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);
96 /* Verbose logging callback */
97 void cdb_verbose_err(const DB_ENV *dbenv, const char *errpfx, const char *msg)
99 syslog(LOG_ALERT, "DB: %s", msg);
103 /* just a little helper function */
104 static void txabort(DB_TXN * tid)
108 ret = tid->abort(tid);
111 syslog(LOG_EMERG, "bdb(): txn_abort: %s", db_strerror(ret));
116 /* this one is even more helpful than the last. */
117 static void txcommit(DB_TXN * tid)
121 ret = tid->commit(tid, 0);
124 syslog(LOG_EMERG, "bdb(): txn_commit: %s", db_strerror(ret));
129 /* are you sensing a pattern yet? */
130 static void txbegin(DB_TXN ** tid)
134 ret = dbenv->txn_begin(dbenv, NULL, tid, 0);
137 syslog(LOG_EMERG, "bdb(): txn_begin: %s", db_strerror(ret));
142 static void dbpanic(DB_ENV * env, int errval)
144 syslog(LOG_EMERG, "bdb(): PANIC: %s", db_strerror(errval));
147 static void cclose(DBC * cursor)
151 if ((ret = cursor->c_close(cursor))) {
152 syslog(LOG_EMERG, "bdb(): c_close: %s", db_strerror(ret));
157 static void bailIfCursor(DBC ** cursors, const char *msg)
161 for (i = 0; i < MAXCDB; i++)
162 if (cursors[i] != NULL) {
163 syslog(LOG_EMERG, "bdb(): cursor still in progress on cdb %02x: %s", i, msg);
169 void cdb_check_handles(void)
171 bailIfCursor(TSD->cursors, "in check_handles");
173 if (TSD->tid != NULL) {
174 syslog(LOG_EMERG, "bdb(): transaction still in progress!");
181 * Cull the database logs
183 static void cdb_cull_logs(void)
192 /* Get the list of names. */
193 if ((ret = dbenv->log_archive(dbenv, &list, flags)) != 0) {
194 syslog(LOG_ERR, "cdb_cull_logs: %s", db_strerror(ret));
198 /* Print the list of names. */
200 for (file = list; *file != NULL; ++file) {
201 syslog(LOG_DEBUG, "Deleting log: %s", *file);
204 snprintf(errmsg, sizeof(errmsg),
205 " ** ERROR **\n \n \n "
206 "Citadel was unable to delete the "
207 "database log file '%s' because of the "
208 "following error:\n \n %s\n \n"
209 " This log file is no longer in use "
210 "and may be safely deleted.\n",
211 *file, strerror(errno));
212 CtdlAideMessage(errmsg, "Database Warning Message");
220 * Manually initiate log file cull.
222 void cmd_cull(char *argbuf) {
223 if (CtdlAccessCheck(ac_internal)) return;
225 cprintf("%d Database log file cull completed.\n", CIT_OK);
230 * Request a checkpoint of the database. Called once per minute by the thread manager.
232 void cdb_checkpoint(void)
236 syslog(LOG_DEBUG, "-- db checkpoint --");
237 ret = dbenv->txn_checkpoint(dbenv, MAX_CHECKPOINT_KBYTES, MAX_CHECKPOINT_MINUTES, 0);
240 syslog(LOG_EMERG, "cdb_checkpoint: txn_checkpoint: %s", db_strerror(ret));
244 /* After a successful checkpoint, we can cull the unused logs */
245 if (config.c_auto_cull) {
253 * Open the various databases we'll be using. Any database which
254 * does not exist should be created. Note that we don't need a
255 * critical section here, because there aren't any active threads
256 * manipulating the database yet.
