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From: Terry Lambert <terry@lambert.org>
Message-Id: <199703291821.LAA06605@phaeton.artisoft.com>
Subject: Re: Panic: "lockmgr: pid %d, not %s %d unlocking"
To: dfr@nlsystems.com (Doug Rabson)
Date: Sat, 29 Mar 1997 11:21:25 -0700 (MST)
Cc: jdp@polstra.com, current@freebsd.org
In-Reply-To: <Pine.BSF.3.95q.970329091224.4554B-100000@kipper.nlsystems.com> from "Doug Rabson" at Mar 29, 97 09:15:36 am
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> > I just got this panic on a -current kernel from March 17th, running
> > on a 486/66DX2 with 16 MB of RAM:
> > 
> > #9  0xf01181fa in panic (fmt=0xf0112e4b "lockmgr: pid %d, not %s %d unlocking")
> >     at ../../kern/kern_shutdown.c:366
> > #10 0xf01132d8 in lockmgr (lkp=0xf0bc3e34, flags=6, interlkp=0xf0ba5b60, 
> >     p=0xf0bf1800) at ../../kern/kern_lock.c:355
> > #11 0xf01af9c3 in ufs_unlock (ap=0xefbffd50) at ../../ufs/ufs/ufs_vnops.c:1784
> > #12 0xf0165b35 in nfs_inactive (ap=0xefbffd78) at vnode_if.h:843
> 
> This looks as if the vnode was recycled unexpectedly from
> NFS to UFS during the call to vm_object_deallocate.  Unfortunately I can't
> see any obvious way this can happen since the vm_object has a ref to the
> vnode and it doesn't look like vm_object_deallocate can get re-entered
> easily.

Actually, it looks like lockmgr() is not reeentrancy locking the global
structures (something which is necessary if the lock management is done
on a calldown rather than a veto basis).


					Regards,
					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.