/*
Unix SMB/CIFS implementation.
Database interface wrapper around ctdbd
- Copyright (C) Volker Lendecke 2007
-
+ 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 "ctdb.h"
#include "ctdb_private.h"
#include "ctdbd_conn.h"
+#include "g_lock.h"
struct db_ctdb_transaction_handle {
struct db_ctdb_ctx *ctx;
- bool in_replay;
- /* we store the reads and writes done under a transaction one
- list stores both reads and writes, the other just writes
- */
+ /*
+ * 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 {
}
+/**
+ * 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(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
*/
{
struct ctdb_rec_data *r;
size_t m_size, r_size;
- struct ctdb_marshall_buffer *m2;
+ struct ctdb_marshall_buffer *m2 = NULL;
- r = db_ctdb_marshall_record(mem_ctx, reqid, key, header, data);
+ r = db_ctdb_marshall_record(talloc_tos(), reqid, key, header, data);
if (r == NULL) {
talloc_free(m);
return NULL;
}
if (m == NULL) {
- m = talloc_zero_size(mem_ctx, offsetof(struct ctdb_marshall_buffer, data));
+ m = (struct ctdb_marshall_buffer *)talloc_zero_size(
+ mem_ctx, offsetof(struct ctdb_marshall_buffer, data));
if (m == NULL) {
- return NULL;
+ goto done;
}
m->db_id = db_id;
}
m_size = talloc_get_size(m);
r_size = talloc_get_size(r);
- m2 = talloc_realloc_size(mem_ctx, m, m_size + r_size);
+ m2 = (struct ctdb_marshall_buffer *)talloc_realloc_size(
+ mem_ctx, m, m_size + r_size);
if (m2 == NULL) {
talloc_free(m);
- return NULL;
+ goto done;
}
memcpy(m_size + (uint8_t *)m2, r, r_size);
- talloc_free(r);
-
m2->count++;
+done:
+ talloc_free(r);
return m2;
}
/*
loop over a marshalling buffer
-
+
- pass r==NULL to start
- loop the number of times indicated by m->count
*/
if (reqid != NULL) {
*reqid = r->reqid;
}
-
+
if (key != NULL) {
key->dptr = &r->data[0];
key->dsize = r->keylen;
return r;
}
-
-
-/* start a transaction on a database */
+/**
+ * CTDB transaction destructor
+ */
static int db_ctdb_transaction_destructor(struct db_ctdb_transaction_handle *h)
{
- tdb_transaction_cancel(h->ctx->wtdb->tdb);
- return 0;
-}
-
-/* start a transaction on a database */
-static int db_ctdb_transaction_fetch_start(struct db_ctdb_transaction_handle *h)
-{
- struct db_record *rh;
- TDB_DATA key;
- struct ctdb_ltdb_header header;
- TALLOC_CTX *tmp_ctx;
- const char *keyname = CTDB_TRANSACTION_LOCK_KEY;
- int ret;
- struct db_ctdb_ctx *ctx = h->ctx;
- TDB_DATA data;
-
- key.dptr = discard_const(keyname);
- key.dsize = strlen(keyname);
-
-again:
- tmp_ctx = talloc_new(h);
-
- rh = fetch_locked_internal(ctx, tmp_ctx, key, true);
- if (rh == NULL) {
- DEBUG(0,(__location__ " Failed to fetch_lock database\n"));
- talloc_free(tmp_ctx);
- return -1;
- }
- talloc_free(rh);
+ NTSTATUS status;
- ret = tdb_transaction_start(ctx->wtdb->tdb);
- if (ret != 0) {
- DEBUG(0,(__location__ " Failed to start tdb transaction\n"));
- talloc_free(tmp_ctx);
+ status = g_lock_unlock(h->ctx->lock_ctx, h->lock_name);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(0, ("g_lock_unlock failed: %s\n", nt_errstr(status)));
return -1;
}
-
- data = tdb_fetch(ctx->wtdb->tdb, key);
- if ((data.dptr == NULL) ||
- (data.dsize < sizeof(struct ctdb_ltdb_header)) ||
- ((struct ctdb_ltdb_header *)data.dptr)->dmaster != get_my_vnn()) {
- SAFE_FREE(data.dptr);
- tdb_transaction_cancel(ctx->wtdb->tdb);
- talloc_free(tmp_ctx);
- goto again;
- }
-
- SAFE_FREE(data.dptr);
- talloc_free(tmp_ctx);
-
return 0;
}
-
