2 * This is a data store backend for the Citadel server which uses Berkeley DB.
4 * Copyright (c) 1987-2012 by the citadel.org team
6 * This program is open source software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version 3.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
16 /*****************************************************************************
17 Tunable configuration parameters for the Berkeley DB back end
18 *****************************************************************************/
20 /* Citadel will checkpoint the db at the end of every session, but only if
21 * the specified number of kilobytes has been written, or if the specified
22 * number of minutes has passed, since the last checkpoint.
24 #define MAX_CHECKPOINT_KBYTES 256
25 #define MAX_CHECKPOINT_MINUTES 15
27 /*****************************************************************************/
36 #include <sys/types.h>
44 #elif defined(HAVE_DB4_DB_H)
47 #error Neither <db.h> nor <db4/db.h> was found by configure. Install db4-devel.
51 #if DB_VERSION_MAJOR < 4 || DB_VERSION_MINOR < 1
52 #error Citadel requires Berkeley DB v4.1 or newer. Please upgrade.
56 #include <libcitadel.h>
59 #include "citserver.h"
62 #include "sysdep_decls.h"
67 #include "ctdl_module.h"
70 static DB *dbp[MAXCDB]; /* One DB handle for each Citadel database */
71 static DB_ENV *dbenv; /* The DB environment (global) */
74 void cdb_abort(void) {
76 "citserver is stopping in order to prevent data loss. uid=%d gid=%d euid=%d egid=%d",
87 /* Verbose logging callback */
88 void cdb_verbose_log(const DB_ENV *dbenv, const char *msg)
90 if (!IsEmptyStr(msg)) {
91 syslog(LOG_DEBUG, "DB: %s", msg);
97 /* Verbose logging callback */
98 void cdb_verbose_err(const DB_ENV *dbenv, const char *errpfx, const char *msg)
100 syslog(LOG_ALERT, "DB: %s", msg);
105 /* just a little helper function */
106 static void txabort(DB_TXN * tid)
110 ret = tid->abort(tid);
113 syslog(LOG_EMERG, "bdb(): txn_abort: %s", db_strerror(ret));
118 /* this one is even more helpful than the last. */
119 static void txcommit(DB_TXN * tid)
123 ret = tid->commit(tid, 0);
126 syslog(LOG_EMERG, "bdb(): txn_commit: %s", db_strerror(ret));
131 /* are you sensing a pattern yet? */
132 static void txbegin(DB_TXN ** tid)
136 ret = dbenv->txn_begin(dbenv, NULL, tid, 0);
139 syslog(LOG_EMERG, "bdb(): txn_begin: %s", db_strerror(ret));
144 static void dbpanic(DB_ENV * env, int errval)
146 syslog(LOG_EMERG, "bdb(): PANIC: %s", db_strerror(errval));
150 static void cclose(DBC * cursor)
154 if ((ret = cursor->c_close(cursor))) {
155 syslog(LOG_EMERG, "bdb(): c_close: %s", db_strerror(ret));
160 static void bailIfCursor(DBC ** cursors, const char *msg)
164 for (i = 0; i < MAXCDB; i++)
165 if (cursors[i] != NULL) {
166 syslog(LOG_EMERG, "bdb(): cursor still in progress on cdb %02x: %s", i, msg);
172 void cdb_check_handles(void)
174 bailIfCursor(TSD->cursors, "in check_handles");
176 if (TSD->tid != NULL) {
177 syslog(LOG_EMERG, "bdb(): transaction still in progress!");
184 * Cull the database logs
186 static void cdb_cull_logs(void)
195 /* Get the list of names. */
196 if ((ret = dbenv->log_archive(dbenv, &list, flags)) != 0) {
197 syslog(LOG_ERR, "cdb_cull_logs: %s", db_strerror(ret));
201 /* Print the list of names. */
203 for (file = list; *file != NULL; ++file) {
204 syslog(LOG_DEBUG, "Deleting log: %s", *file);
207 snprintf(errmsg, sizeof(errmsg),
208 " ** ERROR **\n \n \n "
209 "Citadel was unable to delete the "
210 "database log file '%s' because of the "
211 "following error:\n \n %s\n \n"
212 " This log file is no longer in use "
213 "and may be safely deleted.\n",
214 *file, strerror(errno));
215 CtdlAideMessage(errmsg, "Database Warning Message");
223 * Manually initiate log file cull.
