/source3/lib/dbwrap/dbwrap_ctdb.c
C | 1493 lines | 1071 code | 246 blank | 176 comment | 191 complexity | 099523fd3d79e87f40ef7325e959be12 MD5 | raw file
Possible License(s): Apache-2.0, BSD-3-Clause, GPL-3.0, LGPL-2.1, LGPL-3.0
- /*
- Unix SMB/CIFS implementation.
- Database interface wrapper around ctdbd
- Copyright (C) Volker Lendecke 2007-2009
- Copyright (C) Michael Adam 2009
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
- #include "includes.h"
- #include "system/filesys.h"
- #include "lib/util/tdb_wrap.h"
- #include "util_tdb.h"
- #ifdef CLUSTER_SUPPORT
- /*
- * It is not possible to include ctdb.h and tdb_compat.h (included via
- * some other include above) without warnings. This fixes those
- * warnings.
- */
- #ifdef typesafe_cb
- #undef typesafe_cb
- #endif
- #ifdef typesafe_cb_preargs
- #undef typesafe_cb_preargs
- #endif
- #ifdef typesafe_cb_postargs
- #undef typesafe_cb_postargs
- #endif
- #include "ctdb.h"
- #include "ctdb_private.h"
- #include "ctdbd_conn.h"
- #include "dbwrap/dbwrap.h"
- #include "dbwrap/dbwrap_private.h"
- #include "dbwrap/dbwrap_ctdb.h"
- #include "g_lock.h"
- #include "messages.h"
- struct db_ctdb_transaction_handle {
- struct db_ctdb_ctx *ctx;
- /*
- * we store the reads and writes done under a transaction:
- * - one list stores both reads and writes (m_all),
- * - the other just writes (m_write)
- */
- struct ctdb_marshall_buffer *m_all;
- struct ctdb_marshall_buffer *m_write;
- uint32_t nesting;
- bool nested_cancel;
- char *lock_name;
- };
- struct db_ctdb_ctx {
- struct db_context *db;
- struct tdb_wrap *wtdb;
- uint32 db_id;
- struct db_ctdb_transaction_handle *transaction;
- struct g_lock_ctx *lock_ctx;
- };
- struct db_ctdb_rec {
- struct db_ctdb_ctx *ctdb_ctx;
- struct ctdb_ltdb_header header;
- struct timeval lock_time;
- };
- static NTSTATUS tdb_error_to_ntstatus(struct tdb_context *tdb)
- {
- NTSTATUS status;
- enum TDB_ERROR tret = tdb_error(tdb);
- switch (tret) {
- case TDB_ERR_EXISTS:
- status = NT_STATUS_OBJECT_NAME_COLLISION;
- break;
- case TDB_ERR_NOEXIST:
- status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
- break;
- default:
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- break;
- }
- return status;
- }
- /**
- * fetch a record from the tdb, separating out the header
- * information and returning the body of the record.
- */
- static NTSTATUS db_ctdb_ltdb_fetch(struct db_ctdb_ctx *db,
- TDB_DATA key,
- struct ctdb_ltdb_header *header,
- TALLOC_CTX *mem_ctx,
- TDB_DATA *data)
- {
- TDB_DATA rec;
- NTSTATUS status;
- rec = tdb_fetch_compat(db->wtdb->tdb, key);
- if (rec.dsize < sizeof(struct ctdb_ltdb_header)) {
- status = NT_STATUS_NOT_FOUND;
- if (data) {
- ZERO_STRUCTP(data);
- }
- if (header) {
- header->dmaster = (uint32_t)-1;
- header->rsn = 0;
- }
- goto done;
- }
- if (header) {
- *header = *(struct ctdb_ltdb_header *)rec.dptr;
- }
- if (data) {
- data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
- if (data->dsize == 0) {
- data->dptr = NULL;
- } else {
- data->dptr = (unsigned char *)talloc_memdup(mem_ctx,
- rec.dptr
- + sizeof(struct ctdb_ltdb_header),
- data->dsize);
- if (data->dptr == NULL) {
- status = NT_STATUS_NO_MEMORY;
- goto done;
- }
- }
- }
- status = NT_STATUS_OK;
- done:
- SAFE_FREE(rec.dptr);
- return status;
- }
- /*
- * Store a record together with the ctdb record header
- * in the local copy of the database.
