2 Unix SMB/CIFS implementation.
3 Database interface wrapper around ctdbd
4 Copyright (C) Volker Lendecke 2007
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.
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.
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/>.
21 #ifdef CLUSTER_SUPPORT
23 #include "ctdb_private.h"
24 #include "ctdbd_conn.h"
26 struct db_ctdb_transaction_handle {
27 struct db_ctdb_ctx *ctx;
29 /* we store the reads and writes done under a transaction one
30 list stores both reads and writes, the other just writes
32 struct ctdb_marshall_buffer *m_all;
33 struct ctdb_marshall_buffer *m_write;
37 struct db_context *db;
38 struct tdb_wrap *wtdb;
40 struct db_ctdb_transaction_handle *transaction;
44 struct db_ctdb_ctx *ctdb_ctx;
45 struct ctdb_ltdb_header header;
48 static struct db_record *fetch_locked_internal(struct db_ctdb_ctx *ctx,
53 static NTSTATUS tdb_error_to_ntstatus(struct tdb_context *tdb)
56 enum TDB_ERROR tret = tdb_error(tdb);
60 status = NT_STATUS_OBJECT_NAME_COLLISION;
63 status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
66 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
76 form a ctdb_rec_data record from a key/data pair
78 note that header may be NULL. If not NULL then it is included in the data portion
81 static struct ctdb_rec_data *db_ctdb_marshall_record(TALLOC_CTX *mem_ctx, uint32_t reqid,
83 struct ctdb_ltdb_header *header,
87 struct ctdb_rec_data *d;
89 length = offsetof(struct ctdb_rec_data, data) + key.dsize +
90 data.dsize + (header?sizeof(*header):0);
91 d = (struct ctdb_rec_data *)talloc_size(mem_ctx, length);
97 d->keylen = key.dsize;
98 memcpy(&d->data[0], key.dptr, key.dsize);
100 d->datalen = data.dsize + sizeof(*header);
101 memcpy(&d->data[key.dsize], header, sizeof(*header));
102 memcpy(&d->data[key.dsize+sizeof(*header)], data.dptr, data.dsize);
104 d->datalen = data.dsize;
105 memcpy(&d->data[key.dsize], data.dptr, data.dsize);
111 /* helper function for marshalling multiple records */
112 static struct ctdb_marshall_buffer *db_ctdb_marshall_add(TALLOC_CTX *mem_ctx,
113 struct ctdb_marshall_buffer *m,
117 struct ctdb_ltdb_header *header,
120 struct ctdb_rec_data *r;
121 size_t m_size, r_size;
122 struct ctdb_marshall_buffer *m2;
124 r = db_ctdb_marshall_record(mem_ctx, reqid, key, header, data);
131 m = talloc_zero_size(mem_ctx, offsetof(struct ctdb_marshall_buffer, data));
138 m_size = talloc_get_size(m);
139 r_size = talloc_get_size(r);
141 m2 = talloc_realloc_size(mem_ctx, m, m_size + r_size);
147 memcpy(m_size + (uint8_t *)m2, r, r_size);
156 /* we've finished marshalling, return a data blob with the marshalled records */
157 static TDB_DATA db_ctdb_marshall_finish(struct ctdb_marshall_buffer *m)
160 data.dptr = (uint8_t *)m;
161 data.dsize = talloc_get_size(m);
166 loop over a marshalling buffer
168 - pass r==NULL to start
169 - loop the number of times indicated by m->count
171 static struct ctdb_rec_data *db_ctdb_marshall_loop_next(struct ctdb_marshall_buffer *m, struct ctdb_rec_data *r,
173 struct ctdb_ltdb_header *header,
174 TDB_DATA *key, TDB_DATA *data)
177 r = (struct ctdb_rec_data *)&m->data[0];
179 r = (struct ctdb_rec_data *)(r->length + (uint8_t *)r);
187 key->dptr = &r->data[0];
188 key->dsize = r->keylen;
