Re: kern/46221: Kernel panic in NFS server code

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

The following reply was made to PR kern/46221; it has been noted by GNATS.

From: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
To: Matthias Scheler <tron%zhadum.org.uk@localhost>
Cc: NetBSD GNATS <gnats-bugs%NetBSD.org@localhost>
Subject: Re: kern/46221: Kernel panic in NFS server code
Date: Wed, 21 Mar 2012 19:07:37 +0100

 On Wed, Mar 21, 2012 at 05:12:28PM +0000, Matthias Scheler wrote:
 > On Wed, Mar 21, 2012 at 05:40:39PM +0100, Manuel Bouyer wrote:
 > > >  I guess that an extra check whether "ip" is NULL would prevent the
 > > >  panic. But I'm not sure whether that is the correct fix.
 > > 
 > > Looks like kern/41147. Fixed here:
 > > http://mail-index.netbsd.org/source-changes/2009/09/20/msg001090.html
 > > and then in a better way here:
 > > http://mail-index.netbsd.org/source-changes/2009/11/05/msg002668.html
 > 
 > It seems that we need something like that in "netbsd-6".
 
 The code has changed in this area; I'm not sure the same code will
 work (there is a KASSERT in cleanvnode() that, I think, would
 have fired if we had the same senario). There is also a KASSERT()
 in vget() that we're not returning a clean vnode.
 
 I wonder if while we're slepping on vp->v_interlock, the vnode could
 have been moved to another filesystem ...
 printing the vnode when the problem happens will really help.
 
 -- 
 Manuel Bouyer <bouyer%antioche.eu.org@localhost>
      NetBSD: 26 ans d'experience feront toujours la difference
 --