Re: partially encrypted filesystem

[Maciej Zenczykowski <maze@cela.pl>]

> But the genius is that you don't need to calculate anything.  If the
> data block turns out to be incompressible (those damn .tar.bz2s!), you
> just write the block in-place.  If it is compressible, you write as much
> into that block's entry as you need and leave a gap.  The underlying
> file system doesn't write any data there.  There's no need for an index
> file -- you know exactly where to start reading each block.

You are pushing this down to the file system.  I'd venture too say that 
this will majorly stress the fs code, make its indexing slower and 
majorly fragment the file on disk (if it's later overwritten).  Sure - you 
have less work to do (less to code) - but the end effect might be 
painful, especially on often written files (if the file ain't written to 
then there are much better compression solutions).

Cheers,
MaZe.