- */
- static NTSTATUS db_ctdb_ltdb_store(struct db_ctdb_ctx *db,
- TDB_DATA key,
- struct ctdb_ltdb_header *header,
- TDB_DATA data)
- {
- TALLOC_CTX *tmp_ctx = talloc_stackframe();
- TDB_DATA rec;
- int ret;
- rec.dsize = data.dsize + sizeof(struct ctdb_ltdb_header);
- rec.dptr = (uint8_t *)talloc_size(tmp_ctx, rec.dsize);
- if (rec.dptr == NULL) {
- talloc_free(tmp_ctx);
- return NT_STATUS_NO_MEMORY;
- }
- memcpy(rec.dptr, header, sizeof(struct ctdb_ltdb_header));
- memcpy(sizeof(struct ctdb_ltdb_header) + (uint8_t *)rec.dptr, data.dptr, data.dsize);
- ret = tdb_store(db->wtdb->tdb, key, rec, TDB_REPLACE);
- talloc_free(tmp_ctx);
- return (ret == 0) ? NT_STATUS_OK
- : tdb_error_to_ntstatus(db->wtdb->tdb);
- }
- /*
- form a ctdb_rec_data record from a key/data pair
- note that header may be NULL. If not NULL then it is included in the data portion
- of the record
- */
- static struct ctdb_rec_data *db_ctdb_marshall_record(TALLOC_CTX *mem_ctx, uint32_t reqid,
- TDB_DATA key,
- struct ctdb_ltdb_header *header,
- TDB_DATA data)
- {
- size_t length;
- struct ctdb_rec_data *d;
- length = offsetof(struct ctdb_rec_data, data) + key.dsize +
- data.dsize + (header?sizeof(*header):0);
- d = (struct ctdb_rec_data *)talloc_size(mem_ctx, length);
- if (d == NULL) {
- return NULL;
- }
- d->length = length;
- d->reqid = reqid;
- d->keylen = key.dsize;
- memcpy(&d->data[0], key.dptr, key.dsize);
- if (header) {
- d->datalen = data.dsize + sizeof(*header);
- memcpy(&d->data[key.dsize], header, sizeof(*header));
- memcpy(&d->data[key.dsize+sizeof(*header)], data.dptr, data.dsize);
- } else {
- d->datalen = data.dsize;
- memcpy(&d->data[key.dsize], data.dptr, data.dsize);
- }
- return d;
- }
- /* helper function for marshalling multiple records */
- static struct ctdb_marshall_buffer *db_ctdb_marshall_add(TALLOC_CTX *mem_ctx,
- struct ctdb_marshall_buffer *m,
- uint64_t db_id,
- uint32_t reqid,
- TDB_DATA key,
- struct ctdb_ltdb_header *header,
- TDB_DATA data)
- {
- struct ctdb_rec_data *r;
- size_t m_size, r_size;
- struct ctdb_marshall_buffer *m2 = NULL;
- r = db_ctdb_marshall_record(talloc_tos(), reqid, key, header, data);
- if (r == NULL) {
- talloc_free(m);
- return NULL;
- }
- if (m == NULL) {
- m = (struct ctdb_marshall_buffer *)talloc_zero_size(
- mem_ctx, offsetof(struct ctdb_marshall_buffer, data));
- if (m == NULL) {
- goto done;
- }
- m->db_id = db_id;
- }
- m_size = talloc_get_size(m);
- r_size = talloc_get_size(r);
- m2 = (struct ctdb_marshall_buffer *)talloc_realloc_size(
- mem_ctx, m, m_size + r_size);
- if (m2 == NULL) {
- talloc_free(m);
- goto done;
- }
- memcpy(m_size + (uint8_t *)m2, r, r_size);
- m2->count++;
- done:
- talloc_free(r);
- return m2;
- }
- /* we've finished marshalling, return a data blob with the marshalled records */
- static TDB_DATA db_ctdb_marshall_finish(struct ctdb_marshall_buffer *m)
- {
- TDB_DATA data;
- data.dptr = (uint8_t *)m;
- data.dsize = talloc_get_size(m);
- return data;
- }
- /*
- loop over a marshalling buffer
- - pass r==NULL to start
- - loop the number of times indicated by m->count
- */
- static struct ctdb_rec_data *db_ctdb_marshall_loop_next(struct ctdb_marshall_buffer *m, struct ctdb_rec_data *r,
- uint32_t *reqid,
- struct ctdb_ltdb_header *header,
- TDB_DATA *key, TDB_DATA *data)
- {
- if (r == NULL) {
- r = (struct ctdb_rec_data *)&m->data[0];
- } else {
- r = (struct ctdb_rec_data *)(r->length + (uint8_t *)r);
- }
- if (reqid != NULL) {
- *reqid = r->reqid;
- }
- if (key != NULL) {
- key->dptr = &r->data[0];
- key->dsize = r->keylen;
- }
- if (data != NULL) {
- data->dptr = &r->data[r->keylen];
- data->dsize = r->datalen;
- if (header != NULL) {
- data->dptr += sizeof(*header);
- data->dsize -= sizeof(*header);
- }
- }
- if (header != NULL) {
- if (r->datalen < sizeof(*header)) {
- return NULL;
- }
- *header = *(struct ctdb_ltdb_header *)&r->data[r->keylen];
- }
- return r;
- }
- /**
- * CTDB transaction destructor
- */
- static int db_ctdb_transaction_destructor(struct db_ctdb_transaction_handle *h)
- {
- NTSTATUS status;
- status = g_lock_unlock(h->ctx->lock_ctx, h->lock_name);
- if (!NT_STATUS_IS_OK(status)) {
- DEBUG(0, ("g_lock_unlock failed for %s: %s\n", h->lock_name,
- nt_errstr(status)));
- return -1;
- }
- return 0;
- }
- /**
- * CTDB dbwrap API: transaction_start function
- * starts a transaction on a persistent database
- */
- static int db_ctdb_transaction_start(struct db_context *db)
- {
- struct db_ctdb_transaction_handle *h;
- NTSTATUS status;
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- if (!db->persistent) {
- DEBUG(0,("transactions not supported on non-persistent database 0x%08x\n",
- ctx->db_id));
- return -1;
- }
- if (ctx->transaction) {
- ctx->transaction->nesting++;
- DEBUG(5, (__location__ " transaction start on db 0x%08x: nesting %d -> %d\n",
- ctx->db_id, ctx->transaction->nesting - 1, ctx->transaction->nesting));
- return 0;
- }
- h = talloc_zero(db, struct db_ctdb_transaction_handle);
- if (h == NULL) {
- DEBUG(0,(__location__ " oom for transaction handle\n"));
- return -1;
- }
- h->ctx = ctx;
- h->lock_name = talloc_asprintf(h, "transaction_db_0x%08x",
- (unsigned int)ctx->db_id);
- if (h->lock_name == NULL) {
- DEBUG(0, ("talloc_asprintf failed\n"));
- TALLOC_FREE(h);
- return -1;
- }
- /*
- * Wait a day, i.e. forever...
