Re: Non-GPL export of invalidate_mmap_range

David Weinehall
2004-02-19T09:11:32Z

On Wed, Feb 18, 2004 at 02:51:32PM -0800, Andrew Morton wrote:
> Christoph Hellwig <hch@infradead.org> wrote:
> >
> > I don't understand why IBM is pushing this dubious change right now,
>
> It isn't a dubious change, on technical grounds. It is reasonable for a
> distributed filesystem to want to be able to shoot down pte's which map
> sections of pagecache. Just as it is reasonable for the filesystem to be
> able to shoot down the pagecache itself.
>
> We've exported much lower-level stuff than this, because some in-kernel
> module happened to use it.

Probably not always the right choice, though... I highly suspect we
far to much of our intestines are easily available.

[snip]

> We need to give Paul a reasoned and logically consistent answer to his
> request. For that we need to establish some sort of framework against
> which to make a decision and then make the decision.
>
> One approach is a fait-accomplis from the top-level maintainer. Here,
> we're trying to do it in a different way.
>
> I have proposed two criteria upon which this should be judged:
>
> a) Does the export make technical sense? Do filesystems have
> legitimate need for access to this symbol?
>
> (really, a) is sufficient grounds, but for real-world reasons:)
>
> b) Does the IBM filsystem meet the kernel's licensing requirements?
>
>
> It appears that the answers are a): yes and b) probably.

a.) Definitely
b.) Perhaps

> Please, feel free to add additional criteria. We could also ask "do we
> want to withhold this symbols to encourage IBM to GPL the filesystem" or
> "do we simply refuse to export any symbol which is not used by any GPL
> software" (if so, why?). Over to you.

Well, I wasn't altogether joking when I suggested IBM should GPL gpfs.
A couple of questions:

* Is gpfs a commercial product in the sense that it's something IBM
earns revenue from?
* Does gpfs contain third party "Intellectual Property" (no, I'm not
particularly fond of using that expression, but I digress)

If the answer is NO to both of these questions, why _not_ GPL the code?
If the answer is NO to only the second question, is the revenue from
gpfs big enough to warrant keeping it proprietary?

> But at the end of the day, if we decide to not export this symbol, we owe
> Paul a good, solid reason, yes?

Yup. Silence isn't always golden, sometimes it's outright shitty.

Regards: David Weinehall
--
/) David Weinehall <tao@acc.umu.se> /) Northern lights wander (\
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