2 Unix SMB/CIFS implementation.
3 Database interface wrapper around ctdbd
4 Copyright (C) Volker Lendecke 2007-2009
5 Copyright (C) Michael Adam 2009
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include "system/filesys.h"
23 #ifdef CLUSTER_SUPPORT
25 #include "ctdb_private.h"
26 #include "ctdbd_conn.h"
30 struct db_ctdb_transaction_handle {
31 struct db_ctdb_ctx *ctx;
33 * we store the reads and writes done under a transaction:
34 * - one list stores both reads and writes (m_all),
35 * - the other just writes (m_write)
37 struct ctdb_marshall_buffer *m_all;
38 struct ctdb_marshall_buffer *m_write;
45 struct db_context *db;
46 struct tdb_wrap *wtdb;
48 struct db_ctdb_transaction_handle *transaction;
49 struct g_lock_ctx *lock_ctx;
53 struct db_ctdb_ctx *ctdb_ctx;
54 struct ctdb_ltdb_header header;
55 struct timeval lock_time;
58 static NTSTATUS tdb_error_to_ntstatus(struct tdb_context *tdb)
61 enum TDB_ERROR tret = tdb_error(tdb);
65 status = NT_STATUS_OBJECT_NAME_COLLISION;
68 status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
71 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
80 * fetch a record from the tdb, separating out the header
81 * information and returning the body of the record.
83 static NTSTATUS db_ctdb_ltdb_fetch(struct db_ctdb_ctx *db,
85 struct ctdb_ltdb_header *header,
92 rec = tdb_fetch(db->wtdb->tdb, key);
93 if (rec.dsize < sizeof(struct ctdb_ltdb_header)) {
94 status = NT_STATUS_NOT_FOUND;
99 header->dmaster = (uint32_t)-1;
106 *header = *(struct ctdb_ltdb_header *)rec.dptr;
110 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
111 if (data->dsize == 0) {
114 data->dptr = (unsigned char *)talloc_memdup(mem_ctx,
116 + sizeof(struct ctdb_ltdb_header),
118 if (data->dptr == NULL) {
119 status = NT_STATUS_NO_MEMORY;
125 status = NT_STATUS_OK;
133 * Store a record together with the ctdb record header
134 * in the local copy of the database.
136 static NTSTATUS db_ctdb_ltdb_store(struct db_ctdb_ctx *db,
138 struct ctdb_ltdb_header *header,
141 TALLOC_CTX *tmp_ctx = talloc_stackframe();
145 rec.dsize = data.dsize + sizeof(struct ctdb_ltdb_header);
146 rec.dptr = (uint8_t *)talloc_size(tmp_ctx, rec.dsize);
148 if (rec.dptr == NULL) {
149 talloc_free(tmp_ctx);
150 return NT_STATUS_NO_MEMORY;
153 memcpy(rec.dptr, header, sizeof(struct ctdb_ltdb_header));
154 memcpy(sizeof(struct ctdb_ltdb_header) + (uint8_t *)rec.dptr, data.dptr, data.dsize);
156 ret = tdb_store(db->wtdb->tdb, key, rec, TDB_REPLACE);
158 talloc_free(tmp_ctx);
160 return (ret == 0) ? NT_STATUS_OK
161 : tdb_error_to_ntstatus(db->wtdb->tdb);
166 form a ctdb_rec_data record from a key/data pair
168 note that header may be NULL. If not NULL then it is included in the data portion
171 static struct ctdb_rec_data *db_ctdb_marshall_record(TALLOC_CTX *mem_ctx, uint32_t reqid,
173 struct ctdb_ltdb_header *header,
177 struct ctdb_rec_data *d;
179 length = offsetof(struct ctdb_rec_data, data) + key.dsize +
180 data.dsize + (header?sizeof(*header):0);
181 d = (struct ctdb_rec_data *)talloc_size(mem_ctx, length);
187 d->keylen = key.dsize;
188 memcpy(&d->data[0], key.dptr, key.dsize);
190 d->datalen = data.dsize + sizeof(*header);
191 memcpy(&d->data[key.dsize], header, sizeof(*header));
192 memcpy(&d->data[key.dsize+sizeof(*header)], data.dptr, data.dsize);
194 d->datalen = data.dsize;
195 memcpy(&d->data[key.dsize], data.dptr, data.dsize);
201 /* helper function for marshalling multiple records */
202 static struct ctdb_marshall_buffer *db_ctdb_marshall_add(TALLOC_CTX *mem_ctx,
203 struct ctdb_marshall_buffer *m,
207 struct ctdb_ltdb_header *header,
210 struct ctdb_rec_data *r;
211 size_t m_size, r_size;
212 struct ctdb_marshall_buffer *m2 = NULL;
214 r = db_ctdb_marshall_record(talloc_tos(), reqid, key, header, data);
221 m = (struct ctdb_marshall_buffer *)talloc_zero_size(
222 mem_ctx, offsetof(struct ctdb_marshall_buffer, data));
229 m_size = talloc_get_size(m);
230 r_size = talloc_get_size(r);
232 m2 = (struct ctdb_marshall_buffer *)talloc_realloc_size(
