xfsdocs: document refcount btree and reflink

Document the reference count btree and talk a little bit about how
the reflink feature uses it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

10 files changed
tree: f2e7f44baabb8296941d65b86c99047ba237177d
  1. .gitignore
  2. CHANGES
  3. COPYING
  4. Makefile
  5. README
  6. admin/
  7. design/