Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 30 Nov 2018 05:14:41 -0500
From:   Sasha Levin <sashal@kernel.org>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     Dave Chinner <david@fromorbit.com>, stable@vger.kernel.org,
        linux-kernel@vger.kernel.org, Dave Chinner <dchinner@redhat.com>,
        "Darrick J . Wong" <darrick.wong@oracle.com>,
        linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH AUTOSEL 4.14 25/35] iomap: sub-block dio needs to zeroout
 beyond EOF
Message-ID: <20181130101441.GA213156@sasha-vm>
References: <20181129060110.159878-1-sashal@kernel.org>
 <20181129060110.159878-25-sashal@kernel.org>
 <20181129121458.GK19305@dastard>
 <20181129124756.GA25945@kroah.com>
 <20181129224019.GM19305@dastard>
 <20181130082203.GA26830@kroah.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Disposition: inline
In-Reply-To: <20181130082203.GA26830@kroah.com>
User-Agent: Mutt/1.9.4 (2018-02-28)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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