Return the 64bit number of blocks of storage associated with the device or
instance. Where a "block" is a unit of storage consisting of the number of
bytes returned by the package's "block-size" method. If the size cannot be
determined, or if the number of blocks exceeds the range return -1.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>