On Mon, 30 Sep 1996, Kevin P. Neal wrote:

> Note that JFS figures into this somehow, and I'm not very clear on this
> (Terry?). I don't know how FFS or ext2fs will fit into it, or if they will.
> LFS? (Terry?). Is Margo Seltzer around? (Would she be able to contribute
> any ideas?) Her web pages looked cool (I love web pages with white papers
> online).
> 

Ideally, you would be able to write a meta-data logging layer using
stackable vnodes.  This would enable you to add meta-data logging to
different filesystem types without having to overly modify the various
filesystems.  This is how it's supposed to work in principle anyway.
4.4BSD has them, but unfortunately they're broken.

In practice it's very difficult to design and implement stackable vnodes
correctly, though I'm optimistic someone will rise to the challenge.

Regards,


Mike Hancock