114 lines
4.7 KiB
Plaintext
114 lines
4.7 KiB
Plaintext
From: Chris Dunlap <cdunlap@llnl.gov>
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To: tak1@llnl.gov (James Tak)
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Cc: rogers11@llnl.gov (Leah Rogers), garlick@llnl.gov (Jim Garlick),
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mgary@llnl.gov (Mark Gary), kimcupps@llnl.gov (Kim Cupps)
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Date: Mon, 26 Mar 2007 15:37:07 -0700
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Subject: CDDL/GPL licensing issues for ZFS Linux port
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James,
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We want to port Sun's Zettabyte File System (ZFS) to Linux and
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ultimately redistribute the source code of our work. We've been
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talking with Leah about this and have a meeting scheduled with you
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for this coming Thursday at 2pm. I just wanted to give you a summary
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before the meeting of what we're proposing.
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ZFS is part of OpenSolaris which is licensed under the Common
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Development and Distribution License (CDDL):
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http://www.opensolaris.org/os/licensing/cddllicense.txt
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The Linux kernel is licensed under the GNU General Public License (GPL)
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(specifically, under version 2 of the license only):
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http://www.fsf.org/licensing/licenses/gpl.html
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While these are both Open-Source licenses, the Free Software Foundation
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(FSF) states they are incompatible with one another:
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http://www.fsf.org/licensing/licenses/index_html
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"[CDDL] is a free software license which is not a strong copyleft;
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it has some complex restrictions that make it incompatible with the
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GNU GPL. It requires that all attribution notices be maintained,
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while the GPL only requires certain types of notices. Also, it
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terminates in retaliation for certain aggressive uses of patents.
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So, a module covered by the GPL and a module covered by the CDDL
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cannot legally be linked together."
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As an aside, Sun is reportedly considering releasing OpenSolaris under
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GPL3 (i.e., the upcoming version 3 of the GNU General Public License):
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http://blogs.sun.com/jonathan/entry/hp_and_sun_partnering_around
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http://arstechnica.com/news.ars/post/20060130-6074.html
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http://news.com.com/Sun+considers+GPL+3+license+for+Solaris/2100-1016_3-6032893.html
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Since the GPL3 has not been finalized, it is unclear whether
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incompatibilities will exist between GPL2 and GPL3.
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Linus Torvalds (the original creator of Linux) describes his views
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on the licensing of Linux kernel modules in the following email thread:
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http://linuxmafia.com/faq/Kernel/proprietary-kernel-modules.html
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Most of this thread is in regards to proprietary closed-source
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binary-only modules for Linux. Linus generally considers modules
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written for Linux using the kernel infrastructures to be derived
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works of Linux, even if they don't copy any existing Linux code.
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However, he specifically singles out drivers and filesystems ported
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from other operating systems as not being derived works:
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"It would be rather preposterous to call the Andrew FileSystem a
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'derived work' of Linux, for example, so I think it's perfectly
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OK to have a AFS module, for example."
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"The original binary-only modules were for things that were
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pre-existing works of code, i.e., drivers and filesystems ported
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from other operating systems, which thus could clearly be argued
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to not be derived works..."
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Based on this, it seems our port of Sun's ZFS filesystem to Linux
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would not be considered a derived work of Linux, and therefore not
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covered by the GPL. The issue of the CDDL/GPL license incompatibility
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becomes moot. As such, we should be able to redistribute our changes
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to ZFS in source-code form licensed under the CDDL since this will
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be a derived work of the original ZFS code. There seems to be some
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dissent as to whether a binary module could be redistributed as well,
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but that issue does not concern us. In this instance, we are only
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interested in redistribution of our work in source-code form.
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-Chris
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To: Chris Dunlap <cdunlap@llnl.gov>
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From: James Tak <tak1@llnl.gov>
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Subject: Re: CDDL/GPL licensing issues for ZFS Linux port
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Cc: rogers11@llnl.gov (Leah Rogers), garlick@llnl.gov (Jim Garlick),
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mgary@llnl.gov (Mark Gary), kimcupps@llnl.gov (Kim Cupps)
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Date: Thu, 29 Mar 2007 14:53:01 -0700
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Hi Chris,
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As per our discussion today, the ZFS port you are proposing releasing under
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the CDDL license should be o.k. since it is a derivative work of the
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original ZFS module (under CDDL) and is therefore also subject to CDDL
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under the distribution terms of that license. While the issue of linking
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has been greatly debated in the OS community, I think it is fair to say in
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this instance the ZFS port is not a derivative work of Linux and thus not
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subject to the GPL. Furthermore, it shouldn't be a problem especially
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since even Linus Torvald has expressed that modules such as yours are not
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derived works of Linux.
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Let me know if you have any further questions at x27274. Thanks.
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Regards,
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James
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James S. Tak
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Assistant Laboratory Counsel for Intellectual Property
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Office of Laboratory Counsel
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Lawrence Livermore National Laboratory
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phone: (925) 422-7274
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fax: (925) 423-2231
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tak1@llnl.gov
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