RFC: baseline requirements for Ubuntu rootfs: xattrs and fscaps

[Steve Langasek]

On Mon, Aug 06, 2018 at 02:23:30PM +0100, Robie Basak wrote:
> On Wed, Aug 01, 2018 at 05:58:56PM -0700, Steve Langasek wrote:
> > This will require bugfixes in various places, but ideally on a one-time
> > basis only.  The primary areas of concern are:

> [...]

> >  - Users who are unpacking root tarballs need to take care to pass
> >    --xattrs-include=* to tar.

> I think it's worth pointing out that users unpacking root tarballs to
> filesystems that don't support xattrs will be broken. I'm not sure how
> widespread this is, but I'm thinking of the use of cloud images and the
> Ubuntu Base image. In the interests of moving forward, perhaps it makes
> sense to make this breaking change in Ubuntu.

I think it's exceedingly unlikely that anyone is going to unpack, and
subsequently boot, an Ubuntu root tarball on a filesystem that doesn't
support xattrs.  All the filesystems that Ubuntu supports out of the box as
rootfs (in terms of installers, and filesystem tools preinstalled) support
xattrs.

> Would it be an idea to make it such that booting an Ubuntu system on a
> filesystem that doesn't support xattrs deliberately fails early, to
> avoid users being hit with subtle bugs later? The error could include
> instructions on disabling the check for users who want to proceed
> anyway.

IMHO that would be overengineering for a corner case.

-- 
Steve Langasek                   Give me a lever long enough and a Free OS
Debian Developer                   to set it on, and I can move the world.
Ubuntu Developer                                   https://www.debian.org/
slangasek at ubuntu.com                                     vorlon at debian.org
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <https://lists.ubuntu.com/archives/ubuntu-devel/attachments/20180806/5f7336bc/attachment.sig>