Re: Thinking outside the box on file systems

From: Kyle Moffett
Date: Wed Aug 15 2007 - 12:59:10 EST


On Aug 15, 2007, at 12:02:41, Marc Perkel wrote:
Kyle, thinking further outside the box, files would no longer have owners or permissions. Nor would
directories. People, groups, managers, and other objects with have permissions. One might tag a file with the object that created it so you could implement "self" rights which might be use to replace the concept of /tmp directories.

Well, that's actually kind of close to how SELinux works.

This is the real fundamental design gotcha:
Our current apps *AND* admins speak "UNIX" and "POSIX". They don't speak "MarcPerkelOS" (or even "SELinux"). As long as there is not a reasonably-close-to-1-to-1 mapping between UNIX semantics and your "outside the box" semantics, the latter can't really be used. It would just involve rewriting too much code *AND* retraining too many admins from scratch to make it work. Hell, even Windows and Mac have moved towards a UNIX-like permissions system, precisely because it's a simple model which is relatively easy to teach people how to use. ACLs are just a slight modification of that model to allow two things:
(A) Additional user/group permissions
(B) Default permissions for new child files/dirs/etc

People are having a huge problem with SELinux permissions as is, and portions of that are a fairly standard model that's been worked over in various OSes for many years. I seriously doubt that anything that far "outside the box" is going to be feasible, at least in the near term.

Good new filesystem developments are likely to be ones which preserve the same outer model, yet allow for deeper/more-powerful control for those users/admins who need it.

Cheers,
Kyle Moffett

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/