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(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 (mutexes && tdb_runtime_check_for_robust_mutexes()) {
 841                 tdb_flags |= TDB_MUTEX_LOCKING;
 842         }
 843 #endif
 844
 845 again:
 846         ctdb_db->ltdb = tdb_wrap_open(ctdb_db, ctdb_db->db_path,
 847                                       ctdb->tunable.database_hash_size,
 848                                       tdb_flags,
 849                                       O_CREAT|O_RDWR, mode);
 850         if (ctdb_db->ltdb == NULL) {
 851                 struct stat st;
 852                 int saved_errno = errno;
 853
 854                 if (!persistent) {
 855                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s': %d - %s\n",
 856                                           ctdb_db->db_path,
 857                                           saved_errno,
 858                                           strerror(saved_errno)));
 859                         talloc_free(ctdb_db);
 860                         return -1;
 861                 }
 862
 863                 if (remaining_tries == 0) {
 864                         DEBUG(DEBUG_CRIT,(__location__
 865                                           "Failed to open persistent tdb '%s': %d - %s\n",
 866                                           ctdb_db->db_path,
 867                                           saved_errno,
 868                                           strerror(saved_errno)));
 869                         talloc_free(ctdb_db);
 870                         return -1;
 871                 }
 872
 873                 ret = stat(ctdb_db->db_path, &st);
 874                 if (ret != 0) {
 875                         DEBUG(DEBUG_CRIT,(__location__
 876                                           "Failed to open persistent tdb '%s': %d - %s\n",
 877                                           ctdb_db->db_path,
 878                                           saved_errno,
 879                                           strerror(saved_errno)));
 880                         talloc_free(ctdb_db);
 881                         return -1;
 882                 }
 883
 884                 ret = ctdb_backup_corrupted_tdb(ctdb, ctdb_db);
 885                 if (ret != 0) {
 886                         DEBUG(DEBUG_CRIT,(__location__
 887                                           "Failed to open persistent tdb '%s': %d - %s\n",
 888                                           ctdb_db->db_path,
 889                                           saved_errno,
 890                                           strerror(saved_errno)));
 891                         talloc_free(ctdb_db);
 892                         return -1;
 893                 }
 894
 895                 remaining_tries--;
 896                 mode = st.st_mode;
 897                 goto again;
 898         }
 899
 900         if (!persistent) {
 901                 ctdb_check_db_empty(ctdb_db);
 902         } else {
 903                 ret = tdb_check(ctdb_db->ltdb->tdb, NULL, NULL);
 904                 if (ret != 0) {
 905                         int fd;
 906                         struct stat st;
 907
 908                         DEBUG(DEBUG_CRIT,("tdb_check(%s) failed: %d - %s\n",
 909                                           ctdb_db->db_path, ret,
 910                                           tdb_errorstr(ctdb_db->ltdb->tdb)));
 911                         if (remaining_tries == 0) {
 912                                 talloc_free(ctdb_db);
 913                                 return -1;
 914                         }
 915
 916                         fd = tdb_fd(ctdb_db->ltdb->tdb);
 917                         ret = fstat(fd, &st);
 918                         if (ret != 0) {
 919                                 DEBUG(DEBUG_CRIT,(__location__
 920                                                   "Failed to fstat() persistent tdb '%s': %d - %s\n",
 921                                                   ctdb_db->db_path,
 922                                                   errno,
 923                                                   strerror(errno)));
 924                                 talloc_free(ctdb_db);
 925                                 return -1;
 926                         }
 927
 928                         /* close the TDB */
 929                         talloc_free(ctdb_db->ltdb);
 930                         ctdb_db->ltdb = NULL;
 931
 932                         ret = ctdb_backup_corrupted_tdb(ctdb, ctdb_db);
 933                         if (ret != 0) {
 934                                 DEBUG(DEBUG_CRIT,("Failed to backup corrupted tdb '%s'\n",
 935                                                   ctdb_db->db_path));
 936                                 talloc_free(ctdb_db);
 937                                 return -1;
 938                         }
 939
 940                         remaining_tries--;
 941                         mode = st.st_mode;
 942                         goto again;
 943                 }
 944         }
 945
 946         /* set up a rb tree we can use to track which records we have a
 947            fetch-lock in-flight for so we can defer any additional calls
 948            for the same record.
