Re: Please add ZFS support (from GPL sources)

Re: Please add ZFS support (from GPL sources)

[Alan Cox]

On Thu, 17 Jul 2008 21:13:55 +0200
"Fred ." <eldmannen@gmail.com> wrote:

> Previously we have not been able to have ZFS support due to it being
> licensed under the CDDL and the kernel under the GPL.
> 
> Sun have contributed ZFS support to GRUB under the GPL license. We
> could now use that code to implement support for ZFS in the Linux
> kernel.

No we can't. The GPL ZFS bits don't include the various methods that
would violate the patent so there is no grant. I've several times asked
Sun to simply give permission and they don't even answer. I can only read
the Sun motiviation one way - they want to look open but know that ZFS is
about the only thing that might save Solaris as a product in the data
centre so are not truely prepared to let Linus use it.

This is now further complicated by the fact Sun and NetApp are in
litigation so ZFS is basically "toxic" for the moment and we'd need
permission from both sets of patent holders to proceed.

Alan

Please add ZFS support (from GPL sources)

[Fred .]

Previously we have not been able to have ZFS support due to it being
licensed under the CDDL and the kernel under the GPL.

Sun have contributed ZFS support to GRUB under the GPL license. We
could now use that code to implement support for ZFS in the Linux
kernel.

http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists

Re: Please add ZFS support (from GPL sources)

[H. Peter Anvin]

Fred . wrote:
> Previously we have not been able to have ZFS support due to it being
> licensed under the CDDL and the kernel under the GPL.
> 
> Sun have contributed ZFS support to GRUB under the GPL license. We
> could now use that code to implement support for ZFS in the Linux
> kernel.
> 
> http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists

 From what I can see, it is an absolutely-minimal readonly implementation.

	-hpa

Re: Please add ZFS support (from GPL sources)

[Alexey Dobriyan]

On Thu, Jul 17, 2008 at 09:13:55PM +0200, Fred . wrote:
> Previously we have not been able to have ZFS support due to it being
> licensed under the CDDL and the kernel under the GPL.

Wrong. License is the last of your problems.

> Sun have contributed ZFS support to GRUB under the GPL license.

Only read-only.

> We could now use that code to implement support for ZFS in the Linux
> kernel.
> 
> http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists

And I have some sketches. Not yet ready to send anywhere.

Re: Please add ZFS support (from GPL sources)

[Jeff Garzik]

Fred . wrote:
> Previously we have not been able to have ZFS support due to it being
> licensed under the CDDL and the kernel under the GPL.
> 
> Sun have contributed ZFS support to GRUB under the GPL license. We
> could now use that code to implement support for ZFS in the Linux
> kernel.
> 
> http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists

Linux needs btrfs upstream more than it needs ZFS...

	Jeff

Re: Please add ZFS support (from GPL sources)

[Evgeniy Polyakov]

Fred . wrote:
>Sun have contributed ZFS support to GRUB under the GPL license. We
>could now use that code to implement support for ZFS in the Linux
>kernel.

Why?

-- 
	Evgeniy Polyakov

Re: Please add ZFS support (from GPL sources)

[Mihai Donțu]

On Thursday 17 July 2008, H. Peter Anvin wrote:
> Fred . wrote:
> > Previously we have not been able to have ZFS support due to it being
> > licensed under the CDDL and the kernel under the GPL.
> >
> > Sun have contributed ZFS support to GRUB under the GPL license. We
> > could now use that code to implement support for ZFS in the Linux
> > kernel.
> >
> > http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists
>
>  From what I can see, it is an absolutely-minimal readonly implementation.

There are a number of fs drivers in the kernel which provide read-only 
support. The GPL-ed code might not be much (I haven't looked at it), but if 
someone would spend some time to write a nice, clean patch which can be 
easily improved, I think there would be at least one user out there who would 
find it useful.

Of course, this could open a door for all kinds of incomplete drivers, but 
these days people seem nuts about ZFS.

