Memory system

A memory system, comprising:

• a nonvolatile memory that includes a plurality of storage areas each including a plurality of blocks, each of which is a unit of data-erase, the nonvolatile memory being configured such that parallel write is enabled with respect to the blocks included in the different storage areas;
• a managing unit that holds, for each of the storage areas, a free block list indicating free blocks that are the blocks where valid data is not stored;
• an order rule holding unit that holds an order rule that is information used to determine an order of free block lists;
• a position information storing unit that stores position information indicating the position of the free block list in the order rule;
• a list selecting unit that selects the free block list corresponding to the position indicated by the position information;
• a block selecting unit that selects the free block from the free block list selected by the list selecting unit;
• a writing unit that writes data in the free block selected by the block selecting unit;
• and
• an updating unit that updates, after the free block list is selected by the list selecting unit, the position information stored in the position information storing unit with position information indicating the position of the subsequently selected list,
• wherein the position information storing unit stores position information that indicates the order of each free block list determined on the basis of a long-period order rule generated using a plurality of different order rules.