225 void cmd_cull(char *argbuf) {
226 if (CtdlAccessCheck(ac_internal)) return;
228 cprintf("%d Database log file cull completed.\n", CIT_OK);
233 * Request a checkpoint of the database. Called once per minute by the thread manager.
235 void cdb_checkpoint(void)
239 syslog(LOG_DEBUG, "-- db checkpoint --");
240 ret = dbenv->txn_checkpoint(dbenv, MAX_CHECKPOINT_KBYTES, MAX_CHECKPOINT_MINUTES, 0);
243 syslog(LOG_EMERG, "cdb_checkpoint: txn_checkpoint: %s", db_strerror(ret));
247 /* After a successful checkpoint, we can cull the unused logs */
248 if (config.c_auto_cull) {
256 * Open the various databases we'll be using. Any database which
257 * does not exist should be created. Note that we don't need a
258 * critical section here, because there aren't any active threads
259 * manipulating the database yet.
261 void open_databases(void)
267 int dbversion_major, dbversion_minor, dbversion_patch;
268 int current_dbversion = 0;
270 syslog(LOG_DEBUG, "bdb(): open_databases() starting");
271 syslog(LOG_DEBUG, "Compiled db: %s", DB_VERSION_STRING);
272 syslog(LOG_INFO, " Linked db: %s",
273 db_version(&dbversion_major, &dbversion_minor, &dbversion_patch));
275 current_dbversion = (dbversion_major * 1000000) + (dbversion_minor * 1000) + dbversion_patch;
277 syslog(LOG_DEBUG, "Calculated dbversion: %d", current_dbversion);
278 syslog(LOG_DEBUG, " Previous dbversion: %d", CitControl.MMdbversion);
280 if ( (getenv("SUPPRESS_DBVERSION_CHECK") == NULL)
281 && (CitControl.MMdbversion > current_dbversion) ) {
282 syslog(LOG_EMERG, "You are attempting to run the Citadel server using a version");
283 syslog(LOG_EMERG, "of Berkeley DB that is older than that which last created or");
284 syslog(LOG_EMERG, "updated the database. Because this would probably cause data");
285 syslog(LOG_EMERG, "corruption or loss, the server is aborting execution now.");
289 CitControl.MMdbversion = current_dbversion;
292 syslog(LOG_INFO, "Linked zlib: %s\n", zlibVersion());
295 * Silently try to create the database subdirectory. If it's
296 * already there, no problem.
298 if ((mkdir(ctdl_data_dir, 0700) != 0) && (errno != EEXIST)){
300 "unable to create database directory [%s]: %s",
301 ctdl_data_dir, strerror(errno));
303 if (chmod(ctdl_data_dir, 0700) != 0){
305 "unable to set database directory accessrights [%s]: %s",
306 ctdl_data_dir, strerror(errno));
308 if (chown(ctdl_data_dir, CTDLUID, (-1)) != 0){
310 "unable to set the owner for [%s]: %s",
311 ctdl_data_dir, strerror(errno));
313 syslog(LOG_DEBUG, "bdb(): Setting up DB environment\n");
314 /* db_env_set_func_yield((int (*)(u_long, u_long))sched_yield); */
315 ret = db_env_create(&dbenv, 0);
317 syslog(LOG_EMERG, "bdb(): db_env_create: %s\n", db_strerror(ret));
318 syslog(LOG_EMERG, "exit code %d\n", ret);
321 dbenv->set_errpfx(dbenv, "citserver");
322 dbenv->set_paniccall(dbenv, dbpanic);
323 dbenv->set_errcall(dbenv, cdb_verbose_err);
324 dbenv->set_errpfx(dbenv, "ctdl");
325 #if (DB_VERSION_MAJOR == 4) && (DB_VERSION_MINOR >= 3)
326 dbenv->set_msgcall(dbenv, cdb_verbose_log);
328 dbenv->set_verbose(dbenv, DB_VERB_DEADLOCK, 1);
329 dbenv->set_verbose(dbenv, DB_VERB_RECOVERY, 1);
332 * We want to specify the shared memory buffer pool cachesize,
333 * but everything else is the default.