In second thoughts, maybe a fuse based driver would be better. :)

-- 
Mihai Donțu

Re: Please add ZFS support (from GPL sources)

[Rafael C. de Almeida]

Mihai Donțu wrote:
> On Thursday 17 July 2008, H. Peter Anvin wrote:
>> Fred . wrote:
>>> Previously we have not been able to have ZFS support due to it being
>>> licensed under the CDDL and the kernel under the GPL.
>>>
>>> Sun have contributed ZFS support to GRUB under the GPL license. We
>>> could now use that code to implement support for ZFS in the Linux
>>> kernel.
>>>
>>> http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists
>>  From what I can see, it is an absolutely-minimal readonly implementation.
> 
> There are a number of fs drivers in the kernel which provide read-only 
> support. The GPL-ed code might not be much (I haven't looked at it), but if 
> someone would spend some time to write a nice, clean patch which can be 
> easily improved, I think there would be at least one user out there who would 
> find it useful.
> 
> Of course, this could open a door for all kinds of incomplete drivers, but 
> these days people seem nuts about ZFS.
> 
> In second thoughts, maybe a fuse based driver would be better. :)
> 

I think there's already work being done for zfs on fuse
(http://www.wizy.org/wiki/ZFS_on_FUSE). Not sure how it's going, though.

Re: Please add ZFS support (from GPL sources)

[Matthias Schniedermeyer]

On 17.07.2008 12:28, H. Peter Anvin wrote:
> Fred . wrote:
>> Previously we have not been able to have ZFS support due to it being
>> licensed under the CDDL and the kernel under the GPL.
>>
>> Sun have contributed ZFS support to GRUB under the GPL license. We
>> could now use that code to implement support for ZFS in the Linux
>> kernel.
>>
>> http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists
>
> From what I can see, it is an absolutely-minimal readonly implementation.

Which wasn't problem for NTFS, which was RO for years.

RO is still better than nothing, you can copy files from an ZFS.



Bis denn

-- 
Real Programmers consider "what you see is what you get" to be just as 
bad a concept in Text Editors as it is in women. No, the Real Programmer
wants a "you asked for it, you got it" text editor -- complicated, 
cryptic, powerful, unforgiving, dangerous.

Re: Please add ZFS support (from GPL sources)

[Patrick Draper]

Rafael C. de Almeida wrote:
>
> I think there's already work being done for zfs on fuse
> (http://www.wizy.org/wiki/ZFS_on_FUSE). Not sure how it's going, though.
>   

It's good. I keep all my important files on it, without any trouble. Of 
course, I keep backups
as I would with any filesystem.

Re: Please add ZFS support (from GPL sources)

[Christoph Hellwig]

On Thu, Jul 17, 2008 at 03:45:07PM -0400, Jeff Garzik wrote:
> Fred . wrote:
>> Previously we have not been able to have ZFS support due to it being
>> licensed under the CDDL and the kernel under the GPL.
>>
>> Sun have contributed ZFS support to GRUB under the GPL license. We
>> could now use that code to implement support for ZFS in the Linux
>> kernel.
>>
>> http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists
>
> Linux needs btrfs upstream more than it needs ZFS...

Don't be so harsh.  Adding a read-only for the start zfs driver for
Linux would be useful for various purposes.  And adding read-only
filesystems to Linux is really easy.  So if Fred really cares about it
I'd be very happy to mentor him implementing it.  IT should be a very
good learning exercise for him.

Re: Please add ZFS support (from GPL sources)

[Kevin Winchester]

On Sun, Jul 20, 2008 at 7:57 AM, Christoph Hellwig <hch@infradead.org> wrote:
> On Thu, Jul 17, 2008 at 03:45:07PM -0400, Jeff Garzik wrote:
>> Fred . wrote:
>>> Previously we have not been able to have ZFS support due to it being
>>> licensed under the CDDL and the kernel under the GPL.
>>>
>>> Sun have contributed ZFS support to GRUB under the GPL license. We
>>> could now use that code to implement support for ZFS in the Linux
>>> kernel.
>>>
>>> http://blogs.sun.com/darren/entry/zfs_under_gplv2_already_exists
>>
>> Linux needs btrfs upstream more than it needs ZFS...
>
> Don't be so harsh.  Adding a read-only for the start zfs driver for
> Linux would be useful for various purposes.  And adding read-only
> filesystems to Linux is really easy.  So if Fred really cares about it
> I'd be very happy to mentor him implementing it.  IT should be a very
> good learning exercise for him.

