Re: [ZFS][PANIC] Solaris Assert/zio.c:2548

----- Original Message ----- 
From: "Dan Mack" <mack_at_macktronics.com>
To: "Steven Hartland" <killing_at_multiplay.co.uk>
Cc: <freebsd-fs_at_freebsd.org>; <freebsd-current_at_freebsd.org>; "Larry Rosenman" <ler_at_lerctr.org>
Sent: Monday, July 21, 2014 2:29 AM
Subject: Re: [ZFS][PANIC] Solaris Assert/zio.c:2548


> On Mon, 21 Jul 2014, Steven Hartland wrote:
> 
>>> I just updated to I think 268921 earlier today and this is the first
>>> time I've had a panic (HEAD-268921 that is)
>>> 
>>> I'll try to get some more data if I can get it back up and running.
>>
>> That doesn't look like a related trace tbh.
>>
>>   Regards
>>   Steve
> 
> After rebooting with a dumpdev; I got this :
> 
> kbd2 at ukbd0
> Trying to mount root from zfs:tank []...
> panic: deadlkres: possible deadlock detected for 0xfffff8000e089000, blocked for 1801216 ticks
> 
> cpuid = 6
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe085ef1d8d0
> kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe085ef1d980
> vpanic() at vpanic+0x126/frame 0xfffffe085ef1d9c0
> panic() at panic+0x43/frame 0xfffffe085ef1da20
> deadlkres() at deadlkres+0x35c/frame 0xfffffe085ef1da70
> fork_exit() at fork_exit+0x84/frame 0xfffffe085ef1dab0
> fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe085ef1dab0
> --- trap 0, rip = 0, rsp = 0xfffffe085ef1db70, rbp = 0 ---
> KDB: enter: panic
> [ thread pid 0 tid 100070 ]
> Stopped at      kdb_enter+0x3e: movq    $0,kdb_why
> 
> I cannot seem to get past this yet so I'm open to suggestions.  I'm
> still at the db> prompt if you'd like me to attempt to collect more
> info.

For some reason the deadlock detector is triggering, not sure why.

I'd recommend starting a new thread to discuss this as it doesn't
appear to be related to this thread.

The only thing I could suggest is disabling it to see if it truely
is a deadlock or if something is being really slow.
vfs.zfs.deadman_enabled=0

If this is new then it would be good for you to try and identify
which of the changes introduced it, so do a binary chop on versions
back to your last known good.

    Regards
    Steve