/*
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 .
*/
#include "includes.h"
#include "system/filesys.h"
#include "lib/tdb_wrap/tdb_wrap.h"
#include "util_tdb.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_ctdb.h"
#include "dbwrap/dbwrap_rbt.h"
#include "lib/param/param.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 writes done under a transaction:
*/
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_t 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)
{
enum TDB_ERROR tret = tdb_error(tdb);
return map_nt_error_from_tdb(tret);
}
/**
* 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; icount; 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 NTSTATUS 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 NT_STATUS_OK;
}
status = db_ctdb_ltdb_fetch(h->ctx, key, NULL, mem_ctx, data);
if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
*data = tdb_null;
}
return status;
}
/**
* 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 NTSTATUS 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;
}
return status;
}
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_t *)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_t *)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_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;
}
/**
* Check whether we have a valid local copy of the given record,
* either for reading or for writing.
*/
static bool db_ctdb_can_use_local_copy(TDB_DATA ctdb_data, bool read_only)
{
struct ctdb_ltdb_header *hdr;
if (ctdb_data.dptr == NULL)
return false;
if (ctdb_data.dsize < sizeof(struct ctdb_ltdb_header))
return false;
hdr = (struct ctdb_ltdb_header *)ctdb_data.dptr;
#ifdef HAVE_CTDB_WANT_READONLY_DECL
if (hdr->dmaster != get_my_vnn()) {
/* If we're not dmaster, it must be r/o copy. */
return read_only && (hdr->flags & CTDB_REC_RO_HAVE_READONLY);
}
/* If we want write access, noone can have r/o copies. */
return read_only || !(hdr->flags & CTDB_REC_RO_HAVE_DELEGATIONS);
#else
return (hdr->dmaster == get_my_vnn());
#endif
}
static struct db_record *fetch_locked_internal(struct db_ctdb_ctx *ctx,
TALLOC_CTX *mem_ctx,
TDB_DATA key,
bool tryonly)
{
struct db_record *result;
struct db_ctdb_rec *crec;
NTSTATUS status;
TDB_DATA ctdb_data;
int migrate_attempts = 0;
int lockret;
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_t *)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);
}
lockret = tryonly
? tdb_chainlock_nonblock(ctx->wtdb->tdb, key)
: tdb_chainlock(ctx->wtdb->tdb, key);
if (lockret != 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 (!db_ctdb_can_use_local_copy(ctdb_data, false)) {
SAFE_FREE(ctdb_data.dptr);
tdb_chainunlock(ctx->wtdb->tdb, key);
talloc_set_destructor(result, NULL);
if (tryonly && (migrate_attempts != 0)) {
DEBUG(5, ("record migrated away again\n"));
TALLOC_FREE(result);
return NULL;
}
migrate_attempts += 1;
DEBUG(10, ("ctdb_data.dptr = %p, dmaster = %u (%u) %u\n",
ctdb_data.dptr, ctdb_data.dptr ?
((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster : -1,
get_my_vnn(),
ctdb_data.dptr ?
((struct ctdb_ltdb_header *)ctdb_data.dptr)->flags : 0));
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 for %s key %s needed %d "
"attempts\n", tdb_name(ctx->wtdb->tdb),
hex_encode_talloc(talloc_tos(),
(unsigned char *)key.dptr,
key.dsize),
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_t *)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, false);
}
static struct db_record *db_ctdb_try_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, true);
}
/*
fetch (unlocked, no migration) operation on ctdb
*/
static NTSTATUS 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 (db_ctdb_can_use_local_copy(ctdb_data, true)) {
/* we are the dmaster - avoid the ctdb protocol op */
data->dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
data->dptr = (uint8_t *)talloc_memdup(
mem_ctx, ctdb_data.dptr+sizeof(struct ctdb_ltdb_header),
data->dsize);
SAFE_FREE(ctdb_data.dptr);
if (data->dptr == NULL) {
return NT_STATUS_NO_MEMORY;
}
return NT_STATUS_OK;
}
SAFE_FREE(ctdb_data.dptr);
/*
* We weren't able to get it locally - ask ctdb to fetch it for us.
* If we already had *something*, it's probably worth making a local
* read-only copy.
