Re: unionfs

From: Miklos Szeredi
Date: Thu Mar 11 2004 - 10:45:39 EST

> If you get a response from Al, could you let me know?


> I've been wondering about this myself, and beyond simple
> coolness/usefullness, we may also need the unionfs for mls
> polyinstantiation.
> If you don't hear from Al, please let me know whether you plan to tackle
> it yourself or not.

I'll have to, as this is needed for AVFS. Not unionfs, but something
similar, that allows file/directory lookups for special filenames to
be redirected to another filesystem.

For the time I plan to go along the easy way, and create a filesystem
specifically for AVFS that doesn't need modifications to the kernel.
This will be inefficient in a number of ways: doubling the memory use
by the dentry/inode caches, deeper call chains for all filesystem
operations (even those, that require no intervention).

The next step will be to try to optimize and generalize it to be
usable for other filesystems like unionsfs. I'd really love to have
some input about this from Al or anybody who has any ideas.

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