191 data->dptr = &r->data[r->keylen];
192 data->dsize = r->datalen;
193 if (header != NULL) {
194 data->dptr += sizeof(*header);
195 data->dsize -= sizeof(*header);
199 if (header != NULL) {
200 if (r->datalen < sizeof(*header)) {
203 *header = *(struct ctdb_ltdb_header *)&r->data[r->keylen];
211 /* start a transaction on a database */
212 static int db_ctdb_transaction_destructor(struct db_ctdb_transaction_handle *h)
214 tdb_transaction_cancel(h->ctx->wtdb->tdb);
218 /* start a transaction on a database */
219 static int db_ctdb_transaction_fetch_start(struct db_ctdb_transaction_handle *h)
221 struct db_record *rh;
224 const char *keyname = CTDB_TRANSACTION_LOCK_KEY;
226 struct db_ctdb_ctx *ctx = h->ctx;
229 key.dptr = discard_const(keyname);
230 key.dsize = strlen(keyname);
233 tmp_ctx = talloc_new(h);
235 rh = fetch_locked_internal(ctx, tmp_ctx, key, true);
237 DEBUG(0,(__location__ " Failed to fetch_lock database\n"));
238 talloc_free(tmp_ctx);
243 ret = tdb_transaction_start(ctx->wtdb->tdb);
245 DEBUG(0,(__location__ " Failed to start tdb transaction\n"));
246 talloc_free(tmp_ctx);
250 data = tdb_fetch(ctx->wtdb->tdb, key);
251 if ((data.dptr == NULL) ||
252 (data.dsize < sizeof(struct ctdb_ltdb_header)) ||
253 ((struct ctdb_ltdb_header *)data.dptr)->dmaster != get_my_vnn()) {
254 SAFE_FREE(data.dptr);
255 tdb_transaction_cancel(ctx->wtdb->tdb);
256 talloc_free(tmp_ctx);
260 SAFE_FREE(data.dptr);
261 talloc_free(tmp_ctx);
267 /* start a transaction on a database */
268 static int db_ctdb_transaction_start(struct db_context *db)
270 struct db_ctdb_transaction_handle *h;
272 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
275 if (!db->persistent) {
276 DEBUG(0,("transactions not supported on non-persistent database 0x%08x\n",
281 if (ctx->transaction) {
282 DEBUG(0,("Nested transactions not supported on db 0x%08x\n", ctx->db_id));
286 h = talloc_zero(db, struct db_ctdb_transaction_handle);
288 DEBUG(0,(__location__ " oom for transaction handle\n"));
294 ret = db_ctdb_transaction_fetch_start(h);
300 talloc_set_destructor(h, db_ctdb_transaction_destructor);
302 ctx->transaction = h;
304 DEBUG(5,(__location__ " Started transaction on db 0x%08x\n", ctx->db_id));
312 fetch a record inside a transaction
314 static int db_ctdb_transaction_fetch(struct db_ctdb_ctx *db,
316 TDB_DATA key, TDB_DATA *data)
318 struct db_ctdb_transaction_handle *h = db->transaction;
320 *data = tdb_fetch(h->ctx->wtdb->tdb, key);
322 if (data->dptr != NULL) {
323 uint8_t *oldptr = (uint8_t *)data->dptr;
324 data->dsize -= sizeof(struct ctdb_ltdb_header);
325 if (data->dsize == 0) {
328 data->dptr = (uint8 *)
330 mem_ctx, data->dptr+sizeof(struct ctdb_ltdb_header),
334 if (data->dptr == NULL && data->dsize != 0) {
340 h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 1, key, NULL, *data);
341 if (h->m_all == NULL) {
342 DEBUG(0,(__location__ " Failed to add to marshalling record\n"));
344 talloc_free(data->dptr);
353 static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag);
354 static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec);
356 static struct db_record *db_ctdb_fetch_locked_transaction(struct db_ctdb_ctx *ctx,
360 struct db_record *result;
363 if (!(result = talloc(mem_ctx, struct db_record))) {
