Linus on GPLv3 and ZFS

Posted Jun 12, 2007 18:27 UTC (Tue) by arcticwolf (guest, #8341)
In reply to: Linus on GPLv3 and ZFS by JoeBuck
Parent article: Linus on GPLv3 and ZFS

How would a dual-licensed Linux help, though? If you go that route, you still can't port things like ZFS, since that'd be - if it's GPL'ed at all - GPLv3 only. So the only way to port it would be to essentially split Linux into a GPLv2 version and a GPLv3 version; and given that there'd likely be code (old or new) that would be GPLv2 only, the latter would not even be a superset of the former.

So as long as Linu(x|s) doesn't go GPLv3, period, there would really be no way to make code flow from Solaris to Linux, and in fact, a dual-licensed version of Linux with an "official", integrated GPLv3 branch would actually make it easier for Sun to pull in code from Linux.

But then, maybe Linus is just a strategic genius, too - maybe all his vocal opposition to the GPLv3 is just a clever ploy to lull Sun into a false sense of security, and once they've released Solaris and/or ZFS under the GPLv3, he'll just switch over as well[1] and reach the rewards. ;)

1. Yeah, I know, he can't just do that, but for the sake of the joke, let's pretend he can.

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Linus on GPLv3 and ZFS

Posted Jun 12, 2007 18:52 UTC (Tue) by ajross (guest, #4563) [Link] (8 responses)

The v2 and v3 GPL variants are explicitly compatible with each other in both directions. So there's no reason the kernel couldn't simply ship different parts of the tree under different licenses. No fork would be required except in the case where someone wanted to put together a "GPL2 only" distribution for some reason.

Linus on GPLv3 and ZFS

Posted Jun 12, 2007 19:23 UTC (Tue) by dlang (guest, #313) [Link] (7 responses)

GPLv2 and GPLv3 are not compatible in either direction

the only thing that lets GPLv2 code change to GPLv3 is if people gave the FSF a blank check and said 'GPLv2 or later'

Linus on GPLv3 and ZFS

Posted Jun 12, 2007 21:04 UTC (Tue) by man_ls (guest, #15091) [Link] (6 responses)

True:

When we say that GPLv2 and GPLv3 are incompatible, it means there is no legal way to combine code under GPLv2 with code under GPLv3 in a single program. This is because both GPLv2 and GPLv3 are copyleft licenses: each of them says, If you include code under this license in a larger program, the larger program must be under this license too. There is no way to make them compatible.

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 8:20 UTC (Wed) by forthy (guest, #1525) [Link] (5 responses)

The FSF took great efforts that GPL versions can be made compatible. The paragraph that deals with it is section 9 of the GPL. Read it, especially the last part - many files in the Linux kernel are not explicitely restricted to a specific GPL versions, which means "any version". And section 6 makes sure that everybody receives a license from the original licensor, not from a compilation editor like Linus Torvalds.

The compilation editor (Linus Torvalds) can set terms under which he redistributes the work, i.e. conditions he has to follow. But since everybody receives the license from the original licensors, this "restriction" is null and void, you still can make a compilation yourself which does not restrict the license version, and then, most parts of Linux are compatible with GPLv3 (because you can either choose any GPL or explicitely v2 or later).

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 9:37 UTC (Wed) by man_ls (guest, #15091) [Link] (4 responses)

That kind of compatibility is not much help, unless all of the kernel is licensed as "v2 or later". As long as there is a single file licensed under "v2 only", it becomes impossible to link with a single "v3 only" file.

Meanwhile, relicensing all files under a "v2 or later" license might seem to be a necessary first step to a GPLv3 kernel. But given Linus' reluctance to blanket license, I would rather expect a "dual v2-v3" license, if the migration is to be done at all.

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 13:09 UTC (Wed) by job (guest, #670) [Link] (3 responses)

Maaaybe there was a good reason why the FSF recommended the use of "v2 or later" licensing. Then you basically leave the choice to the user. I never understood what Linus didn't like about that, except some unspecified fear of the FSF, which would be not only ridicolous but also unfortunate.

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 13:36 UTC (Wed) by man_ls (guest, #15091) [Link] (1 responses)

It is not so unreasonable: Linus said:

How can you _ever_ sign anything sight unseen? That's just stupid, and that's totally regardless of any worries about the FSF.