-/* start a transaction on a database */
+/**
+ * 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;
- int ret;
+ NTSTATUS status;
struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
struct db_ctdb_ctx);
}
if (ctx->transaction) {
- DEBUG(0,("Nested transactions not supported on db 0x%08x\n", ctx->db_id));
- return -1;
+ ctx->transaction->nesting++;
+ return 0;
}
h = talloc_zero(db, struct db_ctdb_transaction_handle);
h->ctx = ctx;
- ret = db_ctdb_transaction_fetch_start(h);
- if (ret != 0) {
- talloc_free(h);
+ 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;
}
ctx->transaction = h;
+ DEBUG(5,(__location__ " Started transaction 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;
+ TDB_DATA data;
+ int i;
+
+ if (buf == NULL) {
+ return false;
+ }
+
+ /*
+ * 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;
+
+ rec = db_ctdb_marshall_loop_next(buf, rec, &reqid, &h, &tkey,
+ &tdata);
+ if (rec == NULL) {
+ return false;
+ }
+
+ if (tdb_data_equal(key, tkey)) {
+ found = true;
+ data = tdata;
+ }
+ }
+
+ 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
TDB_DATA key, TDB_DATA *data)
{
struct db_ctdb_transaction_handle *h = db->transaction;
+ NTSTATUS status;
+ bool found;
- *data = tdb_fetch(h->ctx->wtdb->tdb, key);
+ found = pull_newest_from_marshall_buffer(h->m_write, key, NULL,
+ mem_ctx, data);
+ if (found) {
+ return 0;
+ }
- if (data->dptr != NULL) {
- uint8_t *oldptr = (uint8_t *)data->dptr;
- data->dsize -= sizeof(struct ctdb_ltdb_header);
- data->dptr = (uint8 *)
- talloc_memdup(
- mem_ctx, data->dptr+sizeof(struct ctdb_ltdb_header),
- data->dsize);
- SAFE_FREE(oldptr);
- if (data->dptr == NULL) {
- return -1;
- }
+ 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;
}
- if (!h->in_replay) {
- 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;
- }
+ 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;
TDB_DATA key)
{
struct db_record *result;
- NTSTATUS status;
TDB_DATA ctdb_data;
- int migrate_attempts = 0;
if (!(result = talloc(mem_ctx, struct db_record))) {
DEBUG(0, ("talloc failed\n"));
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(ctx->wtdb->tdb, key);
if (ctdb_data.dptr == NULL) {
/* create the record */
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
TDB_DATA key, TDB_DATA data)
{
TALLOC_CTX *tmp_ctx = talloc_new(h);
- int ret;
TDB_DATA rec;
struct ctdb_ltdb_header header;
+ ZERO_STRUCT(header);
+
/* we need the header so we can update the RSN */
- rec = tdb_fetch(h->ctx->wtdb->tdb, key);
- if (rec.dptr == NULL) {
- /* the record doesn't exist - create one with us as dmaster.
- This is only safe because we are in a transaction and this
- is a persistent database */
- ZERO_STRUCT(header);
- header.dmaster = get_my_vnn();
- } else {
- memcpy(&header, rec.dptr, sizeof(struct ctdb_ltdb_header));
+
+ if (!pull_newest_from_marshall_buffer(h->m_write, key, &header,
+ NULL, NULL)) {
+
+ rec = tdb_fetch(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 0;
+ }
+ }
SAFE_FREE(rec.dptr);
}
+ header.dmaster = get_my_vnn();
header.rsn++;
- if (!h->in_replay) {
- 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 -1;
- }
-
- 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 -1;
- }
- }
-
- rec.dptr = talloc_size(tmp_ctx, data.dsize + sizeof(struct ctdb_ltdb_header));
- if (rec.dptr == NULL) {
- DEBUG(0,(__location__ " Failed to alloc record\n"));
+ 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 -1;
}