335 ret = dbenv->set_cachesize(dbenv, 0, 64 * 1024, 0);
337 syslog(LOG_EMERG, "bdb(): set_cachesize: %s\n", db_strerror(ret));
338 dbenv->close(dbenv, 0);
339 syslog(LOG_EMERG, "exit code %d\n", ret);
343 if ((ret = dbenv->set_lk_detect(dbenv, DB_LOCK_DEFAULT))) {
344 syslog(LOG_EMERG, "bdb(): set_lk_detect: %s\n", db_strerror(ret));
345 dbenv->close(dbenv, 0);
346 syslog(LOG_EMERG, "exit code %d\n", ret);
350 flags = DB_CREATE | DB_INIT_MPOOL | DB_PRIVATE | DB_INIT_TXN | DB_INIT_LOCK | DB_THREAD | DB_RECOVER;
351 syslog(LOG_DEBUG, "dbenv->open(dbenv, %s, %d, 0)\n", ctdl_data_dir, flags);
352 ret = dbenv->open(dbenv, ctdl_data_dir, flags, 0);
353 if (ret == DB_RUNRECOVERY) {
354 syslog(LOG_ALERT, "dbenv->open: %s\n", db_strerror(ret));
355 syslog(LOG_ALERT, "Attempting recovery...\n");
357 ret = dbenv->open(dbenv, ctdl_data_dir, flags, 0);
359 if (ret == DB_RUNRECOVERY) {
360 syslog(LOG_ALERT, "dbenv->open: %s\n", db_strerror(ret));
361 syslog(LOG_ALERT, "Attempting catastrophic recovery...\n");
362 flags &= ~DB_RECOVER;
363 flags |= DB_RECOVER_FATAL;
364 ret = dbenv->open(dbenv, ctdl_data_dir, flags, 0);
367 syslog(LOG_EMERG, "dbenv->open: %s\n", db_strerror(ret));
368 dbenv->close(dbenv, 0);
369 syslog(LOG_EMERG, "exit code %d\n", ret);
373 syslog(LOG_INFO, "Starting up DB\n");
375 for (i = 0; i < MAXCDB; ++i) {
377 /* Create a database handle */
378 ret = db_create(&dbp[i], dbenv, 0);
380 syslog(LOG_EMERG, "db_create: %s\n", db_strerror(ret));
381 syslog(LOG_EMERG, "exit code %d\n", ret);
386 /* Arbitrary names for our tables -- we reference them by
387 * number, so we don't have string names for them.
389 snprintf(dbfilename, sizeof dbfilename, "cdb.%02x", i);
391 ret = dbp[i]->open(dbp[i],
396 DB_CREATE | DB_AUTO_COMMIT | DB_THREAD,
400 syslog(LOG_EMERG, "db_open[%02x]: %s\n", i, db_strerror(ret));
402 syslog(LOG_EMERG, "You may need to tune your database; please read http://www.citadel.org/doku.php?id=faq:troubleshooting:out_of_lock_entries for more information.");
404 syslog(LOG_EMERG, "exit code %d\n", ret);
412 /* Make sure we own all the files, because in a few milliseconds
413 * we're going to drop root privs.
