Andi Kleen wrote:

On Tue, Apr 13, 2004 at 06:25:33PM -0700, Hans Reiser wrote:


Andi Kleen wrote:



Amazing. You managed to write all this without ever mentioning
that linux 2.6 already has per process name spaces (=views) in
form of CLONE_NS.

-Andi


Can you specify exclude *.c in them? I think that your =views is a simplistic statement.



You can add any files/directories you want (mount --bind). Excluding
is not directly supported.


Doing it by directories is more natural though as it works with mount points. Basically it mirrors the plan9 implementation and in
plan9 it is extensively used. I don't know of any uses in Linux
so far, but the infrastructure is there in the kernel.


I don't doubt that your proposal is more powerful (and more complicated
and vapour right now), but I think you should mention prior work
in linux and plan9 before discussing clearcase at least.

-Andi





Clearcase is the most powerful instantiation of those ideas in filesystems, and predates plan 9 (it originated with Apollo). I think that it is the appropriate reference academically. Just because it is a piece of shit in its implementation details does not prevent it from standing head and shoulders above the rest of the field in its functionality.

I am still thinking through how we will implement views in Reiser4. It needs to be efficient and scalable to large numbers of bindings. I need to go reading through the per process name space code: I don't know if it will, for instance, scale to a thousand specifications. Clearcase probably also would not.

I am thinking about whether we should exclude names before searching the FS for matches, or after. I think before, but it needs a lot of thought.

--
Hans



Reply via email to