- 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(h->ctx->wtdb->tdb, key, rec, TDB_REPLACE);
+ 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 -1;
+ }
talloc_free(tmp_ctx);
-
- return ret;
+ return 0;
}
return NT_STATUS_OK;
}
-
-/*
- replay a transaction
- */
-static int ctdb_replay_transaction(struct db_ctdb_transaction_handle *h)
-{
- int ret, i;
- struct ctdb_rec_data *rec = NULL;
-
- h->in_replay = true;
-
- ret = db_ctdb_transaction_fetch_start(h);
- if (ret != 0) {
- return ret;
- }
-
- for (i=0;i<h->m_all->count;i++) {
- TDB_DATA key, data;
-
- rec = db_ctdb_marshall_loop_next(h->m_all, rec, NULL, NULL, &key, &data);
- if (rec == NULL) {
- DEBUG(0, (__location__ " Out of records in ctdb_replay_transaction?\n"));
- goto failed;
- }
-
- if (rec->reqid == 0) {
- /* its a store */
- if (db_ctdb_transaction_store(h, key, data) != 0) {
- goto failed;
- }
- } else {
- TDB_DATA data2;
- TALLOC_CTX *tmp_ctx = talloc_new(h);
-
- if (db_ctdb_transaction_fetch(h->ctx, tmp_ctx, key, &data2) != 0) {
- talloc_free(tmp_ctx);
- goto failed;
- }
- if (data2.dsize != data.dsize ||
- memcmp(data2.dptr, data.dptr, data.dsize) != 0) {
- /* the record has changed on us - we have to give up */
- talloc_free(tmp_ctx);
- goto failed;
- }
- talloc_free(tmp_ctx);
- }
- }
-
- return 0;
-
-failed:
- tdb_transaction_cancel(h->ctx->wtdb->tdb);
- return -1;
-}
-
-
/*
commit a transaction
*/
struct db_ctdb_ctx *ctx = talloc_get_type_abort(db->private_data,
struct db_ctdb_ctx);
NTSTATUS rets;
- int ret;
int status;
- struct timeval timeout;
struct db_ctdb_transaction_handle *h = ctx->transaction;
if (h == NULL) {
return -1;
}
- talloc_set_destructor(h, NULL);
+ if (h->nested_cancel) {
+ db->transaction_cancel(db);
+ DEBUG(5,(__location__ " Failed transaction commit after nested cancel\n"));
+ return -1;
+ }
- if (h->m_write == NULL) {
- /* no changes were made */
- talloc_free(h);
+ if (h->nesting != 0) {
+ h->nesting--;
return 0;
}
- /* our commit strategy is quite complex.
-
- - we first try to commit the changes to all other nodes
-
- - if that works, then we commit locally and we are done
-
- - if a commit on another node fails, then we need to cancel
- the transaction, then restart the transaction (thus
- opening a window of time for a pending recovery to
- complete), then replay the transaction, checking all the
- reads and writes (checking that reads give the same data,
- and writes succeed). Then we retry the transaction to the
- other nodes
- */
+ DEBUG(5,(__location__ " Commit transaction on db 0x%08x\n", ctx->db_id));
again:
+ if (h->m_write == NULL) {
+ /* no changes were made, potentially after a retry */
+ goto done;
+ }
+
/* tell ctdbd to commit to the other nodes */
- rets = ctdbd_control_local(messaging_ctdbd_connection(),
- CTDB_CONTROL_TRANS2_COMMIT, h->ctx->db_id, 0,
- db_ctdb_marshall_finish(h->m_write), NULL, NULL, &status);
+ 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) {
- tdb_transaction_cancel(h->ctx->wtdb->tdb);
- sleep(1);
- if (ctdb_replay_transaction(h) != 0) {
- DEBUG(0,(__location__ " Failed to replay transaction\n"));
- ctdbd_control_local(messaging_ctdbd_connection(), CTDB_CONTROL_TRANS2_ERROR,
- h->ctx->db_id, CTDB_CTRL_FLAG_NOREPLY,
- tdb_null, NULL, NULL, NULL);
- h->ctx->transaction = NULL;
- talloc_free(h);
- return -1;
- }
+ /*
+ * TODO:
+ * check the database sequence number and
+ * compare it to the seqnum after applying the
+ * marshall buffer. If it is the same: return success.