258 void open_databases(void)
264 int dbversion_major, dbversion_minor, dbversion_patch;
265 int current_dbversion = 0;
267 syslog(LOG_DEBUG, "bdb(): open_databases() starting");
268 syslog(LOG_DEBUG, "Compiled db: %s", DB_VERSION_STRING);
269 syslog(LOG_INFO, " Linked db: %s",
270 db_version(&dbversion_major, &dbversion_minor, &dbversion_patch));
272 current_dbversion = (dbversion_major * 1000000) + (dbversion_minor * 1000) + dbversion_patch;
274 syslog(LOG_DEBUG, "Calculated dbversion: %d", current_dbversion);
275 syslog(LOG_DEBUG, " Previous dbversion: %d", CitControl.MMdbversion);
277 if ( (getenv("SUPPRESS_DBVERSION_CHECK") == NULL)
278 && (CitControl.MMdbversion > current_dbversion) ) {
279 syslog(LOG_EMERG, "You are attempting to run the Citadel server using a version");
280 syslog(LOG_EMERG, "of Berkeley DB that is older than that which last created or");
281 syslog(LOG_EMERG, "updated the database. Because this would probably cause data");
282 syslog(LOG_EMERG, "corruption or loss, the server is aborting execution now.");
286 CitControl.MMdbversion = current_dbversion;
289 syslog(LOG_INFO, "Linked zlib: %s\n", zlibVersion());
292 * Silently try to create the database subdirectory. If it's
293 * already there, no problem.
295 if ((mkdir(ctdl_data_dir, 0700) != 0) && (errno != EEXIST)){
297 "unable to create database directory [%s]: %s",
298 ctdl_data_dir, strerror(errno));
300 if (chmod(ctdl_data_dir, 0700) != 0){
302 "unable to set database directory accessrights [%s]: %s",
303 ctdl_data_dir, strerror(errno));
305 if (chown(ctdl_data_dir, CTDLUID, (-1)) != 0){
307 "unable to set the owner for [%s]: %s",
308 ctdl_data_dir, strerror(errno));
310 syslog(LOG_DEBUG, "bdb(): Setting up DB environment\n");
311 /* db_env_set_func_yield((int (*)(u_long, u_long))sched_yield); */
312 ret = db_env_create(&dbenv, 0);
314 syslog(LOG_EMERG, "bdb(): db_env_create: %s\n", db_strerror(ret));
315 syslog(LOG_EMERG, "exit code %d\n", ret);
318 dbenv->set_errpfx(dbenv, "citserver");
319 dbenv->set_paniccall(dbenv, dbpanic);
320 dbenv->set_errcall(dbenv, cdb_verbose_err);
321 dbenv->set_errpfx(dbenv, "ctdl");
322 #if (DB_VERSION_MAJOR == 4) && (DB_VERSION_MINOR >= 3)
323 dbenv->set_msgcall(dbenv, cdb_verbose_log);
325 dbenv->set_verbose(dbenv, DB_VERB_DEADLOCK, 1);
326 dbenv->set_verbose(dbenv, DB_VERB_RECOVERY, 1);
329 * We want to specify the shared memory buffer pool cachesize,
330 * but everything else is the default.
332 ret = dbenv->set_cachesize(dbenv, 0, 64 * 1024, 0);
334 syslog(LOG_EMERG, "bdb(): set_cachesize: %s\n", db_strerror(ret));
335 dbenv->close(dbenv, 0);
336 syslog(LOG_EMERG, "exit code %d\n", ret);
340 if ((ret = dbenv->set_lk_detect(dbenv, DB_LOCK_DEFAULT))) {
341 syslog(LOG_EMERG, "bdb(): set_lk_detect: %s\n", db_strerror(ret));
342 dbenv->close(dbenv, 0);
343 syslog(LOG_EMERG, "exit code %d\n", ret);
347 flags = DB_CREATE | DB_INIT_MPOOL | DB_PRIVATE | DB_INIT_TXN | DB_INIT_LOCK | DB_THREAD | DB_RECOVER;
348 syslog(LOG_DEBUG, "dbenv->open(dbenv, %s, %d, 0)\n", ctdl_data_dir, flags);
349 ret = dbenv->open(dbenv, ctdl_data_dir, flags, 0);
350 if (ret == DB_RUNRECOVERY) {
351 syslog(LOG_ALERT, "dbenv->open: %s\n", db_strerror(ret));
352 syslog(LOG_ALERT, "Attempting recovery...\n");
354 ret = dbenv->open(dbenv, ctdl_data_dir, flags, 0);
356 if (ret == DB_RUNRECOVERY) {
357 syslog(LOG_ALERT, "dbenv->open: %s\n", db_strerror(ret));
358 syslog(LOG_ALERT, "Attempting catastrophic recovery...\n");
359 flags &= ~DB_RECOVER;
360 flags |= DB_RECOVER_FATAL;
361 ret = dbenv->open(dbenv, ctdl_data_dir, flags, 0);
364 syslog(LOG_EMERG, "dbenv->open: %s\n", db_strerror(ret));
365 dbenv->close(dbenv, 0);
366 syslog(LOG_EMERG, "exit code %d\n", ret);
370 syslog(LOG_INFO, "Starting up DB\n");
372 for (i = 0; i < MAXCDB; ++i) {
374 /* Create a database handle */
375 ret = db_create(&dbp[i], dbenv, 0);
377 syslog(LOG_EMERG, "db_create: %s\n", db_strerror(ret));
378 syslog(LOG_EMERG, "exit code %d\n", ret);
383 /* Arbitrary names for our tables -- we reference them by
384 * number, so we don't have string names for them.
