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Comment by shawnz

6 years ago

Linus' reasons for not integrating ZFS are absolutely valid and it's no doubt that ZFS can never be included in the mainline kernel. There's absolutely no debate there.

However the person he is replying to was not actually asking to have ZFS included in the mainline kernel. As noted above, that could never happen, and I believe that Linus is only bringing it up to deflect from the real issue. What they were actually asking is for Linux to revert a change that was made for no other reason than to hinder the use of ZFS.

Linux includes a system which restricts what APIs are available to each module based on the license of the module. GPL modules get the full set of APIs whereas non-GPL modules get a reduced set. This is done strictly for political reasons and has no known legal basis as far as I'm aware.

Not too long ago a change was made to reduce the visibility of a certain API required by ZFS so only GPL modules could use it. It's not clear why the change was made, but it was certainly not to improve the functionality of the kernel in any way. So the only plausible explanation to me is that it was done just to hinder the use of ZFS with Linux, which has been a hot political issue for some time now.

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shawnz

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throwaway6779  6 years ago

If I remember correctly, the reasoning for the GPL module stuff was/is, that if kernel modules integrate deeply with the kernel, they fall under gpl. So the GPL flag is basically a guideline of what kernel developers believe is safe to use from non gpl-compatible modules

  • Dylan16807  6 years ago

    But from what I can see, marking the "save SIMD registers" function as GPL is a blatant lie by a kernel developer that wanted to spite certain modules.

    Saving and restoring registers is an astoundingly generic function. If you list all the kernel exports and sort by how much they make your work derivative, it should be near the very bottom.

    • vetinari  6 years ago

      You are not supposed to use FP/SSE in kernel mode.

      It was always frowned upon:

      > In other words: it's still very much a special case, and if the question was "can I just use FP in the kernel" then the answer is still a resounding NO, since other architectures may not support it AT ALL.

      > Linus Torvalds, 2003

      and these specific functions, that were marked as GPL were already deprecated for well over a decade.

      4 replies →

  • shawnz  6 years ago

    This is the commonly recited argument but I don't believe it was ever proven to be legally necessary. Furthermore, even if it was, it's not clear what level of integration is "too deep". So in practice, it's just a way for kernel developers to add political restrictions as they see fit.

    • HorstG  6 years ago

      "Proven" is a maybe impossible standard: Kernel devs hint at the GPLonly exports having been useful in certain cases they prefer not to discuss on a ML. https://lore.kernel.org/lkml/20190110131132.GC20217@kroah.co...

      One can interpret this as something legally significant, or an embarrassing private anecdote, or nothing substantial at all, maybe even just talk. However, I'd give them the benefit of the doubt. Not the least since they could be the ones against Oracle's legal dept...

      1 reply →

    • teddyuk  6 years ago

      Surely the kernel developers can do whatever the hell they like.

      If you don’t like that don’t use it.

supercanuck  6 years ago

>This is done strictly for political reasons and has no known legal basis as far as I'm aware.

let me stop you right there. This being "Oracle," and its litigious nature, how can you truly be aware or sure?

Linus is literally saying there is a legal basis.

  • shawnz  6 years ago

    > This being "Oracle," and its litigious nature, how can you truly be aware or sure?

    The functionality I'm describing has absolutely nothing to do with ZFS or Oracle in any way. If you really think the reach of Oracle is so great, then why not block all Oracle code from ever running on the OS? That seems to me to be just as justified as this change.