+ */
goto again;
}
- /* do the real commit locally */
- ret = tdb_transaction_commit(h->ctx->wtdb->tdb);
- if (ret != 0) {
- DEBUG(0,(__location__ " Failed to commit transaction\n"));
- ctdbd_control_local(messaging_ctdbd_connection(), CTDB_CONTROL_TRANS2_ERROR, h->ctx->db_id,
- CTDB_CTRL_FLAG_NOREPLY, tdb_null, NULL, NULL, NULL);
- h->ctx->transaction = NULL;
- talloc_free(h);
- return ret;
- }
-
- /* tell ctdbd that we are finished with our local commit */
- ctdbd_control_local(messaging_ctdbd_connection(), CTDB_CONTROL_TRANS2_FINISHED,
- h->ctx->db_id, CTDB_CTRL_FLAG_NOREPLY,
- tdb_null, NULL, NULL, NULL);
+done:
h->ctx->transaction = NULL;
talloc_free(h);
return 0;
return -1;
}
+ if (h->nesting != 0) {
+ h->nesting--;
+ h->nested_cancel = true;
+ return 0;
+ }
+
+ DEBUG(5,(__location__ " Cancel transaction on db 0x%08x\n", ctx->db_id));
+
ctx->transaction = NULL;
talloc_free(h);
return 0;
{
struct db_ctdb_rec *crec = talloc_get_type_abort(
rec->private_data, struct db_ctdb_rec);
- TDB_DATA cdata;
- int ret;
- cdata.dsize = sizeof(crec->header) + data.dsize;
-
- if (!(cdata.dptr = SMB_MALLOC_ARRAY(uint8, cdata.dsize))) {
- return NT_STATUS_NO_MEMORY;
- }
-
- memcpy(cdata.dptr, &crec->header, sizeof(crec->header));
- memcpy(cdata.dptr + sizeof(crec->header), data.dptr, data.dsize);
-
- ret = tdb_store(crec->ctdb_ctx->wtdb->tdb, rec->key, cdata, TDB_REPLACE);
-
- SAFE_FREE(cdata.dptr);
-
- return (ret == 0) ? NT_STATUS_OK
- : tdb_error_to_ntstatus(crec->ctdb_ctx->wtdb->tdb);
+ return db_ctdb_ltdb_store(crec->ctdb_ctx, rec->key, &(crec->header), data);
}
-/* for persistent databases the store is a bit different. We have to
- ask the ctdb daemon to push the record to all nodes after the
- store */
-static NTSTATUS db_ctdb_store_persistent(struct db_record *rec, TDB_DATA data, int flag)
-{
- struct db_ctdb_rec *crec;
- struct db_record *record;
- TDB_DATA cdata;
- int ret;
- NTSTATUS status;
- uint32_t count;
- int max_retries = lp_parm_int(-1, "dbwrap ctdb", "max store retries", 5);
-
- for (count = 0, status = NT_STATUS_UNSUCCESSFUL, record = rec;
- (count < max_retries) && !NT_STATUS_IS_OK(status);
- count++)
- {
- if (count > 0) {
- /* retry */
- /*
- * There is a hack here: We use rec as a memory
- * context and re-use it as the record struct ptr.
- * We don't free the record data allocated
- * in each turn. So all gets freed when the caller
- * releases the original record. This is because
- * we don't get the record passed in by reference
- * in the first place and the caller relies on
- * having to free the record himself.
- */
- record = fetch_locked_internal(crec->ctdb_ctx,
- rec,
- rec->key,
- true /* persistent */);
- if (record == NULL) {
- DEBUG(5, ("fetch_locked_internal failed.\n"));
- status = NT_STATUS_NO_MEMORY;
- break;
- }
- }
-
- crec = talloc_get_type_abort(record->private_data,
- struct db_ctdb_rec);
-
- cdata.dsize = sizeof(crec->header) + data.dsize;
-
- if (!(cdata.dptr = SMB_MALLOC_ARRAY(uint8, cdata.dsize))) {
- return NT_STATUS_NO_MEMORY;
- }
-
- crec->header.rsn++;
-
- memcpy(cdata.dptr, &crec->header, sizeof(crec->header));
- memcpy(cdata.dptr + sizeof(crec->header), data.dptr, data.dsize);
-
- status = ctdbd_start_persistent_update(
- messaging_ctdbd_connection(),
- crec->ctdb_ctx->db_id,
- rec->key,
- cdata);
-
- if (NT_STATUS_IS_OK(status)) {
- ret = tdb_store(crec->ctdb_ctx->wtdb->tdb, rec->key,
- cdata, TDB_REPLACE);
- status = (ret == 0)
- ? NT_STATUS_OK
- : tdb_error_to_ntstatus(
- crec->ctdb_ctx->wtdb->tdb);
- }
-
- /*
- * release the lock *now* in order to prevent deadlocks.
