handle block counts of 0. Cleanup block and block count calculations.
Reviewed-by: NScott Teel <scott.teel@pmcs.com>
Reviewed-by: NJustin Lindley <justin.lindley@pmcs.com>
Reviewed-by: NKevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NDon Brace <don.brace@pmcs.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>