386 snprintf(dbfilename, sizeof dbfilename, "cdb.%02x", i);
388 ret = dbp[i]->open(dbp[i],
393 DB_CREATE | DB_AUTO_COMMIT | DB_THREAD,
397 syslog(LOG_EMERG, "db_open[%02x]: %s\n", i, db_strerror(ret));
399 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.");
401 syslog(LOG_EMERG, "exit code %d\n", ret);
409 /* Make sure we own all the files, because in a few milliseconds
410 * we're going to drop root privs.
412 void cdb_chmod_data(void) {
415 char filename[PATH_MAX];
417 dp = opendir(ctdl_data_dir);
419 while (d = readdir(dp), d != NULL) {
420 if (d->d_name[0] != '.') {
421 snprintf(filename, sizeof filename,
422 "%s/%s", ctdl_data_dir, d->d_name);
423 syslog(LOG_DEBUG, "chmod(%s, 0600) returned %d\n",
424 filename, chmod(filename, 0600)
426 syslog(LOG_DEBUG, "chown(%s, CTDLUID, -1) returned %d\n",
427 filename, chown(filename, CTDLUID, (-1))
434 syslog(LOG_DEBUG, "open_databases() finished\n");
435 CtdlRegisterProtoHook(cmd_cull, "CULL", "Cull database logs");
440 * Close all of the db database files we've opened. This can be done
441 * in a loop, since it's just a bunch of closes.
443 void close_databases(void)
448 if ((ret = dbenv->txn_checkpoint(dbenv, 0, 0, 0))) {
450 "txn_checkpoint: %s\n", db_strerror(ret));
453 /* print some statistics... */
455 dbenv->lock_stat_print(dbenv, DB_STAT_ALL);
458 /* close the tables */
459 for (a = 0; a < MAXCDB; ++a) {
460 syslog(LOG_INFO, "Closing database %02x\n", a);
461 ret = dbp[a]->close(dbp[a], 0);
463 syslog(LOG_EMERG, "db_close: %s\n", db_strerror(ret));
468 /* Close the handle. */
469 ret = dbenv->close(dbenv, 0);
471 syslog(LOG_EMERG, "DBENV->close: %s\n", db_strerror(ret));
477 * Decompress a database item if it was compressed on disk
479 void cdb_decompress_if_necessary(struct cdbdata *cdb)
481 static int magic = COMPRESS_MAGIC;
484 (cdb->ptr == NULL) ||
485 (cdb->len < sizeof(magic)) ||
486 (memcmp(cdb->ptr, &magic, sizeof(magic))))
489 /* At this point we know we're looking at a compressed item. */
491 struct CtdlCompressHeader zheader;
492 char *uncompressed_data;
493 char *compressed_data;
494 uLongf destLen, sourceLen;
497 memset(&zheader, 0, sizeof(struct CtdlCompressHeader));
498 cplen = sizeof(struct CtdlCompressHeader);
499 if (sizeof(struct CtdlCompressHeader) > cdb->len)
501 memcpy(&zheader, cdb->ptr, cplen);
503 compressed_data = cdb->ptr;
504 compressed_data += sizeof(struct CtdlCompressHeader);
506 sourceLen = (uLongf) zheader.compressed_len;
507 destLen = (uLongf) zheader.uncompressed_len;
508 uncompressed_data = malloc(zheader.uncompressed_len);
510 if (uncompress((Bytef *) uncompressed_data,
511 (uLongf *) & destLen,
512 (const Bytef *) compressed_data,
513 (uLong) sourceLen) != Z_OK) {
514 syslog(LOG_EMERG, "uncompress() error\n");
519 cdb->len = (size_t) destLen;
520 cdb->ptr = uncompressed_data;
526 * Store a piece of data. Returns 0 if the operation was successful. If a
527 * key already exists it should be overwritten.