- *
- * There is a tradeoff: Usually, the record is still locked
- * after db->store operation. This lock is usually released
- * via the talloc destructor with the TALLOC_FREE to
- * the record. So we have two choices:
- *
- * - Either re-lock the record after the call to persistent_store
- * or cancel_persistent update and this way not changing any
- * assumptions callers may have about the state, but possibly
- * introducing new race conditions.
- *
- * - Or don't lock the record again but just remove the
- * talloc_destructor. This is less racy but assumes that
- * the lock is always released via TALLOC_FREE of the record.
- *
- * I choose the first variant for now since it seems less racy.
- * We can't guarantee that we succeed in getting the lock
- * anyways. The only real danger here is that a caller
- * performs multiple store operations after a fetch_locked()
- * which is currently not the case.
- */
- tdb_chainunlock(crec->ctdb_ctx->wtdb->tdb, rec->key);
- talloc_set_destructor(record, NULL);
-
- /* now tell ctdbd to update this record on all other nodes */
- if (NT_STATUS_IS_OK(status)) {
- status = ctdbd_persistent_store(
- messaging_ctdbd_connection(),
- crec->ctdb_ctx->db_id,
- rec->key,
- cdata);
- } else {
- ctdbd_cancel_persistent_update(
- messaging_ctdbd_connection(),
- crec->ctdb_ctx->db_id,
- rec->key,
- cdata);
- break;
- }
-
- SAFE_FREE(cdata.dptr);
- } /* retry-loop */
-
- if (!NT_STATUS_IS_OK(status)) {
- DEBUG(5, ("ctdbd_persistent_store failed after "
- "%d retries with error %s - giving up.\n",
- count, nt_errstr(status)));
- }
-
- SAFE_FREE(cdata.dptr);
-
- return status;
-}
static NTSTATUS db_ctdb_delete(struct db_record *rec)
{
}
-static NTSTATUS db_ctdb_delete_persistent(struct db_record *rec)
-{
- TDB_DATA data;
-
- /*
- * We have to store the header with empty data. TODO: Fix the
- * tdb-level cleanup
- */
-
- ZERO_STRUCT(data);
-
- return db_ctdb_store_persistent(rec, data, 0);
-
-}
-
static int db_ctdb_record_destr(struct db_record* data)
{
struct db_ctdb_rec *crec = talloc_get_type_abort(
? "Unlocking db %u key %s\n"
: "Unlocking db %u key %.20s\n",
(int)crec->ctdb_ctx->db_id,
- hex_encode(data, (unsigned char *)data->key.dptr,
+ hex_encode_talloc(data, (unsigned char *)data->key.dptr,
data->key.dsize)));
if (tdb_chainunlock(crec->ctdb_ctx->wtdb->tdb, data->key) != 0) {
TDB_DATA ctdb_data;
int migrate_attempts = 0;
- if (ctx->transaction != NULL) {
- return db_ctdb_fetch_locked_transaction(ctx, mem_ctx, key);
- }
-
if (!(result = talloc(mem_ctx, struct db_record))) {
DEBUG(0, ("talloc failed\n"));
return NULL;
again:
if (DEBUGLEVEL >= 10) {
- char *keystr = hex_encode(result, key.dptr, key.dsize);
+ 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;
}
- if (persistent) {
- result->store = db_ctdb_store_persistent;
- result->delete_rec = db_ctdb_delete_persistent;
- } else {
- result->store = db_ctdb_store;
- result->delete_rec = db_ctdb_delete;
- }
+ result->store = db_ctdb_store;
+ result->delete_rec = db_ctdb_delete;
talloc_set_destructor(result, db_ctdb_record_destr);
ctdb_data = tdb_fetch(ctx->wtdb->tdb, 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, db->persistent);
}
return tdb_get_seqnum(ctx->wtdb->tdb);
}
-static int db_ctdb_trans_dummy(struct db_context *db)
+static int db_ctdb_get_flags(struct db_context *db)
{
- /*
- * Not implemented yet, just return ok
- */
- return 0;
+ 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,
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 (!NT_STATUS_IS_OK(ctdbd_db_attach(messaging_ctdbd_connection(),name, &db_ctdb->db_id, tdb_flags))) {
+ db_ctdb->transaction = NULL;
+ db_ctdb->db = result;
+
+ conn = messaging_ctdbd_connection();
+
+ 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(messaging_ctdbd_connection(), db_ctdb, db_ctdb->db_id);
+ db_path = ctdbd_dbpath(conn, db_ctdb, db_ctdb->db_id);
result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
}
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;