415 void cdb_chmod_data(void) {
418 char filename[PATH_MAX];
420 dp = opendir(ctdl_data_dir);
422 while (d = readdir(dp), d != NULL) {
423 if (d->d_name[0] != '.') {
424 snprintf(filename, sizeof filename,
425 "%s/%s", ctdl_data_dir, d->d_name);
426 syslog(LOG_DEBUG, "chmod(%s, 0600) returned %d\n",
427 filename, chmod(filename, 0600)
429 syslog(LOG_DEBUG, "chown(%s, CTDLUID, -1) returned %d\n",
430 filename, chown(filename, CTDLUID, (-1))
437 syslog(LOG_DEBUG, "open_databases() finished\n");
438 CtdlRegisterProtoHook(cmd_cull, "CULL", "Cull database logs");
443 * Close all of the db database files we've opened. This can be done
444 * in a loop, since it's just a bunch of closes.
446 void close_databases(void)
451 if ((ret = dbenv->txn_checkpoint(dbenv, 0, 0, 0))) {
453 "txn_checkpoint: %s\n", db_strerror(ret));
456 /* print some statistics... */
458 dbenv->lock_stat_print(dbenv, DB_STAT_ALL);
461 /* close the tables */
462 for (a = 0; a < MAXCDB; ++a) {
463 syslog(LOG_INFO, "Closing database %02x\n", a);
464 ret = dbp[a]->close(dbp[a], 0);
466 syslog(LOG_EMERG, "db_close: %s\n", db_strerror(ret));
471 /* Close the handle. */
472 ret = dbenv->close(dbenv, 0);
474 syslog(LOG_EMERG, "DBENV->close: %s\n", db_strerror(ret));
480 * Decompress a database item if it was compressed on disk
482 void cdb_decompress_if_necessary(struct cdbdata *cdb)
484 static int magic = COMPRESS_MAGIC;
487 (cdb->ptr == NULL) ||
488 (cdb->len < sizeof(magic)) ||
489 (memcmp(cdb->ptr, &magic, sizeof(magic))))
492 /* At this point we know we're looking at a compressed item. */
494 struct CtdlCompressHeader zheader;
495 char *uncompressed_data;
496 char *compressed_data;
497 uLongf destLen, sourceLen;
500 memset(&zheader, 0, sizeof(struct CtdlCompressHeader));
501 cplen = sizeof(struct CtdlCompressHeader);
502 if (sizeof(struct CtdlCompressHeader) > cdb->len)
504 memcpy(&zheader, cdb->ptr, cplen);
506 compressed_data = cdb->ptr;
507 compressed_data += sizeof(struct CtdlCompressHeader);
509 sourceLen = (uLongf) zheader.compressed_len;
510 destLen = (uLongf) zheader.uncompressed_len;
511 uncompressed_data = malloc(zheader.uncompressed_len);
513 if (uncompress((Bytef *) uncompressed_data,
514 (uLongf *) & destLen,
515 (const Bytef *) compressed_data,
516 (uLong) sourceLen) != Z_OK) {
517 syslog(LOG_EMERG, "uncompress() error\n");
522 cdb->len = (size_t) destLen;
523 cdb->ptr = uncompressed_data;
529 * Store a piece of data. Returns 0 if the operation was successful. If a
530 * key already exists it should be overwritten.