- */
- status = g_lock_lock(ctx->lock_ctx, h->lock_name, G_LOCK_WRITE,
- timeval_set(86400, 0));
- if (!NT_STATUS_IS_OK(status)) {
- DEBUG(0, ("g_lock_lock failed: %s\n", nt_errstr(status)));
- TALLOC_FREE(h);
- return -1;
- }
- talloc_set_destructor(h, db_ctdb_transaction_destructor);
- ctx->transaction = h;
- DEBUG(5,(__location__ " transaction started on db 0x%08x\n", ctx->db_id));
- return 0;
- }
- static bool pull_newest_from_marshall_buffer(struct ctdb_marshall_buffer *buf,
- TDB_DATA key,
- struct ctdb_ltdb_header *pheader,
- TALLOC_CTX *mem_ctx,
- TDB_DATA *pdata)
- {
- struct ctdb_rec_data *rec = NULL;
- struct ctdb_ltdb_header h;
- bool found = false;
- TDB_DATA data;
- int i;
- if (buf == NULL) {
- return false;
- }
- ZERO_STRUCT(h);
- ZERO_STRUCT(data);
- /*
- * Walk the list of records written during this
- * transaction. If we want to read one we have already
- * written, return the last written sample. Thus we do not do
- * a "break;" for the first hit, this record might have been
- * overwritten later.
- */
- for (i=0; i<buf->count; i++) {
- TDB_DATA tkey, tdata;
- uint32_t reqid;
- struct ctdb_ltdb_header hdr;
- ZERO_STRUCT(hdr);
- rec = db_ctdb_marshall_loop_next(buf, rec, &reqid, &hdr, &tkey,
- &tdata);
- if (rec == NULL) {
- return false;
- }
- if (tdb_data_equal(key, tkey)) {
- found = true;
- data = tdata;
- h = hdr;
- }
- }
- if (!found) {
- return false;
- }
- if (pdata != NULL) {
- data.dptr = (uint8_t *)talloc_memdup(mem_ctx, data.dptr,
- data.dsize);
- if ((data.dsize != 0) && (data.dptr == NULL)) {
- return false;
- }
- *pdata = data;
- }
- if (pheader != NULL) {
- *pheader = h;
- }
- return true;
- }
- /*
- fetch a record inside a transaction
- */
- static int db_ctdb_transaction_fetch(struct db_ctdb_ctx *db,
- TALLOC_CTX *mem_ctx,
- TDB_DATA key, TDB_DATA *data)
- {
- struct db_ctdb_transaction_handle *h = db->transaction;
- NTSTATUS status;
- bool found;
- found = pull_newest_from_marshall_buffer(h->m_write, key, NULL,
- mem_ctx, data);
- if (found) {
- return 0;
- }
- status = db_ctdb_ltdb_fetch(h->ctx, key, NULL, mem_ctx, data);
- if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
- *data = tdb_null;
- } else if (!NT_STATUS_IS_OK(status)) {
- return -1;
- }
- h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 1, key,
- NULL, *data);
- if (h->m_all == NULL) {
- DEBUG(0,(__location__ " Failed to add to marshalling "
- "record\n"));
- data->dsize = 0;
- talloc_free(data->dptr);
- return -1;
- }
- return 0;
- }
- /**
- * Fetch a record from a persistent database
- * without record locking and without an active transaction.
- *
- * This just fetches from the local database copy.
- * Since the databases are kept in syc cluster-wide,
- * there is no point in doing a ctdb call to fetch the
- * record from the lmaster. It does even harm since migration
- * of records bump their RSN and hence render the persistent
- * database inconsistent.
- */
- static int db_ctdb_fetch_persistent(struct db_ctdb_ctx *db,
- TALLOC_CTX *mem_ctx,
- TDB_DATA key, TDB_DATA *data)
- {
- NTSTATUS status;
- status = db_ctdb_ltdb_fetch(db, key, NULL, mem_ctx, data);
- if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
- *data = tdb_null;
- } else if (!NT_STATUS_IS_OK(status)) {
- return -1;
- }
- return 0;
- }
- static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag);
- static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec);
- static struct db_record *db_ctdb_fetch_locked_transaction(struct db_ctdb_ctx *ctx,
- TALLOC_CTX *mem_ctx,
- TDB_DATA key)
- {
- struct db_record *result;
- TDB_DATA ctdb_data;
- if (!(result = talloc(mem_ctx, struct db_record))) {
- DEBUG(0, ("talloc failed\n"));
- return NULL;
- }
- result->private_data = ctx->transaction;
- result->key.dsize = key.dsize;
- result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
- if (result->key.dptr == NULL) {
- DEBUG(0, ("talloc failed\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- result->store = db_ctdb_store_transaction;
- result->delete_rec = db_ctdb_delete_transaction;
- if (pull_newest_from_marshall_buffer(ctx->transaction->m_write, key,
- NULL, result, &result->value)) {
- return result;
- }
- ctdb_data = tdb_fetch_compat(ctx->wtdb->tdb, key);
- if (ctdb_data.dptr == NULL) {
- /* create the record */
- result->value = tdb_null;
- return result;
- }
- result->value.dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
- result->value.dptr = NULL;
- if ((result->value.dsize != 0)
