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"
27 struct tdb_wrap *wtdb;
32 struct db_ctdb_ctx *ctdb_ctx;
33 struct ctdb_ltdb_header header;
36 static NTSTATUS db_ctdb_store(struct db_record *rec, TDB_DATA data, int flag)
38 struct db_ctdb_rec *crec = talloc_get_type_abort(
39 rec->private_data, struct db_ctdb_rec);
43 cdata.dsize = sizeof(crec->header) + data.dsize;
45 if (!(cdata.dptr = SMB_MALLOC_ARRAY(uint8, cdata.dsize))) {
46 return NT_STATUS_NO_MEMORY;
49 memcpy(cdata.dptr, &crec->header, sizeof(crec->header));
50 memcpy(cdata.dptr + sizeof(crec->header), data.dptr, data.dsize);
52 ret = tdb_store(crec->ctdb_ctx->wtdb->tdb, rec->key, cdata, TDB_REPLACE);
54 SAFE_FREE(cdata.dptr);
56 return (ret == 0) ? NT_STATUS_OK : NT_STATUS_INTERNAL_DB_CORRUPTION;
60 /* for persistent databases the store is a bit different. We have to
61 ask the ctdb daemon to push the record to all nodes after the
63 static NTSTATUS db_ctdb_store_persistent(struct db_record *rec, TDB_DATA data, int flag)
65 struct db_ctdb_rec *crec = talloc_get_type_abort(
66 rec->private_data, struct db_ctdb_rec);
71 cdata.dsize = sizeof(crec->header) + data.dsize;
73 if (!(cdata.dptr = SMB_MALLOC_ARRAY(uint8, cdata.dsize))) {
74 return NT_STATUS_NO_MEMORY;
79 memcpy(cdata.dptr, &crec->header, sizeof(crec->header));
80 memcpy(cdata.dptr + sizeof(crec->header), data.dptr, data.dsize);
82 status = ctdbd_start_persistent_update(messaging_ctdbd_connection(), crec->ctdb_ctx->db_id, rec->key, cdata);
84 if (NT_STATUS_IS_OK(status)) {
85 ret = tdb_store(crec->ctdb_ctx->wtdb->tdb, rec->key, cdata, TDB_REPLACE);
86 status = (ret == 0) ? NT_STATUS_OK : NT_STATUS_INTERNAL_DB_CORRUPTION;
89 /* now tell ctdbd to update this record on all other nodes */
90 if (NT_STATUS_IS_OK(status)) {
91 status = ctdbd_persistent_store(messaging_ctdbd_connection(), crec->ctdb_ctx->db_id, rec->key, cdata);
93 ctdbd_cancel_persistent_update(messaging_ctdbd_connection(), crec->ctdb_ctx->db_id, rec->key, cdata);
96 SAFE_FREE(cdata.dptr);
101 static NTSTATUS db_ctdb_delete(struct db_record *rec)
103 struct db_ctdb_rec *crec = talloc_get_type_abort(
104 rec->private_data, struct db_ctdb_rec);
109 * We have to store the header with empty data. TODO: Fix the
113 data.dptr = (uint8 *)&crec->header;
114 data.dsize = sizeof(crec->header);
116 ret = tdb_store(crec->ctdb_ctx->wtdb->tdb, rec->key, data, TDB_REPLACE);
118 return (ret == 0) ? NT_STATUS_OK : NT_STATUS_INTERNAL_DB_CORRUPTION;
121 static int db_ctdb_record_destr(struct db_record* data)
123 struct db_ctdb_rec *crec = talloc_get_type_abort(
124 data->private_data, struct db_ctdb_rec);
126 DEBUG(10, (DEBUGLEVEL > 10
127 ? "Unlocking db %u key %s\n"
128 : "Unlocking db %u key %.20s\n",
129 (int)crec->ctdb_ctx->db_id,
130 hex_encode(data, (unsigned char *)data->key.dptr,
133 if (tdb_chainunlock(crec->ctdb_ctx->wtdb->tdb, data->key) != 0) {
134 DEBUG(0, ("tdb_chainunlock failed\n"));
141 static struct db_record *db_ctdb_fetch_locked(struct db_context *db,
145 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
147 struct db_record *result;
148 struct db_ctdb_rec *crec;
151 int migrate_attempts = 0;
153 if (!(result = talloc(mem_ctx, struct db_record))) {
154 DEBUG(0, ("talloc failed\n"));
158 if (!(crec = TALLOC_ZERO_P(result, struct db_ctdb_rec))) {
159 DEBUG(0, ("talloc failed\n"));
164 result->private_data = (void *)crec;
165 crec->ctdb_ctx = ctx;
167 result->key.dsize = key.dsize;
168 result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
169 if (result->key.dptr == NULL) {
170 DEBUG(0, ("talloc failed\n"));
176 * Do a blocking lock on the record
180 if (DEBUGLEVEL >= 10) {
181 char *keystr = hex_encode(result, key.dptr, key.dsize);
182 DEBUG(10, (DEBUGLEVEL > 10
183 ? "Locking db %u key %s\n"
184 : "Locking db %u key %.20s\n",
185 (int)crec->ctdb_ctx->db_id, keystr));
189 if (tdb_chainlock(ctx->wtdb->tdb, key) != 0) {
190 DEBUG(3, ("tdb_chainlock failed\n"));
195 if (db->persistent) {
196 result->store = db_ctdb_store_persistent;
198 result->store = db_ctdb_store;
200 result->delete_rec = db_ctdb_delete;
201 talloc_set_destructor(result, db_ctdb_record_destr);
203 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
206 * See if we have a valid record and we are the dmaster. If so, we can
207 * take the shortcut and just return it.
