Apparatus, system, and method for ensuring data validity in a data storage process

• US 8,316,277 B2
• Filed: 04/05/2008
• Issued: 11/20/2012
• Est. Priority Date: 12/06/2007
• Status: Active Grant

• Current Assignee: Unification Technologies LLC (Acacia Research Corporation)
• Original Assignee: Fusion-IO Incorporated (Western Digital Corporation)
• Inventors: Flynn, David, Thatcher, Jonathan, Strasser, John
• Primary Examiner(s): MASKULINSKI, MICHAEL C
• Application Number:
  US12/098,427
• Publication Number:
  US 20090150744A1
• Time in Patent Office: 1,690 Days
• Field of Search: None
• US Class Current: 714/763
• CPC Class Codes: G06F 11/1048 using arrangements adapted for a specific error detection or correction feature
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0674 Disk device
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H05K 7/1444 Complex or three-dimensional-arrangements; Stepped or dual mother boards

Abstract

An apparatus, system, and method are disclosed for ensuring data validity in a data storage process. A data receiver module receives a storage block and existing parity information. An ECC generation module generates error correcting code (“ECC”) check bits for the data of the storage block in response to receiving the storage block and the existing parity information. The ECC check bits for the storage block are generated using a block code, a convolutional code, etc. A pre-storage consistency module uses the data of the storage block, the existing parity information, and the ECC check bits to determine if the data of the storage block, the existing parity information, and the ECC check bits are consistent. A data storage module stores the data of the storage block and the ECC check bits the data storage device without storing the existing parity information.

Claims

1. An apparatus to protect data, the apparatus comprising:

an ECC generation module configured to generate error correcting code (“

ECC”

) check bits for data of a storage block in response to receiving the storage block and existing parity information generated for the storage block;

a pre-storage consistency module configured to use the data of the storage block, the existing parity information, and the ECC check bits to determine if the data of the storage block, the existing parity information, and the ECC check bits are consistent; and

a data storage module configured to store the data of the storage block and the ECC check bits for the storage block on a data storage device, wherein the existing parity information for the storage block is not stored on the data storage device;

wherein the ECC generation module, the pre-storage consistency module, and the data storage module comprise one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

2. The apparatus of claim 1, wherein the pre-storage consistency module is independent of the ECC generation module.

3. The apparatus of claim 1, further comprising an ECC check bit parity module configured to use the ECC check bits to generate ECC check bit parity information and wherein the pre-storage consistency module uses the ECC check bit parity information to determine consistency;

wherein the ECC check bit parity module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

4. The apparatus of claim 3, wherein the pre-storage consistency module is configured to use the data of the storage block and the existing parity information in a function independent from the ECC generation module and the ECC check bit parity module to generate alternate parity information and to check the alternate parity information against the ECC check bit parity information to determine consistency.

5. The apparatus of claim 1, further comprising:

a data retriever module configured to retrieve a storage block stored on the data storage device and ECC check bits for data of the retrieved storage block in response to a read request;

a parity generation module configured to generate parity information for the data of the retrieved storage block and for the ECC check bits;

an ECC detection module that uses the ECC check bits stored in conjunction with the retrieved storage block to generate an ECC syndrome to determine if the data of the retrieved storage block and the generated parity has an error;

and a post-storage consistency module configured to use the data from the retrieved storage block, the generated parity information generated by the parity generation module, and the ECC syndrome to determine if the data, generated parity information, and the ECC syndrome are consistent;

wherein the data retriever module, the parity generation module, the ECC detection module, and the post-storage consistency module comprise one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

6. The apparatus of claim 5, further comprising an ECC correction module configured to correct one or more errors in the data of the storage block and to update one or more parity bits in response to the ECC detection module determining that the data of the retrieved storage block and the generated parity has an error;

wherein the ECC correction module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

7. The apparatus of claim 5, further comprising an ECC syndrome parity module configured to use the ECC syndrome to generate ECC syndrome parity information and wherein the post-storage consistency module is configured to use the ECC syndrome parity information to determine consistency;

wherein the ECC syndrome parity module comprises one or more of logic hardware and executable code stored on a non- transitory computer readable medium.

8. The apparatus of claim 5, further comprising a post-retrieval parity check module configured to check parity of the retrieved storage block and the ECC check bits using the generated parity information from the retrieved storage block and ECC check bits in response to the ECC detection module completing determining if the data of the retrieved storage block has an error;

wherein the post-retrieval parity check module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

9. The apparatus of claim 1, wherein the ECC generation module is configured to generate an error checking code for the existing parity information of the storage block, the error checking code stored with the ECC check bits for the storage block.

10. The apparatus of claim 1, wherein the ECC generation module is configured to generate ECC check bits for the data of the storage block combined with the existing parity information such that the generated ECC check bits do not distinguish between data and parity information.

11. The apparatus of claim 1, further comprising a pre-storage parity check module configured to check parity of the data of the storage block using the existing parity information and a parity of the ECC check bits, wherein the parity check module checks parity prior to the data storage module storing the storage block and ECC check bits.