 949          */
 950         ctdb_db->deferred_fetch = trbt_create(ctdb_db, 0);
 951         if (ctdb_db->deferred_fetch == NULL) {
 952                 DEBUG(DEBUG_ERR,("Failed to create deferred fetch rb tree for ctdb database\n"));
 953                 talloc_free(ctdb_db);
 954                 return -1;
 955         }
 956
 957         DLIST_ADD(ctdb->db_list, ctdb_db);
 958
 959         /* setting this can help some high churn databases */
 960         tdb_set_max_dead(ctdb_db->ltdb->tdb, ctdb->tunable.database_max_dead);
 961
 962         /*
 963            all databases support the "null" function. we need this in
 964            order to do forced migration of records
 965         */
 966         ret = ctdb_daemon_set_call(ctdb, ctdb_db->db_id, ctdb_null_func, CTDB_NULL_FUNC);
 967         if (ret != 0) {
 968                 DEBUG(DEBUG_CRIT,("Failed to setup null function for '%s'\n", ctdb_db->db_name));
 969                 talloc_free(ctdb_db);
 970                 return -1;
 971         }
 972
 973         /*
 974            all databases support the "fetch" function. we need this
 975            for efficient Samba3 ctdb fetch
 976         */
 977         ret = ctdb_daemon_set_call(ctdb, ctdb_db->db_id, ctdb_fetch_func, CTDB_FETCH_FUNC);
 978         if (ret != 0) {
 979                 DEBUG(DEBUG_CRIT,("Failed to setup fetch function for '%s'\n", ctdb_db->db_name));
 980                 talloc_free(ctdb_db);
 981                 return -1;
 982         }
 983
 984         /*
 985            all databases support the "fetch_with_header" function. we need this
 986            for efficient readonly record fetches
 987         */
 988         ret = ctdb_daemon_set_call(ctdb, ctdb_db->db_id, ctdb_fetch_with_header_func, CTDB_FETCH_WITH_HEADER_FUNC);
 989         if (ret != 0) {
 990                 DEBUG(DEBUG_CRIT,("Failed to setup fetch function for '%s'\n", ctdb_db->db_name));
 991                 talloc_free(ctdb_db);
 992                 return -1;
 993         }
 994
 995         ret = ctdb_vacuum_init(ctdb_db);
 996         if (ret != 0) {
 997                 DEBUG(DEBUG_CRIT,("Failed to setup vacuuming for "
 998                                   "database '%s'\n", ctdb_db->db_name));
 999                 talloc_free(ctdb_db);
1000                 return -1;
1001         }
1002
1003
1004         DEBUG(DEBUG_NOTICE,("Attached to database '%s' with flags 0x%x\n",
1005                             ctdb_db->db_path, tdb_flags));
1006
1007         /* success */
1008         return 0;
1009 }
1010
1011
1012 struct ctdb_deferred_attach_context {
1013         struct ctdb_deferred_attach_context *next, *prev;
1014         struct ctdb_context *ctdb;
1015         struct ctdb_req_control *c;
1016 };
1017
1018
1019 static int ctdb_deferred_attach_destructor(struct ctdb_deferred_attach_context *da_ctx)
1020 {
1021         DLIST_REMOVE(da_ctx->ctdb->deferred_attach, da_ctx);
1022
1023         return 0;
1024 }
1025
1026 static void ctdb_deferred_attach_timeout(struct event_context *ev, struct timed_event *te, struct timeval t, void *private_data)
1027 {
1028         struct ctdb_deferred_attach_context *da_ctx = talloc_get_type(private_data, struct ctdb_deferred_attach_context);
1029         struct ctdb_context *ctdb = da_ctx->ctdb;
1030
1031         ctdb_request_control_reply(ctdb, da_ctx->c, NULL, -1, NULL);
1032         talloc_free(da_ctx);
1033 }
1034
1035 static void ctdb_deferred_attach_callback(struct event_context *ev, struct timed_event *te, struct timeval t, void *private_data)
1036 {
1037         struct ctdb_deferred_attach_context *da_ctx = talloc_get_type(private_data, struct ctdb_deferred_attach_context);
1038         struct ctdb_context *ctdb = da_ctx->ctdb;
1039
1040         /* This talloc-steals the packet ->c */
1041         ctdb_input_pkt(ctdb, (struct ctdb_req_header *)da_ctx->c);
1042         talloc_free(da_ctx);
1043 }
1044
1045 int ctdb_process_deferred_attach(struct ctdb_context *ctdb)
1046 {
1047         struct ctdb_deferred_attach_context *da_ctx;
1048
1049         /* call it from the main event loop as soon as the current event
1050            finishes.
