- don't allow any locks to be held when a transaction starts,
otherwise we can end up with deadlock (plus lack of lock nesting
- in posix locks would mean the lock is lost)
+ in POSIX locks would mean the lock is lost)
- if the caller gains a lock during the transaction but doesn't
release it then fail the commit
- allow for nested calls to tdb_transaction_start(), re-using the
- existing transaction record. If the inner transaction is cancelled
+ existing transaction record. If the inner transaction is canceled
then a subsequent commit will fail
- keep a mirrored copy of the tdb hash chain heads to allow for the
- allow callers to mix transaction and non-transaction use of tdb,
although once a transaction is started then an exclusive lock is
- gained until the transaction is committed or cancelled
+ gained until the transaction is committed or canceled
- the commit stategy involves first saving away all modified data
into a linearised buffer in the transaction recovery area, then
/*
- write while in a transaction - this varient never expands the transaction blocks, it only
+ write while in a transaction - this variant never expands the transaction blocks, it only
updates existing blocks. This means it cannot change the recovery size
*/
static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
/* add a write to the transaction elements, so subsequent
reads see the zero data */
ecode = transaction_write(tdb, tdb->map_size, NULL, addition);
- if (ecode != TDB_SUCCESS) {
- tdb->ecode = ecode;
- return ecode;
+ if (ecode == TDB_SUCCESS) {
+ tdb->map_size += addition;
}
- tdb->map_size += addition;
return ecode;
}
start a tdb transaction. No token is returned, as only a single
transaction is allowed to be pending per tdb_context
*/
-int tdb_transaction_start(struct tdb_context *tdb)
+enum TDB_ERROR tdb_transaction_start(struct tdb_context *tdb)
{
enum TDB_ERROR ecode;
/* some sanity checks */
if (tdb->read_only || (tdb->flags & TDB_INTERNAL)) {
- tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
- "tdb_transaction_start: cannot start a transaction"
- " on a read-only or internal db");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+ "tdb_transaction_start: cannot start a"
+ " transaction on a read-only or internal db");
}
/* cope with nested tdb_transaction_start() calls */
if (tdb->transaction != NULL) {
- tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
- "tdb_transaction_start:"
- " already inside transaction");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
+ "tdb_transaction_start:"
+ " already inside transaction");
}
if (tdb_has_hash_locks(tdb)) {
/* the caller must not have any locks when starting a
transaction as otherwise we'll be screwed by lack
- of nested locks in posix */
- tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
- "tdb_transaction_start: cannot start a transaction"
- " with locks held");
- return -1;
+ of nested locks in POSIX */
+ return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
+ "tdb_transaction_start: cannot start a"
+ " transaction with locks held");
}
tdb->transaction = (struct tdb_transaction *)
calloc(sizeof(struct tdb_transaction), 1);
if (tdb->transaction == NULL) {
- tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
- "tdb_transaction_start: cannot allocate");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+ "tdb_transaction_start: cannot allocate");
}
/* get the transaction write lock. This is a blocking lock. As
make this async, which we will probably do in the future */
ecode = tdb_transaction_lock(tdb, F_WRLCK);
if (ecode != TDB_SUCCESS) {
- tdb->ecode = ecode;
SAFE_FREE(tdb->transaction->blocks);
SAFE_FREE(tdb->transaction);
- return -1;
+ return ecode;
}
/* get a read lock over entire file. This is upgraded to a write
lock during the commit */
ecode = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, true);
if (ecode != TDB_SUCCESS) {
- tdb->ecode = ecode;
goto fail_allrecord_lock;
}
transaction specific methods */
tdb->transaction->io_methods = tdb->methods;
tdb->methods = &transaction_methods;
- return 0;
+ return TDB_SUCCESS;
fail_allrecord_lock:
tdb_transaction_unlock(tdb, F_WRLCK);
SAFE_FREE(tdb->transaction->blocks);
SAFE_FREE(tdb->transaction);
- return -1;
+ return ecode;
}
allocate the recovery area, or use an existing recovery area if it is
large enough
*/
-static int tdb_recovery_allocate(struct tdb_context *tdb,
- tdb_len_t *recovery_size,
- tdb_off_t *recovery_offset,
