Re: @HCV - I don't quite get your point
I hope you agree with me that Canonical is naive to think they can commit this violation and get away with it. Oracle's lawyers will tear them into pieces.
Nope, you've got the wrong end of the stick entirely. Oracle don't and won't give a damn. They didn't when FreeBSD incorporated ZFS, and they won't here.
No, it's the GPListas and the kernel devs who may get cross, but Canonical's lawyers think that they have no reason to do so. The trouble lies partly in the fact that GPL2 has not really been tested conclusively in a court case in this area.
Anyway the whole thing is nuts, and it's only the foamy mouthed zealots who care. ZFS is a fine bit of code that everyone wants to use, and it is open source.
The Linux crowd's normal response to this sort of problem is to reproduce the software; they did this with DTRACE, creating FTRACE. However they have failed to reproduce ZFS satisfactorily. The ongoing lack of ZFS or a decent reproduction of it in Linux is making Linux look bad.
I think Canonical are being quite brave and are trying to move Linux on for the benefit of all. We should applaud that. Incorporating ZFS will not harm anyone or make any existing or future code more or less open. There's loads of people who are compiling their own ZFS.ko anyway, and obstructing Canonical would be peevishness itself.
Personally I think that the clauses in GPL2 that force GPL2 onto derivative works have become a big obstacle to progress. If they were updated to permit use of other acceptable open source licenses too then there'd be no real problems. The GPL2 is just words, not a sacrosanct document that mere mortals cannot change.
The same goes for any other restrictive document such as the US constitution and magna carta, both of which have been amended and or partly repealed. Good grief, if even US politicians can occasionally agree on amending the constitution, how bad does that make the GPListas look?