364 DEBUG(0, ("talloc failed\n"));
368 result->private_data = ctx->transaction;
370 result->key.dsize = key.dsize;
371 result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
372 if (result->key.dptr == NULL) {
373 DEBUG(0, ("talloc failed\n"));
378 result->store = db_ctdb_store_transaction;
379 result->delete_rec = db_ctdb_delete_transaction;
381 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
382 if (ctdb_data.dptr == NULL) {
383 /* create the record */
384 result->value = tdb_null;
388 result->value.dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
389 result->value.dptr = NULL;
391 if ((result->value.dsize != 0)
392 && !(result->value.dptr = (uint8 *)talloc_memdup(
393 result, ctdb_data.dptr + sizeof(struct ctdb_ltdb_header),
394 result->value.dsize))) {
395 DEBUG(0, ("talloc failed\n"));
399 SAFE_FREE(ctdb_data.dptr);
404 static int db_ctdb_record_destructor(struct db_record *rec)
406 struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
407 rec->private_data, struct db_ctdb_transaction_handle);
408 int ret = h->ctx->db->transaction_commit(h->ctx->db);
410 DEBUG(0,(__location__ " transaction_commit failed\n"));
416 auto-create a transaction for persistent databases
418 static struct db_record *db_ctdb_fetch_locked_persistent(struct db_ctdb_ctx *ctx,
423 struct db_record *rec;
425 res = db_ctdb_transaction_start(ctx->db);
430 rec = db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
432 ctx->db->transaction_cancel(ctx->db);
436 /* destroy this transaction when we release the lock */
437 talloc_set_destructor((struct db_record *)talloc_new(rec), db_ctdb_record_destructor);
443 stores a record inside a transaction
445 static int db_ctdb_transaction_store(struct db_ctdb_transaction_handle *h,
446 TDB_DATA key, TDB_DATA data)
448 TALLOC_CTX *tmp_ctx = talloc_new(h);
451 struct ctdb_ltdb_header header;
453 /* we need the header so we can update the RSN */
454 rec = tdb_fetch(h->ctx->wtdb->tdb, key);
455 if (rec.dptr == NULL) {
456 /* the record doesn't exist - create one with us as dmaster.
457 This is only safe because we are in a transaction and this
458 is a persistent database */
460 header.dmaster = get_my_vnn();
462 memcpy(&header, rec.dptr, sizeof(struct ctdb_ltdb_header));
463 rec.dsize -= sizeof(struct ctdb_ltdb_header);
464 /* a special case, we are writing the same data that is there now */
465 if (data.dsize == rec.dsize &&
466 memcmp(data.dptr, rec.dptr + sizeof(struct ctdb_ltdb_header), data.dsize) == 0) {
468 talloc_free(tmp_ctx);
477 h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 0, key, NULL, data);
478 if (h->m_all == NULL) {
479 DEBUG(0,(__location__ " Failed to add to marshalling record\n"));
480 talloc_free(tmp_ctx);
485 h->m_write = db_ctdb_marshall_add(h, h->m_write, h->ctx->db_id, 0, key, &header, data);
486 if (h->m_write == NULL) {
487 DEBUG(0,(__location__ " Failed to add to marshalling record\n"));
488 talloc_free(tmp_ctx);
492 rec.dsize = data.dsize + sizeof(struct ctdb_ltdb_header);
493 rec.dptr = talloc_size(tmp_ctx, rec.dsize);
494 if (rec.dptr == NULL) {
495 DEBUG(0,(__location__ " Failed to alloc record\n"));
496 talloc_free(tmp_ctx);
499 memcpy(rec.dptr, &header, sizeof(struct ctdb_ltdb_header));
500 memcpy(sizeof(struct ctdb_ltdb_header) + (uint8_t *)rec.dptr, data.dptr, data.dsize);
