Hi all,

This patch set goes along with the fifth revision of an RFC adding to
XFS kernel support for tracking reverse-mappings of physical blocks to
file and metadata; and support for mapping multiple file logical
blocks to the same physical block, more commonly known as reflinking.

The two patches in this series document the clone, clone_range, and
dedupe ioctls in the form of man pages.

The patch set is based on a whole pile of proposed patches against the
current (4.5) upstream kernel; the ioctls are simply hoisted version
of the private btrfs ioctls.

Comments and questions are, as always, welcome.

--D