NFSv4 stuck

[Russell L. Carter]

On 01/12/17 16:08, Rick Macklem wrote:
> Slawa Olhovchenkov wrote:
>
>> On Thu, Jan 12, 2017 at 01:13:58PM +0700, Eugene Grosbein wrote:
>>
>>> 12.01.2017 6:50, Slawa Olhovchenkov пишет:
>>>> On Wed, Jan 11, 2017 at 03:20:22PM -0800, Michael Sinatra wrote:
>>>>
>>>>> On 01/11/17 14:59, Slawa Olhovchenkov wrote:
>>>>>> On Wed, Jan 11, 2017 at 10:39:42PM +0000, Rick Macklem wrote:
>>>>>>
>>>>>>> "umount -f" is your only chance. However, if there is already a non-forced
>>>>>>> dismount stuck, it won't work because the non-forced dismount will have
>>>>>>> the mounted-on vnode locked.
>>>>>>
>>>>>> I am use 'intr,soft' flags -- why ignored?
>>>>>
>>>>> intr and soft are considered dangerous with nfsv4.  See the "BUGS"
>>>>> section of the mount_nfs(8) man page.
>>>>
>>>> Currently I am see dangerous w/o intr: system need reboot, application
>>>> don't killable.
>>>
>>> NFSv4 confiders "intr,soft" dangerous for data generated by poorly written applications, not for a OS.
>>
>> What data? In may case no data.
> Certain NFSv4 operations (such as open and byte range locking) are strictly ordered using a
> seqid#. If you fail an RPC in progress (via a soft timeout or intr via a signal) then this seqid gets
> out of sync between client and server and your mount is badly broken.
>
> I do not believe this caused your hang though, since processes were sleeping on rpccon, which
> means they were trying to do a new TCP connection to the server unsuccessfully.
> - Which normally indicates a problem with your underlying network fabric.
> stuff snipped...

FWIW I see this hang too, requiring a hard reset of the power to
get the server to reboot.  I learned the hard way about umount -f.
Modestly annoying when you reboot the package server and then
forget to umount -f && mount package server, and *then* do
'pkg install some-package'

My linux clients don't have this problem.

This is on 11/stable

Russell



> rick
>
> _______________________________________________
> freebsd-net at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-net
> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>