529 int cdb_store(int cdb, const void *ckey, int ckeylen, void *cdata, int cdatalen)
536 struct CtdlCompressHeader zheader;
537 char *compressed_data = NULL;
539 size_t buffer_len = 0;
542 memset(&dkey, 0, sizeof(DBT));
543 memset(&ddata, 0, sizeof(DBT));
545 /* no, we don't care for this error. */
548 ddata.size = cdatalen;
551 /* Only compress Visit records. Everything else is uncompressed. */
552 if (cdb == CDB_VISIT) {
554 zheader.magic = COMPRESS_MAGIC;
555 zheader.uncompressed_len = cdatalen;
556 buffer_len = ((cdatalen * 101) / 100) + 100
557 + sizeof(struct CtdlCompressHeader);
558 destLen = (uLongf) buffer_len;
559 compressed_data = malloc(buffer_len);
560 if (compress2((Bytef *) (compressed_data + sizeof(struct CtdlCompressHeader)),
561 &destLen, (Bytef *) cdata, (uLongf) cdatalen, 1) != Z_OK)
563 syslog(LOG_EMERG, "compress2() error\n");
566 zheader.compressed_len = (size_t) destLen;
567 memcpy(compressed_data, &zheader, sizeof(struct CtdlCompressHeader));
568 ddata.size = (size_t) (sizeof(struct CtdlCompressHeader) + zheader.compressed_len);
569 ddata.data = compressed_data;
572 if (TSD->tid != NULL) {
573 ret = dbp[cdb]->put(dbp[cdb], /* db */
574 TSD->tid, /* transaction ID */
579 syslog(LOG_EMERG, "cdb_store(%d): %s", cdb, db_strerror(ret));
583 free(compressed_data);
587 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
592 if ((ret = dbp[cdb]->put(dbp[cdb], /* db */
593 tid, /* transaction ID */
597 if (ret == DB_LOCK_DEADLOCK) {
601 syslog(LOG_EMERG, "cdb_store(%d): %s", cdb, db_strerror(ret));
607 free(compressed_data);
617 * Delete a piece of data. Returns 0 if the operation was successful.
619 int cdb_delete(int cdb, void *key, int keylen)
626 memset(&dkey, 0, sizeof dkey);
630 if (TSD->tid != NULL) {
631 ret = dbp[cdb]->del(dbp[cdb], TSD->tid, &dkey, 0);
633 syslog(LOG_EMERG, "cdb_delete(%d): %s\n", cdb, db_strerror(ret));
634 if (ret != DB_NOTFOUND) {
639 bailIfCursor(TSD->cursors, "attempt to delete during r/o cursor");
644 if ((ret = dbp[cdb]->del(dbp[cdb], tid, &dkey, 0))
645 && ret != DB_NOTFOUND) {
646 if (ret == DB_LOCK_DEADLOCK) {
650 syslog(LOG_EMERG, "cdb_delete(%d): %s\n",
651 cdb, db_strerror(ret));
661 static DBC *localcursor(int cdb)
666 if (TSD->cursors[cdb] == NULL)
667 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &curs, 0);
669 ret = TSD->cursors[cdb]->c_dup(TSD->cursors[cdb], &curs, DB_POSITION);
672 syslog(LOG_EMERG, "localcursor: %s\n", db_strerror(ret));
681 * Fetch a piece of data. If not found, returns NULL. Otherwise, it returns
682 * a struct cdbdata which it is the caller's responsibility to free later on
683 * using the cdb_free() routine.
685 struct cdbdata *cdb_fetch(int cdb, const void *key, int keylen)
687 struct cdbdata *tempcdb;
691 memset(&dkey, 0, sizeof(DBT));
693 /* no we don't care about this error. */
696 if (TSD->tid != NULL) {
697 memset(&dret, 0, sizeof(DBT));
698 dret.flags = DB_DBT_MALLOC;
699 ret = dbp[cdb]->get(dbp[cdb], TSD->tid, &dkey, &dret, 0);
704 memset(&dret, 0, sizeof(DBT));
705 dret.flags = DB_DBT_MALLOC;
707 curs = localcursor(cdb);
709 ret = curs->c_get(curs, &dkey, &dret, DB_SET);
712 while (ret == DB_LOCK_DEADLOCK);
716 if ((ret != 0) && (ret != DB_NOTFOUND)) {
717 syslog(LOG_EMERG, "cdb_fetch(%d): %s\n", cdb, db_strerror(ret));
723 tempcdb = (struct cdbdata *) malloc(sizeof(struct cdbdata));
725 if (tempcdb == NULL) {
726 syslog(LOG_EMERG, "cdb_fetch: Cannot allocate memory for tempcdb\n");
728 return NULL; /* make it easier for static analysis... */
732 tempcdb->len = dret.size;
733 tempcdb->ptr = dret.data;
734 cdb_decompress_if_necessary(tempcdb);
741 * Free a cdbdata item.
