Date: Tue, 17 Apr 2001 10:45:02 -0700 (PDT) From: Matt Dillon <dillon@earth.backplane.com> To: Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: Kirk McKusick <mckusick@mckusick.com>, Julian Elischer <julian@elischer.org>, Rik van Riel <riel@conectiva.com.br>, freebsd-hackers@FreeBSD.ORG, David Xu <bsddiy@21cn.com> Subject: Re: vm balance Message-ID: <200104171745.f3HHj2K95255@earth.backplane.com> References: <24577.987528856@critter>
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:> I don't think NFS relies on vnodes never being freed.
:
:It does, in some case nfs stashes a vnode pointer and the v_id
:value away, and some time later tries to use that pair to try to
:refind the vnode again. If you free vnodes, it will still think
:the pointer is a vnode and if junk happens to be right it will
:think it is still a vnode. QED: Bad things (TM) will happen.
:
:# cd /sys/nfs
:# grep v_id *
:nfs_nqlease.c: vpid = vp->v_id;
:nfs_nqlease.c: if (vpid == vp->v_id) {
:nfs_nqlease.c: if (vpid == vp->v_id &&
:nfs_vnops.c: vpid = newvp->v_id;
:nfs_vnops.c: if (vpid == newvp->v_id) {
:
:--
:Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
hahahahahahahaha.. Look at the code more closely. v_id is not
managed by NFS, it's managed by vfs_cache.c. There's a big XXX
comment just before cache_purge() that explains it. Believe me,
NFS is the least of your worries here.
-Matt
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