If Fred declines, is anyone free to take you up on the offer?  I have
no filesystem experience and almost no experience with kernel code in
general, so I would not be anyone's first choice for a task like this.
 However, since it mainly appears to be an integration exercise (using
the code from GRUB and making it work in linux), it might well be
doable for me.  As a bonus, being highly inexperienced, I have no
expectations of doing anything correctly, and thus would not react
badly to lots of criticism.

So to summarize - if anyone else would like to undertake this work,
they probably should.  But if no one has the time/will, then I would
be happy to give it a try.

Thanks,
-- 
Kevin Winchester

Re: Please add ZFS support (from GPL sources)

[Dave Kleikamp]

On Sun, 2008-07-20 at 09:35 -0300, Kevin Winchester wrote:
> As a bonus, being highly inexperienced, I have no
> expectations of doing anything correctly, and thus would not react
> badly to lots of criticism.

That's definitely the right attitude to take.  When I ported jfs to
linux, I was completely new to Linux and open source, so tried to defer
to the experienced developers whenever possible.  Christoph was a
terrific help, offering a lot of suggestions and patches.  JFS is a much
better file system because of his help.

There have been others contributing code that have not taken criticism
so well, and what started out as an offer of help turned into emotional
arguments and personal attacks.  This really hampers getting your code
accepted into the kernel and your ability to work within the community.

> So to summarize - if anyone else would like to undertake this work,
> they probably should.  But if no one has the time/will, then I would
> be happy to give it a try.

Thanks for offering.  I don't know who else may be interested in this,
but good luck and thanks to you or whoever takes this up.

Thanks,
Shaggy
-- 
David Kleikamp
IBM Linux Technology Center

Re: Please add ZFS support (from GPL sources)

[Christoph Hellwig]

On Sun, Jul 20, 2008 at 09:35:45AM -0300, Kevin Winchester wrote:
> If Fred declines, is anyone free to take you up on the offer?  I have
> no filesystem experience and almost no experience with kernel code in
> general, so I would not be anyone's first choice for a task like this.
>  However, since it mainly appears to be an integration exercise (using
> the code from GRUB and making it work in linux), it might well be
> doable for me.  As a bonus, being highly inexperienced, I have no
> expectations of doing anything correctly, and thus would not react
> badly to lots of criticism.
> 
> So to summarize - if anyone else would like to undertake this work,
> they probably should.  But if no one has the time/will, then I would
> be happy to give it a try.

Yes, this offer is of course up to everyone interested.  But it's not
purely an integration effort in the traditional sense, the grub
filesystem interface is quite different from the Linux one, and the code
structure and style is quite different.  But if you're willing to learn
it should be very interesting.

Re: Please add ZFS support (from GPL sources)

[Kevin Winchester]

On Mon, Jul 21, 2008 at 4:28 AM, Christoph Hellwig <hch@infradead.org> wrote:
> On Sun, Jul 20, 2008 at 09:35:45AM -0300, Kevin Winchester wrote:
>> If Fred declines, is anyone free to take you up on the offer?  I have
>> no filesystem experience and almost no experience with kernel code in
>> general, so I would not be anyone's first choice for a task like this.
>>  However, since it mainly appears to be an integration exercise (using
>> the code from GRUB and making it work in linux), it might well be
>> doable for me.  As a bonus, being highly inexperienced, I have no
>> expectations of doing anything correctly, and thus would not react
>> badly to lots of criticism.
>>
>> So to summarize - if anyone else would like to undertake this work,
>> they probably should.  But if no one has the time/will, then I would
>> be happy to give it a try.
>
> Yes, this offer is of course up to everyone interested.  But it's not
> purely an integration effort in the traditional sense, the grub
> filesystem interface is quite different from the Linux one, and the code
> structure and style is quite different.  But if you're willing to learn
> it should be very interesting.
>

No one else seems to have volunteered, so I would certainly like to
give it a try.  I guess I need to get the ZFS grub code, create a ZFS
filesystem, and start looking around for information on linux
filesystem development and ZFS (obviously without looking at any CDDL
licensed code).

Once I get a handle on that, I'll see where I can get before I need to
ask a thousand questions.