1051          */
1052         while ((da_ctx = ctdb->deferred_attach) != NULL) {
1053                 DLIST_REMOVE(ctdb->deferred_attach, da_ctx);
1054                 event_add_timed(ctdb->ev, da_ctx, timeval_current_ofs(1,0), ctdb_deferred_attach_callback, da_ctx);
1055         }
1056
1057         return 0;
1058 }
1059
1060 /*
1061   a client has asked to attach a new database
1062  */
1063 int32_t ctdb_control_db_attach(struct ctdb_context *ctdb, TDB_DATA indata,
1064                                TDB_DATA *outdata, uint64_t tdb_flags,
1065                                bool persistent, uint32_t client_id,
1066                                struct ctdb_req_control *c,
1067                                bool *async_reply)
1068 {
1069         const char *db_name = (const char *)indata.dptr;
1070         struct ctdb_db_context *db;
1071         struct ctdb_node *node = ctdb->nodes[ctdb->pnn];
1072         struct ctdb_client *client = NULL;
1073         bool with_jenkinshash, with_mutexes;
1074
1075         if (ctdb->tunable.allow_client_db_attach == 0) {
1076                 DEBUG(DEBUG_ERR, ("DB Attach to database %s denied by tunable "
1077                                   "AllowClientDBAccess == 0\n", db_name));
1078                 return -1;
1079         }
1080
1081         /* dont allow any local clients to attach while we are in recovery mode
1082          * except for the recovery daemon.
1083          * allow all attach from the network since these are always from remote
1084          * recovery daemons.
1085          */
1086         if (client_id != 0) {
1087                 client = ctdb_reqid_find(ctdb, client_id, struct ctdb_client);
1088         }
1089         if (client != NULL) {
1090                 /* If the node is inactive it is not part of the cluster
1091                    and we should not allow clients to attach to any
1092                    databases
1093                 */
1094                 if (node->flags & NODE_FLAGS_INACTIVE) {
1095                         DEBUG(DEBUG_ERR,("DB Attach to database %s refused since node is inactive (flags=0x%x)\n", db_name, node->flags));
1096                         return -1;
1097                 }
1098
1099                 if (ctdb->recovery_mode == CTDB_RECOVERY_ACTIVE &&
1100                     client->pid != ctdb->recoverd_pid &&
1101                     ctdb->runstate < CTDB_RUNSTATE_RUNNING) {
1102                         struct ctdb_deferred_attach_context *da_ctx = talloc(client, struct ctdb_deferred_attach_context);
1103
1104                         if (da_ctx == NULL) {
1105                                 DEBUG(DEBUG_ERR,("DB Attach to database %s deferral for client with pid:%d failed due to OOM.\n", db_name, client->pid));
1106                                 return -1;
1107                         }
1108
1109                         da_ctx->ctdb = ctdb;
1110                         da_ctx->c = talloc_steal(da_ctx, c);
1111                         talloc_set_destructor(da_ctx, ctdb_deferred_attach_destructor);
1112                         DLIST_ADD(ctdb->deferred_attach, da_ctx);
1113
1114                         event_add_timed(ctdb->ev, da_ctx, timeval_current_ofs(ctdb->tunable.deferred_attach_timeout, 0), ctdb_deferred_attach_timeout, da_ctx);
1115
1116                         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));
1117                         *async_reply = true;
1118                         return 0;
1119                 }
1120         }
1121
1122         /* the client can optionally pass additional tdb flags, but we
1123            only allow a subset of those on the database in ctdb. Note
1124            that tdb_flags is passed in via the (otherwise unused)
1125            srvid to the attach control */
1126 #ifdef TDB_MUTEX_LOCKING
1127         tdb_flags &= (TDB_NOSYNC|TDB_INCOMPATIBLE_HASH|TDB_MUTEX_LOCKING);
1128 #else
1129         tdb_flags &= (TDB_NOSYNC|TDB_INCOMPATIBLE_HASH);
1130 #endif