502 ret = tdb_store(h->ctx->wtdb->tdb, key, rec, TDB_REPLACE);
504 talloc_free(tmp_ctx);
511 a record store inside a transaction
513 static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag)
515 struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
516 rec->private_data, struct db_ctdb_transaction_handle);
519 ret = db_ctdb_transaction_store(h, rec->key, data);
521 return tdb_error_to_ntstatus(h->ctx->wtdb->tdb);
527 a record delete inside a transaction
529 static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec)
531 struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
532 rec->private_data, struct db_ctdb_transaction_handle);
535 ret = db_ctdb_transaction_store(h, rec->key, tdb_null);
537 return tdb_error_to_ntstatus(h->ctx->wtdb->tdb);
546 static int ctdb_replay_transaction(struct db_ctdb_transaction_handle *h)
549 struct ctdb_rec_data *rec = NULL;
552 talloc_free(h->m_write);
555 ret = db_ctdb_transaction_fetch_start(h);
560 for (i=0;i<h->m_all->count;i++) {
563 rec = db_ctdb_marshall_loop_next(h->m_all, rec, NULL, NULL, &key, &data);
565 DEBUG(0, (__location__ " Out of records in ctdb_replay_transaction?\n"));
569 if (rec->reqid == 0) {
571 if (db_ctdb_transaction_store(h, key, data) != 0) {
576 TALLOC_CTX *tmp_ctx = talloc_new(h);
578 if (db_ctdb_transaction_fetch(h->ctx, tmp_ctx, key, &data2) != 0) {
579 talloc_free(tmp_ctx);
582 if (data2.dsize != data.dsize ||
583 memcmp(data2.dptr, data.dptr, data.dsize) != 0) {
584 /* the record has changed on us - we have to give up */
585 talloc_free(tmp_ctx);
588 talloc_free(tmp_ctx);
595 tdb_transaction_cancel(h->ctx->wtdb->tdb);
603 static int db_ctdb_transaction_commit(struct db_context *db)
605 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
611 struct db_ctdb_transaction_handle *h = ctx->transaction;
612 enum ctdb_controls failure_control = CTDB_CONTROL_TRANS2_ERROR;
615 DEBUG(0,(__location__ " transaction commit with no open transaction on db 0x%08x\n", ctx->db_id));
619 DEBUG(5,(__location__ " Commit transaction on db 0x%08x\n", ctx->db_id));
621 talloc_set_destructor(h, NULL);
623 /* our commit strategy is quite complex.
625 - we first try to commit the changes to all other nodes
627 - if that works, then we commit locally and we are done
629 - if a commit on another node fails, then we need to cancel
630 the transaction, then restart the transaction (thus
631 opening a window of time for a pending recovery to
632 complete), then replay the transaction, checking all the
633 reads and writes (checking that reads give the same data,
634 and writes succeed). Then we retry the transaction to the
639 if (h->m_write == NULL) {
640 /* no changes were made, potentially after a retry */
641 tdb_transaction_cancel(h->ctx->wtdb->tdb);
643 ctx->transaction = NULL;
647 /* tell ctdbd to commit to the other nodes */
648 rets = ctdbd_control_local(messaging_ctdbd_connection(),
649 CTDB_CONTROL_TRANS2_COMMIT, h->ctx->db_id, 0,
650 db_ctdb_marshall_finish(h->m_write), NULL, NULL, &status);
651 if (!NT_STATUS_IS_OK(rets) || status != 0) {
652 tdb_transaction_cancel(h->ctx->wtdb->tdb);
655 /* work out what error code we will give if we
656 have to fail the operation */
657 switch ((enum ctdb_trans2_commit_error)status) {