- && !(result->value.dptr = (uint8 *)talloc_memdup(
- result, ctdb_data.dptr + sizeof(struct ctdb_ltdb_header),
- result->value.dsize))) {
- DEBUG(0, ("talloc failed\n"));
- TALLOC_FREE(result);
- }
- SAFE_FREE(ctdb_data.dptr);
- return result;
- }
- static int db_ctdb_record_destructor(struct db_record **recp)
- {
- struct db_record *rec = talloc_get_type_abort(*recp, struct db_record);
- struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
- rec->private_data, struct db_ctdb_transaction_handle);
- int ret = h->ctx->db->transaction_commit(h->ctx->db);
- if (ret != 0) {
- DEBUG(0,(__location__ " transaction_commit failed\n"));
- }
- return 0;
- }
- /*
- auto-create a transaction for persistent databases
- */
- static struct db_record *db_ctdb_fetch_locked_persistent(struct db_ctdb_ctx *ctx,
- TALLOC_CTX *mem_ctx,
- TDB_DATA key)
- {
- int res;
- struct db_record *rec, **recp;
- res = db_ctdb_transaction_start(ctx->db);
- if (res == -1) {
- return NULL;
- }
- rec = db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
- if (rec == NULL) {
- ctx->db->transaction_cancel(ctx->db);
- return NULL;
- }
- /* destroy this transaction when we release the lock */
- recp = talloc(rec, struct db_record *);
- if (recp == NULL) {
- ctx->db->transaction_cancel(ctx->db);
- talloc_free(rec);
- return NULL;
- }
- *recp = rec;
- talloc_set_destructor(recp, db_ctdb_record_destructor);
- return rec;
- }
- /*
- stores a record inside a transaction
- */
- static NTSTATUS db_ctdb_transaction_store(struct db_ctdb_transaction_handle *h,
- TDB_DATA key, TDB_DATA data)
- {
- TALLOC_CTX *tmp_ctx = talloc_new(h);
- TDB_DATA rec;
- struct ctdb_ltdb_header header;
- ZERO_STRUCT(header);
- /* we need the header so we can update the RSN */
- if (!pull_newest_from_marshall_buffer(h->m_write, key, &header,
- NULL, NULL)) {
- rec = tdb_fetch_compat(h->ctx->wtdb->tdb, key);
- if (rec.dptr != NULL) {
- memcpy(&header, rec.dptr,
- sizeof(struct ctdb_ltdb_header));
- rec.dsize -= sizeof(struct ctdb_ltdb_header);
- /*
- * a special case, we are writing the same
- * data that is there now
- */
- if (data.dsize == rec.dsize &&
- memcmp(data.dptr,
- rec.dptr + sizeof(struct ctdb_ltdb_header),
- data.dsize) == 0) {
- SAFE_FREE(rec.dptr);
- talloc_free(tmp_ctx);
- return NT_STATUS_OK;
- }
- }
- SAFE_FREE(rec.dptr);
- }
- header.dmaster = get_my_vnn();
- header.rsn++;
- h->m_all = db_ctdb_marshall_add(h, h->m_all, h->ctx->db_id, 0, key,
- NULL, data);
- if (h->m_all == NULL) {
- DEBUG(0,(__location__ " Failed to add to marshalling "
- "record\n"));
- talloc_free(tmp_ctx);
- return NT_STATUS_NO_MEMORY;
- }
- h->m_write = db_ctdb_marshall_add(h, h->m_write, h->ctx->db_id, 0, key, &header, data);
- if (h->m_write == NULL) {
- DEBUG(0,(__location__ " Failed to add to marshalling record\n"));
- talloc_free(tmp_ctx);
- return NT_STATUS_NO_MEMORY;
- }
- talloc_free(tmp_ctx);
- return NT_STATUS_OK;
- }
- /*
- a record store inside a transaction
- */
- static NTSTATUS db_ctdb_store_transaction(struct db_record *rec, TDB_DATA data, int flag)
- {
- struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
- rec->private_data, struct db_ctdb_transaction_handle);
- NTSTATUS status;
- status = db_ctdb_transaction_store(h, rec->key, data);
- return status;
- }
- /*
- a record delete inside a transaction
- */
- static NTSTATUS db_ctdb_delete_transaction(struct db_record *rec)
- {
- struct db_ctdb_transaction_handle *h = talloc_get_type_abort(
- rec->private_data, struct db_ctdb_transaction_handle);
- NTSTATUS status;
- status = db_ctdb_transaction_store(h, rec->key, tdb_null);
- return status;
- }
- /**
- * Fetch the db sequence number of a persistent db directly from the db.
- */
- static NTSTATUS db_ctdb_fetch_db_seqnum_from_db(struct db_ctdb_ctx *db,
- uint64_t *seqnum)
- {
- NTSTATUS status;
- const char *keyname = CTDB_DB_SEQNUM_KEY;
- TDB_DATA key;
- TDB_DATA data;
- struct ctdb_ltdb_header header;
- TALLOC_CTX *mem_ctx = talloc_stackframe();
- if (seqnum == NULL) {
- return NT_STATUS_INVALID_PARAMETER;
- }
- key = string_term_tdb_data(keyname);
- status = db_ctdb_ltdb_fetch(db, key, &header, mem_ctx, &data);
- if (!NT_STATUS_IS_OK(status) &&
- !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND))
- {
- goto done;
- }
- status = NT_STATUS_OK;
- if (data.dsize != sizeof(uint64_t)) {
- *seqnum = 0;
- goto done;
- }
- *seqnum = *(uint64_t *)data.dptr;
- done:
- TALLOC_FREE(mem_ctx);
- return status;
- }
- /**
- * Store the database sequence number inside a transaction.