233 mem_ctx, m, m_size + r_size);
239 memcpy(m_size + (uint8_t *)m2, r, r_size);
248 /* we've finished marshalling, return a data blob with the marshalled records */
249 static TDB_DATA db_ctdb_marshall_finish(struct ctdb_marshall_buffer *m)
252 data.dptr = (uint8_t *)m;
253 data.dsize = talloc_get_size(m);
258 loop over a marshalling buffer
260 - pass r==NULL to start
261 - loop the number of times indicated by m->count
263 static struct ctdb_rec_data *db_ctdb_marshall_loop_next(struct ctdb_marshall_buffer *m, struct ctdb_rec_data *r,
265 struct ctdb_ltdb_header *header,
266 TDB_DATA *key, TDB_DATA *data)
269 r = (struct ctdb_rec_data *)&m->data[0];
271 r = (struct ctdb_rec_data *)(r->length + (uint8_t *)r);
279 key->dptr = &r->data[0];
280 key->dsize = r->keylen;
283 data->dptr = &r->data[r->keylen];
284 data->dsize = r->datalen;
285 if (header != NULL) {
286 data->dptr += sizeof(*header);
287 data->dsize -= sizeof(*header);
291 if (header != NULL) {
292 if (r->datalen < sizeof(*header)) {
295 *header = *(struct ctdb_ltdb_header *)&r->data[r->keylen];
302 * CTDB transaction destructor
304 static int db_ctdb_transaction_destructor(struct db_ctdb_transaction_handle *h)
308 status = g_lock_unlock(h->ctx->lock_ctx, h->lock_name);
309 if (!NT_STATUS_IS_OK(status)) {
310 DEBUG(0, ("g_lock_unlock failed: %s\n", nt_errstr(status)));
317 * CTDB dbwrap API: transaction_start function
318 * starts a transaction on a persistent database
320 static int db_ctdb_transaction_start(struct db_context *db)
322 struct db_ctdb_transaction_handle *h;
324 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
327 if (!db->persistent) {
328 DEBUG(0,("transactions not supported on non-persistent database 0x%08x\n",
333 if (ctx->transaction) {
334 ctx->transaction->nesting++;
338 h = talloc_zero(db, struct db_ctdb_transaction_handle);
340 DEBUG(0,(__location__ " oom for transaction handle\n"));
346 h->lock_name = talloc_asprintf(h, "transaction_db_0x%08x",
347 (unsigned int)ctx->db_id);
348 if (h->lock_name == NULL) {
349 DEBUG(0, ("talloc_asprintf failed\n"));
355 * Wait a day, i.e. forever...
357 status = g_lock_lock(ctx->lock_ctx, h->lock_name, G_LOCK_WRITE,
358 timeval_set(86400, 0));
359 if (!NT_STATUS_IS_OK(status)) {
360 DEBUG(0, ("g_lock_lock failed: %s\n", nt_errstr(status)));
365 talloc_set_destructor(h, db_ctdb_transaction_destructor);
367 ctx->transaction = h;
369 DEBUG(5,(__location__ " Started transaction on db 0x%08x\n", ctx->db_id));
374 static bool pull_newest_from_marshall_buffer(struct ctdb_marshall_buffer *buf,
376 struct ctdb_ltdb_header *pheader,
380 struct ctdb_rec_data *rec = NULL;
381 struct ctdb_ltdb_header h;
394 * Walk the list of records written during this
395 * transaction. If we want to read one we have already
396 * written, return the last written sample. Thus we do not do
397 * a "break;" for the first hit, this record might have been
401 for (i=0; i<buf->count; i++) {
402 TDB_DATA tkey, tdata;
404 struct ctdb_ltdb_header hdr;
408 rec = db_ctdb_marshall_loop_next(buf, rec, &reqid, &hdr, &tkey,
414 if (tdb_data_equal(key, tkey)) {
426 data.dptr = (uint8_t *)talloc_memdup(mem_ctx, data.dptr,
428 if ((data.dsize != 0) && (data.dptr == NULL)) {
434 if (pheader != NULL) {
442 fetch a record inside a transaction
444 static int db_ctdb_transaction_fetch(struct db_ctdb_ctx *db,
446 TDB_DATA key, TDB_DATA *data)
448 struct db_ctdb_transaction_handle *h = db->transaction;
452 found = pull_newest_from_marshall_buffer(h->m_write, key, NULL,
458 status = db_ctdb_ltdb_fetch(h->ctx, key, NULL, mem_ctx, data);
460 if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
462 } else if (!NT_STATUS_IS_OK(status)) {
466 h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 1, key,
468 if (h->m_all == NULL) {
469 DEBUG(0,(__location__ " Failed to add to marshalling "
472 talloc_free(data->dptr);
480 * Fetch a record from a persistent database
481 * without record locking and without an active transaction.
