journal_wipe — Wipe journal contents
| int journal_wipe ( | journal_t * journal, | 
| int write ); | 
   Wipe out all of the contents of a journal, safely.  This will produce
   a warning if the journal contains any valid recovery information.
   Must be called between journal_init_*() and journal_load.
   
If 'write' is non-zero, then we wipe out the journal on disk; otherwise we merely suppress recovery.