1131
1132         /* see if we already have this name */
1133         db = ctdb_db_handle(ctdb, db_name);
1134         if (db) {
1135                 if (db->persistent != persistent) {
1136                         DEBUG(DEBUG_ERR, ("ERROR: DB Attach %spersistent to %spersistent "
1137                                           "database %s\n", persistent ? "" : "non-",
1138                                           db-> persistent ? "" : "non-", db_name));
1139                         return -1;
1140                 }
1141                 outdata->dptr  = (uint8_t *)&db->db_id;
1142                 outdata->dsize = sizeof(db->db_id);
1143                 tdb_add_flags(db->ltdb->tdb, tdb_flags);
1144                 return 0;
1145         }
1146
1147         with_jenkinshash = (tdb_flags & TDB_INCOMPATIBLE_HASH) ? true : false;
1148 #ifdef TDB_MUTEX_LOCKING
1149         with_mutexes = (tdb_flags & TDB_MUTEX_LOCKING) ? true : false;
1150 #else
1151         with_mutexes = false;
1152 #endif
1153
1154         if (ctdb_local_attach(ctdb, db_name, persistent, NULL,
1155                               with_jenkinshash, with_mutexes) != 0) {
1156                 return -1;
1157         }
1158
1159         db = ctdb_db_handle(ctdb, db_name);
1160         if (!db) {
1161                 DEBUG(DEBUG_ERR,("Failed to find db handle for name '%s'\n", db_name));
1162                 return -1;
1163         }
1164
1165         /* remember the flags the client has specified */
1166         tdb_add_flags(db->ltdb->tdb, tdb_flags);
1167
1168         outdata->dptr  = (uint8_t *)&db->db_id;
1169         outdata->dsize = sizeof(db->db_id);
1170
1171         /* Try to ensure it's locked in mem */
1172         lockdown_memory(ctdb->valgrinding);
1173
1174         /* tell all the other nodes about this database */
1175         ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_ALL, tdb_flags,
1176                                  persistent?CTDB_CONTROL_DB_ATTACH_PERSISTENT:
1177                                                 CTDB_CONTROL_DB_ATTACH,
1178                                  0, CTDB_CTRL_FLAG_NOREPLY,
1179                                  indata, NULL, NULL);
1180
1181         /* success */
1182         return 0;
1183 }
1184
1185 /*
1186  * a client has asked to detach from a database
1187  */
1188 int32_t ctdb_control_db_detach(struct ctdb_context *ctdb, TDB_DATA indata,
1189                                uint32_t client_id)
1190 {
1191         uint32_t db_id;
1192         struct ctdb_db_context *ctdb_db;
1193         struct ctdb_client *client = NULL;
1194
1195         db_id = *(uint32_t *)indata.dptr;
1196         ctdb_db = find_ctdb_db(ctdb, db_id);
1197         if (ctdb_db == NULL) {
1198                 DEBUG(DEBUG_ERR, ("Invalid dbid 0x%08x in DB detach\n",
1199                                   db_id));
1200                 return -1;
1201         }
1202
1203         if (ctdb->tunable.allow_client_db_attach == 1) {
1204                 DEBUG(DEBUG_ERR, ("DB detach from database %s denied. "
1205                                   "Clients are allowed access to databases "
1206                                   "(AllowClientDBAccess == 1)\n",
1207                                   ctdb_db->db_name));
1208                 return -1;
1209         }
1210
1211         if (ctdb_db->persistent) {
1212                 DEBUG(DEBUG_ERR, ("DB detach from persistent database %s "
1213                                   "denied\n", ctdb_db->db_name));
1214                 return -1;
1215         }
1216
1217         /* Cannot detach from database when in recovery */
1218         if (ctdb->recovery_mode == CTDB_RECOVERY_ACTIVE) {
1219                 DEBUG(DEBUG_ERR, ("DB detach denied while in recovery\n"));
1220                 return -1;
1221         }
1222
1223         /* If a control comes from a client, then broadcast it to all nodes.
1224          * Do the actual detach only if the control comes from other daemons.
