Merge git://oss.sgi.com:8090/oss/git/xfs-2.6

* git://oss.sgi.com:8090/oss/git/xfs-2.6:
  [XFS] Provide XFS support for the splice syscall.
  [XFS] Reenable write barriers by default.
  [XFS] Make project quota enforcement return an error code consistent with
  [XFS] Implement the silent parameter to fill_super, previously ignored.
  [XFS] Cleanup comment to remove reference to obsoleted function