- tdb_len_t *recovery_max_size)
+static enum TDB_ERROR tdb_recovery_allocate(struct tdb_context *tdb,
+ tdb_len_t *recovery_size,
+ tdb_off_t *recovery_offset,
+ tdb_len_t *recovery_max_size)
{
struct tdb_recovery_record rec;
const struct tdb_methods *methods = tdb->transaction->io_methods;
recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
if (TDB_OFF_IS_ERR(recovery_head)) {
- tdb_logerr(tdb, recovery_head, TDB_LOG_ERROR,
- "tdb_recovery_allocate:"
- " failed to read recovery head");
- return -1;
+ return tdb_logerr(tdb, recovery_head, TDB_LOG_ERROR,
+ "tdb_recovery_allocate:"
+ " failed to read recovery head");
}
if (recovery_head != 0) {
ecode = methods->tread(tdb, recovery_head, &rec, sizeof(rec));
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_recovery_allocate:"
- " failed to read recovery record");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_recovery_allocate:"
+ " failed to read recovery record");
}
tdb_convert(tdb, &rec, sizeof(rec));
/* ignore invalid recovery regions: can happen in crash */
/* it fits in the existing area */
*recovery_max_size = rec.max_len;
*recovery_offset = recovery_head;
- return 0;
+ return TDB_SUCCESS;
}
/* we need to free up the old recovery area, then allocate a
ecode = add_free_record(tdb, recovery_head,
sizeof(rec) + rec.max_len);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_recovery_allocate:"
- " failed to free previous recovery area");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_recovery_allocate:"
+ " failed to free previous"
+ " recovery area");
}
}
tdb->map_size = tdb->transaction->old_map_size;
ecode = methods->expand_file(tdb, addition);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_recovery_allocate:"
- " failed to create recovery area");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_recovery_allocate:"
+ " failed to create recovery area");
}
/* we have to reset the old map size so that we don't try to
ecode = methods->twrite(tdb, offsetof(struct tdb_header, recovery),
&recovery_head, sizeof(tdb_off_t));
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_recovery_allocate:"
- " failed to write recovery head");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_recovery_allocate:"
+ " failed to write recovery head");
}
transaction_write_existing(tdb, offsetof(struct tdb_header, recovery),
&recovery_head,
sizeof(tdb_off_t));
- return 0;
+ return TDB_SUCCESS;
}
/* Set up header for the recovery record. */
/*
setup the recovery data that will be used on a crash during commit
*/
-static int transaction_setup_recovery(struct tdb_context *tdb,
- tdb_off_t *magic_offset)
+static enum TDB_ERROR transaction_setup_recovery(struct tdb_context *tdb,
+ tdb_off_t *magic_offset)
{
tdb_len_t recovery_size;
unsigned char *data, *p;
/*
check that the recovery area has enough space
*/
- if (tdb_recovery_allocate(tdb, &recovery_size,
- &recovery_offset, &recovery_max_size) == -1) {
- return -1;
+ ecode = tdb_recovery_allocate(tdb, &recovery_size,
+ &recovery_offset, &recovery_max_size);
+ if (ecode != TDB_SUCCESS) {
+ return ecode;
}
data = (unsigned char *)malloc(recovery_size + sizeof(*rec));
if (data == NULL) {
- tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
- "transaction_setup_recovery: cannot allocate");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+ "transaction_setup_recovery:"
+ " cannot allocate");
}
rec = (struct tdb_recovery_record *)data;
continue;
}
if (offset + length > tdb->map_size) {
- tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
- "tdb_transaction_setup_recovery:"
- " transaction data over new region boundary");
free(data);
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+ "tdb_transaction_setup_recovery:"
+ " transaction data over new region"
+ " boundary");
}
memcpy(p, &offset, sizeof(offset));
memcpy(p + sizeof(offset), &length, sizeof(length));
p + sizeof(offset) + sizeof(length),
length);
if (ecode != TDB_SUCCESS) {
- tdb->ecode = ecode;
free(data);
- return -1;
+ return ecode;
}
p += sizeof(offset) + sizeof(length) + length;
}
ecode = methods->twrite(tdb, recovery_offset, data,
sizeof(*rec) + recovery_size);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_setup_recovery:"
- " failed to write recovery data");
free(data);
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_setup_recovery:"
+ " failed to write recovery data");
}
transaction_write_existing(tdb, recovery_offset, data,
sizeof(*rec) + recovery_size);
sizeof(*rec) + recovery_size);
