[PATCH RFC 1/2] xfs: add sb_meta_uuid field to superblock

[Eric Sandeen]

hohum, having done all that, it now occurs to me that perhaps
a simpler approach would be to add an sb_user_uuid in this same slot.

We could then set that to anything we want, with no other code changes,
and "all" we'd need is a blkid update to look there to see if it's set,
and some minor work in xfs_db to allow us to set it.  o_O

-Eric