Re: silent semantic changes with reiser4

Alexander Lyamin
2004-08-29T15:03:13Z

Fri, Aug 27, 2004 at 11:08:57PM -0700, Paul Jackson wrote:
> Hans wrote:
> > We create filename/pseudos/backup, and that tells the archiver what to
> > do.....
>
> Instead of exposing the old semantics under a new interface, why not
> expose the new semantics under a new interface.

yeah. that could work.

> There exist plenty of programs that know the old Unix semantics. There
> don't exist many working programs that use the new semantics that you're
> adding.
>
> I raise again the example of how Windows adapted to long filenames. Old
> DOS and FAT programs, including my Unix backups of today, see a 8.3 name
> space. Only code that knows the new magic sees the long names.
>
> If given the choice of breaking much old, existing stuff, or some new,
> mostly not yet existing stuff, does not it make more sense to break what
> mostly doesn't exist yet?
>
> One possible way to do this, of no doubt many:
>
> * Stealing a corner of the existing filename space for
> some magic names with the new semantics.
>
> * A new option on open(2), hence opendir(3), that lights up
> these magic names.
>
> * Doing any of the classic pathname calls with such a
> new magic name exposes the new semantics - such calls
> as:
> access execve mkdir mknod mount readlink
> rename rmdir stat truncate unlink
>
> This means essentially constructing a map between old and new,
> such that changes made in either view are sane and visible
> from the other view.

It would be intresting to hear comments from Hans Reiser on proposals stated above...

--
"the liberation loophole will make it clear.."
lex lyamin