
1608                 return -1;
1609         }
1610
1611         len = offsetof(struct ctdb_db_statistics, hot_keys_wire);
1612         for (i = 0; i < MAX_HOT_KEYS; i++) {
1613                 len += ctdb_db->statistics.hot_keys[i].key.dsize;
1614         }
1615
1616         stats = talloc_size(outdata, len);
1617         if (stats == NULL) {
1618                 DEBUG(DEBUG_ERR,("Failed to allocate db statistics structure\n"));
1619                 return -1;
1620         }
1621
1622         *stats = ctdb_db->statistics;
1623
1624         stats->num_hot_keys = MAX_HOT_KEYS;
1625
1626         ptr = &stats->hot_keys_wire[0];
1627         for (i = 0; i < MAX_HOT_KEYS; i++) {
1628                 memcpy(ptr, ctdb_db->statistics.hot_keys[i].key.dptr,
1629                        ctdb_db->statistics.hot_keys[i].key.dsize);
1630                 ptr += ctdb_db->statistics.hot_keys[i].key.dsize;
1631         }
1632
1633         outdata->dptr  = (uint8_t *)stats;
1634         outdata->dsize = len;
1635
1636         return 0;
1637 }