There is no 'modern' ZFS-like fs in Linux nowadays.
I obviously have nothing like inside knowledge, but I assume the reason there have not been lawsuits over this, is that whoever could bring one (would it be only Oracle?) expects there are even-odds that they would lose? Thus the risk of setting an adverse precedent isn't worth the damages they might be awarded from suing Canonical?
But Sun ensured that they can only gnash their teeth.
The source of "license incompatibility" btw is the same as from using GPLv3 code in kernel - CDDL adds an extra restriction in form of patent protections (just like Apache 2)
I am not a lawyer.
My understanding is that Canonical is shipping ZFS with Ubuntu. Or do I misunderstand? Has Canonical not actually done the big, bad thing of distributing the Linux kernel with ZFS? Did they find some clever just-so workaround so as to technically not be violation of the Linux kernel's license terms?
Otherwise, if Canonical has actually done the big, bad thing, who has standing to bring suit? Would the Linux Foundation sue Canonical, or would Oracle?
I ask this in all humility, and I suspect there is a chance that my questions are nonsense and I don't know enough to know why.
Yes. Oracle have that copyright.
That's the whole fucking point.
Anything from before the fork is still licensed (and pretty much everything after) is still under the CDDL which is possibly in conflict with the GPL.
It would be an interesting lawsuit as the judge might well ask why as copyright holder of ZFS they can't solve the problem they are suing over. But I think you underestimate the deviousness of oracle's legal dept.
The CDDL being unacceptable is the same issue that GPL3 or Apache is unacceptable - unlike GPLv2, CDDL mandates patent licensing as far as the code is considered.
Additionally, GPLv2 does not prevent shipping ZFS combined with GPL code, because CDDL code is not derivative work of GPLv2 code. So it's legal to ship.
It could be problematic to upstream, because kernel development would demand streamlining to the point that the code would be derivative.
Additionally, two or three kernel contributors decided that the long standing consensus on derivative work is not correct and sued Canonical. So far nothing happened out of that, Los Alamos National Laboratory also laughed it off.
Venue shopping being what it is, though...
* read-only and minimal
* fully aware of different Linux boot environments
* GPLv3 license compatible, clean-room implementation by the OpenSolaris/Illumos team. The implementation predates Ubuntu’s interest.The CDDL code is not a derivative work of GPLv2 code, but the combined work as a whole is a derivative work of GPLv2 code (assuming by "combined" we are talking about shipping an executable made by compiling and linking GPLv2 and CDDL code together). Shipping that work does require permission from both the GPLv2 code copyright owners and the CDDL code copyright owners unless the code from on or the other can be justified under fair use or if it was a part of the GPLv2 or CDDL code that is not subject to copyright.
What Canonical does is ship ZFS as a kernel module. That contains minimal GPLv2 code from the kernel that should be justifiable as fair use (which seems like a decent bet after the Oracle vs Google case).
The CDDL-only parts of the driver are portable between OSes, removing the "derivative code" argument (similar argumentation goes back to introduction of AFS driver for Linux, IIRC).
Remember, GPLv2 does not talk about linking. Derivativeness is decided by source code, among other things whether or not the non-GPL code can't exist/operate without GPL code.
A lot of people focus on the fact that the CDDL allows binaries to be arbitrarily licensed so long as you provide the sources, but the issue is that the GPL requires that the source code of both combined and derived works be under the GPL and the CDDL requires that the source code be under the CDDL (i.e., the source code cannot be sublicensed). This means that (if you concluded that OpenZFS is a derived work of Linux or that it is a combined work when shipped as a kernel module) a combination may be a violation of both licenses.
However, the real question is whether a judge would look at two open source licenses that are incompatible due to a technicality and would conclude that Oracle is suffering actual harm (even though OpenZFS has decades of modifications from the Oracle version). They might also consider that Oracle themselves released DTrace (also under the CDDL) for their Linux distribution in 2012 as proof that Oracle doesn't consider it to be license violation either. If we did see Canonical get sued, maybe we'd finally be able to find out through discovery if the CDDL was intentionally designed to be GPL incompatible or not (a very contentious topic).
[1]: https://sfconservancy.org/blog/2016/feb/25/zfs-and-linux/
Unlike the GPL, the CDDL (and MPL) has an opt-out upgrade clause and all of OpenSolaris (or more accurately, almosf all software under the CDDL) can be upgraded to "CDDL-1.1 OR CDDL-2.0" unilaterally by Oracle even if they do not own the copyrights. See section 4 of the CDDL.
1) Making CDDL compatible with GPLv2 puts everyone using CDDL code at mercy of Oracle patents
2) OpenZFS is actually not required to upgrade, and the team has indicated they won't. So you end up with a fork you need to carry yourself. Might even force OpenZFS to ensure that it's specifically 1.0.
Ultimately it means Oracle can't do much with this.
1) They could just adapt MPL-2.0, which provides GPLv2+ compatibility while still providing the same patent grants.
2) The upgrade is chosen by downstream users. The OpenZFS project could ask individual contributiors to choose to license their future contributions differently but that will only affect future versions and isn't a single decision made by the project leads. I don't know in what context that discussion was in but given that the have not already opted-out of future CDDL versions kind of indicates that they can imagine future CDDL versions they would choose to upgrade to.
Also, OpenZFS is under CDDL-1.1 not 1.0.