Apparatus, System, and Method for Accessing Auto-Commit Memory

• US 20130227201A1
• Filed: 03/15/2013
• Published: 08/29/2013
• Est. Priority Date: 12/13/2010
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Fusion-IO Incorporated (Western Digital Corporation)
• Inventors: Talagala, Nisha, Flynn, David
• Granted Patent: US 9,208,071 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 13/28 using burst mode transfer, e.g. direct memory access DMA, cycle steal G06F13/32 takes precedence
• CPC Class Codes: G06F 2212/202 Non-volatile memory
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

Apparatuses, systems, methods, and computer program products are disclosed for providing access to auto-commit memory. An auto-commit memory module is configured to cause an auto-commit memory to commit stored data to a non-volatile memory medium in response to a failure condition. A mapping module is configured to determine whether to associate a range of data with the auto-commit memory. A bypass module is configured to service a request for the range of data directly from the auto-commit memory in response to the auto-commit mapping module determining to associate the range of data with the auto-commit memory.

Claims

1. A method comprising:

receiving a request for data, the request comprising a namespace identifier;

identifying a relationship between the namespace identifier and a memory configured to commit data to non-volatile media in response to a restart event; and

satisfying the request using the buffer in response to the identified relationship associating the namespace identifier with the auto-commit buffer.

2. The method of claim 1, wherein a user space device driver receives and satisfies the request using the memory directly without passing the request through an operating system storage stack.

3. The method of claim 1, further comprising satisfying the request using the non-volatile media in response to the identified relationship associating the namespace identifier with the non-volatile media.

4. The method of claim 1, wherein satisfying the request using the memory comprises mapping the data into virtual memory of a requesting client.

5. The method of claim 4, further comprising unmapping the data from virtual memory in response to access to the virtual memory exceeding a traffic threshold for the virtual memory.

6. The method of claim 1, further comprising,

arming the memory with metadata specifying a logical block address of the non-volatile media to which the data of the memory is to be committed in response to the restart event, the namespace identifier persistently mapped to the logical block address;

and

committing the data of the memory to the logical block address of the non-volatile media in response to detecting the restart event.

7. The method of claim 1, further comprising,

tracking which portions of data of the memory have been updated;

and

committing the updated portions of data of the memory to the non-volatile media separately from non-updated portions in response to detecting the restart event.

8. The method of claim 1, wherein the namespace identifier is a member of a persistent namespace, the persistent namespace configured to survive the restart event and configured to grant a client access to data of the namespace identifier subsequent to the restart event.

9. The method of claim 8, wherein the persistent namespace comprises a logical unit number (LUN) namespace for a storage device of the non-volatile media and the namespace identifier comprises a LUN address within the LUN namespace.

10. The method of claim 8, wherein the persistent namespace comprises a file system namespace and the namespace identifier comprises a file identifier of the file system namespace.

11. The method of claim 1, wherein identifying the relationship between the namespace identifier and the memory comprises one of identifying an existing relationship between the namespace identifier and the memory, and creating a relationship between the namespace identifier and the memory.

12. The method of claim 1, wherein the relationship associates the namespace identifier with the memory in response to one or more of detecting an existing relationship between the namespace identifier and the memory;

detecting an auto-commit flag for the request; and

dynamically assigning the namespace identifier for association with the memory.

13. The method of claim 1, wherein the memory is within an isolation zone of a non-volatile device comprising the non-volatile media and the isolation zone is configured to receive power from a secondary power source.

14. The method of claim 13, wherein a storage capacity of a plurality of memory buffers, including the memory, within the isolation zone is selected such that a power hold-up time provided by the secondary power source allows the plurality of memory buffers to commit data to the non-volatile media during the power hold-up time in response to the restart event.

15. An apparatus comprising:

an auto-commit memory module configured to cause an auto-commit memory to commit stored data to a non-volatile memory medium in response to a failure condition;

a mapping module configured to determine whether to associate a range of addresses for data with the auto-commit memory; and

a bypass module configured to service a request for the range of addresses for data directly from the auto-commit memory in response to the auto-commit mapping module determining to associate the range of addresses for data with the auto-commit memory.

16. The apparatus of claim 15, further comprising a request module configured to receive the request for the range of addresses for data, the mapping module configured to determine to associate the range of addresses for data with the auto-commit memory in response to an auto-commit flag of the request.

17. The apparatus of claim 15, further comprising a request module configured to intercept requests for the non-volatile memory medium, the mapping module configured to dynamically determine to associate the range of addresses for data with the auto-commit memory in response to the request module intercepting the request for the range of addresses.

18. The apparatus of claim 15, wherein the bypass module is configured to service the request for the range of addresses for data directly from the auto-commit memory by bypassing a kernel storage stack and satisfying the request from user-space.

19. The apparatus of claim 15, wherein the request for the range of addresses for data comprises a write request and the bypass module is configured to service the write request by copying data of the write request into a virtual memory location of a requesting client in response to the mapping module determining to associate the range of addresses for data with the auto-commit memory, the virtual memory location backed by the auto-commit memory.

20. A system comprising:

a recording device comprising one or more auto-commit pages configured to preserve data of the auto-commit pages in response to a restart event; and

a device driver for the recording device, the device driver configured to cause the data of the auto-commit pages to be mapped, from kernel-space, into virtual memory and to service requests, from user-space, for the data of the auto-commit pages.

21. The system of claim 20, further comprising a host associated with the virtual memory, the host comprising a processor in communication with the recording device, the device driver executing on the processor.

22. A computer program product comprising a computer readable storage medium storing computer usable program code executable to perform operations, the operations comprising:

intercepting a storage request for a memory device, the storage request comprising a file identifier and an offset;

servicing the storage request from an auto-commit memory of the memory device in response to determining that the offset and the file identifier are mapped to the auto-commit memory; and

mapping the offset and the file identifier to the auto-commit memory in response to determining that the file identifier is not mapped to the auto-commit memory.

23. The computer program product of claim 22, wherein the operations further comprise enforcing file system access permissions for data of the offset and the file identifier using virtual memory access controls.

24. An apparatus comprising:

means for associating a logical identifier with a page of auto-commit memory;

means for bypassing an operating system storage stack to satisfy a storage request for data of the page of auto-commit memory directly; and

means for preserving the data of the page of auto-commit memory in response to a failure condition.

25. The apparatus of claim 24, further comprising means for providing access to the preserved data after the failure condition.