483 * This just fetches from the local database copy.
484 * Since the databases are kept in syc cluster-wide,
485 * there is no point in doing a ctdb call to fetch the
486 * record from the lmaster. It does even harm since migration
487 * of records bump their RSN and hence render the persistent
488 * database inconsistent.
490 static int db_ctdb_fetch_persistent(struct db_ctdb_ctx *db,
492 TDB_DATA key, TDB_DATA *data)
496 status = db_ctdb_ltdb_fetch(db, key, NULL, mem_ctx, data);
498 if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
500 } else if (!NT_STATUS_IS_OK(status)) {
507 static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag);
508 static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec);
510 static struct db_record *db_ctdb_fetch_locked_transaction(struct db_ctdb_ctx *ctx,
514 struct db_record *result;
517 if (!(result = talloc(mem_ctx, struct db_record))) {
518 DEBUG(0, ("talloc failed\n"));
522 result->private_data = ctx->transaction;
524 result->key.dsize = key.dsize;
525 result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
526 if (result->key.dptr == NULL) {
527 DEBUG(0, ("talloc failed\n"));
532 result->store = db_ctdb_store_transaction;
533 result->delete_rec = db_ctdb_delete_transaction;
535 if (pull_newest_from_marshall_buffer(ctx->transaction->m_write, key,
536 NULL, result, &result->value)) {
540 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
541 if (ctdb_data.dptr == NULL) {
542 /* create the record */
543 result->value = tdb_null;
547 result->value.dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
548 result->value.dptr = NULL;
550 if ((result->value.dsize != 0)
551 && !(result->value.dptr = (uint8 *)talloc_memdup(
552 result, ctdb_data.dptr + sizeof(struct ctdb_ltdb_header),
553 result->value.dsize))) {
554 DEBUG(0, ("talloc failed\n"));
558 SAFE_FREE(ctdb_data.dptr);
563 static int db_ctdb_record_destructor(struct db_record **recp)
565 struct db_record *rec = talloc_get_type_abort(*recp, struct db_record);
566 struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
567 rec->private_data, struct db_ctdb_transaction_handle);
568 int ret = h->ctx->db->transaction_commit(h->ctx->db);
570 DEBUG(0,(__location__ " transaction_commit failed\n"));
576 auto-create a transaction for persistent databases
578 static struct db_record *db_ctdb_fetch_locked_persistent(struct db_ctdb_ctx *ctx,
583 struct db_record *rec, **recp;
585 res = db_ctdb_transaction_start(ctx->db);
590 rec = db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
592 ctx->db->transaction_cancel(ctx->db);
596 /* destroy this transaction when we release the lock */
597 recp = talloc(rec, struct db_record *);
599 ctx->db->transaction_cancel(ctx->db);
604 talloc_set_destructor(recp, db_ctdb_record_destructor);
610 stores a record inside a transaction
612 static NTSTATUS db_ctdb_transaction_store(struct db_ctdb_transaction_handle *h,
613 TDB_DATA key, TDB_DATA data)
615 TALLOC_CTX *tmp_ctx = talloc_new(h);
617 struct ctdb_ltdb_header header;
621 /* we need the header so we can update the RSN */
623 if (!pull_newest_from_marshall_buffer(h->m_write, key, &header,
626 rec = tdb_fetch(h->ctx->wtdb->tdb, key);
628 if (rec.dptr != NULL) {
629 memcpy(&header, rec.dptr,
630 sizeof(struct ctdb_ltdb_header));
631 rec.dsize -= sizeof(struct ctdb_ltdb_header);
634 * a special case, we are writing the same
635 * data that is there now
637 if (data.dsize == rec.dsize &&
639 rec.dptr + sizeof(struct ctdb_ltdb_header),
642 talloc_free(tmp_ctx);
649 header.dmaster = get_my_vnn();
652 h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 0, key,
654 if (h->m_all == NULL) {
655 DEBUG(0,(__location__ " Failed to add to marshalling "
657 talloc_free(tmp_ctx);
658 return NT_STATUS_NO_MEMORY;
661 h->m_write = db_ctdb_marshall_add(h, h->m_write, h->ctx->db_id, 0, key, &header, data);
662 if (h->m_write == NULL) {
663 DEBUG(0,(__location__ " Failed to add to marshalling record\n"));
664 talloc_free(tmp_ctx);
665 return NT_STATUS_NO_MEMORY;
668 talloc_free(tmp_ctx);
674 a record store inside a transaction
676 static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag)
678 struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
679 rec->private_data, struct db_ctdb_transaction_handle);
682 status = db_ctdb_transaction_store(h, rec->key, data);
687 a record delete inside a transaction
689 static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec)
691 struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
692 rec->private_data, struct db_ctdb_transaction_handle);
695 status = db_ctdb_transaction_store(h, rec->key, tdb_null);
700 * Fetch the db sequence number of a persistent db directly from the db.
