Re: kern/42228: Kernel deadlock prevents further file system access

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

On Sun, Oct 25, 2009 at 12:10:01PM +0000, tron%zhadum.org.uk@localhost wrote:
> >Description:
> My NetBSD/amd64 5.0/5.0_STABLE server has locked up at multiple occasions.
> The symptoms are always identical:
> 1.) The system still responds to ICMP Echo packets.
> 2.) Services that don't access the file system (frequently) like e.g.
>     BIND still work.
> 3.) Any other processes (Postfix, Apache, inetd, etc.) are stuck.
> I have to recover the machine by dropping into "ddb" and using "sync"
> or "reboot" to force a restart.
> 
> The system managed to write a crash dump (to "raid0b" in case it
> matters) after several of the crashes but "savecore" always claims
> there is no crash dump once the system is back up. The only debug
> information I therefore have is the stack trace of multiple of
> the hung process after the latest incident. The stack traces all
> look like this:
> 
> sleepq_block
> turnstile_block
> rw_vector_enter
> vlockmgr
> VOP_LOCK
> vn_lock
> namei
> 
> The function after "namei" differs from case to case. Examples are
> vn_open() or do_sys_stat().

this looks a lot like the ffs VOP_RENAME race issue.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--