Re: mutex lock panic on halt/shutdown unmounting GPT/RAID filesystem

[David Brownlee <abs%absd.org@localhost>]

On 5 July 2011 16:57, John D. Baker <jdbaker%mylinuxisp.com@localhost> wrote:
> I'm building (built, rather, now testing) a machine to be my new file
> server.  I'm using a NetBSD-5.1_STABLE/i386 kernel made from GENERIC
> plus "options RF_RAID5_RS=1" to get RAID-5 w/rotated sparing.  The raid
> is built across 8 1TB Hitachi SATA drives using a 4-port siisata
> (sii3124-based) PCIe card and the onboard ahcisata ports of an intel
> D945GCL board.  The system disk is on the parallel ATA bus.
>
> The machine has 4GB of RAM, although only a little over 3.5GB is
> actually visible, naturally.  As such, I only defined a token 2GB
> of swap space.
>
> I have the RAID in a single filesystem defined using GPT and wedges.
> All file systems are mounted with the "log" option.
>
> Prior to having the RAID intialized, newfs'ed and mounted, nothing
> appeared amiss.
>
> Once the big filesystem was online, the system will panic when shutting
> down (e.g.: shutdown -r now) with "mutex lock error: locking against
> myself".  Unfortunately it all goes by too fast to read.  It saves the
> crashdump, but I think the subsequent savecore has problems--the memory
> image is there, but the kernel image is only 10 bytes in size.  It
> displays "(null) bad address".
>
> This appears to happen AFTER the big filesystem is successfully unmounted
> but BEFORE the system disk's filesystems have been unmounted.  Console
> and dmesg indicates that the OS partitions get the log-replay treatment
> when starting up again.  The RAID and its filesystem are intact.
>
> I've determined that if I manually unmount the GPT/RAID filesystem
> before shutting down it doesn't panic.
>
> Any clues?
>
> Need more data?

Possible additional data point - I have a raid1 (root) + 3*raid5
(data) system which has been running netbsd-5 for a while without
issue which now seems subject to similar symptoms - panic on
reboot/shutdown, which certainly was not having this problem earlier
in the netbsd-5 timeline...

I have some 2TB disks on order for a new build which should just be
small raid1 for boot and larger raid5*5 on the same set of disks which
I should be able to play with to try to reproduce at more leisure...