Kernel panic in laundromat_main on 5.3.0-46-generic (Ubuntu HWE)

Kernel panic in laundromat_main on 5.3.0-46-generic (Ubuntu HWE)

[sea you]

Hi all,

Today we've seen a kernel panic that looks like related to delegations
and laundromat

...
[1388051.959652] Call Trace:
[1388051.959984]  unhash_delegation_locked+0x39/0xa0 [nfsd]
[1388051.960631]  laundromat_main+0x235/0x5a0 [nfsd]
[1388051.961234]  process_one_work+0x1fd/0x3f0
[1388051.961803]  worker_thread+0x34/0x410
[1388051.962281]  kthread+0x121/0x140
[1388051.962698]  ? process_one_work+0x3f0/0x3f0
[1388051.963210]  ? kthread_park+0xb0/0xb0
[1388051.963690]  ret_from_fork+0x22/0x40
....

In the link below you'll find what has been captured from the console.

https://pastebin.com/raw/CdpMfUAK

I couldn't really find any reference to this in the mailing list
history so I assume we might have hit a bug that is unknown so far.

Best regards,
Doma

Re: Kernel panic in laundromat_main on 5.3.0-46-generic (Ubuntu HWE)

[sea you]

After upgrading the kernel to 5.4.0-39-generic, the very same happened again.
You could find more information here on LaunchPad
https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe/+bug/1885265

Anyone else experienced this? This definitely looks like a bug to me
at this point.

On Thu, May 14, 2020 at 12:26 PM sea you <seayou@gmail.com> wrote:
>
> Hi all,
>
> Today we've seen a kernel panic that looks like related to delegations
> and laundromat
>
> ...
> [1388051.959652] Call Trace:
> [1388051.959984]  unhash_delegation_locked+0x39/0xa0 [nfsd]
> [1388051.960631]  laundromat_main+0x235/0x5a0 [nfsd]
> [1388051.961234]  process_one_work+0x1fd/0x3f0
> [1388051.961803]  worker_thread+0x34/0x410
> [1388051.962281]  kthread+0x121/0x140
> [1388051.962698]  ? process_one_work+0x3f0/0x3f0
> [1388051.963210]  ? kthread_park+0xb0/0xb0
> [1388051.963690]  ret_from_fork+0x22/0x40
> ....
>
> In the link below you'll find what has been captured from the console.
>
> https://pastebin.com/raw/CdpMfUAK
>
> I couldn't really find any reference to this in the mailing list
> history so I assume we might have hit a bug that is unknown so far.
>
> Best regards,
> Doma

Re: Kernel panic in laundromat_main on 5.3.0-46-generic (Ubuntu HWE)

[Chuck Lever]

Hi-

> On Aug 12, 2020, at 5:24 AM, sea you <seayou@gmail.com> wrote:
> 
> After upgrading the kernel to 5.4.0-39-generic, the very same happened again.
> You could find more information here on LaunchPad
> https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe/+bug/1885265
> 
> Anyone else experienced this? This definitely looks like a bug to me
> at this point.

Thanks for the bug report.

This appears to be a distributor's kernel and ZFS (which is an out-
of-tree filesystem) is the backend.

The distributor will have to drill down on this issue with a recent
upstream kernel and a native filesystem to demonstrate we have an
upstream bug.


> On Thu, May 14, 2020 at 12:26 PM sea you <seayou@gmail.com> wrote:
>> 
>> Hi all,
>> 
>> Today we've seen a kernel panic that looks like related to delegations
>> and laundromat
>> 
>> ...
>> [1388051.959652] Call Trace:
>> [1388051.959984]  unhash_delegation_locked+0x39/0xa0 [nfsd]
>> [1388051.960631]  laundromat_main+0x235/0x5a0 [nfsd]
>> [1388051.961234]  process_one_work+0x1fd/0x3f0
>> [1388051.961803]  worker_thread+0x34/0x410
>> [1388051.962281]  kthread+0x121/0x140
>> [1388051.962698]  ? process_one_work+0x3f0/0x3f0
>> [1388051.963210]  ? kthread_park+0xb0/0xb0
>> [1388051.963690]  ret_from_fork+0x22/0x40
>> ....
>> 
>> In the link below you'll find what has been captured from the console.
>> 
>> https://pastebin.com/raw/CdpMfUAK
>> 
>> I couldn't really find any reference to this in the mailing list
>> history so I assume we might have hit a bug that is unknown so far.
>> 
>> Best regards,
>> Doma

--
Chuck Lever