-- 
Kevin Winchester

Re: Please add ZFS support (from GPL sources)

[Kevin Winchester]

(Added back CCs)

On Mon, Jul 21, 2008 at 11:23 AM, Fred . <eldmannen@gmail.com> wrote:
> On Mon, Jul 21, 2008 at 1:39 PM, Kevin Winchester
> <kjwinchester@gmail.com> wrote:
>> On Mon, Jul 21, 2008 at 4:28 AM, Christoph Hellwig <hch@infradead.org> wrote:
>>> On Sun, Jul 20, 2008 at 09:35:45AM -0300, Kevin Winchester wrote:
>>>> If Fred declines, is anyone free to take you up on the offer?  I have
>>>> no filesystem experience and almost no experience with kernel code in
>>>> general, so I would not be anyone's first choice for a task like this.
>>>>  However, since it mainly appears to be an integration exercise (using
>>>> the code from GRUB and making it work in linux), it might well be
>>>> doable for me.  As a bonus, being highly inexperienced, I have no
>>>> expectations of doing anything correctly, and thus would not react
>>>> badly to lots of criticism.
>>>>
>>>> So to summarize - if anyone else would like to undertake this work,
>>>> they probably should.  But if no one has the time/will, then I would
>>>> be happy to give it a try.
>>>
>>> Yes, this offer is of course up to everyone interested.  But it's not
>>> purely an integration effort in the traditional sense, the grub
>>> filesystem interface is quite different from the Linux one, and the code
>>> structure and style is quite different.  But if you're willing to learn
>>> it should be very interesting.
>>>
>>
>> No one else seems to have volunteered, so I would certainly like to
>> give it a try.  I guess I need to get the ZFS grub code, create a ZFS
>> filesystem, and start looking around for information on linux
>> filesystem development and ZFS (obviously without looking at any CDDL
>> licensed code).
>>
>> Once I get a handle on that, I'll see where I can get before I need to
>> ask a thousand questions.
>>
> Code can be found here;
> * http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/grub/grub-0.95/stage2/
>
> But it may be covered by patents by Sun. So maybe not allowed make an
> implementation. :(
> Maybe you should consult SFLC (Software Freedom Law Center) first or something.
>

I would have no idea of the legal implications here.  Do I really need
to get the lawyers involved just to use GPLv2 code from another
project in linux?

-- 
Kevin Winchester

Re: Please add ZFS support (from GPL sources)

[Bernd Petrovitsch]

On Mon, 2008-07-21 at 11:40 -0300, Kevin Winchester wrote:
[....]
> > But it may be covered by patents by Sun. So maybe not allowed make an
> > implementation. :(
> > Maybe you should consult SFLC (Software Freedom Law Center) first or something.

Since basically *you* wanted that feature in the first place (and for
whatever reason do not even start to work on it), I would have assumed
that *you* already checked out all implications - especially the legal
ones.
So which patents may be relevant IYHO?

	Bernd
-- 
Firmix Software GmbH                   http://www.firmix.at/
mobil: +43 664 4416156                 fax: +43 1 7890849-55
          Embedded Linux Development and Services

Re: Please add ZFS support (from GPL sources)

[jim owens]

Kevin Winchester wrote:
> 
> On Mon, Jul 21, 2008 at 11:23 AM, Fred . <eldmannen@gmail.com> wrote:
> 
>>On Mon, Jul 21, 2008 at 1:39 PM, Kevin Winchester
>>>
>>>No one else seems to have volunteered, so I would certainly like to
>>>give it a try.  I guess I need to get the ZFS grub code, create a ZFS
>>>filesystem, and start looking around for information on linux
>>>filesystem development and ZFS (obviously without looking at any CDDL
>>>licensed code).
>>
>>Code can be found here;
>>* http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/grub/grub-0.95/stage2/
>>
>>But it may be covered by patents by Sun. So maybe not allowed make an
>>implementation. :(
>>Maybe you should consult SFLC (Software Freedom Law Center) first or something.
>>
> I would have no idea of the legal implications here.  Do I really need
> to get the lawyers involved just to use GPLv2 code from another
> project in linux?