743 * Note that we only free the 'ptr' portion if it is not NULL. This allows
744 * other code to assume ownership of that memory simply by storing the
745 * pointer elsewhere and then setting 'ptr' to NULL. cdb_free() will then
748 void cdb_free(struct cdbdata *cdb)
756 void cdb_close_cursor(int cdb)
758 if (TSD->cursors[cdb] != NULL) {
759 cclose(TSD->cursors[cdb]);
762 TSD->cursors[cdb] = NULL;
766 * Prepare for a sequential search of an entire database.
767 * (There is guaranteed to be no more than one traversal in
768 * progress per thread at any given time.)
770 void cdb_rewind(int cdb)
774 if (TSD->cursors[cdb] != NULL) {
776 "cdb_rewind: must close cursor on database %d before reopening.\n", cdb);
778 /* cclose(TSD->cursors[cdb]); */
782 * Now initialize the cursor
784 ret = dbp[cdb]->cursor(dbp[cdb], TSD->tid, &TSD->cursors[cdb], 0);
786 syslog(LOG_EMERG, "cdb_rewind: db_cursor: %s\n", db_strerror(ret));
793 * Fetch the next item in a sequential search. Returns a pointer to a
794 * cdbdata structure, or NULL if we've hit the end.
796 struct cdbdata *cdb_next_item(int cdb)
799 struct cdbdata *cdbret;
802 /* Initialize the key/data pair so the flags aren't set. */
803 memset(&key, 0, sizeof(key));
804 memset(&data, 0, sizeof(data));
805 data.flags = DB_DBT_MALLOC;
807 ret = TSD->cursors[cdb]->c_get(TSD->cursors[cdb], &key, &data, DB_NEXT);
810 if (ret != DB_NOTFOUND) {
811 syslog(LOG_EMERG, "cdb_next_item(%d): %s\n", cdb, db_strerror(ret));
814 cdb_close_cursor(cdb);
815 return NULL; /* presumably, end of file */
818 cdbret = (struct cdbdata *) malloc(sizeof(struct cdbdata));
819 cdbret->len = data.size;
820 cdbret->ptr = data.data;
821 cdb_decompress_if_necessary(cdbret);
829 * Transaction-based stuff. I'm writing this as I bake cookies...
832 void cdb_begin_transaction(void)
835 bailIfCursor(TSD->cursors, "can't begin transaction during r/o cursor");
837 if (TSD->tid != NULL) {
838 syslog(LOG_EMERG, "cdb_begin_transaction: ERROR: nested transaction\n");
845 void cdb_end_transaction(void)
849 for (i = 0; i < MAXCDB; i++)
850 if (TSD->cursors[i] != NULL) {
852 "cdb_end_transaction: WARNING: cursor %d still open at transaction end\n",
854 cclose(TSD->cursors[i]);
855 TSD->cursors[i] = NULL;
858 if (TSD->tid == NULL) {
860 "cdb_end_transaction: ERROR: txcommit(NULL) !!\n");
870 * Truncate (delete every record)
872 void cdb_trunc(int cdb)
878 if (TSD->tid != NULL) {
879 syslog(LOG_EMERG, "cdb_trunc must not be called in a transaction.");
882 bailIfCursor(TSD->cursors, "attempt to write during r/o cursor");
887 if ((ret = dbp[cdb]->truncate(dbp[cdb], /* db */
888 NULL, /* transaction ID */
889 &count, /* #rows deleted */
891 if (ret == DB_LOCK_DEADLOCK) {
895 syslog(LOG_EMERG, "cdb_truncate(%d): %s\n", cdb, db_strerror(ret));
897 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.");