1225          */
1226         if (client_id != 0) {
1227                 client = ctdb_reqid_find(ctdb, client_id, struct ctdb_client);
1228                 if (client != NULL) {
1229                         /* forward the control to all the nodes */
1230                         ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_ALL, 0,
1231                                                  CTDB_CONTROL_DB_DETACH, 0,
1232                                                  CTDB_CTRL_FLAG_NOREPLY,
1233                                                  indata, NULL, NULL);
1234                         return 0;
1235                 }
1236                 DEBUG(DEBUG_ERR, ("Client has gone away. Failing DB detach "
1237                                   "for database '%s'\n", ctdb_db->db_name));
1238                 return -1;
1239         }
1240
1241         /* Detach database from recoverd */
1242         if (ctdb_daemon_send_message(ctdb, ctdb->pnn,
1243                                      CTDB_SRVID_DETACH_DATABASE,
1244                                      indata) != 0) {
1245                 DEBUG(DEBUG_ERR, ("Unable to detach DB from recoverd\n"));
1246                 return -1;
1247         }
1248
1249         /* Disable vacuuming and drop all vacuuming data */
1250         talloc_free(ctdb_db->vacuum_handle);
1251         talloc_free(ctdb_db->delete_queue);
1252
1253         /* Terminate any deferred fetch */
1254         talloc_free(ctdb_db->deferred_fetch);
1255
1256         /* Terminate any traverses */
1257         while (ctdb_db->traverse) {
1258                 talloc_free(ctdb_db->traverse);
1259         }
1260
1261         /* Terminate any revokes */
1262         while (ctdb_db->revokechild_active) {
1263                 talloc_free(ctdb_db->revokechild_active);
1264         }
1265
1266         /* Free readonly tracking database */
1267         if (ctdb_db->readonly) {
1268                 talloc_free(ctdb_db->rottdb);
1269         }
1270
1271         DLIST_REMOVE(ctdb->db_list, ctdb_db);
1272
1273         DEBUG(DEBUG_NOTICE, ("Detached from database '%s'\n",
1274                              ctdb_db->db_name));
1275         talloc_free(ctdb_db);
1276
1277         return 0;
1278 }
1279
1280 /*
1281   attach to all existing persistent databases
1282  */
1283 static int ctdb_attach_persistent(struct ctdb_context *ctdb,
1284                                   const char *unhealthy_reason)
1285 {
1286         DIR *d;
1287         struct dirent *de;
1288
1289         /* open the persistent db directory and scan it for files */
1290         d = opendir(ctdb->db_directory_persistent);
1291         if (d == NULL) {
1292                 return 0;
1293         }
1294
1295         while ((de=readdir(d))) {
1296                 char *p, *s, *q;
1297                 size_t len = strlen(de->d_name);
1298                 uint32_t node;
1299                 int invalid_name = 0;
1300
1301                 s = talloc_strdup(ctdb, de->d_name);
1302                 if (s == NULL) {
1303                         closedir(d);
1304                         CTDB_NO_MEMORY(ctdb, s);
1305                 }
1306
1307                 /* only accept names ending in .tdb */
1308                 p = strstr(s, ".tdb.");
1309                 if (len < 7 || p == NULL) {
1310                         talloc_free(s);
1311                         continue;
1312                 }
1313
1314                 /* only accept names ending with .tdb. and any number of digits */
1315                 q = p+5;
1316                 while (*q != 0 && invalid_name == 0) {
1317                         if (!isdigit(*q++)) {
1318                                 invalid_name = 1;
1319                         }
1320                 }
1321                 if (invalid_name == 1 || sscanf(p+5, "%u", &node) != 1 || node != ctdb->pnn) {
1322                         DEBUG(DEBUG_ERR,("Ignoring persistent database '%s'\n", de->d_name));
1323                         talloc_free(s);
1324                         continue;
1325                 }
1326                 p[4] = 0;
1327
1328                 if (ctdb_local_attach(ctdb, s, true, unhealthy_reason, false, false) != 0) {
1329                         DEBUG(DEBUG_ERR,("Failed to attach to persistent database '%s'\n", de->d_name));
1330                         closedir(d);
1331                         talloc_free(s);
1332                         return -1;
