Monday, 6 August 2018

Re: RFC: baseline requirements for Ubuntu rootfs: xattrs and fscaps

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

> 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