Memory system having a controller with a data erasure processing function

A memory system connectable to a host, the memory system comprising:

• a non-volatile memory;
• and
• a controller electrically connected to the non-volatile memory and configured to control the non-volatile memory,
• wherein the controller comprises a data erasure processing function and is configured to:
• specify a partition format of a predetermined partition included in the non-volatile memory based on master boot record information stored in the non-volatile memory,
• specify a first sector and a second sector of the predetermined partition based on the specified partition format,
• specify a file system that manages the predetermined partition based on first information included in the first sector and second information included in the second sector,
• specify logically erased first data and physically erase the first data when logical erasure of data in the predetermined partition is detected by a method consistent with the specified file system,
• read a superblock included in the second sector as the second information,
• specify the file system as a first file system when a magic number set at a first offset of the superblock indicates a first value,
• specify a current number of free i-nodes and a current number of free blocks when the file system is specified as the first file system,
• when the specified current number of free i-nodes is greater than a previous number of free i-nodes and the specified current number of free blocks is greater than a previous number of free blocks, detect logical erasure of data in the predetermined partition, and
• physically erase the first data.

A memory system connectable to a host, the memory system comprising:

• a non-volatile memory;
• and
• a controller electrically connected to the non-volatile memory and configured to control the non-volatile memory,
• wherein the controller comprises a data erasure processing function and is configured to:
• specify a partition format of a predetermined partition included in the non-volatile memory based on master boot record information stored in the non-volatile memory,
• specify a first sector and a second sector of the predetermined partition based on the specified partition format,
• specify a file system that manages the predetermined partition based on first information included in the first sector and second information included in the second sector,
• specify logically erased first data and physically erase the first data when logical erasure of data in the predetermined partition is detected by a method consistent with the specified file system,
• read a superblock included in the second sector as the second information,
• specify the file system as a second file system when a magic number set at a second offset of the superblock indicates a second value,
• specify a current number of valid i-nodes, a current number of valid nodes, and a current number of valid blocks when the file system is specified as the second file system,
• when the specified current number of valid i-nodes is smaller than a previous number of valid i-nodes, the specified current number of valid nodes is smaller than a previous number of valid nodes and the specified current number of valid blocks is smaller than a previous number of valid blocks, detect logical erasure of data in the predetermined partition, and
• physically erase the first data.

A memory system connectable to a host, the memory system comprising:

• a non-volatile memory;
• and
• a controller electrically connected to the non-volatile memory and configured to control the non-volatile memory,
• wherein the controller comprises a data erasure processing function and is configured to:
• specify a partition format of a predetermined partition included in the non-volatile memory based on master boot record information stored in the non-volatile memory,
• specify a first sector and a second sector of the predetermined partition based on the specified partition format,
• specify a file system that manages the predetermined partition based on first information included in the first sector and second information included in the second sector,
• specify logically erased first data and physically erase the first data when logical erasure of data in the predetermined partition is detected by a method consistent with the specified file system,
• read a file system name set at a third offset of the first sector as the first information, and
• when the file system name indicates a third file system, specify the file system as the third file system, wherein
• the third offset is 0x03.

A memory system connectable to a host, the memory system comprising:

• a non-volatile memory;
• and
• a controller electrically connected to the non-volatile memory and configured to control the non-volatile memory,
• wherein the controller comprises a data erasure processing function and is configured to:
• specify a partition format of a predetermined partition included in the non-volatile memory based on master boot record information stored in the non-volatile memory,
• specify a first sector and a second sector of the predetermined partition based on the specified partition format,
• specify a file system that manages the predetermined partition based on first information included in the first sector and second information included in the second sector,
• specify logically erased first data and physically erase the first data when logical erasure of data in the predetermined partition is detected by a method consistent with the specified file system,
• read a superblock included in the second sector as the second information, and
• specify the file system as a second file system when a magic number set at a second offset of the superblock indicates a second value,
• wherein
• the second offset is 0x00, and
• the second value is 0xF2F52010.