Having just gone through open sourcing with lawyers, I would
say anything with a GPLv2 is safe. Any patent Sun has on things
released under GPLv2 is open for use.

I don't know anything about CDDL rules, but if you don't look at
it, you won't be legally contaminated.

I have not looked at the ZFS grub code, but a general warning
based on my experience with other filesystem bootstrap code
is that it may be very limited and not be able to deal with
all structures on a ZFS filesystem... you won't know until
you hit one of them and fail.

jim

Re: Please add ZFS support (from GPL sources)

[Christoph Hellwig]

On Mon, Jul 21, 2008 at 04:50:54PM +0200, Bernd Petrovitsch wrote:
> On Mon, 2008-07-21 at 11:40 -0300, Kevin Winchester wrote:
> [....]
> > > But it may be covered by patents by Sun. So maybe not allowed make an
> > > implementation. :(
> > > Maybe you should consult SFLC (Software Freedom Law Center) first or something.
> 
> Since basically *you* wanted that feature in the first place (and for
> whatever reason do not even start to work on it),

Either you or I have lost track here.  Fred without a lastname asked for
ZFS support based on the grub code, and never replied again in this
thread.  Kevin volunteered to work on it.

Re: Please add ZFS support (from GPL sources)

[Bernd Petrovitsch]

On Tue, 2008-07-22 at 03:44 -0400, Christoph Hellwig wrote:
> On Mon, Jul 21, 2008 at 04:50:54PM +0200, Bernd Petrovitsch wrote:
> > On Mon, 2008-07-21 at 11:40 -0300, Kevin Winchester wrote:
> > [....]
> > > > But it may be covered by patents by Sun. So maybe not allowed make an
> > > > implementation. :(
> > > > Maybe you should consult SFLC (Software Freedom Law Center) first or something.

That was quoted from a reply since that didn't make it in my mailbox
(and perhaps on the list as the "Cc: added" suggests).
 
> > Since basically *you* wanted that feature in the first place (and for
> > whatever reason do not even start to work on it),
> 
> Either you or I have lost track here.  Fred without a lastname asked for
> ZFS support based on the grub code, and never replied again in this

ACK.
To summarize:
- First he requests that someone else implements/ports/... something
   (for whatever reason) to GPL/the kernel/....
- Then some advice, hints and a kind soul offers help (no problem for
   me).
- And then the original requester comes up with "you might have check
   for potential patent problems" on technical mailinglist (at least
most
   of the time;-).

The following open questions for me were/are:
- Why is *that* important for the original requester?
- Why didn't he do his (legal) homework before or simply ignore that or
   - at  least - stated it in the original mail[0].
- Which aspect/unresolved problem/potential problem will come next?

> thread.  Kevin volunteered to work on it.

I have no problem with that.
Heck, personally I don't have a problem if someone takes the ZFS source
and makes a (completely separate) GPLv2 patch to use it in kernel-space
(and not "only" with FUSE).

The legal implications?
Apart from the generic lawyer answer "it depends on the circumstances",
I don't know.

	Bernd

[0]: What's the English phrase for the German "Salami-Taktik"? You don't
         come up with the whole problem at once but try to solve it in
small
         steps luring the problem solver (which gets only the next step
         presented) into it so that s/he can't stop (for whatever reason
-
         it is heavily used in the commercial world).
-- 
Firmix Software GmbH                   http://www.firmix.at/
mobil: +43 664 4416156                 fax: +43 1 7890849-55
          Embedded Linux Development and Services

Re: Please add ZFS support (from GPL sources)

[Chen Zheng]

On Jul 21, 7:39 am 2008, Kevin Winchester
>No one else seems to have volunteered, so I would certainly like to
>give it a try.  I guess I need to get the ZFS grub code, create a ZFS
>filesystem, and start looking around for information on linux
>filesystem development and ZFS (obviously without looking at any CDDL
>licensed code).

>Once I get a handle on that, I'll see where I can get before I need to
>ask a thousand questions.

Hi Kevin,  a few weeks ago I wrote a python module for fun,  which can read
most of zfs data structure. Based on ondiskformat0822.pdf, I started
it from scratch.

http://code.google.com/p/zfspy/

It maybe useful if you want to learn zfs on disk data structure.