702 static NTSTATUS db_ctdb_fetch_db_seqnum_from_db(struct db_ctdb_ctx *db,
706 const char *keyname = CTDB_DB_SEQNUM_KEY;
709 struct ctdb_ltdb_header header;
710 TALLOC_CTX *mem_ctx = talloc_stackframe();
712 if (seqnum == NULL) {
713 return NT_STATUS_INVALID_PARAMETER;
716 key = string_term_tdb_data(keyname);
718 status = db_ctdb_ltdb_fetch(db, key, &header, mem_ctx, &data);
719 if (!NT_STATUS_IS_OK(status) &&
720 !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND))
725 status = NT_STATUS_OK;
727 if (data.dsize != sizeof(uint64_t)) {
732 *seqnum = *(uint64_t *)data.dptr;
735 TALLOC_FREE(mem_ctx);
740 * Store the database sequence number inside a transaction.
742 static NTSTATUS db_ctdb_store_db_seqnum(struct db_ctdb_transaction_handle *h,
746 const char *keyname = CTDB_DB_SEQNUM_KEY;
750 key = string_term_tdb_data(keyname);
752 data.dptr = (uint8_t *)&seqnum;
753 data.dsize = sizeof(uint64_t);
755 status = db_ctdb_transaction_store(h, key, data);
763 static int db_ctdb_transaction_commit(struct db_context *db)
765 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
769 struct db_ctdb_transaction_handle *h = ctx->transaction;
770 uint64_t old_seqnum, new_seqnum;
774 DEBUG(0,(__location__ " transaction commit with no open transaction on db 0x%08x\n", ctx->db_id));
778 if (h->nested_cancel) {
779 db->transaction_cancel(db);
780 DEBUG(5,(__location__ " Failed transaction commit after nested cancel\n"));
784 if (h->nesting != 0) {
789 if (h->m_write == NULL) {
791 * No changes were made, so don't change the seqnum,
792 * don't push to other node, just exit with success.
798 DEBUG(5,(__location__ " Commit transaction on db 0x%08x\n", ctx->db_id));
801 * As the last db action before committing, bump the database sequence
802 * number. Note that this undoes all changes to the seqnum records
803 * performed under the transaction. This record is not meant to be
804 * modified by user interaction. It is for internal use only...
806 rets = db_ctdb_fetch_db_seqnum_from_db(ctx, &old_seqnum);
807 if (!NT_STATUS_IS_OK(rets)) {
808 DEBUG(1, (__location__ " failed to fetch the db sequence number "
809 "in transaction commit on db 0x%08x\n", ctx->db_id));
814 new_seqnum = old_seqnum + 1;
816 rets = db_ctdb_store_db_seqnum(h, new_seqnum);
817 if (!NT_STATUS_IS_OK(rets)) {
818 DEBUG(1, (__location__ "failed to store the db sequence number "
819 " in transaction commit on db 0x%08x\n", ctx->db_id));
825 /* tell ctdbd to commit to the other nodes */
826 rets = ctdbd_control_local(messaging_ctdbd_connection(),
827 CTDB_CONTROL_TRANS3_COMMIT,
829 db_ctdb_marshall_finish(h->m_write),
830 NULL, NULL, &status);
831 if (!NT_STATUS_IS_OK(rets) || status != 0) {
833 * The TRANS3_COMMIT control should only possibly fail when a
834 * recovery has been running concurrently. In any case, the db
835 * will be the same on all nodes, either the new copy or the
836 * old copy. This can be detected by comparing the old and new
837 * local sequence numbers.