1333                 }
1334
1335                 DEBUG(DEBUG_INFO,("Attached to persistent database %s\n", s));
1336
1337                 talloc_free(s);
1338         }
1339         closedir(d);
1340         return 0;
1341 }
1342
1343 int ctdb_attach_databases(struct ctdb_context *ctdb)
1344 {
1345         int ret;
1346         char *persistent_health_path = NULL;
1347         char *unhealthy_reason = NULL;
1348         bool first_try = true;
1349
1350         persistent_health_path = talloc_asprintf(ctdb, "%s/%s.%u",
1351                                                  ctdb->db_directory_state,
1352                                                  PERSISTENT_HEALTH_TDB,
1353                                                  ctdb->pnn);
1354         if (persistent_health_path == NULL) {
1355                 DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
1356                 return -1;
1357         }
1358
1359 again:
1360
1361         ctdb->db_persistent_health = tdb_wrap_open(ctdb, persistent_health_path,
1362                                                    0, TDB_DISALLOW_NESTING,
1363                                                    O_CREAT | O_RDWR, 0600);
1364         if (ctdb->db_persistent_health == NULL) {
1365                 struct tdb_wrap *tdb;
1366
1367                 if (!first_try) {
1368                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s': %d - %s\n",
1369                                           persistent_health_path,
1370                                           errno,
1371                                           strerror(errno)));
1372                         talloc_free(persistent_health_path);
1373                         talloc_free(unhealthy_reason);
1374                         return -1;
1375                 }
1376                 first_try = false;
1377
1378                 unhealthy_reason = talloc_asprintf(ctdb, "WARNING - '%s' %s - %s",
1379                                                    persistent_health_path,
1380                                                    "was cleared after a failure",
1381                                                    "manual verification needed");
1382                 if (unhealthy_reason == NULL) {
1383                         DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
1384                         talloc_free(persistent_health_path);
1385                         return -1;
1386                 }
1387
1388                 DEBUG(DEBUG_CRIT,("Failed to open tdb '%s' - retrying after CLEAR_IF_FIRST\n",
1389                                   persistent_health_path));
1390                 tdb = tdb_wrap_open(ctdb, persistent_health_path,
1391                                     0, TDB_CLEAR_IF_FIRST | TDB_DISALLOW_NESTING,
1392                                     O_CREAT | O_RDWR, 0600);
1393                 if (tdb) {
1394                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s' - with CLEAR_IF_FIRST: %d - %s\n",
1395                                           persistent_health_path,
1396                                           errno,
1397                                           strerror(errno)));
1398                         talloc_free(persistent_health_path);
1399                         talloc_free(unhealthy_reason);
1400                         return -1;
1401                 }
1402
1403                 talloc_free(tdb);
1404                 goto again;
1405         }
1406         ret = tdb_check(ctdb->db_persistent_health->tdb, NULL, NULL);
1407         if (ret != 0) {
1408                 struct tdb_wrap *tdb;
1409
1410                 talloc_free(ctdb->db_persistent_health);
1411                 ctdb->db_persistent_health = NULL;
1412
1413                 if (!first_try) {
1414                         DEBUG(DEBUG_CRIT,("tdb_check('%s') failed\n",
1415                                           persistent_health_path));
1416                         talloc_free(persistent_health_path);
1417                         talloc_free(unhealthy_reason);
1418                         return -1;
1419                 }
1420                 first_try = false;
1421
1422                 unhealthy_reason = talloc_asprintf(ctdb, "WARNING - '%s' %s - %s",
1423                                                    persistent_health_path,
1424                                                    "was cleared after a failure",
