When should I replay a journal ?

[K . G .]

Hi,

I'm implementing the journal for HFS+, and I think I can replay
transactions at two differents places, either when checking the
filesystem, or when opening it. If I replay when opening, this means the
FS could be modified by things as simple as 'print $part'. Is that good
? Does the user knows and wants that this happens ? On the other way,
putting it in the check part means printing the partition could report
inaccurate informations... Maybe I should put it in 'open' with an
exception asking the user if he wants transactions to be replayed ?

Cheers,
Guillaume