01r1_Grow_add: It contains 3 kinds of growing array.
1. 2 active disk in md array, grow and add new disk into array.
2. 2 active and 1 spare disk in md array, grow and add new disk
into array.
3. 2 active and 1 spare disk in md array, grow the device-number
and make spare disk as active disk in array.
Signed-off-by: Zhilong Liu <zlliu@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>
Zhilong Liu