btrfs as default filesystem for F22?

[Josh Boyer]

On Wed, Oct 8, 2014 at 1:52 AM, Thorsten Leemhuis <fedora at leemhuis.info> wrote:
> Josh Boyer wrote on 07.10.2014 21:15:
>> On Tue, Oct 7, 2014 at 2:24 PM, Josef Bacik <josef at toxicpanda.com> wrote:
>> [...]
>>>> I think the point is somewhat valid though. To just keep repeating the
>>>> mantra 'its not ready' is not going to make it any more ready. If suse
>>>> can identify a stable subset of btrfs features and use it as their
>>>> default file system with those restrictions, why can't we do the same ?
>>>> The approach makes sense to me, at least...
>>> Because they still have the support staff for when users don't listen,
>>> Fedora doesn't.
>> As an aside, I looked at their 3.16.2-1.1.gdcee397 kernel-source SRPM.
>> I can't find any patches that limit btrfs usage.  I could totally be
>> wrong, but if someone knows of a patch that limits the features please
>> point me to it.
>
> Due to a coincidence I yesterday took a quick look myself and didn't
> spot anything. But in case you haven't looked further: I found one in
> the SLE-Kernels:
>
> http://kernel.opensuse.org/cgit/kernel-source/tree/patches.suse/btrfs-8888-add-allow_unsupported-module-parameter.patch?h=SLE11-SP3
> http://kernel.opensuse.org/cgit/kernel-source/tree/patches.suse/btrfs-8888-add-allow_unsupported-module-parameter.patch?h=SLE12

Yes, I found the same yesterday after doing some digging.  It's not in
OpenSuSE 13.2 though, so it seems they're just going with whatever
upstream provides there.

I'm not thrilled with adding that patch to Fedora at all.  It
accomplishes the goal, but it would break any existing user that is
using one of those btrfs features because the mount would fail.
Fedora would likely just have to taint and then ignore reports with
the taint set, which doesn't make for a great user experience either.
They get away with this in SLE12 because it's roughly the first time
btrfs is available in a supported fashion.  I suspect they hit the
same concerns in OpenSuSE that Fedora would though, which is why it
isn't there.

If someone was interested in the history of the patch in OpenSuSE and
wants to dig into it, that would be neat to read.

josh