- */
- static NTSTATUS db_ctdb_store_db_seqnum(struct db_ctdb_transaction_handle *h,
- uint64_t seqnum)
- {
- NTSTATUS status;
- const char *keyname = CTDB_DB_SEQNUM_KEY;
- TDB_DATA key;
- TDB_DATA data;
- key = string_term_tdb_data(keyname);
- data.dptr = (uint8_t *)&seqnum;
- data.dsize = sizeof(uint64_t);
- status = db_ctdb_transaction_store(h, key, data);
- return status;
- }
- /*
- commit a transaction
- */
- static int db_ctdb_transaction_commit(struct db_context *db)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- NTSTATUS rets;
- int status;
- struct db_ctdb_transaction_handle *h = ctx->transaction;
- uint64_t old_seqnum, new_seqnum;
- int ret;
- if (h == NULL) {
- DEBUG(0,(__location__ " transaction commit with no open transaction on db 0x%08x\n", ctx->db_id));
- return -1;
- }
- if (h->nested_cancel) {
- db->transaction_cancel(db);
- DEBUG(5,(__location__ " Failed transaction commit after nested cancel\n"));
- return -1;
- }
- if (h->nesting != 0) {
- h->nesting--;
- DEBUG(5, (__location__ " transaction commit on db 0x%08x: nesting %d -> %d\n",
- ctx->db_id, ctx->transaction->nesting + 1, ctx->transaction->nesting));
- return 0;
- }
- if (h->m_write == NULL) {
- /*
- * No changes were made, so don't change the seqnum,
- * don't push to other node, just exit with success.
- */
- ret = 0;
- goto done;
- }
- DEBUG(5,(__location__ " transaction commit on db 0x%08x\n", ctx->db_id));
- /*
- * As the last db action before committing, bump the database sequence
- * number. Note that this undoes all changes to the seqnum records
- * performed under the transaction. This record is not meant to be
- * modified by user interaction. It is for internal use only...
- */
- rets = db_ctdb_fetch_db_seqnum_from_db(ctx, &old_seqnum);
- if (!NT_STATUS_IS_OK(rets)) {
- DEBUG(1, (__location__ " failed to fetch the db sequence number "
- "in transaction commit on db 0x%08x\n", ctx->db_id));
- ret = -1;
- goto done;
- }
- new_seqnum = old_seqnum + 1;
- rets = db_ctdb_store_db_seqnum(h, new_seqnum);
- if (!NT_STATUS_IS_OK(rets)) {
- DEBUG(1, (__location__ "failed to store the db sequence number "
- " in transaction commit on db 0x%08x\n", ctx->db_id));
- ret = -1;
- goto done;
- }
- again:
- /* tell ctdbd to commit to the other nodes */
- rets = ctdbd_control_local(messaging_ctdbd_connection(),
- CTDB_CONTROL_TRANS3_COMMIT,
- h->ctx->db_id, 0,
- db_ctdb_marshall_finish(h->m_write),
- NULL, NULL, &status);
- if (!NT_STATUS_IS_OK(rets) || status != 0) {
- /*
- * The TRANS3_COMMIT control should only possibly fail when a
- * recovery has been running concurrently. In any case, the db
- * will be the same on all nodes, either the new copy or the
- * old copy. This can be detected by comparing the old and new
- * local sequence numbers.
- */
- rets = db_ctdb_fetch_db_seqnum_from_db(ctx, &new_seqnum);
- if (!NT_STATUS_IS_OK(rets)) {
- DEBUG(1, (__location__ " failed to refetch db sequence "
- "number after failed TRANS3_COMMIT\n"));
- ret = -1;
- goto done;
- }
- if (new_seqnum == old_seqnum) {
- /* Recovery prevented all our changes: retry. */
- goto again;
- } else if (new_seqnum != (old_seqnum + 1)) {
- DEBUG(0, (__location__ " ERROR: new_seqnum[%lu] != "
- "old_seqnum[%lu] + (0 or 1) after failed "
- "TRANS3_COMMIT - this should not happen!\n",
- (unsigned long)new_seqnum,
- (unsigned long)old_seqnum));
- ret = -1;
- goto done;
- }
- /*
- * Recovery propagated our changes to all nodes, completing
- * our commit for us - succeed.
- */
- }
- ret = 0;
- done:
- h->ctx->transaction = NULL;
- talloc_free(h);
- return ret;
- }
- /*
- cancel a transaction
- */
- static int db_ctdb_transaction_cancel(struct db_context *db)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- struct db_ctdb_transaction_handle *h = ctx->transaction;
- if (h == NULL) {
- DEBUG(0,(__location__ " transaction cancel with no open transaction on db 0x%08x\n", ctx->db_id));
- return -1;
- }
- if (h->nesting != 0) {
- h->nesting--;
- h->nested_cancel = true;
- DEBUG(5, (__location__ " transaction cancel on db 0x%08x: nesting %d -> %d\n",
- ctx->db_id, ctx->transaction->nesting + 1, ctx->transaction->nesting));
- return 0;
- }
- DEBUG(5,(__location__ " Cancel transaction on db 0x%08x\n", ctx->db_id));
- ctx->transaction = NULL;
- talloc_free(h);
- return 0;
- }
- static NTSTATUS db_ctdb_store(struct db_record *rec, TDB_DATA data, int flag)
- {
- struct db_ctdb_rec *crec = talloc_get_type_abort(
- rec->private_data, struct db_ctdb_rec);