658 case CTDB_TRANS2_COMMIT_SUCCESS:
659 case CTDB_TRANS2_COMMIT_SOMEFAIL:
660 case CTDB_TRANS2_COMMIT_TIMEOUT:
661 failure_control = CTDB_CONTROL_TRANS2_ERROR;
663 case CTDB_TRANS2_COMMIT_ALLFAIL:
664 failure_control = CTDB_CONTROL_TRANS2_FINISHED;
668 if (ctdb_replay_transaction(h) != 0) {
669 DEBUG(0,(__location__ " Failed to replay transaction\n"));
670 ctdbd_control_local(messaging_ctdbd_connection(), failure_control,
671 h->ctx->db_id, CTDB_CTRL_FLAG_NOREPLY,
672 tdb_null, NULL, NULL, NULL);
673 h->ctx->transaction = NULL;
675 ctx->transaction = NULL;
678 if (++retries == 10) {
679 DEBUG(0,(__location__ " Giving up transaction on db 0x%08x after %d retries\n",
680 h->ctx->db_id, retries));
681 ctdbd_control_local(messaging_ctdbd_connection(), failure_control,
682 h->ctx->db_id, CTDB_CTRL_FLAG_NOREPLY,
683 tdb_null, NULL, NULL, NULL);
684 h->ctx->transaction = NULL;
686 ctx->transaction = NULL;
692 /* do the real commit locally */
693 ret = tdb_transaction_commit(h->ctx->wtdb->tdb);
695 DEBUG(0,(__location__ " Failed to commit transaction\n"));
696 ctdbd_control_local(messaging_ctdbd_connection(), CTDB_CONTROL_TRANS2_ERROR, h->ctx->db_id,
697 CTDB_CTRL_FLAG_NOREPLY, tdb_null, NULL, NULL, NULL);
698 h->ctx->transaction = NULL;
703 /* tell ctdbd that we are finished with our local commit */
704 ctdbd_control_local(messaging_ctdbd_connection(), CTDB_CONTROL_TRANS2_FINISHED,
705 h->ctx->db_id, CTDB_CTRL_FLAG_NOREPLY,
706 tdb_null, NULL, NULL, NULL);
707 h->ctx->transaction = NULL;
716 static int db_ctdb_transaction_cancel(struct db_context *db)
718 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
720 struct db_ctdb_transaction_handle *h = ctx->transaction;
723 DEBUG(0,(__location__ " transaction cancel with no open transaction on db 0x%08x\n", ctx->db_id));
727 DEBUG(5,(__location__ " Cancel transaction on db 0x%08x\n", ctx->db_id));
729 ctx->transaction = NULL;
735 static NTSTATUS db_ctdb_store(struct db_record *rec, TDB_DATA data, int flag)
737 struct db_ctdb_rec *crec = talloc_get_type_abort(
738 rec->private_data, struct db_ctdb_rec);
742 cdata.dsize = sizeof(crec->header) + data.dsize;
744 if (!(cdata.dptr = SMB_MALLOC_ARRAY(uint8, cdata.dsize))) {
745 return NT_STATUS_NO_MEMORY;
748 memcpy(cdata.dptr, &crec->header, sizeof(crec->header));
749 memcpy(cdata.dptr + sizeof(crec->header), data.dptr, data.dsize);
751 ret = tdb_store(crec->ctdb_ctx->wtdb->tdb, rec->key, cdata, TDB_REPLACE);
753 SAFE_FREE(cdata.dptr);
755 return (ret == 0) ? NT_STATUS_OK
756 : tdb_error_to_ntstatus(crec->ctdb_ctx->wtdb->tdb);
761 static NTSTATUS db_ctdb_delete(struct db_record *rec)
766 * We have to store the header with empty data. TODO: Fix the
772 return db_ctdb_store(rec, data, 0);
776 static int db_ctdb_record_destr(struct db_record* data)
778 struct db_ctdb_rec *crec = talloc_get_type_abort(
779 data->private_data, struct db_ctdb_rec);
781 DEBUG(10, (DEBUGLEVEL > 10
782 ? "Unlocking db %u key %s\n"
783 : "Unlocking db %u key %.20s\n",
784 (int)crec->ctdb_ctx->db_id,
785 hex_encode(data, (unsigned char *)data->key.dptr,
788 if (tdb_chainunlock(crec->ctdb_ctx->wtdb->tdb, data->key) != 0) {
789 DEBUG(0, ("tdb_chainunlock failed\n"));
796 static struct db_record *fetch_locked_internal(struct db_ctdb_ctx *ctx,
