Re: consolidate btrfs checksumming, repair and bio splitting

[Chris Mason <clm@meta.com>]

On 10/31/22 8:19 AM, David Sterba wrote:
> On Wed, Oct 26, 2022 at 07:41:45AM -0400, Steven Rostedt wrote:
>> On Wed, 26 Oct 2022 07:36:45 +0000
>> Johannes Thumshirn <Johannes.Thumshirn@wdc.com> wrote:
>>> On 24.10.22 19:11, David Sterba wrote:
>>>> On Mon, Oct 24, 2022 at 11:25:04AM -0400, Chris Mason wrote:
>>>>> On 10/24/22 10:44 AM, Christoph Hellwig wrote:
>>>>>> On Mon, Oct 24, 2022 at 08:12:29AM +0000, Johannes Thumshirn wrote:
>>>>>>> David, what's your plan to progress with this series?
>>>>>>
>>>>>> FYI, I object to merging any of my code into btrfs without a proper
>>>>>> copyright notice, and I also need to find some time to remove my
>>>>>> previous significant changes given that the btrfs maintainer
>>>>>> refuses to take the proper and legally required copyright notice.
>>>>>>
>>>>>> So don't waste any of your time on this.
>>>>>
>>>>> Christoph's request is well within the norms for the kernel, given that
>>>>> he's making substantial changes to these files.  I talked this over with
>>>>> GregKH, who pointed me at:
>>>>>
>>>>>
>>>>> Even if we'd taken up some of the other policies suggested by this doc,
>>>>> I'd still defer to preferences of developers who have made significant
>>>>> changes.
>>>>
>>>> I've asked for recommendations or best practice similar to the SPDX
>>>> process. Something that TAB can acknowledge and that is perhaps also
>>>> consulted with lawyers. And understood within the linux project,
>>>> not just that some dudes have an argument because it's all clear as mud
>>>> and people are used to do things differently.
>>>>
>>>> The link from linux foundation blog is nice but unless this is codified
>>>> into the process it's just somebody's blog post. Also there's a paragraph
>>>> about "Why not list every copyright holder?" that covers several points
>>>> why I don't want to do that.
>>>>
>>>> But, if TAB says so I will do, perhaps spending hours of unproductive
>>>> time looking up the whole history of contributors and adding year, name,
>>>> company whatever to files.
>>
>> There's no requirement to list every copyright holder, as most developers do
>> not require it for acceptance. The issue I see here is that there's someone
>> that does require it for you to accept their code.
> 
> That this time it is a hard requirement is a first occurrence for me
> acting as maintainer. In past years we had new code and I asked if the
> notice needs to be there and asked for resend without it. The reason is
> that we have git and complete change history, but that is apparently not
> sufficient for everybody.
> 
>> The policy is simple. If someone requires a copyright notice for their
>> code, you simply add it, or do not take their code. You can be specific
>> about what that code is that is copyrighted. Perhaps just around the code in
>> question or a description at the top.
> 
> Let's say it's OK for substantial amount of code. What if somebody
> moves existing code that he did not write to a new file and adds a
> copyright notice? We got stuck there, both sides have different answer.
> I see it at minimum as unfair to the original code authors if not
> completely wrong because it could appear as "stealing" ownership.

One option is to add a copyright line as suggested by the
LF blog post "Copyright The Btrfs Contributors", and to make it clear
the original authors of the old file are welcome to send patches
if they feel it is required.

> 
>> Looking over the thread, I'm still confused at what the issue is. Is it
>> that if you add one copyright notice you must do it for everyone else? Is
>> everyone else asking for it? If not, just add the one and be done with it.
> 
> My motivation is to be fair to all contributors and stick to the project
> standards (ideally defined in process). Adding a copyright notice after
> several years of not taking them would rightfully raise questions from
> past and current contributors what would deserve to be mentioned as
> copyright holders.
> 
> This leaves me with 'all or nothing', where 'all' means to add the
> notices where applicable and we can continue perhaps with more
> contributions in the future. But that'll cost time and inventing how to
> do it so everybody is satisfied with the result.

Everyone understands that you're trying to be fair, and I'm sure our
major contributors are happy to help.  I think the most reasonable
path forward is to add the blanket Btrfs Contributor copyright line
above and be open to additional lines for major changes (past or
present).

I'm definitely not suggesting that you (or anyone else) sit down with
git history and try to determine the perfect set of copyright lines for
past contributions.  It's just not required at all.

-chris