NAMESPACE - RESIZING

• US 20180260334A1
• Filed: 03/10/2017
• Published: 09/13/2018
• Est. Priority Date: 03/10/2017
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Toshiba Memory Corporation (Kioxia Corporation)
• Inventors: Asano, Shigehiro, Margetts, Julien, Rose, Philip David
• Granted Patent: US 10,866,732 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/1041 Resource optimization
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A data storage device capable of namespace re-sizing comprises a nonvolatile semiconductor storage device containing data accessed via a logical address that includes a namespace identifier and a logical block address, and a controller. The storage device can convert the namespace identifier to a base address using a first look up table. The storage device can further convert the logical block address to namespace allocation units of storage. The storage device can also determine a pointer using the base address, the namespace allocation units, and a second look up table. Further, the storage device can determine a full logical cluster address using the pointer.

Claims

1. A data storage device comprising:

a nonvolatile semiconductor storage device containing data accessed via a logical address that includes a namespace identifier and a logical block address; and

a controller configured to;

convert the namespace identifier to a base address using a first look up table;

convert the logical block address to namespace allocation units of storage;

determine a pointer using the base address, the namespace allocation units, and a second look up table; and

determine a full logical cluster address using the pointer.

2. The data storage device of claim 1, wherein the controller is further configured to define a plurality of allocation units of storage addressed by the logical cluster address;

allocate a subset of the plurality of units of storage to a namespace associated with the namespace identifier; and

add a set of entries to the second look up table containing the namespace identifier and a pointer to the logical cluster address for each of the subset of the plurality of units of storage.

3. The data storage device of claim 1, wherein the controller is further configured to increase the size of the namespace associated with a namespace identifier by:

allocating additional allocation units to that namespace identifier;

adding, for each of the additional allocation units, a new entry to the end of the second look up table, the new entry containing the namespace identifier and a logical pointer to the logical cluster address of the additional unit of storage; and

re-ordering the entries in the second look up table such that the new entry is contiguous with the set of entries containing the same namespace identifier.

4. The data storage device of claim 1, wherein the controller is configured to determine a physical address within the nonvolatile semiconductor storage device based on a full logical cluster address to physical address mapping table.

5. The data storage device of claim 1, wherein the first look up table comprises internal base addresses which are indexed by namespace identifiers.

6. The data storage device of claim 1, wherein the logical block address comprises a first portion and a second portion, and wherein the base address is formed using the first portion of the logical block address, and the logical cluster address is formed using the second portion of the logical block address.

7. The data storage device of claim 6, wherein the controller is further configured to define a plurality of units of storage addressed by the first portion of the logical block address,

allocate a subset of the plurality of units of storage to a namespace associated with the namespace identifier, and

add a set of entries to the second look up table containing the namespace identifier and the first portion of the logical cluster address for each of the subset of the plurality of units of storage.

8. The data storage device of claim 7, wherein the controller is further configured to:

increase the size of the namespace associated with the namespace identifier by allocating additional units of storage from the plurality of units of storage;

add, for each of the additional units of storage, a new entry to the end of the second look up table, the new entry containing the namespace identifier and the first portion of the logical cluster address of the additional unit of storage; and

re-order the entries in the second look up table to ensure the new entry is contiguous with the set of entries containing the same namespace identifier.

9. The data storage device of claim 1, wherein the controller is further configured to decrease the size of the namespace associated with a namespace identifier by deleting the last entry in the second look up table containing the namespace identifier and the pointer associated with the namespace identifier.

10. A method comprising:

converting, by a controller, a namespace identifier to a base address using a first look up table, the namespace identifier associated with a logical address allocated to data for a nonvolatile semiconductor storage device;

converting a logical block address associated with the logical address to namespace allocation units of storage;

determining a pointer using the base address, the namespace allocation units, and a second look up table; and

determining a full logical cluster address using the pointer.

11. The method of claim 10, further comprising:

allocating, by the controller, a subset of a plurality of units of storage to a namespace associated with the namespace identifier, wherein the controller defines the plurality of allocation units of storage addressed by the logical cluster address; and

adding, by the controller, a set of entries to the second look up table containing the namespace identifier and a pointer to the logical cluster address for each of the subset of the plurality of units of storage.

12. The method of claim 10, further comprising:

increasing the size of the namespace associated with a namespace identifier by;

allocating additional allocation units to the namespace identifier;

adding, for each of the additional allocation units, a new entry to the end of the second look up table, the new entry containing the namespace identifier and a logical pointer to the logical cluster address of the additional unit of storage; and

re-ordering the entries in the second look up table such that the new entry is contiguous with the set of entries containing the same namespace identifier.

13. The method of claim 10, further comprising:

determining a physical address within the nonvolatile semiconductor storage device based on a full logical cluster address to physical address mapping table.

14. The method of claim 10, further comprising:

defining a plurality of units of storage addressed by a first portion of the logical block address, wherein the logical block address comprises the first portion and a second portion, and wherein the base address is formed using the first portion of the logical block address, and the logical cluster address is formed using the second portion of the logical block address;

allocating a subset of the plurality of units of storage to a namespace associated with the namespace identifier; and

adding a set of entries to the second look up table containing the namespace identifier and the first portion of the logical cluster address for each of the subset of the plurality of units of storage.

15. The method of claim 14, further comprising, when the controller is further configured to increase the size of the namespace associated with the namespace identifier by allocating additional units of storage from the plurality of units of storage:

adding, for each of the additional units of storage, a new entry to the end of the second look up table, the new entry containing the namespace identifier and the first portion of the logical cluster address of the additional unit of storage, and

re-ordering the entries in the second look up table to ensure the new entry is contiguous with the set of entries containing the same namespace identifier.

16. The method of claim 10, further comprising:

decreasing the size of the namespace associated with a namespace identifier by deleting the last entry in the second look up table containing the namespace identifier and the pointer associated with the namespace identifier.

17. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method comprising:

converting, by a controller, a namespace identifier to a base address using a first look up table, the namespace identifier associated with a logical address allocated to data for a nonvolatile semiconductor storage device;

converting a logical block address associated with the logical address to namespace allocation units of storage;

determining a pointer using the base address, the namespace allocation units, and a second look up table; and

determining a full logical cluster address using the pointer.