Subject: Re: diffs for UVM/UBC improvements available
To: Chuck Silvers <>
From: Frank van der Linden <>
List: tech-kern
Date: 05/22/2001 15:00:38
On Tue, May 22, 2001 at 02:38:33AM -0700, Chuck Silvers wrote:
>  - move the vnode lock from struct vnode back into the fs-specific data.
>    the layered filesystems don't have a separate lock for their vnodes,
>    so the lock isn't really a vnode property.

With that change you have taken a piece of shared code and re-duplicated
it into all FS code (except the stacked code). I'm not sure I see the
point in this. Also, the idea of having a lock element in the vnode
structure was, as I recall (Bill Studenmund did it and will know) to
be able to use the same lock for all layers of a layered filesystem.
I.e. the upper layers just have pointers to the lower layer's lock.

How did you do this now that this no longer exist? Have you tested
the known-working layered filesystems (null and layer)?

I think I agree with removing VOP_ISLOCKED, arguably any code that
needs it has problems. But better think about this some more.

Anyway, as Bill said, these are really unrelated issues to the actual
UBC changes, they don't seem to be necessary to implement them.

- Frank
Frank van der Linden                 
Quality NetBSD CDs, Support & Service.