Re: [PATCH AUTOSEL 4.14 25/35] iomap: sub-block dio needs to zeroout beyond EOF

Sasha Levin
2018-11-30T10:14:48Z

On Fri, Nov 30, 2018 at 09:22:03AM +0100, Greg KH wrote:
>On Fri, Nov 30, 2018 at 09:40:19AM +1100, Dave Chinner wrote:
>> I stopped my tests at 5 billion ops yesterday (i.e. 20 billion ops
>> aggregate) to focus on testing the copy_file_range() changes, but
>> Darrick's tests are still ongoing and have passed 40 billion ops in
>> aggregate over the past few days.
>>
>> The reason we are running these so long is that we've seen fsx data
>> corruption failures after 12+ hours of runtime and hundreds of
>> millions of ops. Hence the testing for backported fixes will need to
>> replicate these test runs across multiple configurations for
>> multiple days before we have any confidence that we've actually
>> fixed the data corruptions and not introduced any new ones.
>>
>> If you pull only a small subset of the fixes, the fsx will still
>> fail and we have no real way of actually verifying that there have
>> been no regression introduced by the backport. IOWs, there's a
>> /massive/ amount of QA needed for ensuring that these backports work
>> correctly.
>>
>> Right now the XFS developers don't have the time or resources
>> available to validate stable backports are correct and regression
>> fre because we are focussed on ensuring the upstream fixes we've
>> already made (and are still writing) are solid and reliable.
>
>Ok, that's fine, so users of XFS should wait until the 4.20 release
>before relying on it? :)

It's getting to the point that with the amount of known issues with XFS
on LTS kernels it makes sense to mark it as CONFIG_BROKEN.

>I understand your reluctance to want to backport anything, but it really
>feels like you are not even allowing for fixes that are "obviously
>right" to be backported either, even after they pass testing. Which
>isn't ok for your users.

Do the XFS maintainers expect users to always use the latest upstream
kernel?

--
Thanks,
Sasha