*/
status = ctdbd_fetch(messaging_ctdbd_connection(), ctx->db_id, key,
mem_ctx, data,
ctdb_data.dsize >= sizeof(struct ctdb_ltdb_header));
if (!NT_STATUS_IS_OK(status)) {
DEBUG(5, ("ctdbd_fetch failed: %s\n", nt_errstr(status)));
}
return status;
}
static NTSTATUS db_ctdb_parse_record(struct db_context *db, TDB_DATA key,
void (*parser)(TDB_DATA key,
TDB_DATA data,
void *private_data),
void *private_data)
{
NTSTATUS status;
TDB_DATA data;
status = db_ctdb_fetch(db, talloc_tos(), key, &data);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
parser(key, data, private_data);
TALLOC_FREE(data.dptr);
return NT_STATUS_OK;
}
struct traverse_state {
struct db_context *db;
int (*fn)(struct db_record *rec, void *private_data);
void *private_data;
int count;
};
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) == 0)
{
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;
}
/* wrapper to use traverse_persistent_callback with dbwrap */
static int traverse_persistent_callback_dbwrap(struct db_record *rec, void* data)
{
return traverse_persistent_callback(NULL, rec->key, rec->value, data);
}
static int db_ctdb_traverse(struct db_context *db,
int (*fn)(struct db_record *rec,
void *private_data),
void *private_data)
{
NTSTATUS status;
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;
state.count = 0;
if (db->persistent) {
struct tdb_context *ltdb = ctx->wtdb->tdb;
int ret;
/* for persistent databases we don't need to do a ctdb traverse,
we can do a faster local traverse */
ret = tdb_traverse(ltdb, traverse_persistent_callback, &state);
if (ret < 0) {
return ret;
}
if (ctx->transaction && ctx->transaction->m_write) {
/*
* we now have to handle keys not yet
* present at transaction start
*/
struct db_context *newkeys = db_open_rbt(talloc_tos());
struct ctdb_marshall_buffer *mbuf = ctx->transaction->m_write;
struct ctdb_rec_data *rec=NULL;
int i;
int count = 0;
if (newkeys == NULL) {
return -1;
}
for (i=0; icount; i++) {
TDB_DATA key;
rec =db_ctdb_marshall_loop_next(mbuf, rec,
NULL, NULL,
&key, NULL);
SMB_ASSERT(rec != NULL);
if (!tdb_exists(ltdb, key)) {
dbwrap_store(newkeys, key, tdb_null, 0);
}
}
status = dbwrap_traverse(newkeys,
traverse_persistent_callback_dbwrap,
&state,
&count);
talloc_free(newkeys);
if (!NT_STATUS_IS_OK(status)) {
return -1;
}
ret += count;
}
return ret;
}
status = ctdbd_traverse(ctx->db_id, traverse_callback, &state);
if (!NT_STATUS_IS_OK(status)) {
return -1;
}
return state.count;
}
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);
state->count++;
}
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 &&
strcmp((const char*)kbuf.dptr, 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);
state->count++;
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)
{
NTSTATUS status;
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;
state.count = 0;
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);
}
status = ctdbd_traverse(ctx->db_id, traverse_read_callback, &state);
if (!NT_STATUS_IS_OK(status)) {
return -1;
}
return state.count;
}
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 void db_ctdb_id(struct db_context *db, const uint8_t **id,
size_t *idlen)
{
struct db_ctdb_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_ctdb_ctx);
*id = (uint8_t *)&ctx->db_id;
*idlen = sizeof(ctx->db_id);
}
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,
enum dbwrap_lock_order lock_order)
{
struct db_context *result;
struct db_ctdb_ctx *db_ctdb;
char *db_path;
struct ctdbd_connection *conn;
struct loadparm_context *lp_ctx;
struct ctdb_db_priority prio;
NTSTATUS status;
int cstatus;
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);
result->lock_order = lock_order;
/* 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);
}
prio.db_id = db_ctdb->db_id;
prio.priority = lock_order;
status = ctdbd_control_local(
conn, CTDB_CONTROL_SET_DB_PRIORITY, 0, 0,
make_tdb_data((uint8_t *)&prio, sizeof(prio)),
NULL, NULL, &cstatus);
if (!NT_STATUS_IS_OK(status) || (cstatus != 0)) {
DEBUG(1, ("CTDB_CONTROL_SET_DB_PRIORITY failed: %s, %d\n",
nt_errstr(status), cstatus));
TALLOC_FREE(result);
return NULL;
}
lp_ctx = loadparm_init_s3(db_path, loadparm_s3_helpers());
db_ctdb->wtdb = tdb_wrap_open(db_ctdb, db_path, hash_size, tdb_flags,
O_RDWR, 0, lp_ctx);
talloc_unlink(db_path, lp_ctx);
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->try_fetch_locked = db_ctdb_try_fetch_locked;
result->parse_record = db_ctdb_parse_record;
result->traverse = db_ctdb_traverse;
result->traverse_read = db_ctdb_traverse_read;
result->get_seqnum = db_ctdb_get_seqnum;
result->transaction_start = db_ctdb_transaction_start;
result->transaction_commit = db_ctdb_transaction_commit;
result->transaction_cancel = db_ctdb_transaction_cancel;
result->id = db_ctdb_id;
result->stored_callback = NULL;
DEBUG(3,("db_open_ctdb: opened database '%s' with dbid 0x%x\n",
name, db_ctdb->db_id));
return result;
}
#else /* CLUSTER_SUPPORT */
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,
enum dbwrap_lock_order lock_order)
{
DEBUG(3, ("db_open_ctdb: no cluster support!\n"));
return NULL;
}
#endif