int tdb_transaction_lock(struct tdb_context *tdb, int ltype);
int tdb_transaction_unlock(struct tdb_context *tdb, int ltype);
int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len);
int tdb_transaction_lock(struct tdb_context *tdb, int ltype);
int tdb_transaction_unlock(struct tdb_context *tdb, int ltype);
int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len);