Move a little more processing into the core code, and lift the previous
do_unmap callback into the sbc_ops structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAndy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>