839 rets = db_ctdb_fetch_db_seqnum_from_db(ctx, &new_seqnum);
840 if (!NT_STATUS_IS_OK(rets)) {
841 DEBUG(1, (__location__ " failed to refetch db sequence "
842 "number after failed TRANS3_COMMIT\n"));
847 if (new_seqnum == old_seqnum) {
848 /* Recovery prevented all our changes: retry. */
850 } else if (new_seqnum != (old_seqnum + 1)) {
851 DEBUG(0, (__location__ " ERROR: new_seqnum[%lu] != "
852 "old_seqnum[%lu] + (0 or 1) after failed "
853 "TRANS3_COMMIT - this should not happen!\n",
854 (unsigned long)new_seqnum,
855 (unsigned long)old_seqnum));
860 * Recovery propagated our changes to all nodes, completing
861 * our commit for us - succeed.
868 h->ctx->transaction = NULL;
877 static int db_ctdb_transaction_cancel(struct db_context *db)
879 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
881 struct db_ctdb_transaction_handle *h = ctx->transaction;
884 DEBUG(0,(__location__ " transaction cancel with no open transaction on db 0x%08x\n", ctx->db_id));
888 if (h->nesting != 0) {
890 h->nested_cancel = true;
894 DEBUG(5,(__location__ " Cancel transaction on db 0x%08x\n", ctx->db_id));
896 ctx->transaction = NULL;
902 static NTSTATUS db_ctdb_store(struct db_record *rec, TDB_DATA data, int flag)
904 struct db_ctdb_rec *crec = talloc_get_type_abort(
905 rec->private_data, struct db_ctdb_rec);
907 return db_ctdb_ltdb_store(crec->ctdb_ctx, rec->key, &(crec->header), data);
912 #ifdef CTDB_CONTROL_SCHEDULE_FOR_DELETION
913 static NTSTATUS db_ctdb_send_schedule_for_deletion(struct db_record *rec)
916 struct ctdb_control_schedule_for_deletion *dd;
919 struct db_ctdb_rec *crec = talloc_get_type_abort(
920 rec->private_data, struct db_ctdb_rec);
922 indata.dsize = offsetof(struct ctdb_control_schedule_for_deletion, key) + rec->key.dsize;
923 indata.dptr = talloc_zero_array(crec, uint8_t, indata.dsize);
924 if (indata.dptr == NULL) {
925 DEBUG(0, (__location__ " talloc failed!\n"));
926 return NT_STATUS_NO_MEMORY;
929 dd = (struct ctdb_control_schedule_for_deletion *)(void *)indata.dptr;
930 dd->db_id = crec->ctdb_ctx->db_id;
931 dd->hdr = crec->header;
932 dd->keylen = rec->key.dsize;
933 memcpy(dd->key, rec->key.dptr, rec->key.dsize);
935 status = ctdbd_control_local(messaging_ctdbd_connection(),
936 CTDB_CONTROL_SCHEDULE_FOR_DELETION,
937 crec->ctdb_ctx->db_id,
938 CTDB_CTRL_FLAG_NOREPLY, /* flags */
943 talloc_free(indata.dptr);
945 if (!NT_STATUS_IS_OK(status) || cstatus != 0) {
946 DEBUG(1, (__location__ " Error sending local control "
947 "SCHEDULE_FOR_DELETION: %s, cstatus = %d\n",
948 nt_errstr(status), cstatus));
949 if (NT_STATUS_IS_OK(status)) {
950 status = NT_STATUS_UNSUCCESSFUL;
958 static NTSTATUS db_ctdb_delete(struct db_record *rec)
964 * We have to store the header with empty data. TODO: Fix the
970 status = db_ctdb_store(rec, data, 0);
971 if (!NT_STATUS_IS_OK(status)) {
975 #ifdef CTDB_CONTROL_SCHEDULE_FOR_DELETION
976 status = db_ctdb_send_schedule_for_deletion(rec);
982 static int db_ctdb_record_destr(struct db_record* data)
984 struct db_ctdb_rec *crec = talloc_get_type_abort(
985 data->private_data, struct db_ctdb_rec);
988 DEBUG(10, (DEBUGLEVEL > 10
989 ? "Unlocking db %u key %s\n"
990 : "Unlocking db %u key %.20s\n",
991 (int)crec->ctdb_ctx->db_id,
992 hex_encode_talloc(data, (unsigned char *)data->key.dptr,
995 if (tdb_chainunlock(crec->ctdb_ctx->wtdb->tdb, data->key) != 0) {
996 DEBUG(0, ("tdb_chainunlock failed\n"));
1000 threshold = lp_ctdb_locktime_warn_threshold();
1001 if (threshold != 0) {
1002 double timediff = timeval_elapsed(&crec->lock_time);
1003 if ((timediff * 1000) > threshold) {
1004 DEBUG(0, ("Held tdb lock %f seconds\n", timediff));
1011 static struct db_record *fetch_locked_internal(struct db_ctdb_ctx *ctx,
1012 TALLOC_CTX *mem_ctx,
