This change sets the LBPRZ flag in EVPD page b2h and READ CAPACITY (16)
based on a new unmap_zeroes_data device attribute. This flag is set
automatically for iblock based on underlying block device queue's
discard_zeroes_data flag.
Signed-off-by: NJamie Pocas <jamie.pocas@emc.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>