1425                                                    "manual verification needed");
1426                 if (unhealthy_reason == NULL) {
1427                         DEBUG(DEBUG_CRIT,(__location__ " talloc_asprintf() failed\n"));
1428                         talloc_free(persistent_health_path);
1429                         return -1;
1430                 }
1431
1432                 DEBUG(DEBUG_CRIT,("tdb_check('%s') failed - retrying after CLEAR_IF_FIRST\n",
1433                                   persistent_health_path));
1434                 tdb = tdb_wrap_open(ctdb, persistent_health_path,
1435                                     0, TDB_CLEAR_IF_FIRST | TDB_DISALLOW_NESTING,
1436                                     O_CREAT | O_RDWR, 0600);
1437                 if (tdb) {
1438                         DEBUG(DEBUG_CRIT,("Failed to open tdb '%s' - with CLEAR_IF_FIRST: %d - %s\n",
1439                                           persistent_health_path,
1440                                           errno,
1441                                           strerror(errno)));
1442                         talloc_free(persistent_health_path);
1443                         talloc_free(unhealthy_reason);
1444                         return -1;
1445                 }
1446
1447                 talloc_free(tdb);
1448                 goto again;
1449         }
1450         talloc_free(persistent_health_path);
1451
1452         ret = ctdb_attach_persistent(ctdb, unhealthy_reason);
1453         talloc_free(unhealthy_reason);
1454         if (ret != 0) {
1455                 return ret;
1456         }
1457
1458         return 0;
1459 }
1460
1461 /*
1462   called when a broadcast seqnum update comes in
1463  */
1464 int32_t ctdb_ltdb_update_seqnum(struct ctdb_context *ctdb, uint32_t db_id, uint32_t srcnode)
1465 {
1466         struct ctdb_db_context *ctdb_db;
1467         if (srcnode == ctdb->pnn) {
1468                 /* don't update ourselves! */
1469                 return 0;
1470         }
1471
1472         ctdb_db = find_ctdb_db(ctdb, db_id);
1473         if (!ctdb_db) {
1474                 DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in ctdb_ltdb_update_seqnum\n", db_id));
1475                 return -1;
1476         }
1477
1478         if (ctdb_db->unhealthy_reason) {
1479                 DEBUG(DEBUG_ERR,("db(%s) unhealty in ctdb_ltdb_update_seqnum: %s\n",
1480                                  ctdb_db->db_name, ctdb_db->unhealthy_reason));
1481                 return -1;
1482         }
1483
1484         tdb_increment_seqnum_nonblock(ctdb_db->ltdb->tdb);
1485         ctdb_db->seqnum = tdb_get_seqnum(ctdb_db->ltdb->tdb);
1486         return 0;
1487 }
1488
1489 /*
1490   timer to check for seqnum changes in a ltdb and propogate them
1491  */
1492 static void ctdb_ltdb_seqnum_check(struct event_context *ev, struct timed_event *te,
1493                                    struct timeval t, void *p)
1494 {
1495         struct ctdb_db_context *ctdb_db = talloc_get_type(p, struct ctdb_db_context);
1496         struct ctdb_context *ctdb = ctdb_db->ctdb;
1497         uint32_t new_seqnum = tdb_get_seqnum(ctdb_db->ltdb->tdb);
1498         if (new_seqnum != ctdb_db->seqnum) {
1499                 /* something has changed - propogate it */
1500                 TDB_DATA data;
1501                 data.dptr = (uint8_t *)&ctdb_db->db_id;
1502                 data.dsize = sizeof(uint32_t);
1503                 ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_VNNMAP, 0,
1504                                          CTDB_CONTROL_UPDATE_SEQNUM, 0, CTDB_CTRL_FLAG_NOREPLY,
1505                                          data, NULL, NULL);
1506         }
1507         ctdb_db->seqnum = new_seqnum;
1508
1509         /* setup a new timer */
1510         ctdb_db->seqnum_update =
1511                 event_add_timed(ctdb->ev, ctdb_db,
1512                                 timeval_current_ofs(ctdb->tunable.seqnum_interval/1000, (ctdb->tunable.seqnum_interval%1000)*1000),
1513                                 ctdb_ltdb_seqnum_check, ctdb_db);
1514 }
1515
1516 /*
1517   enable seqnum handling on this db
1518  */
1519 int32_t ctdb_ltdb_enable_seqnum(struct ctdb_context *ctdb, uint32_t db_id)
1520 {
1521         struct ctdb_db_context *ctdb_db;
1522         ctdb_db = find_ctdb_db(ctdb, db_id);
1523         if (!ctdb_db) {
