Namespace change propagation in non-volatile memory devices

• US 10,223,254 B1
• Filed: 11/16/2017
• Issued: 03/05/2019
• Est. Priority Date: 11/16/2017
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Frolikov, Alex
• Primary Examiner(s): Rigol, Yaima
• Application Number:
  US15/814,634
• Time in Patent Office: 474 Days
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0811 with multilevel cache hierarchies
• CPC Class Codes: G06F 12/0884 Parallel mode, e.g. in parallel with main memory or CPU
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A computer storage device having a host interface, a controller, non-volatile storage media, and firmware. The firmware instructs the controller to: generate mapping data defining mapping, from logical block addresses in namespaces configured on the non-volatile storage media, to logical block addresses in a capacity of the non-volatile storage media; maintain an active copy of the mapping data; generate cached copies of the mapping data from the active copy; generate a shadow copy from the active copy; implement changes in the shadow copy; after the changes are made in the shadow copy, activate the shadow copy and simultaneously deactivate the previously active copy; and update the cached copies according to the newly activated copy, as a response to the change in active copy identification.

Claims

1. A computer storage device, comprising:

a controller;

non-volatile storage media; and

firmware containing instructions which, when executed by the controller, instruct the controller to at least;

identify a first copy of mapping data as active, the mapping data defining mapping, from logical block addresses in one or more namespaces configured on the non-volatile storage media, to logical block addresses in a capacity of the non-volatile storage media;

cache the first copy in one or more memory areas in the computer storage device as one or more second copies of the mapping data in one or more running instances of a first component of the firmware;

replicate the first copy to create a third copy;

implement changes in the third copy while the first copy is being identified as active;

after the changes are made in the third copy, identify the third copy as active and simultaneously make the first copy inactive; and

update the one or more second copies according to the third copy in response to making the third copy active and the first copy inactive.

2. The computer storage device of claim 1, wherein the controller includes a plurality of processors that execute the one or more running instances of the first component of the firmware in parallel.

3. The computer storage device of claim 2, wherein the one or more memory areas are in cache memory of the plurality of processors.

4. The computer storage device of claim 2, wherein the one or more memory areas are different sections of the non-volatile storage media that can be accessed in parallel.

5. The computer storage device of claim 2, further comprising:

a plurality of sections of dynamic random access memory that can be accessed in parallel, wherein each of the one or more second copies is on a separate section of the plurality of sections.

6. The computer storage device of claim 2, wherein the first component of the firmware is not allowed to change mapping, from logical block addresses in one or more namespaces configured on the non-volatile storage media, to logical block addresses in the capacity of the non-volatile storage media.

7. The computer storage device of claim 6, wherein the computer storage device contains no more than a single running instance of a second component of the firmware that is allowed to change mapping, from logical block addresses in one or more namespaces configured on the non-volatile storage media, to logical block addresses in the capacity of the non-volatile storage media.

8. The computer storage device of claim 7, further comprising:

an active indicator, wherein the firmware causes the active indicator to identify the first copy as being active before the changes are implemented in the third copy and the third copy as being active after the changes are implemented in the third copy.

9. The computer storage device of claim 8, wherein, in response to a change in the active indicator, the firmware causes the one or more running instances to invalidate the one or more second copies cached for the one or more running instances of the first component of the firmware.

10. The computer storage device of claim 1, wherein, in response to implementing the changes in the third copy while the first copy is being identified as active, the firmware causes identification of a particular namespace and transmission of a request to the one or more running instances of the first component of the firmware to pause or delay data access in the particular namespace.

11. The computer storage device of claim 10, wherein the request is discarded after the second copies are updated according to the third copy.

12. The computer storage device of claim 11, wherein the request is generated in accordance with a data access policy configured in the computer storage device.

13. The computer storage device of claim 10, wherein the request causes a pause in data write operations in the particular namespace, but not in data read operations in the particular namespace.

14. The computer storage device of claim 10, wherein the request causes a pause in data read operations in the particular namespace, but not in data write operations in the particular namespace.

15. A method implemented in a computer storage device, the method comprising:

storing a first copy of mapping data, the mapping data defining mapping, from logical block addresses in one or more namespaces configured on a non-volatile storage media of the computer storage device, to logical block addresses in a capacity of the non-volatile storage media;

configuring an active indicator to identify the first copy as active;

caching the first copy in one or more memory areas in the computer storage device as one or more second copies of the mapping data in one or more running instances of a first firmware component being executed by a controller of the computer storage device;

replicating the first copy to create a third copy;

changing the third copy while the first copy is being identified as active;

after changing the third copy, changing the active indicator to identify the third copy as active and thus simultaneously render the first copy inactive; and

in response to the changing of the active indicator, updating the second copies according to the third copy.

16. The method of claim 15, wherein the controller includes a plurality of processors that execute the one or more running instances of the first component of the firmware in parallel;

and different ones of the second copies are in one of;

cache memory of different ones of the processors;

different sections of dynamic random access memory of the computer storage device that can be accessed in parallel; and

different sections of the non-volatile storage media that can be accessed in parallel.

17. The method of claim 16, wherein the computer storage device contains no more than a single running instance of firmware that is capable of changing mapping, from logical block addresses in one or more namespaces configured on the non-volatile storage media, to logical block addresses in the capacity of the non-volatile storage media.

18. A non-transitory computer storage medium storing instructions which, when executed by a controller of a computer storage device, cause the controller to perform a method, the method comprising:

storing a first copy of mapping data, the mapping data defining mapping, from logical block addresses in one or more namespaces configured on a non-volatile storage media of the computer storage device, to logical block addresses in a capacity of the non-volatile storage media;

configuring an active indicator to identify the first copy as active;

caching the first copy in one or more memory areas in the computer storage device as one or more second copies of the mapping data in one or more running instances of a first instruction component being executed by a controller of the computer storage device;

replicating the first copy to create a third copy;

changing the third copy while the first copy is being identified as active;

after changing the third copy, changing the active indicator to identify the third copy as active and thus simultaneously rendering the first copy inactive; and

in response to the changing of the active indicator, updating the second copies according to the third copy.

19. The non-transitory computer storage medium of claim 18, wherein the method further comprises, in response to a determination to change mapping from logical block addresses in one or more namespaces configured on the non-volatile storage media, to logical block addresses in the capacity of the non-volatile storage media:

identifying a particular namespace; and

transmitting a request to the one or more running instances of the first component of the firmware to pause or delay data access operations in the particular namespace.

20. The non-transitory computer storage medium device of claim 19, wherein the data access operations are identified accordance with a data access policy configured in the computer storage device and includes at least one of:

data write operations in the particular namespace; and

data read operations in the particular namespace.