- return db_ctdb_ltdb_store(crec->ctdb_ctx, rec->key, &(crec->header), data);
- }
- #ifdef HAVE_CTDB_CONTROL_SCHEDULE_FOR_DELETION_DECL
- static NTSTATUS db_ctdb_send_schedule_for_deletion(struct db_record *rec)
- {
- NTSTATUS status;
- struct ctdb_control_schedule_for_deletion *dd;
- TDB_DATA indata;
- int cstatus;
- struct db_ctdb_rec *crec = talloc_get_type_abort(
- rec->private_data, struct db_ctdb_rec);
- indata.dsize = offsetof(struct ctdb_control_schedule_for_deletion, key) + rec->key.dsize;
- indata.dptr = talloc_zero_array(crec, uint8_t, indata.dsize);
- if (indata.dptr == NULL) {
- DEBUG(0, (__location__ " talloc failed!\n"));
- return NT_STATUS_NO_MEMORY;
- }
- dd = (struct ctdb_control_schedule_for_deletion *)(void *)indata.dptr;
- dd->db_id = crec->ctdb_ctx->db_id;
- dd->hdr = crec->header;
- dd->keylen = rec->key.dsize;
- memcpy(dd->key, rec->key.dptr, rec->key.dsize);
- status = ctdbd_control_local(messaging_ctdbd_connection(),
- CTDB_CONTROL_SCHEDULE_FOR_DELETION,
- crec->ctdb_ctx->db_id,
- CTDB_CTRL_FLAG_NOREPLY, /* flags */
- indata,
- NULL, /* outdata */
- NULL, /* errmsg */
- &cstatus);
- talloc_free(indata.dptr);
- if (!NT_STATUS_IS_OK(status) || cstatus != 0) {
- DEBUG(1, (__location__ " Error sending local control "
- "SCHEDULE_FOR_DELETION: %s, cstatus = %d\n",
- nt_errstr(status), cstatus));
- if (NT_STATUS_IS_OK(status)) {
- status = NT_STATUS_UNSUCCESSFUL;
- }
- }
- return status;
- }
- #endif
- static NTSTATUS db_ctdb_delete(struct db_record *rec)
- {
- TDB_DATA data;
- NTSTATUS status;
- /*
- * We have to store the header with empty data. TODO: Fix the
- * tdb-level cleanup
- */
- ZERO_STRUCT(data);
- status = db_ctdb_store(rec, data, 0);
- if (!NT_STATUS_IS_OK(status)) {
- return status;
- }
- #ifdef HAVE_CTDB_CONTROL_SCHEDULE_FOR_DELETION_DECL
- status = db_ctdb_send_schedule_for_deletion(rec);
- #endif
- return status;
- }
- static int db_ctdb_record_destr(struct db_record* data)
- {
- struct db_ctdb_rec *crec = talloc_get_type_abort(
- data->private_data, struct db_ctdb_rec);
- int threshold;
- DEBUG(10, (DEBUGLEVEL > 10
- ? "Unlocking db %u key %s\n"
- : "Unlocking db %u key %.20s\n",
- (int)crec->ctdb_ctx->db_id,
- hex_encode_talloc(data, (unsigned char *)data->key.dptr,
- data->key.dsize)));
- tdb_chainunlock(crec->ctdb_ctx->wtdb->tdb, data->key);
- threshold = lp_ctdb_locktime_warn_threshold();
- if (threshold != 0) {
- double timediff = timeval_elapsed(&crec->lock_time);
- if ((timediff * 1000) > threshold) {
- DEBUG(0, ("Held tdb lock %f seconds\n", timediff));
- }
- }
- return 0;
- }
- static struct db_record *fetch_locked_internal(struct db_ctdb_ctx *ctx,
- TALLOC_CTX *mem_ctx,
- TDB_DATA key)
- {
- struct db_record *result;
- struct db_ctdb_rec *crec;
- NTSTATUS status;
- TDB_DATA ctdb_data;
- int migrate_attempts = 0;
- if (!(result = talloc(mem_ctx, struct db_record))) {
- DEBUG(0, ("talloc failed\n"));
- return NULL;
- }
- if (!(crec = talloc_zero(result, struct db_ctdb_rec))) {
- DEBUG(0, ("talloc failed\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- result->private_data = (void *)crec;
- crec->ctdb_ctx = ctx;
- result->key.dsize = key.dsize;
- result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize);
- if (result->key.dptr == NULL) {
- DEBUG(0, ("talloc failed\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- /*
- * Do a blocking lock on the record
- */
- again:
- if (DEBUGLEVEL >= 10) {
- char *keystr = hex_encode_talloc(result, key.dptr, key.dsize);
- DEBUG(10, (DEBUGLEVEL > 10
- ? "Locking db %u key %s\n"
- : "Locking db %u key %.20s\n",
- (int)crec->ctdb_ctx->db_id, keystr));
- TALLOC_FREE(keystr);
- }
- if (tdb_chainlock(ctx->wtdb->tdb, key) != 0) {
- DEBUG(3, ("tdb_chainlock failed\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- result->store = db_ctdb_store;
- result->delete_rec = db_ctdb_delete;
- talloc_set_destructor(result, db_ctdb_record_destr);
- ctdb_data = tdb_fetch_compat(ctx->wtdb->tdb, key);
- /*
- * See if we have a valid record and we are the dmaster. If so, we can
- * take the shortcut and just return it.
- */
- if ((ctdb_data.dptr == NULL) ||
- (ctdb_data.dsize < sizeof(struct ctdb_ltdb_header)) ||
- ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster != get_my_vnn()
- #if 0
- || (random() % 2 != 0)
- #endif
- ) {
- SAFE_FREE(ctdb_data.dptr);
- tdb_chainunlock(ctx->wtdb->tdb, key);
- talloc_set_destructor(result, NULL);
- migrate_attempts += 1;
- DEBUG(10, ("ctdb_data.dptr = %p, dmaster = %u (%u)\n",
- ctdb_data.dptr, ctdb_data.dptr ?
- ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster : -1,
- get_my_vnn()));
- status = ctdbd_migrate(messaging_ctdbd_connection(), ctx->db_id,
- key);
- if (!NT_STATUS_IS_OK(status)) {
- DEBUG(5, ("ctdb_migrate failed: %s\n",
- nt_errstr(status)));
- TALLOC_FREE(result);
- return NULL;
- }
- /* now its migrated, try again */
- goto again;
- }
- if (migrate_attempts > 10) {
- DEBUG(0, ("db_ctdb_fetch_locked needed %d attempts\n",
- migrate_attempts));
- }
- GetTimeOfDay(&crec->lock_time);
- memcpy(&crec->header, ctdb_data.dptr, sizeof(crec->header));
- result->value.dsize = ctdb_data.dsize - sizeof(crec->header);
- result->value.dptr = NULL;
- if ((result->value.dsize != 0)
- && !(result->value.dptr = (uint8 *)talloc_memdup(
- result, ctdb_data.dptr + sizeof(crec->header),
- result->value.dsize))) {
- DEBUG(0, ("talloc failed\n"));
- TALLOC_FREE(result);
- }
- SAFE_FREE(ctdb_data.dptr);
- return result;
- }
- static struct db_record *db_ctdb_fetch_locked(struct db_context *db,
- TALLOC_CTX *mem_ctx,
- TDB_DATA key)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- if (ctx->transaction != NULL) {
- return db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
- }
- if (db->persistent) {
- return db_ctdb_fetch_locked_persistent(ctx, mem_ctx, key);
- }
- return fetch_locked_internal(ctx, mem_ctx, key);
- }
- /*
- fetch (unlocked, no migration) operation on ctdb
- */
- static int db_ctdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
- TDB_DATA key, TDB_DATA *data)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- NTSTATUS status;
- TDB_DATA ctdb_data;
- if (ctx->transaction) {
- return db_ctdb_transaction_fetch(ctx, mem_ctx, key, data);
- }
- if (db->persistent) {
- return db_ctdb_fetch_persistent(ctx, mem_ctx, key, data);
- }
- /* try a direct fetch */
- ctdb_data = tdb_fetch_compat(ctx->wtdb->tdb, key);
- /*
- * See if we have a valid record and we are the dmaster. If so, we can
- * take the shortcut and just return it.
- * we bypass the dmaster check for persistent databases
- */
- if ((ctdb_data.dptr != NULL) &&
- (ctdb_data.dsize >= sizeof(struct ctdb_ltdb_header)) &&
- ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster == get_my_vnn())
- {
- /* we are the dmaster - avoid the ctdb protocol op */
- data->dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
- if (data->dsize == 0) {
- SAFE_FREE(ctdb_data.dptr);
- data->dptr = NULL;
- return 0;
- }
- data->dptr = (uint8 *)talloc_memdup(
- mem_ctx, ctdb_data.dptr+sizeof(struct ctdb_ltdb_header),
- data->dsize);
- SAFE_FREE(ctdb_data.dptr);
- if (data->dptr == NULL) {
- return -1;
- }
- return 0;
- }
- SAFE_FREE(ctdb_data.dptr);
- /* we weren't able to get it locally - ask ctdb to fetch it for us */
- status = ctdbd_fetch(messaging_ctdbd_connection(), ctx->db_id, key,
- mem_ctx, data);
- if (!NT_STATUS_IS_OK(status)) {
- DEBUG(5, ("ctdbd_fetch failed: %s\n", nt_errstr(status)));
- return -1;
- }
- return 0;
- }
- struct traverse_state {
- struct db_context *db;
- int (*fn)(struct db_record *rec, void *private_data);
- void *private_data;
- };
- static void traverse_callback(TDB_DATA key, TDB_DATA data, void *private_data)
- {
- struct traverse_state *state = (struct traverse_state *)private_data;
- struct db_record *rec;
- TALLOC_CTX *tmp_ctx = talloc_new(state->db);
- /* we have to give them a locked record to prevent races */
- rec = db_ctdb_fetch_locked(state->db, tmp_ctx, key);
- if (rec && rec->value.dsize > 0) {
- state->fn(rec, state->private_data);
- }
- talloc_free(tmp_ctx);
- }
- static int traverse_persistent_callback(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
- void *private_data)
- {
- struct traverse_state *state = (struct traverse_state *)private_data;
- struct db_record *rec;
- TALLOC_CTX *tmp_ctx = talloc_new(state->db);
- int ret = 0;
- /*
- * Skip the __db_sequence_number__ key:
- * This is used for persistent transactions internally.
- */
- if (kbuf.dsize == strlen(CTDB_DB_SEQNUM_KEY) + 1 &&
- strcmp((const char*)kbuf.dptr, CTDB_DB_SEQNUM_KEY))
- {
- goto done;
- }
- /* we have to give them a locked record to prevent races */
- rec = db_ctdb_fetch_locked(state->db, tmp_ctx, kbuf);
- if (rec && rec->value.dsize > 0) {
- ret = state->fn(rec, state->private_data);
- }
- done:
- talloc_free(tmp_ctx);
- return ret;
- }
- static int db_ctdb_traverse(struct db_context *db,
- int (*fn)(struct db_record *rec,
- void *private_data),
- void *private_data)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- struct traverse_state state;
- state.db = db;
- state.fn = fn;
- state.private_data = private_data;
- if (db->persistent) {
- /* for persistent databases we don't need to do a ctdb traverse,
- we can do a faster local traverse */
- return tdb_traverse(ctx->wtdb->tdb, traverse_persistent_callback, &state);
- }
- ctdbd_traverse(ctx->db_id, traverse_callback, &state);
- return 0;
- }
- static NTSTATUS db_ctdb_store_deny(struct db_record *rec, TDB_DATA data, int flag)
- {
- return NT_STATUS_MEDIA_WRITE_PROTECTED;
- }
- static NTSTATUS db_ctdb_delete_deny(struct db_record *rec)
- {
- return NT_STATUS_MEDIA_WRITE_PROTECTED;
- }
- static void traverse_read_callback(TDB_DATA key, TDB_DATA data, void *private_data)
- {
- struct traverse_state *state = (struct traverse_state *)private_data;
- struct db_record rec;
- rec.key = key;
- rec.value = data;
- rec.store = db_ctdb_store_deny;
- rec.delete_rec = db_ctdb_delete_deny;
- rec.private_data = state->db;
- state->fn(&rec, state->private_data);
- }
- static int traverse_persistent_callback_read(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
- void *private_data)
- {
- struct traverse_state *state = (struct traverse_state *)private_data;
- struct db_record rec;
- /*
- * Skip the __db_sequence_number__ key:
- * This is used for persistent transactions internally.
