Methods and apparatus for file management using partitioned file metadata

• US 7,970,806 B2
• Filed: 01/17/2008
• Issued: 06/28/2011
• Est. Priority Date: 10/12/2007
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Go, Gwang-ok, Park, Jeong-woo, Cho, Jun-young
• Primary Examiner(s): Trujillo; James
• Assistant Examiner(s): Davanlou; Soheila
• Application Number:
  US12/015,878
• Publication Number:
  US 20090100115A1
• Time in Patent Office: 1,258 Days
• Field of Search: 707/999.002, 707/999.205, 707/824, 707/828
• US Class Current: 707/824
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 16/1847 specifically adapted to static storage, e.g. adapted to flash memory or SSD
• CPC Class Codes: G06F 2212/1044 Space efficiency improvement
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 2212/7207 management of metadata or control data
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

Management of files in a memory, such as a flash memory, includes storing in the memory a first node including a first type of metadata of the file, a second node including data of the file and a third node including a second type of metadata of the file including file status and memory location information for the first and second nodes. The third node may include a node including memory location information for the second node and a node including an index table that cross-references a memory location for the memory location information for the second node to a memory location of the first node. Methods and devices may be provided.

Claims

1. A method of managing a file in a memory, the method comprising:

storing in the memory a first node comprising a first type of metadata of the file, a second node comprising data of the file and a third node comprising a second type of metadata of the file comprising file status and memory location information for the first and second nodes, wherein the third node comprises a node comprising memory location information for the second node and a node comprising an index table that cross-references a memory location for the memory location information for the second node to a memory location of the first node.

2. The method of claim 1, further comprising performing a file write operation wherein data of the file and the second type of metadata of the file are written as new nodes in the memory without writing the first type metadata in a new node in the memory.

3. The method of claim 2, further comprising periodically writing new nodes comprising respective portions of the data of the file and new nodes comprising the second type of metadata including memory location information for nodes comprising the portions of the data.

4. The method of claim 1, further comprising:

retrieving memory locations for nodes comprising the first type of metadata based on the index table;

reading nodes comprising the first type of metadata responsive to the retrieved memory locations;

identifying the first node from among the read nodes comprising the first type of metadata;

retrieving a memory location of the node comprising memory location information for the second node corresponding to the identified first node; and

accessing the second node responsive to the retrieved memory location of the node comprising memory location information for the second node corresponding to the identified first node.

5. The method of claim 1, further comprising:

reading the third node to retrieve memory location information for the first node and/or the second node; and

accessing the first node and/or the second node based on the retrieved memory location information.

6. The method of claim 1, wherein the first type of metadata comprises information less likely to change than the second type of metadata.

7. The method of claim 1, wherein the first type of metadata comprises file identification information and/or file creation information and wherein the second type of metadata comprises file status information.

8. The method of claim 1, wherein the memory is arranged as a plurality of blocks, each comprising a plurality of pages, and wherein the second node is allocated a page.

9. A method of managing a file in memory, the method comprising:

managing a first class of metadata of the file comprising file identification information and a second class of metadata of the file comprising file state information and memory location information of the file as respective first and second types of nodes in the memory.

10. The method of claim 9, wherein, over a series of write operations for the file, the second type of node is written to the memory more frequently than the first type of node.

11. The method of claim 9 comprising, in a file write operation for the file, writing a new node of the second type to a new memory location without writing a new node of the first type.

12. An apparatus comprising:

a memory control circuit configured to communicate with a memory; and

a file system manager circuit operatively coupled to the memory control circuit and configured to cause the memory control circuit to store in the memory a first node comprising a first type of metadata of a file, a second node comprising data of the file and a third node comprising a second type of metadata of the file comprising file status and memory location metadata for the first and second nodes, wherein the third node comprises a node comprising memory location information for the second node and a node comprising an index table that cross-references a memory location for the memory location information for the second node to a memory location of the first node.

13. The apparatus of claim 12, wherein the file system manager circuit is configured to cause a file write operation wherein data of the file and the second type of metadata of the file are written as new nodes in the memory without writing the first type metadata in a new node in the memory.

14. The apparatus of claim 13, wherein the file system manager circuit is configured to cause periodic writing of new nodes comprising respective portions of the data of the file and new nodes comprising the second type of metadata including memory location information for nodes comprising the portions of the data.

15. The apparatus of claim 12, wherein the first type of metadata comprises information less likely to change than the second type of metadata.

16. The apparatus of claim 12, wherein the first type of metadata comprises file identification information and/or file creation information and wherein the second type of metadata comprises file status information.

17. A computer program product comprising computer program code embodied in a computer-readable storage medium, the computer program code comprising:

program code configured to cause storage in the memory of a first node comprising a first type of metadata of a file, a second node comprising data of the file in the memory and a third node comprising a second type of metadata of the file comprising file status and memory location information for the first and second nodes, wherein the third node comprises a node comprising memory location information for the second node and a node comprising an index table that cross-references a memory location for the memory location information for the second node to a memory location of the first node.

18. The computer program product of claim 17, wherein the computer program code further comprises program code configured to cause a file write operation wherein data of the file and the second type of metadata of the file are written as new nodes in the memory without writing the first type metadata in a new node in the memory.

19. The computer program product of claim 18, wherein the computer program code further comprises program code configured to cause periodic writing of new nodes comprising respective portions of the data of the file and new nodes comprising the second type of metadata including memory location information for nodes comprising the portions of the data.

20. A memory device comprising:

a storage medium wherein a file is stored as a first node comprising a first type of metadata of the file, a second node comprising data of the file and a third node comprising a second type of metadata of the file including file status information and memory location information for the first and second nodes, wherein the third node comprises a node comprising memory location information for the second node and a node comprising an index table that cross-references a memory location for the memory location information for the second node to a memory location of the first node.

21. The device of claim 20, wherein the first type of metadata comprises information less likely to change than the second type of metadata.