Re: silent semantic changes with reiser4

[Alexander Lyamin <flx@msu.ru>]

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