210 if ((ctdb_data.dptr == NULL) ||
211 (ctdb_data.dsize < sizeof(struct ctdb_ltdb_header)) ||
212 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster != get_my_vnn()
214 || (random() % 2 != 0)
217 SAFE_FREE(ctdb_data.dptr);
218 tdb_chainunlock(ctx->wtdb->tdb, key);
219 talloc_set_destructor(result, NULL);
221 migrate_attempts += 1;
223 DEBUG(10, ("ctdb_data.dptr = %p, dmaster = %u (%u)\n",
224 ctdb_data.dptr, ctdb_data.dptr ?
225 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster : -1,
228 status = ctdbd_migrate(messaging_ctdbd_connection(),ctx->db_id, key);
229 if (!NT_STATUS_IS_OK(status)) {
230 DEBUG(5, ("ctdb_migrate failed: %s\n",
235 /* now its migrated, try again */
239 if (migrate_attempts > 10) {
240 DEBUG(0, ("db_ctdb_fetch_locked needed %d attempts\n",
244 memcpy(&crec->header, ctdb_data.dptr, sizeof(crec->header));
246 result->value.dsize = ctdb_data.dsize - sizeof(crec->header);
247 result->value.dptr = NULL;
249 if ((result->value.dsize != 0)
250 && !(result->value.dptr = (uint8 *)talloc_memdup(
251 result, ctdb_data.dptr + sizeof(crec->header),
252 result->value.dsize))) {
253 DEBUG(0, ("talloc failed\n"));
257 SAFE_FREE(ctdb_data.dptr);
263 fetch (unlocked, no migration) operation on ctdb
265 static int db_ctdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
266 TDB_DATA key, TDB_DATA *data)
268 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
273 /* try a direct fetch */
274 ctdb_data = tdb_fetch(ctx->wtdb->tdb, key);
277 * See if we have a valid record and we are the dmaster. If so, we can
278 * take the shortcut and just return it.
279 * we bypass the dmaster check for persistent databases
281 if ((ctdb_data.dptr != NULL) &&
282 (ctdb_data.dsize >= sizeof(struct ctdb_ltdb_header)) &&
284 ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster == get_my_vnn())) {
285 /* we are the dmaster - avoid the ctdb protocol op */
287 data->dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
288 if (data->dsize == 0) {
289 SAFE_FREE(ctdb_data.dptr);
294 data->dptr = (uint8 *)talloc_memdup(
295 mem_ctx, ctdb_data.dptr+sizeof(struct ctdb_ltdb_header),
298 SAFE_FREE(ctdb_data.dptr);
300 if (data->dptr == NULL) {
306 SAFE_FREE(ctdb_data.dptr);
308 /* we weren't able to get it locally - ask ctdb to fetch it for us */
309 status = ctdbd_fetch(messaging_ctdbd_connection(),ctx->db_id, key, mem_ctx, data);
310 if (!NT_STATUS_IS_OK(status)) {
311 DEBUG(5, ("ctdbd_fetch failed: %s\n", nt_errstr(status)));
318 struct traverse_state {
319 struct db_context *db;
320 int (*fn)(struct db_record *rec, void *private_data);
324 static void traverse_callback(TDB_DATA key, TDB_DATA data, void *private_data)
326 struct traverse_state *state = (struct traverse_state *)private_data;
327 struct db_record *rec;
328 TALLOC_CTX *tmp_ctx = talloc_new(state->db);
329 /* we have to give them a locked record to prevent races */
330 rec = db_ctdb_fetch_locked(state->db, tmp_ctx, key);
331 if (rec && rec->value.dsize > 0) {
332 state->fn(rec, state->private_data);
334 talloc_free(tmp_ctx);
337 static int traverse_persistent_callback(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
340 struct traverse_state *state = (struct traverse_state *)private_data;
341 struct db_record *rec;
342 TALLOC_CTX *tmp_ctx = talloc_new(state->db);
344 /* we have to give them a locked record to prevent races */
345 rec = db_ctdb_fetch_locked(state->db, tmp_ctx, kbuf);
346 if (rec && rec->value.dsize > 0) {
347 ret = state->fn(rec, state->private_data);
349 talloc_free(tmp_ctx);
353 static int db_ctdb_traverse(struct db_context *db,
354 int (*fn)(struct db_record *rec,
358 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
360 struct traverse_state state;
364 state.private_data = private_data;
366 if (db->persistent) {
367 /* for persistent databases we don't need to do a ctdb traverse,
