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>They don't need to merge it into the kernel though. Then could you explain what this commit is: http://kernel.ubuntu.com/git/ubuntu/ubuntu-xenial.git/commit/

>They don't need to merge it into the kernel though. Then could you explain what this commit is: http://kernel.ubuntu.com/git/ubuntu/ubuntu-xenial.git/commit/zfs?id=b65ce14d3445e8fe69b5d59aaaf2699319714179 http://kernel.ubuntu.com/git/ubuntu/ubuntu-xenial.git/commit... Canonical cannot ship ZFS in binary form. Kernel modules are derivative works of the kernel, and thus they must be distributed under GPLv2.

ryao 11y ago
A user editing the wiki posted incorrect information that he inferred from the use of DKMS. It happens.
2trill2spill 11y ago
ZFS is not a derivative work of the Linux kernel seeing as it was developed on Solaris and later Illumos.
- davexunit 11y ago
  ZFS on Linux doesn't work unless it's linked against interfaces provided by Linux. This is a derivative work, and thus the combined work must be distributed under GPLv2.
  - shmerl 11y ago
    GPL doesn't stop you from linking post installation. See http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue
  - jamespo 11y ago
    Userland software doesn't work unless it can use system calls provided by the Linux kernel either.
    - mjg59 11y ago
      The kernel copyright file expressly states that using the standard system call interface does not create a derivative work. There is no such statement about in-kernel symbols.
      - ryao 11y ago
        > The kernel copyright file expressly states that using the standard system call interface does not create a derivative work. There is no such statement about in-kernel symbols. There is no legal precedent suggesting that was actually necessary either. Or are you aware of a court case
      - prutschman 11y ago
        That's a good assurance that would probably estop a Linux copyright holder from later claiming that a binary using only the system call interface is an infringing derivative work. It doesn't have the power to define a binary module using an internal interface as a derivative work; that can only be done by a court interpreting copyright law in a particular jurisdiction. In the United States, different Federal Circuit courts have different views of what constitutes a derivative work in software.
  - ryao 11y ago
    Linking does not matter for the GPL. What matters it he legal concept of a derivative work. It just so happens that linking to a dynamic library bears a strong resemblance to a derivative work. LKMs and plugins in general are an entirely different matter. GPL software that supports plugins implicitly allows proprietary software to be loaded into it. That is why the FSF had been opposed to allowing plugins in GCC for years until competition from Clang required that they become more tolerant or face irrelevance. That being said, would anyone who believes this "linking to the kernel" argument please explain what linking actually means and how it is related to the GPL when the term "link" is not even present in the GPL?
  - ryao 11y ago
    Kernel modules are not derivative works of the kernel under copyright law (which was originally designed around literary works). Some might argue that kernel modules that were developed on Linux are, but ZFS itself is ported from another platform, so that is a moot point. The only case where you cannot distribute ZFS is if you link it into the vmlinux binary that your bootloader loads. In that case, it is no longer a LKM and you can claim the binary is a derived work of Linux. That is what I believe shmeri meant.
shmerl 11y ago
> Canonical cannot ship ZFS in binary form. Building kernel module on the fly when deploying ZFS is an acceptable workaround. I think that's exactly how it was planned to be used in Debian. I really have no clue what Canonical are planning though.

ryao 11y ago

A user editing the wiki posted incorrect information that he inferred from the use of DKMS. It happens.

2trill2spill 11y ago

ZFS is not a derivative work of the Linux kernel seeing as it was developed on Solaris and later Illumos.

davexunit 11y ago
ZFS on Linux doesn't work unless it's linked against interfaces provided by Linux. This is a derivative work, and thus the combined work must be distributed under GPLv2.
- shmerl 11y ago
  GPL doesn't stop you from linking post installation. See http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue
- jamespo 11y ago
  Userland software doesn't work unless it can use system calls provided by the Linux kernel either.
  - mjg59 11y ago
    The kernel copyright file expressly states that using the standard system call interface does not create a derivative work. There is no such statement about in-kernel symbols.
    - ryao 11y ago
      > The kernel copyright file expressly states that using the standard system call interface does not create a derivative work. There is no such statement about in-kernel symbols. There is no legal precedent suggesting that was actually necessary either. Or are you aware of a court case
    - prutschman 11y ago
      That's a good assurance that would probably estop a Linux copyright holder from later claiming that a binary using only the system call interface is an infringing derivative work. It doesn't have the power to define a binary module using an internal interface as a derivative work; that can only be done by a court interpreting copyright law in a particular jurisdiction. In the United States, different Federal Circuit courts have different views of what constitutes a derivative work in software.
- ryao 11y ago
  Linking does not matter for the GPL. What matters it he legal concept of a derivative work. It just so happens that linking to a dynamic library bears a strong resemblance to a derivative work. LKMs and plugins in general are an entirely different matter. GPL software that supports plugins implicitly allows proprietary software to be loaded into it. That is why the FSF had been opposed to allowing plugins in GCC for years until competition from Clang required that they become more tolerant or face irrelevance. That being said, would anyone who believes this "linking to the kernel" argument please explain what linking actually means and how it is related to the GPL when the term "link" is not even present in the GPL?
- ryao 11y ago
  Kernel modules are not derivative works of the kernel under copyright law (which was originally designed around literary works). Some might argue that kernel modules that were developed on Linux are, but ZFS itself is ported from another platform, so that is a moot point. The only case where you cannot distribute ZFS is if you link it into the vmlinux binary that your bootloader loads. In that case, it is no longer a LKM and you can claim the binary is a derived work of Linux. That is what I believe shmeri meant.

shmerl 11y ago

> Canonical cannot ship ZFS in binary form. Building kernel module on the fly when deploying ZFS is an acceptable workaround. I think that's exactly how it was planned to be used in Debian. I really have no clue what Canonical are planning though.