532 int cdb_store(int cdb, const void *ckey, int ckeylen, void *cdata, int cdatalen)
539 struct CtdlCompressHeader zheader;
540 char *compressed_data = NULL;
542 size_t buffer_len = 0;
545 memset(&dkey, 0, sizeof(DBT));
546 memset(&ddata, 0, sizeof(DBT));
548 /* no, we don't care for this error. */
551 ddata.size = cdatalen;
554 /* Only compress Visit records. Everything else is uncompressed. */
555 if (cdb == CDB_VISIT) {
557 zheader.magic = COMPRESS_MAGIC;
558 zheader.uncompressed_len = cdatalen;
559 buffer_len = ((cdatalen * 101) / 100) + 100
560 + sizeof(struct CtdlCompressHeader);
561 destLen = (uLongf) buffer_len;
562 compressed_data = malloc(buffer_len);
563 if (compress2((Bytef *) (compressed_data + sizeof(struct CtdlCompressHeader)),
564 &destLen, (Bytef *) cdata, (uLongf) cdatalen, 1) != Z_OK)
566 syslog(LOG_EMERG, "compress2() error\n");
569 zheader.compressed_len = (size_t) destLen;
570 memcpy(compressed_data, &zheader, sizeof(struct CtdlCompressHeader));
571 ddata.size = (size_t) (sizeof(struct CtdlCompressHeader) + zheader.compressed_len);
572 ddata.data = compressed_data;
575 if (TSD->tid != NULL) {
576 ret = dbp[cdb]->put(dbp[cdb], /* db */
577 TSD->tid, /* transaction ID */
582 syslog(LOG_EMERG, "cdb_store(%d): %s", cdb, db_strerror(ret));
586 free(compressed_data);
590 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
595 if ((ret = dbp[cdb]->put(dbp[cdb], /* db */
596 tid, /* transaction ID */
600 if (ret == DB_LOCK_DEADLOCK) {
604 syslog(LOG_EMERG, "cdb_store(%d): %s", cdb, db_strerror(ret));
610 free(compressed_data);
620 * Delete a piece of data. Returns 0 if the operation was successful.
622 int cdb_delete(int cdb, void *key, int keylen)
629 memset(&dkey, 0, sizeof dkey);
633 if (TSD->tid != NULL) {
634 ret = dbp[cdb]->del(dbp[cdb], TSD->tid, &dkey, 0);
636 syslog(LOG_EMERG, "cdb_delete(%d): %s\n", cdb, db_strerror(ret));
637 if (ret != DB_NOTFOUND) {
642 bailIfCursor(TSD->cursors, "attempt to delete during r/o cursor");
647 if ((ret = dbp[cdb]->del(dbp[cdb], tid, &dkey, 0))
648 && ret != DB_NOTFOUND) {
649 if (ret == DB_LOCK_DEADLOCK) {
653 syslog(LOG_EMERG, "cdb_delete(%d): %s\n",
654 cdb, db_strerror(ret));
664 static DBC *localcursor(int cdb)
669 if (TSD->cursors[cdb] == NULL)
670 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &curs, 0);
672 ret = TSD->cursors[cdb]->c_dup(TSD->cursors[cdb], &curs, DB_POSITION);
675 syslog(LOG_EMERG, "localcursor: %s\n", db_strerror(ret));
684 * Fetch a piece of data. If not found, returns NULL. Otherwise, it returns
685 * a struct cdbdata which it is the caller's responsibility to free later on
686 * using the cdb_free() routine.
688 struct cdbdata *cdb_fetch(int cdb, const void *key, int keylen)
690 struct cdbdata *tempcdb;
694 memset(&dkey, 0, sizeof(DBT));
696 /* no we don't care about this error. */
699 if (TSD->tid != NULL) {
700 memset(&dret, 0, sizeof(DBT));
701 dret.flags = DB_DBT_MALLOC;
702 ret = dbp[cdb]->get(dbp[cdb], TSD->tid, &dkey, &dret, 0);
707 memset(&dret, 0, sizeof(DBT));
708 dret.flags = DB_DBT_MALLOC;
710 curs = localcursor(cdb);
712 ret = curs->c_get(curs, &dkey, &dret, DB_SET);
715 while (ret == DB_LOCK_DEADLOCK);
719 if ((ret != 0) && (ret != DB_NOTFOUND)) {
720 syslog(LOG_EMERG, "cdb_fetch(%d): %s\n", cdb, db_strerror(ret));
726 tempcdb = (struct cdbdata *) malloc(sizeof(struct cdbdata));
728 if (tempcdb == NULL) {
729 syslog(LOG_EMERG, "cdb_fetch: Cannot allocate memory for tempcdb\n");
731 return NULL; /* make it easier for static analysis... */
735 tempcdb->len = dret.size;
736 tempcdb->ptr = dret.data;
737 cdb_decompress_if_necessary(tempcdb);
744 * Free a cdbdata item.