Said that way, it looks like the correct thing to do. However, given that (as you say) "v2 or later" licensing gives the choice to the user, I'm not particularly worried about misuse.

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 21:56 UTC (Wed) by notamisfit (guest, #40886) [Link]

It creates the possibility that code created in a downstream work may not be usable upstream. Linus has put his cards on the table in the past; he wants code back.

Linus on GPLv3 and ZFS

Posted Jun 14, 2007 1:59 UTC (Thu) by error27 (subscriber, #8346) [Link]

Instead of "ridiculous and unfortunate" I would say "justified by current events."

Linus on GPLv3 and ZFS

Posted Jun 12, 2007 19:06 UTC (Tue) by proski (guest, #104) [Link] (3 responses)

We could also theorize that Linus is hinting at the possibility of switching Linux to GPLv3 to dissuade Sun from releasing ZFS under GPLv3.

But why would not Linus want ZFS in the kernel? The history of Linux shows that reimplemented code is more successful that ported code. XFS and JFS are rarely used, whereas ext2 and ext3 are wildly popular.

Patent issues: GPLv3 and ZFS

Posted Jun 12, 2007 19:30 UTC (Tue) by dwheeler (guest, #1216) [Link] (1 responses)

Patent issues. If Sun releases ZFS under GPLv3, ZFS is patented, and its patents on ZFS are valid, then anyone else using GPLv3 can use ZFS. They can even "bring in" the GPLv3 code and completely rewrite it, so the IMPLEMENTATION may be different but they'd still be okay legally (I think). Using GPLv2 wouldn't give them access to patents released only under GPLv3.

Patent issues: GPLv3 and ZFS

Posted Jun 12, 2007 20:01 UTC (Tue) by atai (subscriber, #10977) [Link]

One would expect Sun already considered this aspect already assuming Sun will release OpenSolaris under the GPL v3.

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 1:48 UTC (Wed) by wolfrider (guest, #3105) [Link]

> JFS [is] rarely used

--Depends on who you ask. I use JFS now almost exclusively for Vmware and "bkps" (read: large) filesystems, where before I would use ReiserfsV3 with notail.

--After seeing how fast (and reliable) JFS is, I switched almost all my Reiser filesystems over to it - and have been much happier. Reiser is great for root and squid (tail-packing) but not ideal when you're trying to run a VM from a USB2 IDE drive. JFS makes it usable.

Linus on GPLv3 and ZFS

Posted Jun 12, 2007 20:43 UTC (Tue) by JoeBuck (guest, #2330) [Link] (3 responses)

If all of the kernel code were GPLv2 || GPLv3, it could be combined with a GPLv3 ZFS. The collection as a whole would be GPLv3 only if ZFS were added, but ZFS could be a module, and everything would be legal, while embedded software developers who want to do DRM could still use the rest of Linux (except ZFS).

Linus on GPLv3 and ZFS

Posted Jun 12, 2007 22:28 UTC (Tue) by cyperpunks (subscriber, #39406) [Link] (2 responses)

Linus is right, Sun don't want Linux source code, they want Linux' kernel hackers (and
then later Linux' users).

Of course CDDL is hopeless is this regard as hackers must transfer copyright to Sun, who
want to do that?

Sun have to fix the bootstrap problem too: it's now not possible to build a complete
free Solaris "distribution". You must use some non free Sun tools at some point.

Who wants to contribute to project you can't build yourself?

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 0:00 UTC (Wed) by JoeBuck (guest, #2330) [Link]

To be fair, Sun's launching a project, called "Indiana", to correct that deficiency and produce something that would resemble a GNU/Linux distribution. It will take them some time to do it, but I'm looking forward to it.

Linus on GPLv3 and ZFS

Posted Jun 13, 2007 12:36 UTC (Wed) by paulj (subscriber, #341) [Link]

Of course CDDL is hopeless is this regard as hackers must transfer copyright to Sun, who want to do that?

This is false.

You need to sign a contributors agreement with Sun, granting Sun joint ownership, if you wish to have Sun incorporate any contribution to various open-source projects which Sun founded and maintain (such as OpenSolaris, amongst other projects).

However the CDDL does not require any copyright transfership, and you're quite free to take and hack away on CDDLed code, like OpenSolaris, without giving copyright ownership to Sun or anyone else.