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