801 struct db_record *result;
802 struct db_ctdb_rec *crec;
805 int migrate_attempts = 0;
807 if (!(result = talloc(mem_ctx, struct db_record))) {
808 DEBUG(0, ("talloc failed\n"));
812 if (!(crec = TALLOC_ZERO_P(result, struct db_ctdb_rec))) {
813 DEBUG(0, ("talloc failed\n"));
818 result->private_data = (void *)crec;
819 crec->ctdb_ctx = ctx;
821 result->key.dsize = key.dsize;
822 result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
823 if (result->key.dptr == NULL) {
824 DEBUG(0, ("talloc failed\n"));
830 * Do a blocking lock on the record
834 if (DEBUGLEVEL >= 10) {
835 char *keystr = hex_encode(result, key.dptr, key.dsize);
836 DEBUG(10, (DEBUGLEVEL > 10
837 ? "Locking db %u key %s\n"
838 : "Locking db %u key %.20s\n",
839 (int)crec->ctdb_ctx->db_id, keystr));
843 if (tdb_chainlock(ctx->wtdb->tdb, key) != 0) {
844 DEBUG(3, ("tdb_chainlock failed\n"));
849 result->store = db_ctdb_store;
850 result->delete_rec = db_ctdb_delete;
851 talloc_set_destructor(result, db_ctdb_record_destr);
853 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
856 * See if we have a valid record and we are the dmaster. If so, we can
857 * take the shortcut and just return it.
860 if ((ctdb_data.dptr == NULL) ||
861 (ctdb_data.dsize < sizeof(struct ctdb_ltdb_header)) ||
862 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster != get_my_vnn()
864 || (random() % 2 != 0)
867 SAFE_FREE(ctdb_data.dptr);
868 tdb_chainunlock(ctx->wtdb->tdb, key);
869 talloc_set_destructor(result, NULL);
871 migrate_attempts += 1;
873 DEBUG(10, ("ctdb_data.dptr = %p, dmaster = %u (%u)\n",
874 ctdb_data.dptr, ctdb_data.dptr ?
875 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster : -1,
878 status = ctdbd_migrate(messaging_ctdbd_connection(),ctx->db_id, key);
879 if (!NT_STATUS_IS_OK(status)) {
880 DEBUG(5, ("ctdb_migrate failed: %s\n",
885 /* now its migrated, try again */
889 if (migrate_attempts > 10) {
890 DEBUG(0, ("db_ctdb_fetch_locked needed %d attempts\n",
894 memcpy(&crec->header, ctdb_data.dptr, sizeof(crec->header));
896 result->value.dsize = ctdb_data.dsize - sizeof(crec->header);
897 result->value.dptr = NULL;
899 if ((result->value.dsize != 0)
900 && !(result->value.dptr = (uint8 *)talloc_memdup(
901 result, ctdb_data.dptr + sizeof(crec->header),
902 result->value.dsize))) {
903 DEBUG(0, ("talloc failed\n"));
907 SAFE_FREE(ctdb_data.dptr);
912 static struct db_record *db_ctdb_fetch_locked(struct db_context *db,
916 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
919 if (ctx->transaction != NULL) {
920 return db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
923 if (db->persistent) {
924 return db_ctdb_fetch_locked_persistent(ctx, mem_ctx, key);
927 return fetch_locked_internal(ctx, mem_ctx, key, db->persistent);
931 fetch (unlocked, no migration) operation on ctdb
933 static int db_ctdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
934 TDB_DATA key, TDB_DATA *data)
936 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
941 if (ctx->transaction) {
942 return db_ctdb_transaction_fetch(ctx, mem_ctx, key, data);
945 /* try a direct fetch */
946 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
949 * See if we have a valid record and we are the dmaster. If so, we can
950 * take the shortcut and just return it.
