Subject: RE: CVS commit: src
To: Bill Studenmund <wrstuden@NetBSD.org>
From: Gordon Waidhofer <email@example.com>
Date: 06/24/2004 20:58:19
> In terms of getting to this, I think I'd much prefer moving to internal
I'd vote for that, I think. Does internal and
advisory/non-exclusive mean the same thing?
> One of the bigest problems I encountered when getting layered
> file systems working was ambiguity in what was was happeneing with
> locking. So I pushed everything to use exclusive real locks; to be
> consistent (and a bit facist). If we go to making locks advisory, I'm
> concerned that things would get ambiguous again, and we're back in a mess.
That helps explain things a lot. Thank you.
I don't know anything about the layered file
system stuff, but now I know what to worry about.
I'll bet that's a good -- and illuminating -- war story.
I was about to ask if VOP_LOCK/VOP_LEASE/VOP_WRITE/VOP_UNLOCK
sequences, and the like, are a concern. But I just checked and
the VOP_LEASE is before the vn_lock() in vn_write().