368 we can do a faster local traverse */
369 return tdb_traverse(ctx->wtdb->tdb, traverse_persistent_callback, &state);
373 ctdbd_traverse(ctx->db_id, traverse_callback, &state);
377 static NTSTATUS db_ctdb_store_deny(struct db_record *rec, TDB_DATA data, int flag)
379 return NT_STATUS_MEDIA_WRITE_PROTECTED;
382 static NTSTATUS db_ctdb_delete_deny(struct db_record *rec)
384 return NT_STATUS_MEDIA_WRITE_PROTECTED;
387 static void traverse_read_callback(TDB_DATA key, TDB_DATA data, void *private_data)
389 struct traverse_state *state = (struct traverse_state *)private_data;
390 struct db_record rec;
393 rec.store = db_ctdb_store_deny;
394 rec.delete_rec = db_ctdb_delete_deny;
395 rec.private_data = state->db;
396 state->fn(&rec, state->private_data);
399 static int traverse_persistent_callback_read(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
402 struct traverse_state *state = (struct traverse_state *)private_data;
403 struct db_record rec;
406 rec.store = db_ctdb_store_deny;
407 rec.delete_rec = db_ctdb_delete_deny;
408 rec.private_data = state->db;
410 if (rec.value.dsize <= sizeof(struct ctdb_ltdb_header)) {
411 /* a deleted record */
414 rec.value.dsize -= sizeof(struct ctdb_ltdb_header);
415 rec.value.dptr += sizeof(struct ctdb_ltdb_header);
417 return state->fn(&rec, state->private_data);
420 static int db_ctdb_traverse_read(struct db_context *db,
421 int (*fn)(struct db_record *rec,
425 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
427 struct traverse_state state;
431 state.private_data = private_data;
433 if (db->persistent) {
434 /* for persistent databases we don't need to do a ctdb traverse,
435 we can do a faster local traverse */
436 return tdb_traverse_read(ctx->wtdb->tdb, traverse_persistent_callback_read, &state);
439 ctdbd_traverse(ctx->db_id, traverse_read_callback, &state);
443 static int db_ctdb_get_seqnum(struct db_context *db)
445 struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
447 return tdb_get_seqnum(ctx->wtdb->tdb);
450 static int db_ctdb_trans_dummy(struct db_context *db)
453 * Not implemented yet, just return ok
458 struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
460 int hash_size, int tdb_flags,
461 int open_flags, mode_t mode)
463 struct db_context *result;
464 struct db_ctdb_ctx *db_ctdb;
467 if (!lp_clustering()) {
468 DEBUG(10, ("Clustering disabled -- no ctdb\n"));
472 if (!(result = TALLOC_ZERO_P(mem_ctx, struct db_context))) {
473 DEBUG(0, ("talloc failed\n"));
478 if (!(db_ctdb = TALLOC_P(result, struct db_ctdb_ctx))) {
479 DEBUG(0, ("talloc failed\n"));
484 if (!NT_STATUS_IS_OK(ctdbd_db_attach(messaging_ctdbd_connection(),name, &db_ctdb->db_id, tdb_flags))) {
485 DEBUG(0, ("ctdbd_db_attach failed for %s\n", name));
490 db_path = ctdbd_dbpath(messaging_ctdbd_connection(), db_ctdb, db_ctdb->db_id);
492 result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
494 /* only pass through specific flags */
495 tdb_flags &= TDB_SEQNUM;
497 /* honor permissions if user has specified O_CREAT */
498 if (open_flags & O_CREAT) {
499 chmod(db_path, mode);
502 db_ctdb->wtdb = tdb_wrap_open(db_ctdb, db_path, hash_size, tdb_flags, O_RDWR, 0);
503 if (db_ctdb->wtdb == NULL) {
504 DEBUG(0, ("Could not open tdb %s: %s\n", db_path, strerror(errno)));
508 talloc_free(db_path);
510 result->private_data = (void *)db_ctdb;
511 result->fetch_locked = db_ctdb_fetch_locked;
512 result->fetch = db_ctdb_fetch;
513 result->traverse = db_ctdb_traverse;
514 result->traverse_read = db_ctdb_traverse_read;
515 result->get_seqnum = db_ctdb_get_seqnum;
516 result->transaction_start = db_ctdb_trans_dummy;
517 result->transaction_commit = db_ctdb_trans_dummy;
518 result->transaction_cancel = db_ctdb_trans_dummy;
520 DEBUG(3,("db_open_ctdb: opened database '%s' with dbid 0x%x\n",
521 name, db_ctdb->db_id));