951 * we bypass the dmaster check for persistent databases
953 if ((ctdb_data.dptr != NULL) &&
954 (ctdb_data.dsize >= sizeof(struct ctdb_ltdb_header)) &&
956 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster == get_my_vnn())) {
957 /* we are the dmaster - avoid the ctdb protocol op */
959 data->dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
960 if (data->dsize == 0) {
961 SAFE_FREE(ctdb_data.dptr);
966 data->dptr = (uint8 *)talloc_memdup(
967 mem_ctx, ctdb_data.dptr+sizeof(struct ctdb_ltdb_header),
970 SAFE_FREE(ctdb_data.dptr);
972 if (data->dptr == NULL) {
978 SAFE_FREE(ctdb_data.dptr);
980 /* we weren't able to get it locally - ask ctdb to fetch it for us */
981 status = ctdbd_fetch(messaging_ctdbd_connection(),ctx->db_id, key, mem_ctx, data);
982 if (!NT_STATUS_IS_OK(status)) {
983 DEBUG(5, ("ctdbd_fetch failed: %s\n", nt_errstr(status)));
990 struct traverse_state {
991 struct db_context *db;
992 int (*fn)(struct db_record *rec, void *private_data);
996 static void traverse_callback(TDB_DATA key, TDB_DATA data, void *private_data)
998 struct traverse_state *state = (struct traverse_state *)private_data;
999 struct db_record *rec;
1000 TALLOC_CTX *tmp_ctx = talloc_new(state->db);
1001 /* we have to give them a locked record to prevent races */
1002 rec = db_ctdb_fetch_locked(state->db, tmp_ctx, key);
1003 if (rec && rec->value.dsize > 0) {
1004 state->fn(rec, state->private_data);
1006 talloc_free(tmp_ctx);
1009 static int traverse_persistent_callback(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
1012 struct traverse_state *state = (struct traverse_state *)private_data;
1013 struct db_record *rec;
1014 TALLOC_CTX *tmp_ctx = talloc_new(state->db);
1016 /* we have to give them a locked record to prevent races */
1017 rec = db_ctdb_fetch_locked(state->db, tmp_ctx, kbuf);
1018 if (rec && rec->value.dsize > 0) {
1019 ret = state->fn(rec, state->private_data);
1021 talloc_free(tmp_ctx);
1025 static int db_ctdb_traverse(struct db_context *db,
1026 int (*fn)(struct db_record *rec,
1027 void *private_data),
1030 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1031 struct db_ctdb_ctx);
1032 struct traverse_state state;
1036 state.private_data = private_data;
1038 if (db->persistent) {
1039 /* for persistent databases we don't need to do a ctdb traverse,
1040 we can do a faster local traverse */
1041 return tdb_traverse(ctx->wtdb->tdb, traverse_persistent_callback, &state);
1045 ctdbd_traverse(ctx->db_id, traverse_callback, &state);
1049 static NTSTATUS db_ctdb_store_deny(struct db_record *rec, TDB_DATA data, int flag)
1051 return NT_STATUS_MEDIA_WRITE_PROTECTED;
1054 static NTSTATUS db_ctdb_delete_deny(struct db_record *rec)
1056 return NT_STATUS_MEDIA_WRITE_PROTECTED;
1059 static void traverse_read_callback(TDB_DATA key, TDB_DATA data, void *private_data)
1061 struct traverse_state *state = (struct traverse_state *)private_data;
1062 struct db_record rec;
1065 rec.store = db_ctdb_store_deny;
1066 rec.delete_rec = db_ctdb_delete_deny;
1067 rec.private_data = state->db;
1068 state->fn(&rec, state->private_data);
1071 static int traverse_persistent_callback_read(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
