LOGICAL INTERFACE FOR CONTEXTUAL STORAGE

• US 20130073821A1
• Filed: 03/19/2012
• Published: 03/21/2013
• Est. Priority Date: 03/18/2011
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Fusion-IO Incorporated (Western Digital Corporation)
• Inventors: Flynn, David, Wipfel, Robert, Nellans, David, Strasser, John
• Granted Patent: US 8,966,191 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 12/00 Accessing, addressing or allocating within memory systems or architectures digital input from, or digital output to record carriers, e.g. to disk storage units, G06F3/06
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 13/16 for access to memory bus G06F13/28 takes precedence
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0629 Configuration or reconfiguration of storage systems
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 16/06 Auxiliary circuits, e.g. for writing into memory

Abstract

A virtual storage layer (VSL) presents logical address space of a non-volatile storage device. The VSL maintains logical interfaces to the non-volatile storage device, which may include arbitrary, any-to-any mappings between logical identifiers and storage resources. Data may be stored on the non-volatile storage device in a contextual format, which includes persistent metadata that defines the logical interface of the data. The VSL may modify the logical interface of data that is stored in the contextual format. The modified logical interface may be inconsistent with the existing contextual format of the data on the non-volatile storage media. The VSL may provide access to the data in the inconsistent contextual format through the modified logical interface. The contextual format of the data may be updated to be consistent with the modified logical interface in a write out-of-place storage operation.

Claims

1. A method for managing a non-volatile storage medium, comprising:

modifying a logical interface of data stored in a contextual format on a non-volatile storage medium, wherein the contextual format of the data on the non-volatile storage medium is inconsistent with the modified logical interface of the data;

providing access to the data in the inconsistent contextual format through the modified logical interface; and

updating the contextual format of the data on a non-volatile storage medium to be consistent with the modified logical interface.

2. The method of claim 1, further comprising modifying the logical interface of the data in response to a request.

3. The method of claim 2, further comprising acknowledging modification of the logical interface before updating the contextual format of the data on the non-volatile storage medium to be consistent with the modified logical interface.

4. The method of claim 1, further comprising storing a persistent note on the non-volatile storage medium indicative of the modification to the logical interface.

5. The method of claim 4, further comprising invalidating the persistent note on the non-volatile storage medium in response to at least one of updating the contextual format of the data on the non-volatile storage medium to be consistent with the modified logical interface and storing the modified logical interface on a non-volatile storage medium.

6. The method of claim 1, further comprising updating the contextual format of the data on the non-volatile storage medium independent of a path for servicing storage requests.

7. The method of claim 1, further comprising:

determining that the contextual format of the data is inconsistent with the modified logical interface of the data in response to reclaiming a storage division of the non-volatile storage medium comprising data in the inconsistent contextual format; and

relocating the data to another storage division of non-volatile storage medium, wherein relocating comprises updating the contextual format of the data to be consistent with the modified logical interface.

8. The method of claim 1, further comprising referencing the modified logical interface through a reference entry in an index.

9. The method of claim 8, further comprising removing the reference entry from the index in response to updating the contextual format of the data to be consistent with the modified logical interface.

10. The method of claim 1, further comprising modifying the logical interface of the data in response to a move request, wherein the modified logical interface associates the data with a new logical identifier.

11. The method of claim 1, further comprising modifying the logical interface of the data in response to a clone request, wherein the modified logical interface associates the data with two or more logical identifiers.

12. The method of claim 1, further comprising updating the contextual format of the data on the non-volatile storage medium to associate the data with two or more logical identifiers in response to identifying duplicate data.

13. The method of claim 12, further comprising invalidating a duplicate copy of the data on the non-volatile storage medium.

14. A system for managing a logical interface of data stored in a contextual format, comprising:

a storage controller configured to receive a request to a logical interface of data stored in a contextual format on a media storage location of a non-volatile storage medium;

a virtual storage layer configured to modify the logical interface in response to the request, wherein the contextual format of the data on the non-volatile storage medium is inconsistent with the modified logical interface, and wherein the virtual storage layer is configured to reference the data in the inconsistent contextual format through the modified logical interface; and

a storage controller configured to update the contextual format of the data on media storage locations different from media storage locations storing the inconsistent contextual format of the data while the virtual storage layer provides access to the data through the modified logical interface.

15. The system of claim 14, wherein the virtual storage layer is configured to store a persistent note on the non-volatile storage medium to associate the data with the modified logical interface, and to invalidate the persistent note in response to updating the contextual format of the data to be consistent with the modified logical interface.

16. The system of claim 14, wherein the virtual storage layer is configured to reference the data stored in the contextual format that is inconsistent with the modified logical interface through a reference entry in an index.

17. The system of claim 14, wherein the virtual storage layer is configured to update the contextual format of the data by a process that is independent of servicing storage requests.

18. A non-transitory machine-readable storage medium comprising instructions to cause a processor to perform a method for managing a logical interface of data stored in a contextual format, the method comprising:

modifying a logical interface of data stored in a contextual format on a non-volatile storage medium, wherein the contextual format of the data on the non-volatile storage medium is inconsistent with the modified logical interface of the data;

providing access to the data in the inconsistent contextual format through the modified logical interface; and

updating the contextual format of the data on the non-volatile storage medium to be consistent with the modified logical interface independent of a path for servicing storage requests.

19. The non-transitory machine-readable storage medium of claim 18, the method further comprising:

modifying the logical interface of the data stored in the contextual format on the non-volatile storage medium in response to a request; and

acknowledging modification of the logical interface before updating the contextual format of the data on the non-volatile storage medium.

20. The non-transitory machine-readable storage medium of claim 18, the method further comprising storing a persistent note on the non-volatile storage medium to associate the data with the modified logical interface.

21. The non-transitory machine-readable storage medium of claim 18, wherein the modified logical interface references the data using a logical identifier that is not associated with the data in the inconsistent contextual format on the non-volatile storage medium.

22. The non-transitory machine-readable storage medium of claim 18, wherein the modified logical interface references the data using a different logical identifier than a logical identifier associated with the data in the inconsistent contextual format on the non-volatile storage medium.

23. An interface for referencing a storage resource, comprising:

a storage controller configured to present a logical interface of data stored in a contextual format on a non-volatile storage medium;

a virtual storage layer (VSL) configured to maintain an association between a logical identifier of the logical interface and a medium storage location of data on the non-volatile storage medium; and

wherein the storage controller is configured to receive a request to modify the logical interface of the data;

wherein

the VSL is further configured to modify the logical interface in response to the request wherein modifying the logical interface comprises modifying one or more logical identifiers of the logical interface, and wherein the contextual format of the data on the non-volatile storage medium is inconsistent with the modified logical interface, and

wherein the storage controller is configured to provide access, through the modified logical interface, to the data in the contextual format that is inconsistent with the modified logical interface.

24. The interface of claim 23, wherein the virtual storage layer acknowledges the modification of the logical interface before the contextual format of the data is updated to be consistent with the modified logical interface.

25. The interface of claim 23, wherein the virtual storage layer acknowledges the modification of the logical interface in response to storing a persistent note on the non-volatile storage medium comprising the modified logical interface.