if (ecode != TDB_SUCCESS) {
free(data);
- tdb->ecode = ecode;
- return -1;
+ return ecode;
}
free(data);
ecode = methods->twrite(tdb, *magic_offset, &magic, sizeof(magic));
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_setup_recovery:"
- " failed to write recovery magic");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_setup_recovery:"
+ " failed to write recovery magic");
}
transaction_write_existing(tdb, *magic_offset, &magic, sizeof(magic));
/* ensure the recovery magic marker is on disk */
- ecode = transaction_sync(tdb, *magic_offset, sizeof(magic));
- if (ecode != TDB_SUCCESS) {
- tdb->ecode = ecode;
- return -1;
- }
-
- return 0;
+ return transaction_sync(tdb, *magic_offset, sizeof(magic));
}
-static int _tdb_transaction_prepare_commit(struct tdb_context *tdb)
+static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
{
const struct tdb_methods *methods;
enum TDB_ERROR ecode;
if (tdb->transaction == NULL) {
- tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
- "tdb_transaction_prepare_commit: no transaction");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+ "tdb_transaction_prepare_commit:"
+ " no transaction");
}
if (tdb->transaction->prepared) {
_tdb_transaction_cancel(tdb);
- tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
- "tdb_transaction_prepare_commit:"
- " transaction already prepared");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+ "tdb_transaction_prepare_commit:"
+ " transaction already prepared");
}
if (tdb->transaction->transaction_error) {
_tdb_transaction_cancel(tdb);
- tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_ERROR,
- "tdb_transaction_prepare_commit:"
- " transaction error pending");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_ERROR,
+ "tdb_transaction_prepare_commit:"
+ " transaction error pending");
}
if (tdb->transaction->nesting != 0) {
tdb->transaction->nesting--;
- return 0;
+ return TDB_SUCCESS;
}
/* check for a null transaction */
if (tdb->transaction->blocks == NULL) {
- return 0;
+ return TDB_SUCCESS;
}
methods = tdb->transaction->io_methods;
"tdb_transaction_prepare_commit:"
" failed to upgrade hash locks");
_tdb_transaction_cancel(tdb);
- return -1;
+ return ecode;
}
/* get the open lock - this prevents new users attaching to the database
"tdb_transaction_prepare_commit:"
" failed to get open lock");
_tdb_transaction_cancel(tdb);
- return -1;
+ return ecode;
}
/* Since we have whole db locked, we don't need the expansion lock. */
if (!(tdb->flags & TDB_NOSYNC)) {
/* write the recovery data to the end of the file */
- if (transaction_setup_recovery(tdb, &tdb->transaction->magic_offset) == -1) {
- tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+ ecode = transaction_setup_recovery(tdb,
+ &tdb->transaction
+ ->magic_offset);
+ if (ecode != TDB_SUCCESS) {
+ tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
"tdb_transaction_prepare_commit:"
" failed to setup recovery data");
_tdb_transaction_cancel(tdb);
- return -1;
+ return ecode;
}
}
"tdb_transaction_prepare_commit:"
" expansion failed");
_tdb_transaction_cancel(tdb);
- return -1;
+ return ecode;
}
}
/* Keep the open lock until the actual commit */
-
- return 0;
+ return TDB_SUCCESS;
}
/*
prepare to commit the current transaction
*/
-int tdb_transaction_prepare_commit(struct tdb_context *tdb)
+enum TDB_ERROR tdb_transaction_prepare_commit(struct tdb_context *tdb)
{
return _tdb_transaction_prepare_commit(tdb);
}
/*
commit the current transaction
*/
-int tdb_transaction_commit(struct tdb_context *tdb)
+enum TDB_ERROR tdb_transaction_commit(struct tdb_context *tdb)
{
const struct tdb_methods *methods;
int i;
enum TDB_ERROR ecode;
if (tdb->transaction == NULL) {
- tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
- "tdb_transaction_commit: no transaction");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+ "tdb_transaction_commit: no transaction");
}
tdb_trace(tdb, "tdb_transaction_commit");
if (tdb->transaction->nesting != 0) {
tdb->transaction->nesting--;
- return 0;
+ return TDB_SUCCESS;
}
/* check for a null transaction */
if (tdb->transaction->blocks == NULL) {
_tdb_transaction_cancel(tdb);
- return 0;
+ return TDB_SUCCESS;
}
if (!tdb->transaction->prepared) {
- int ret = _tdb_transaction_prepare_commit(tdb);
- if (ret)
- return ret;
+ ecode = _tdb_transaction_prepare_commit(tdb);
+ if (ecode != TDB_SUCCESS)
+ return ecode;
}
methods = tdb->transaction->io_methods;
_tdb_transaction_cancel(tdb);
- return -1;
