extern handle_t *journal_start(journal_t *, int nblocks);
extern int journal_restart (handle_t *, int nblocks);
extern int journal_extend (handle_t *, int nblocks);
extern handle_t *journal_start(journal_t *, int nblocks);
extern int journal_restart (handle_t *, int nblocks);
extern int journal_extend (handle_t *, int nblocks);