Subject: Re: mnt_leaf, v_vnlock, VLAYER
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Bill Studenmund <>
List: tech-kern
Date: 12/05/2005 09:21:15
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On Mon, Dec 05, 2005 at 01:21:50AM -0500, der Mouse wrote:
> We (=3DNetBSD) may decide we don't care about supporting any such
> filesystems, but if so, we should make that decision consciously,
> rather than by not realizing the possibility exists.

And where in this have we said we want to preclude this? While such a
layer is NOT on my priority list, I think it'd be fine for someone to add
such a layer. Thought we'd really need vmsfs or whatever first. :-)

I feel your concern is mis-placed. Nothing in this thread will preclude=20
what you're describing.

What we're contemplating is changing the vnode system so that it=20
more-explicitly holds the concept of a cloud of vnodes, and most=20
importantly that it "understands" that vnodes can be more complicated than=
just simple leaf nodes.

That doesn't mean we can't support fan-in, where two or more vnodes get=20
turned into one upper node. That's how what you're talking about works,=20
and also how unionfs works. I think it's an important and useful idea. :-)

Thank you for explaining how Eunice worked, though. :-)

Take care,


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