1015 struct db_record *result;
1016 struct db_ctdb_rec *crec;
1019 int migrate_attempts = 0;
1021 if (!(result = talloc(mem_ctx, struct db_record))) {
1022 DEBUG(0, ("talloc failed\n"));
1026 if (!(crec = TALLOC_ZERO_P(result, struct db_ctdb_rec))) {
1027 DEBUG(0, ("talloc failed\n"));
1028 TALLOC_FREE(result);
1032 result->private_data = (void *)crec;
1033 crec->ctdb_ctx = ctx;
1035 result->key.dsize = key.dsize;
1036 result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
1037 if (result->key.dptr == NULL) {
1038 DEBUG(0, ("talloc failed\n"));
1039 TALLOC_FREE(result);
1044 * Do a blocking lock on the record
1048 if (DEBUGLEVEL >= 10) {
1049 char *keystr = hex_encode_talloc(result, key.dptr, key.dsize);
1050 DEBUG(10, (DEBUGLEVEL > 10
1051 ? "Locking db %u key %s\n"
1052 : "Locking db %u key %.20s\n",
1053 (int)crec->ctdb_ctx->db_id, keystr));
1054 TALLOC_FREE(keystr);
1057 if (tdb_chainlock(ctx->wtdb->tdb, key) != 0) {
1058 DEBUG(3, ("tdb_chainlock failed\n"));
1059 TALLOC_FREE(result);
1063 result->store = db_ctdb_store;
1064 result->delete_rec = db_ctdb_delete;
1065 talloc_set_destructor(result, db_ctdb_record_destr);
1067 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
1070 * See if we have a valid record and we are the dmaster. If so, we can
1071 * take the shortcut and just return it.
1074 if ((ctdb_data.dptr == NULL) ||
1075 (ctdb_data.dsize < sizeof(struct ctdb_ltdb_header)) ||
1076 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster != get_my_vnn()
1078 || (random() % 2 != 0)
1081 SAFE_FREE(ctdb_data.dptr);
1082 tdb_chainunlock(ctx->wtdb->tdb, key);
1083 talloc_set_destructor(result, NULL);
1085 migrate_attempts += 1;
1087 DEBUG(10, ("ctdb_data.dptr = %p, dmaster = %u (%u)\n",
1088 ctdb_data.dptr, ctdb_data.dptr ?
1089 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster : -1,
1092 status = ctdbd_migrate(messaging_ctdbd_connection(), ctx->db_id,
1094 if (!NT_STATUS_IS_OK(status)) {
1095 DEBUG(5, ("ctdb_migrate failed: %s\n",
1096 nt_errstr(status)));
1097 TALLOC_FREE(result);
1100 /* now its migrated, try again */
1104 if (migrate_attempts > 10) {
1105 DEBUG(0, ("db_ctdb_fetch_locked needed %d attempts\n",
1109 GetTimeOfDay(&crec->lock_time);
1111 memcpy(&crec->header, ctdb_data.dptr, sizeof(crec->header));
1113 result->value.dsize = ctdb_data.dsize - sizeof(crec->header);
1114 result->value.dptr = NULL;
1116 if ((result->value.dsize != 0)
1117 && !(result->value.dptr = (uint8 *)talloc_memdup(
1118 result, ctdb_data.dptr + sizeof(crec->header),
1119 result->value.dsize))) {
1120 DEBUG(0, ("talloc failed\n"));
1121 TALLOC_FREE(result);
1124 SAFE_FREE(ctdb_data.dptr);
1129 static struct db_record *db_ctdb_fetch_locked(struct db_context *db,
1130 TALLOC_CTX *mem_ctx,
1133 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1134 struct db_ctdb_ctx);
1136 if (ctx->transaction != NULL) {
1137 return db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
1140 if (db->persistent) {
1141 return db_ctdb_fetch_locked_persistent(ctx, mem_ctx, key);
1144 return fetch_locked_internal(ctx, mem_ctx, key);
1148 fetch (unlocked, no migration) operation on ctdb
1150 static int db_ctdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
1151 TDB_DATA key, TDB_DATA *data)
1153 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1154 struct db_ctdb_ctx);
1158 if (ctx->transaction) {
1159 return db_ctdb_transaction_fetch(ctx, mem_ctx, key, data);
1162 if (db->persistent) {
1163 return db_ctdb_fetch_persistent(ctx, mem_ctx, key, data);
1166 /* try a direct fetch */
1167 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
1170 * See if we have a valid record and we are the dmaster. If so, we can
1171 * take the shortcut and just return it.