746 * Note that we only free the 'ptr' portion if it is not NULL. This allows
747 * other code to assume ownership of that memory simply by storing the
748 * pointer elsewhere and then setting 'ptr' to NULL. cdb_free() will then
751 void cdb_free(struct cdbdata *cdb)
759 void cdb_close_cursor(int cdb)
761 if (TSD->cursors[cdb] != NULL) {
762 cclose(TSD->cursors[cdb]);
765 TSD->cursors[cdb] = NULL;
769 * Prepare for a sequential search of an entire database.
770 * (There is guaranteed to be no more than one traversal in
771 * progress per thread at any given time.)
773 void cdb_rewind(int cdb)
777 if (TSD->cursors[cdb] != NULL) {
779 "cdb_rewind: must close cursor on database %d before reopening.\n", cdb);
781 /* cclose(TSD->cursors[cdb]); */
785 * Now initialize the cursor
787 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &TSD->cursors[cdb], 0);
789 syslog(LOG_EMERG, "cdb_rewind: db_cursor: %s\n", db_strerror(ret));
796 * Fetch the next item in a sequential search. Returns a pointer to a
797 * cdbdata structure, or NULL if we've hit the end.
799 struct cdbdata *cdb_next_item(int cdb)
802 struct cdbdata *cdbret;
805 /* Initialize the key/data pair so the flags aren't set. */
806 memset(&key, 0, sizeof(key));
807 memset(&data, 0, sizeof(data));
808 data.flags = DB_DBT_MALLOC;
810 ret = TSD->cursors[cdb]->c_get(TSD->cursors[cdb], &key, &data, DB_NEXT);
813 if (ret != DB_NOTFOUND) {
814 syslog(LOG_EMERG, "cdb_next_item(%d): %s\n", cdb, db_strerror(ret));
817 cdb_close_cursor(cdb);
818 return NULL; /* presumably, end of file */
821 cdbret = (struct cdbdata *) malloc(sizeof(struct cdbdata));
822 cdbret->len = data.size;
823 cdbret->ptr = data.data;
824 cdb_decompress_if_necessary(cdbret);
832 * Transaction-based stuff. I'm writing this as I bake cookies...
835 void cdb_begin_transaction(void)
838 bailIfCursor(TSD->cursors, "can't begin transaction during r/o cursor");
840 if (TSD->tid != NULL) {
841 syslog(LOG_EMERG, "cdb_begin_transaction: ERROR: nested transaction\n");
848 void cdb_end_transaction(void)
852 for (i = 0; i < MAXCDB; i++)
853 if (TSD->cursors[i] != NULL) {
855 "cdb_end_transaction: WARNING: cursor %d still open at transaction end\n",
857 cclose(TSD->cursors[i]);
858 TSD->cursors[i] = NULL;
861 if (TSD->tid == NULL) {
863 "cdb_end_transaction: ERROR: txcommit(NULL) !!\n");
873 * Truncate (delete every record)
875 void cdb_trunc(int cdb)
881 if (TSD->tid != NULL) {
882 syslog(LOG_EMERG, "cdb_trunc must not be called in a transaction.");
885 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
890 if ((ret = dbp[cdb]->truncate(dbp[cdb], /* db */
891 NULL, /* transaction ID */
892 &count, /* #rows deleted */
894 if (ret == DB_LOCK_DEADLOCK) {
898 syslog(LOG_EMERG, "cdb_truncate(%d): %s\n", cdb, db_strerror(ret));
900 syslog(LOG_EMERG, "You may need to tune your database; please read http://www.citadel.org/doku.php?id=faq:troubleshooting:out_of_lock_entries for more information.");