vrele: negative ref cnt (was: Re: Crash dumps not working correctly for amd64?)

[Sean Chittenden]

So, buried in the last email I sent out was the actual panic string for 
the dumps I've been having.  Has anyone else seen this or is this a 
known problem?  I haven't been able to extract a correct dump yet.  I 
just dd(1)'ed the swap partition hoping that next time it dumps, there 
will be a clean dump that I can extract a backtrace from, however I'm 
not too hopeful that this will work as a fix for me.  Regardless, I'd 
assume that twa(1) + amd64 work fine together?  This crash seems to 
emanate from the file system code so I doubt it's driver related.  
Anyone know what could lead to this?  Feel free to send me in the 
direction of fs@ if I'm not the only one having this problem or that 
this isn't amd64 specific.  Right now I can generally trigger this once 
every 24hrs, so it's becoming something of a problem for me and without 
a valid dump, I'm not sure where to begin.  -sc

> # savecore -vf
> bounds number: 9
> checking for kernel dump on device /dev/da0s1b
> mediasize = 3221225472
> sectorsize = 512
> magic mismatch on last dump header on /dev/da0s1b
> forcing magic on /dev/da0s1b
> savecore: first and last dump headers disagree on /dev/da0s1b
> savecore: reboot after panic: vrele: negative ref cnt
> Checking for available free space
> Dump header from device /dev/da0s1b
>   Architecture: amd64
>   Architecture Version: 16777216
>   Dump Length: 2146631680B (2047 MB)
>   Blocksize: 512
>   Dumptime: Thu Dec 16 03:06:24 2004
>   Hostname: nfs.example.com
>   Magic: FreeBSD Kernel Dump
>   Version String: FreeBSD 5.3-STABLE #1: Wed Dec  8 22:20:38 PST 2004
>     root at nfs.example.com:/usr/obj/usr/src/sys/NFS
>   Panic String: vrele: negative ref cnt
>   Dump Parity: 1999448632
>   Bounds: 9
>   Dump Status: bad
> savecore: writing core to vmcore.9
> 2146631680

-- 
Sean Chittenden