1172 * we bypass the dmaster check for persistent databases
1174 if ((ctdb_data.dptr != NULL) &&
1175 (ctdb_data.dsize >= sizeof(struct ctdb_ltdb_header)) &&
1176 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster == get_my_vnn())
1178 /* we are the dmaster - avoid the ctdb protocol op */
1180 data->dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
1181 if (data->dsize == 0) {
1182 SAFE_FREE(ctdb_data.dptr);
1187 data->dptr = (uint8 *)talloc_memdup(
1188 mem_ctx, ctdb_data.dptr+sizeof(struct ctdb_ltdb_header),
1191 SAFE_FREE(ctdb_data.dptr);
1193 if (data->dptr == NULL) {
1199 SAFE_FREE(ctdb_data.dptr);
1201 /* we weren't able to get it locally - ask ctdb to fetch it for us */
1202 status = ctdbd_fetch(messaging_ctdbd_connection(), ctx->db_id, key,
1204 if (!NT_STATUS_IS_OK(status)) {
1205 DEBUG(5, ("ctdbd_fetch failed: %s\n", nt_errstr(status)));
1212 struct traverse_state {
1213 struct db_context *db;
1214 int (*fn)(struct db_record *rec, void *private_data);
1218 static void traverse_callback(TDB_DATA key, TDB_DATA data, void *private_data)
1220 struct traverse_state *state = (struct traverse_state *)private_data;
1221 struct db_record *rec;
1222 TALLOC_CTX *tmp_ctx = talloc_new(state->db);
1223 /* we have to give them a locked record to prevent races */
1224 rec = db_ctdb_fetch_locked(state->db, tmp_ctx, key);
1225 if (rec && rec->value.dsize > 0) {
1226 state->fn(rec, state->private_data);
1228 talloc_free(tmp_ctx);
1231 static int traverse_persistent_callback(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
1234 struct traverse_state *state = (struct traverse_state *)private_data;
1235 struct db_record *rec;
1236 TALLOC_CTX *tmp_ctx = talloc_new(state->db);
1238 /* we have to give them a locked record to prevent races */
1239 rec = db_ctdb_fetch_locked(state->db, tmp_ctx, kbuf);
1240 if (rec && rec->value.dsize > 0) {
1241 ret = state->fn(rec, state->private_data);
1243 talloc_free(tmp_ctx);
1247 static int db_ctdb_traverse(struct db_context *db,
1248 int (*fn)(struct db_record *rec,
1249 void *private_data),
1252 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1253 struct db_ctdb_ctx);
1254 struct traverse_state state;
1258 state.private_data = private_data;
1260 if (db->persistent) {
1261 /* for persistent databases we don't need to do a ctdb traverse,
1262 we can do a faster local traverse */
1263 return tdb_traverse(ctx->wtdb->tdb, traverse_persistent_callback, &state);
1267 ctdbd_traverse(ctx->db_id, traverse_callback, &state);
1271 static NTSTATUS db_ctdb_store_deny(struct db_record *rec, TDB_DATA data, int flag)
1273 return NT_STATUS_MEDIA_WRITE_PROTECTED;
1276 static NTSTATUS db_ctdb_delete_deny(struct db_record *rec)
1278 return NT_STATUS_MEDIA_WRITE_PROTECTED;
1281 static void traverse_read_callback(TDB_DATA key, TDB_DATA data, void *private_data)
1283 struct traverse_state *state = (struct traverse_state *)private_data;
1284 struct db_record rec;
1287 rec.store = db_ctdb_store_deny;
1288 rec.delete_rec = db_ctdb_delete_deny;
1289 rec.private_data = state->db;
1290 state->fn(&rec, state->private_data);
1293 static int traverse_persistent_callback_read(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
1296 struct traverse_state *state = (struct traverse_state *)private_data;
1297 struct db_record rec;
1300 rec.store = db_ctdb_store_deny;
1301 rec.delete_rec = db_ctdb_delete_deny;
1302 rec.private_data = state->db;
1304 if (rec.value.dsize <= sizeof(struct ctdb_ltdb_header)) {