- */
- if (kbuf.dsize == strlen(CTDB_DB_SEQNUM_KEY) + 1 &&
- strncmp((const char*)kbuf.dptr, CTDB_DB_SEQNUM_KEY,
- strlen(CTDB_DB_SEQNUM_KEY)) == 0)
- {
- return 0;
- }
- rec.key = kbuf;
- rec.value = dbuf;
- rec.store = db_ctdb_store_deny;
- rec.delete_rec = db_ctdb_delete_deny;
- rec.private_data = state->db;
- if (rec.value.dsize <= sizeof(struct ctdb_ltdb_header)) {
- /* a deleted record */
- return 0;
- }
- rec.value.dsize -= sizeof(struct ctdb_ltdb_header);
- rec.value.dptr += sizeof(struct ctdb_ltdb_header);
- return state->fn(&rec, state->private_data);
- }
- static int db_ctdb_traverse_read(struct db_context *db,
- int (*fn)(struct db_record *rec,
- void *private_data),
- void *private_data)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- struct traverse_state state;
- state.db = db;
- state.fn = fn;
- state.private_data = private_data;
- if (db->persistent) {
- /* for persistent databases we don't need to do a ctdb traverse,
- we can do a faster local traverse */
- return tdb_traverse_read(ctx->wtdb->tdb, traverse_persistent_callback_read, &state);
- }
- ctdbd_traverse(ctx->db_id, traverse_read_callback, &state);
- return 0;
- }
- static int db_ctdb_get_seqnum(struct db_context *db)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- return tdb_get_seqnum(ctx->wtdb->tdb);
- }
- static int db_ctdb_get_flags(struct db_context *db)
- {
- struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
- struct db_ctdb_ctx);
- return tdb_get_flags(ctx->wtdb->tdb);
- }
- struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
- const char *name,
- int hash_size, int tdb_flags,
- int open_flags, mode_t mode)
- {
- struct db_context *result;
- struct db_ctdb_ctx *db_ctdb;
- char *db_path;
- struct ctdbd_connection *conn;
- if (!lp_clustering()) {
- DEBUG(10, ("Clustering disabled -- no ctdb\n"));
- return NULL;
- }
- if (!(result = talloc_zero(mem_ctx, struct db_context))) {
- DEBUG(0, ("talloc failed\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- if (!(db_ctdb = talloc(result, struct db_ctdb_ctx))) {
- DEBUG(0, ("talloc failed\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- db_ctdb->transaction = NULL;
- db_ctdb->db = result;
- conn = messaging_ctdbd_connection();
- if (conn == NULL) {
- DEBUG(1, ("Could not connect to ctdb\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- if (!NT_STATUS_IS_OK(ctdbd_db_attach(conn, name, &db_ctdb->db_id, tdb_flags))) {
- DEBUG(0, ("ctdbd_db_attach failed for %s\n", name));
- TALLOC_FREE(result);
- return NULL;
- }
- db_path = ctdbd_dbpath(conn, db_ctdb, db_ctdb->db_id);
- result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
- /* only pass through specific flags */
- tdb_flags &= TDB_SEQNUM;
- /* honor permissions if user has specified O_CREAT */
- if (open_flags & O_CREAT) {
- chmod(db_path, mode);
- }
- db_ctdb->wtdb = tdb_wrap_open(db_ctdb, db_path, hash_size, tdb_flags, O_RDWR, 0);
- if (db_ctdb->wtdb == NULL) {
- DEBUG(0, ("Could not open tdb %s: %s\n", db_path, strerror(errno)));
- TALLOC_FREE(result);
- return NULL;
- }
- talloc_free(db_path);
- if (result->persistent) {
- db_ctdb->lock_ctx = g_lock_ctx_init(db_ctdb,
- ctdb_conn_msg_ctx(conn));
- if (db_ctdb->lock_ctx == NULL) {
- DEBUG(0, ("g_lock_ctx_init failed\n"));
- TALLOC_FREE(result);
- return NULL;
- }
- }
- result->private_data = (void *)db_ctdb;
- result->fetch_locked = db_ctdb_fetch_locked;
- result->fetch = db_ctdb_fetch;
- result->traverse = db_ctdb_traverse;
- result->traverse_read = db_ctdb_traverse_read;
- result->get_seqnum = db_ctdb_get_seqnum;
- result->get_flags = db_ctdb_get_flags;
- result->transaction_start = db_ctdb_transaction_start;
- result->transaction_commit = db_ctdb_transaction_commit;
- result->transaction_cancel = db_ctdb_transaction_cancel;
- DEBUG(3,("db_open_ctdb: opened database '%s' with dbid 0x%x\n",
- name, db_ctdb->db_id));
- return result;
- }
- #endif