Linus Torvalds warned developers not to use the module for the ZFS file system designed by Sun Microsystems - and now owned by Oracle - due to licensing issues.
As it became known, Torvalds warned kernel developers against using ZFS in Linux, an OpenZFS application, and refuses to merge any ZFS code until Oracle changes its open source license.
ZFS is licensed under the Sun Common Development and Distribution License (CDDL), unlike the Linux kernel, licensed under the GNU General Public License (GPL).
Torvalds expressed his opinion in response to a developer who argued that a recent change to the kernel "destroyed one important module: the ZFS".
Linux kernel maker refuses to merge ZFS to core because it can't risk a lawsuit from Oracle - which is still trying to sue Google for copyright infringement when using Java APIs on Android - and Torvalds it won't do anything until Oracle founder Larry Ellison signs off on its use of Linux.
"If someone adds a kernel unit like ZFS, it works entirely on its own initiative, I can't maintain it and I can't commit to other people's kernel changes," Torvalds explained.
"And frankly, there is no way I can merge some of the ZFS versions until I get a formal letter from Oracle signed by its chief legal officer or preferably by Larry Ellison himself who says it is legal to do so. do and deal with the end result as a GPL product, ”continued Torvalds.
"Others believe it may be right to merge the ZFS code into the Kernel and that is their decision. But given the controversial nature of Oracle and licensing questions, there is no way I can feel safe with it. "
The problem of licensing is explained by the developers of ZFS on Linux.
“While both are open source licenses, they are restrictive licenses. Their combination causes problems because it prevents the use of exclusively licensed code segments, with code segments exclusively available from another license for the same system, "ZFS developers write.
"In the case of the kernel, this prevents us from distributing ZFS to Linux as part of the kernel. However, there is nothing mentioned in any license preventing it from being distributed in the form of a module or source code. "
Torvalds also referred to this issue in his response and rejected the idea of a proposed layer separating ZFS to address problems that combine two projects with different licenses, notably because of the copyright lawsuit of Oracle's Java API.
"And I have no interest in separating ZFS," Torvalds replied, as some seem to be thinking of isolating the two projects. That doesn't add any value to us, and given Oracle's intellectual property rights, I don't think it's a real licensing win, ”he explained.
His final words on this issue are as follows: “Do not use ZFS. It is so simple. It has always been a project that has caused issues and complications and licensing issues just make it useless. "