Data storage device using metadata and mapping table to identify valid user data on non-volatile media

• US 8,667,248 B1
• Filed: 06/16/2011
• Issued: 03/04/2014
• Est. Priority Date: 08/31/2010
• Status: Active Grant

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Neppalli, Srinivas
• Primary Examiner(s): Rones, Charles
• Assistant Examiner(s): BIRKHIMER, CHRISTOPHER D
• Application Number:
  US13/162,035
• Time in Patent Office: 992 Days
• Field of Search: None
• US Class Current: 711/202
• CPC Class Codes: G06F 12/0238 Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 2212/7207 management of metadata or control data

Abstract

A data storage device is disclosed including a non-volatile media having a first and a second plurality of physical locations, the first plurality of physical locations storing user data and the non-volatile media storing first metadata associating each of the first plurality of physical locations with a logical block address (LBA), and a mapping table including a mapping of each LBA to a current physical location. The data storage device further includes control circuitry that reads the first metadata to obtain a first plurality of LBAs, reads the mapping table to determine a current physical location for the first plurality of LBAs, and compares the current physical location of each of the first plurality of LBAs to a corresponding one of the first plurality of physical locations to identify valid user data in the first plurality of physical locations for migration into the second plurality of physical locations.

Claims

1. A data storage device comprising:

a non-volatile media comprising a first and a second plurality of physical locations, the first plurality of physical locations storing user data and the non-volatile media storing first metadata associating each of the first plurality of physical locations with a logical block address (LBA);

a mapping table comprising a mapping of each LBA to a current physical location; and

control circuitry operable to;

read the first metadata to obtain a first plurality of LBAs;

read the mapping table to determine a current physical location for the first plurality of LBAs; and

compare the current physical location from the mapping table of each of the first plurality of LBAs to a corresponding one of the first plurality of physical locations to identify valid user data in the first plurality of physical locations for migration into the second plurality of physical locations, wherein the valid user data is user data in a physical location of the first plurality of physical locations that matches the current physical location.

2. The data storage device as recited in claim 1, wherein the control circuitry is further operable to:

write the valid user data into the second plurality of physical locations, and

determine second metadata associating each of the first plurality of LBAs associated with valid user data to a corresponding one of the second plurality of physical locations.

3. The data storage device as recited in claim 2, wherein the control circuitry is further operable to update the mapping table after writing each valid user data into the second plurality of physical locations.

4. The data storage device as recited in claim 2, wherein writing the valid user data into the second plurality of physical locations occurs during a garbage collection operation.

5. The data storage device as recited in claim 2, wherein the non-volatile media comprises a disk surface comprising a circular buffer having a head and a tail, and wherein the first plurality of physical locations is located at the tail of the circular buffer and the second plurality of physical locations is located at the head of the circular buffer.

6. The data storage device as recited in claim 2, where the control circuitry is further operable to write the second metadata into one of the second plurality of physical locations.

7. The data storage device as recited in claim 2, wherein the non-volatile media comprises a disk surface comprising a first zone comprising a first plurality of tracks and a second zone comprising a second plurality of tracks, and wherein the first plurality of physical locations are located on at least one of the first plurality of tracks and the second plurality of physical locations are located on at least one of the second plurality of tracks.

8. The data storage device as recited in claim 7, wherein the control circuitry is further operable to sequentially write in one direction the valid user data into the second plurality of physical locations on at least one of the second plurality of tracks.

9. The data storage device as recited in claim 7, wherein the control circuitry is further operable to write the second metadata on at least one of the second plurality of tracks.

10. The data storage device as recited in claim 1, wherein the control circuitry is further operable to:

add the physical location of each valid user data to a valid data list; and

write each valid user data in the valid data list into the second plurality of physical locations.

11. The data storage device as recited in claim 1, further comprising a semiconductor memory comprising a buffer, wherein the control circuitry is further operable to:

write each valid user data from a corresponding one of the first plurality of physical locations into the buffer; and

write each valid user data from the buffer into one of the second plurality of physical locations.

12. The data storage device as recited in claim 1, wherein the control circuitry is further operable to:

determine second metadata associating each of the first plurality of LBAs with valid user data to a corresponding one of the second plurality of physical locations; and

write the valid user data and the second metadata into the second plurality of physical locations.

13. A method of operating a data storage device, the data storage device comprising a non-volatile media comprising a first and a second plurality of physical locations, the first plurality of physical locations storing user data and the non-volatile media storing first metadata associating each of the first plurality of physical locations with a logical block address (LBA), and a mapping table comprising a mapping of each LBA to a current physical location, the method comprising:

reading the first metadata to obtain a first plurality of LBAs;

reading the mapping table to determine a current physical location for the first plurality of LBAs; and

comparing the current physical location from the mapping table of each of the first plurality of LBAs to a corresponding one of the first plurality of physical locations to identify valid user data in the first plurality of physical locations for migration into the second plurality of physical locations, wherein the valid user data is user data in a physical location of the first plurality of physical locations that matches the current physical location.

14. The method as recited in claim 13, further comprising:

writing the valid user data into the second plurality of physical locations, and

determining second metadata associating each of the first plurality of LBAs associated with valid user data to a corresponding one of the second plurality of physical locations.

15. The method as recited in claim 14, further comprising updating the mapping table after writing each valid user data into the second plurality of physical locations.

16. The method as recited in claim 14, further comprising writing the valid user data into the second plurality of physical locations during a garbage collection operation.

17. The method as recited in claim 14, wherein the non-volatile media comprises a disk surface comprising a circular buffer having a head and a tail, and wherein the first plurality of physical locations is located at the tail of the circular buffer and the second plurality of physical locations is located at the head of the circular buffer.

18. The method as recited in claim 14, further comprising writing the second metadata into one of the second plurality of physical locations.

19. The method as recited in claim 14, wherein the non-volatile media comprises a disk surface comprising a first zone comprising a first plurality of tracks and a second zone comprising a second plurality of tracks, and wherein the first plurality of physical locations are located on at least one of the first plurality of tracks and the second plurality of physical locations are located on at least one of the second plurality of tracks.

20. The method as recited in claim 19, further comprising sequentially writing in one direction the valid user data into the second plurality of physical locations on at least one of the second plurality of tracks.

21. The method as recited in claim 19, further comprising writing the second metadata on at least one of the second plurality of tracks.

22. The method as recited in claim 13, further comprising:

adding the physical location of each valid user data to a valid data list; and

writing each valid user data in the valid data list into the second plurality of physical locations.

23. The method as recited in claim 13, wherein:

the data storage device further comprises a semiconductor memory comprising a buffer; and

further comprising;

writing each valid user data from a corresponding one of the first plurality of physical locations into the buffer; and

writing each valid user data from the buffer into one of the second plurality of physical locations.

24. The method as recited in claim 13, further comprising:

determining second metadata associating each of the first plurality of LBAs with valid user data to a corresponding one of the second plurality of physical locations; and

writing the valid user data and the second metadata into the second plurality of physical locations.