1074 struct traverse_state *state = (struct traverse_state *)private_data;
1075 struct db_record rec;
1078 rec.store = db_ctdb_store_deny;
1079 rec.delete_rec = db_ctdb_delete_deny;
1080 rec.private_data = state->db;
1082 if (rec.value.dsize <= sizeof(struct ctdb_ltdb_header)) {
1083 /* a deleted record */
1086 rec.value.dsize -= sizeof(struct ctdb_ltdb_header);
1087 rec.value.dptr += sizeof(struct ctdb_ltdb_header);
1089 return state->fn(&rec, state->private_data);
1092 static int db_ctdb_traverse_read(struct db_context *db,
1093 int (*fn)(struct db_record *rec,
1094 void *private_data),
1097 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1098 struct db_ctdb_ctx);
1099 struct traverse_state state;
1103 state.private_data = private_data;
1105 if (db->persistent) {
1106 /* for persistent databases we don't need to do a ctdb traverse,
1107 we can do a faster local traverse */
1108 return tdb_traverse_read(ctx->wtdb->tdb, traverse_persistent_callback_read, &state);
1111 ctdbd_traverse(ctx->db_id, traverse_read_callback, &state);
1115 static int db_ctdb_get_seqnum(struct db_context *db)
1117 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
1118 struct db_ctdb_ctx);
1119 return tdb_get_seqnum(ctx->wtdb->tdb);
1122 struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
1124 int hash_size, int tdb_flags,
1125 int open_flags, mode_t mode)
1127 struct db_context *result;
1128 struct db_ctdb_ctx *db_ctdb;
1131 if (!lp_clustering()) {
1132 DEBUG(10, ("Clustering disabled -- no ctdb\n"));
1136 if (!(result = TALLOC_ZERO_P(mem_ctx, struct db_context))) {
1137 DEBUG(0, ("talloc failed\n"));
1138 TALLOC_FREE(result);
1142 if (!(db_ctdb = TALLOC_P(result, struct db_ctdb_ctx))) {
1143 DEBUG(0, ("talloc failed\n"));
1144 TALLOC_FREE(result);
1148 db_ctdb->transaction = NULL;
1149 db_ctdb->db = result;
1151 if (!NT_STATUS_IS_OK(ctdbd_db_attach(messaging_ctdbd_connection(),name, &db_ctdb->db_id, tdb_flags))) {
1152 DEBUG(0, ("ctdbd_db_attach failed for %s\n", name));
1153 TALLOC_FREE(result);
1157 db_path = ctdbd_dbpath(messaging_ctdbd_connection(), db_ctdb, db_ctdb->db_id);
1159 result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
1161 /* only pass through specific flags */
1162 tdb_flags &= TDB_SEQNUM;
1164 /* honor permissions if user has specified O_CREAT */
1165 if (open_flags & O_CREAT) {
1166 chmod(db_path, mode);
1169 db_ctdb->wtdb = tdb_wrap_open(db_ctdb, db_path, hash_size, tdb_flags, O_RDWR, 0);
1170 if (db_ctdb->wtdb == NULL) {
1171 DEBUG(0, ("Could not open tdb %s: %s\n", db_path, strerror(errno)));
1172 TALLOC_FREE(result);
1175 talloc_free(db_path);
1177 result->private_data = (void *)db_ctdb;
1178 result->fetch_locked = db_ctdb_fetch_locked;
1179 result->fetch = db_ctdb_fetch;
1180 result->traverse = db_ctdb_traverse;
1181 result->traverse_read = db_ctdb_traverse_read;
1182 result->get_seqnum = db_ctdb_get_seqnum;
1183 result->transaction_start = db_ctdb_transaction_start;
1184 result->transaction_commit = db_ctdb_transaction_commit;
1185 result->transaction_cancel = db_ctdb_transaction_cancel;
1187 DEBUG(3,("db_open_ctdb: opened database '%s' with dbid 0x%x\n",
1188 name, db_ctdb->db_id));