+ return ecode;
}
SAFE_FREE(tdb->transaction->blocks[i]);
}
/* ensure the new data is on disk */
ecode = transaction_sync(tdb, 0, tdb->map_size);
if (ecode != TDB_SUCCESS) {
- tdb->ecode = ecode;
- return -1;
+ return ecode;
}
/*
transaction locks */
_tdb_transaction_cancel(tdb);
- return 0;
+ return TDB_SUCCESS;
}
database write access already established (including the open
lock to prevent new processes attaching)
*/
-int tdb_transaction_recover(struct tdb_context *tdb)
+enum TDB_ERROR tdb_transaction_recover(struct tdb_context *tdb)
{
tdb_off_t recovery_head, recovery_eof;
unsigned char *data, *p;
/* find the recovery area */
recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
if (TDB_OFF_IS_ERR(recovery_head)) {
- tdb_logerr(tdb, recovery_head, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " failed to read recovery head");
- return -1;
+ return tdb_logerr(tdb, recovery_head, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to read recovery head");
}
if (recovery_head == 0) {
/* we have never allocated a recovery record */
- return 0;
+ return TDB_SUCCESS;
}
/* read the recovery record */
ecode = tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec));
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " failed to read recovery record");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to read recovery record");
}
if (rec.magic != TDB_RECOVERY_MAGIC) {
/* there is no valid recovery data */
- return 0;
+ return TDB_SUCCESS;
}
if (tdb->read_only) {
- tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " attempt to recover read only database");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " attempt to recover read only database");
}
recovery_eof = rec.eof;
data = (unsigned char *)malloc(rec.len);
if (data == NULL) {
- tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " failed to allocate recovery data");
- return -1;
+ return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to allocate recovery data");
}
/* read the full recovery data */
ecode = tdb->methods->tread(tdb, recovery_head + sizeof(rec), data,
rec.len);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " failed to read recovery data");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to read recovery data");
}
/* recover the file data */
ecode = tdb->methods->twrite(tdb, ofs, p, len);
if (ecode != TDB_SUCCESS) {
free(data);
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " failed to recover %zu bytes at offset %zu",
- (size_t)len, (size_t)ofs);
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to recover %zu bytes"
+ " at offset %zu",
+ (size_t)len, (size_t)ofs);
}
p += len;
}
ecode = transaction_sync(tdb, 0, tdb->map_size);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_recover: failed to sync recovery");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to sync recovery");
}
/* if the recovery area is after the recovered eof then remove it */
recovery),
0);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " failed to remove recovery head");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to remove recovery head");
}
}
+ offsetof(struct tdb_recovery_record, magic),
TDB_RECOVERY_INVALID_MAGIC);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_recover:"
- " failed to remove recovery magic");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to remove recovery magic");
}
ecode = transaction_sync(tdb, 0, recovery_eof);
if (ecode != TDB_SUCCESS) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_transaction_recover: failed to sync2 recovery");
- return -1;
+ return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+ "tdb_transaction_recover:"
+ " failed to sync2 recovery");
}
tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
(size_t)recovery_eof);
/* all done */
- return 0;
+ return TDB_SUCCESS;
}
-/* Any I/O failures we say "needs recovery". */
-bool tdb_needs_recovery(struct tdb_context *tdb)
+tdb_bool_err tdb_needs_recovery(struct tdb_context *tdb)
{
tdb_off_t recovery_head;
struct tdb_recovery_record rec;
/* find the recovery area */
recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
if (TDB_OFF_IS_ERR(recovery_head)) {
- tdb->ecode = recovery_head;
- return true;
+ return recovery_head;
}
if (recovery_head == 0) {
/* read the recovery record */
ecode = tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec));
if (ecode != TDB_SUCCESS) {
- tdb->ecode = ecode;
- return true;
+ return ecode;
}
return (rec.magic == TDB_RECOVERY_MAGIC);