1524                 DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in ctdb_ltdb_enable_seqnum\n", db_id));
1525                 return -1;
1526         }
1527
1528         if (ctdb_db->seqnum_update == NULL) {
1529                 ctdb_db->seqnum_update =
1530                         event_add_timed(ctdb->ev, ctdb_db,
1531                                         timeval_current_ofs(ctdb->tunable.seqnum_interval/1000, (ctdb->tunable.seqnum_interval%1000)*1000),
1532                                         ctdb_ltdb_seqnum_check, ctdb_db);
1533         }
1534
1535         tdb_enable_seqnum(ctdb_db->ltdb->tdb);
1536         ctdb_db->seqnum = tdb_get_seqnum(ctdb_db->ltdb->tdb);
1537         return 0;
1538 }
1539
1540 int32_t ctdb_control_set_db_priority(struct ctdb_context *ctdb, TDB_DATA indata,
1541                                      uint32_t client_id)
1542 {
1543         struct ctdb_db_priority *db_prio = (struct ctdb_db_priority *)indata.dptr;
1544         struct ctdb_db_context *ctdb_db;
1545
1546         ctdb_db = find_ctdb_db(ctdb, db_prio->db_id);
1547         if (!ctdb_db) {
1548                 if (!(ctdb->nodes[ctdb->pnn]->flags & NODE_FLAGS_INACTIVE)) {
1549                         DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in ctdb_set_db_priority\n",
1550                                          db_prio->db_id));
1551                 }
1552                 return 0;
1553         }
1554
1555         if ((db_prio->priority<1) || (db_prio->priority>NUM_DB_PRIORITIES)) {
1556                 DEBUG(DEBUG_ERR,("Trying to set invalid priority : %u\n", db_prio->priority));
1557                 return 0;
1558         }
1559
1560         ctdb_db->priority = db_prio->priority;
1561         DEBUG(DEBUG_INFO,("Setting DB priority to %u for db 0x%08x\n", db_prio->priority, db_prio->db_id));
1562
1563         if (client_id != 0) {
1564                 /* Broadcast the update to the rest of the cluster */
1565                 ctdb_daemon_send_control(ctdb, CTDB_BROADCAST_ALL, 0,
1566                                          CTDB_CONTROL_SET_DB_PRIORITY, 0,
1567                                          CTDB_CTRL_FLAG_NOREPLY, indata,
1568                                          NULL, NULL);
1569         }
1570         return 0;
1571 }
1572
1573
1574 int ctdb_set_db_sticky(struct ctdb_context *ctdb, struct ctdb_db_context *ctdb_db)
1575 {
1576         if (ctdb_db->sticky) {
1577                 return 0;
1578         }
1579
1580         if (ctdb_db->persistent) {
1581                 DEBUG(DEBUG_ERR,("Trying to set persistent database with sticky property\n"));
1582                 return -1;
1583         }
1584
1585         ctdb_db->sticky_records = trbt_create(ctdb_db, 0);
1586
1587         ctdb_db->sticky = true;
1588
1589         DEBUG(DEBUG_NOTICE,("set db sticky %s\n", ctdb_db->db_name));
1590
1591         return 0;
1592 }
1593
1594 int32_t ctdb_control_get_db_statistics(struct ctdb_context *ctdb,
1595                                 uint32_t db_id,
1596                                 TDB_DATA *outdata)
1597 {
1598         struct ctdb_db_context *ctdb_db;
1599         struct ctdb_db_statistics *stats;
1600         int i;
1601         int len;
1602         char *ptr;
1603
1604         ctdb_db = find_ctdb_db(ctdb, db_id);
1605         if (!ctdb_db) {
1606                 DEBUG(DEBUG_ERR,("Unknown db_id 0x%x in get_db_statistics\n", db_id));
1607                 return -1;
1608         }
1609
1610         len = offsetof(struct ctdb_db_statistics, hot_keys_wire);
1611         for (i = 0; i < MAX_HOT_KEYS; i++) {
1612                 len += ctdb_db->statistics.hot_keys[i].key.dsize;
1613         }
1614
1615         stats = talloc_size(outdata, len);
1616         if (stats == NULL) {
1617                 DEBUG(DEBUG_ERR,("Failed to allocate db statistics structure\n"));
1618                 return -1;
1619         }
1620
1621         *stats = ctdb_db->statistics;
1622
1623         stats->num_hot_keys = MAX_HOT_KEYS;
1624
1625         ptr = &stats->hot_keys_wire[0];
1626         for (i = 0; i < MAX_HOT_KEYS; i++) {
1627                 memcpy(ptr, ctdb_db->statistics.hot_keys[i].key.dptr,
1628                        ctdb_db->statistics.hot_keys[i].key.dsize);
1629                 ptr += ctdb_db->statistics.hot_keys[i].key.dsize;
1630         }
1631
1632         outdata->dptr  = (uint8_t *)stats;
1633         outdata->dsize = len;
1634
1635         return 0;
1636 }