[PATCH] mkfs.xfs: add [-U uuid] option

[Eric Sandeen]

On 9/21/15 5:18 PM, Dave Chinner wrote:
> On Mon, Sep 21, 2015 at 08:04:20PM +0300, Mika Eloranta wrote:
>> The UUID can now be optionally specified during filesystem
>> creation.
> 
> Which UUID are you wanting to set - the metadata uuid or the user
> visible UUID label? Or both?

At mkfs time it should be the same / both.  (the only reason they need
to diverge is a post-mkfs user-visible change on a V5 fs).

 Can you explain the use case for this?
> i.e. I'm trying to work out why Why doesn't mkfs.xfs +
> xfs_admin -U <uuid> doesn't work for you?
> 
> We need some explaination in the commit message so that when we look
> at this in a couple of years time we know why we added this to
> mkfs...

I'm a little curious to know why it's desired, but it's also so trivial
it seems worth accepting if it's useful to someone.

mke2fs (mkfs.ext[234]) and mkfs.btrfs can do this today as well, so
something seems to be driving the desire for the feature.

-Eric