1305 /* a deleted record */
1308 rec.value.dsize -= sizeof(struct ctdb_ltdb_header);
1309 rec.value.dptr += sizeof(struct ctdb_ltdb_header);
1311 return state->fn(&rec, state->private_data);
1314 static int db_ctdb_traverse_read(struct db_context *db,
1315 int (*fn)(struct db_record *rec,
1316 void *private_data),
1319 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1320 struct db_ctdb_ctx);
1321 struct traverse_state state;
1325 state.private_data = private_data;
1327 if (db->persistent) {
1328 /* for persistent databases we don't need to do a ctdb traverse,
1329 we can do a faster local traverse */
1330 return tdb_traverse_read(ctx->wtdb->tdb, traverse_persistent_callback_read, &state);
1333 ctdbd_traverse(ctx->db_id, traverse_read_callback, &state);
1337 static int db_ctdb_get_seqnum(struct db_context *db)
1339 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1340 struct db_ctdb_ctx);
1341 return tdb_get_seqnum(ctx->wtdb->tdb);
1344 static int db_ctdb_get_flags(struct db_context *db)
1346 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1347 struct db_ctdb_ctx);
1348 return tdb_get_flags(ctx->wtdb->tdb);
1351 struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
1353 int hash_size, int tdb_flags,
1354 int open_flags, mode_t mode)
1356 struct db_context *result;
1357 struct db_ctdb_ctx *db_ctdb;
1359 struct ctdbd_connection *conn;
1361 if (!lp_clustering()) {
1362 DEBUG(10, ("Clustering disabled -- no ctdb\n"));
1366 if (!(result = TALLOC_ZERO_P(mem_ctx, struct db_context))) {
1367 DEBUG(0, ("talloc failed\n"));
1368 TALLOC_FREE(result);
1372 if (!(db_ctdb = TALLOC_P(result, struct db_ctdb_ctx))) {
1373 DEBUG(0, ("talloc failed\n"));
1374 TALLOC_FREE(result);
1378 db_ctdb->transaction = NULL;
1379 db_ctdb->db = result;
1381 conn = messaging_ctdbd_connection();
1383 DEBUG(1, ("Could not connect to ctdb\n"));
1384 TALLOC_FREE(result);
1388 if (!NT_STATUS_IS_OK(ctdbd_db_attach(conn, name, &db_ctdb->db_id, tdb_flags))) {
1389 DEBUG(0, ("ctdbd_db_attach failed for %s\n", name));
1390 TALLOC_FREE(result);
1394 db_path = ctdbd_dbpath(conn, db_ctdb, db_ctdb->db_id);
1396 result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
1398 /* only pass through specific flags */
1399 tdb_flags &= TDB_SEQNUM;
1401 /* honor permissions if user has specified O_CREAT */
1402 if (open_flags & O_CREAT) {
1403 chmod(db_path, mode);
1406 db_ctdb->wtdb = tdb_wrap_open(db_ctdb, db_path, hash_size, tdb_flags, O_RDWR, 0);
1407 if (db_ctdb->wtdb == NULL) {
1408 DEBUG(0, ("Could not open tdb %s: %s\n", db_path, strerror(errno)));
1409 TALLOC_FREE(result);
1412 talloc_free(db_path);
1414 if (result->persistent) {
1415 db_ctdb->lock_ctx = g_lock_ctx_init(db_ctdb,
1416 ctdb_conn_msg_ctx(conn));
1417 if (db_ctdb->lock_ctx == NULL) {
1418 DEBUG(0, ("g_lock_ctx_init failed\n"));
1419 TALLOC_FREE(result);
1424 result->private_data = (void *)db_ctdb;
1425 result->fetch_locked = db_ctdb_fetch_locked;
1426 result->fetch = db_ctdb_fetch;
1427 result->traverse = db_ctdb_traverse;
1428 result->traverse_read = db_ctdb_traverse_read;
1429 result->get_seqnum = db_ctdb_get_seqnum;
1430 result->get_flags = db_ctdb_get_flags;
1431 result->transaction_start = db_ctdb_transaction_start;
1432 result->transaction_commit = db_ctdb_transaction_commit;
1433 result->transaction_cancel = db_ctdb_transaction_cancel;
1435 DEBUG(3,("db_open_ctdb: opened database '%s' with dbid 0x%x\n",
1436 name, db_ctdb->db_id));