12. The apparatus of claim 1, further comprising a decoding module configured to decode data of the storage block, resulting in parity and un-encoded data of the storage block, in a single process step such that there is no gap in error detection capability;

wherein the decoding module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

13. The apparatus of claim 1, further comprising a parity consistency module configured to maintain no gap in error detection capability by using parity information for the data of the storage block from the decoding module generating the parity until the data receiver module receives the parity and the data in the form of the storage block, wherein the parity consistency module is configured to maintain parity through at least one of encrypting the data, compressing the data, and a user-defined, application-specific function;

wherein the parity consistency module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

14. The apparatus of claim 1, wherein the data storage module does not store parity information of the ECC check bits.

15. A system to protect data, the system comprising:

a data storage device;

a storage controller that controls storage of data in the data storage device;

an ECC generation module configured to generate error correcting code (“

ECC”

) check bits for data of a storage block in response to receiving the storage block and existing parity information generated for the storage block;

a pre-storage consistency module configured to use the data of the storage block, the existing parity information, and the ECC check bits to determine if the data of the storage block, the existing parity information, and the ECC check bits are consistent;

wherein the pre-storage consistency module is independent of the ECC generation module; and

a data storage module configured to store the data of the storage block and the ECC check bits for the storage block on the data storage device in response to the pre-storage consistency module determining that the data of the storage block, the existing parity information, and the ECC check bits are consistent, wherein the existing parity information for the storage block is not stored on the data storage device;

wherein the ECC generation module, the pre-storage consistency module, and the data storage module comprise one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

16. The system of claim 15, further comprising one or more of a system bus and a network, the storage controller configured to receive the storage block from one of a CPU and a memory over at least one of the system bus and the network.

17. The system of claim 15, further comprising an overall consistency module configured to maintain protection of the data with no gap in error detection capability from receipt of the data until the data storage module stores the data of the storage block;

wherein the overall consistency module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

18. The system of claim 15, wherein further comprising a decoding module configured to decode data of the storage block, resulting in parity and un-encoded data of the storage block, in a single process step such that there is no gap in error detection capability from when the data is in an encoded form to when the data includes parity information;

wherein the decoding module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

19. The system of claim 15, further comprising an encoding module configured to encode data of the storage block protected with parity information, resulting in encoded data of the storage block, in a single process step such that there is no gap in error detection capability from when the data includes parity information to when the data is in an encoded form;

wherein the encoding module comprises one or more of logic hardware and executable code stored on a non-transitory computer readable medium.

20. A computer program product comprising a non-transitory computer readable medium having computer usable program code stored thereon, the code being executable to perform operations for protecting data, the operations of the computer program product comprising:

generating error correcting code (“

ECC”

) check bits for data of a storage block in response to receiving the storage block and existing parity information generated for the storage block;

using the data of the storage block, the existing parity information, and the ECC check bits to determine if the data of the storage block, the existing parity information, and the ECC check bits are consistent; and

storing the data of the storage block and the ECC check bits for the storage block on a data storage device in response to determining that the data of the storage block, the existing parity information, and the ECC check bits are consistent, wherein the existing parity information for the storage block is not stored on the data storage device.

21. A method for protecting data, the method comprising:

generating error correcting code (“

ECC”

) check bits for data of a storage block in response to receiving the storage block and existing parity information generated for the storage block;

determining if the data of the storage block, the existing parity information, and the ECC check bits are consistent using the data of the storage block, the existing parity information, and the ECC check bits; and

storing the data of the storage block and the ECC check bits for the storage block on a data storage device, wherein the existing parity information for the storage block is not stored on the data storage device.

22. The method of claim 21, further comprising:

generating ECC check bit parity information using the ECC check bits; and

determine consistency using the ECC check bit parity information.

23. The method of claim 22, further comprising:

generating alternate parity information using the data of the storage block and the existing parity information; and

checking the alternate parity information against the ECC check bit parity information to determine consistency.

24. The method of claim 21, further comprising:

retrieving a storage block stored on the data storage device and ECC check bits for data of the retrieved storage block in response to a read request;

generating parity information for the data of the retrieved storage block and for the ECC check bits;

generating an ECC syndrome, using the ECC check bits stored in conjunction with the retrieved storage block, to determine if the data of the retrieved storage block and the generated parity has an error; and

determining if the data, the generated parity information, and the ECC syndrome are consistent using the data from the retrieved storage block, the generated parity information for the data of the retrieved storage block, and the ECC syndrome.

25. The method of claim 24, further comprising correcting one or more errors in the data of the retrieved storage block and updating one or more parity bits, each in response to determining that the data of the retrieved storage block and the generated parity has an error.

26. The method of claim 21, further comprising checking parity of the data of the storage block using the existing parity information and parity information for the ECC check bits prior to storing the storage block and ECC check bits.

27. The method of claim 21, further comprising decoding data of the storage block, resulting in parity and un-encoded data of the storage block, in a single process step without a gap in error detection capability.