TRANSACTION-SAFE FAT FILE SYSTEM IMPROVEMENTS

• US 20080177939A1
• Filed: 03/27/2008
• Published: 07/24/2008
• Est. Priority Date: 10/22/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Gopalan, Yadhu N., Patel, Sachin
• Granted Patent: US 8,024,507 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 16/1865 Transactional file systems
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• 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]
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

Concepts for enhancing operation of transaction-safe file allocation table systems are described. The concepts include writing a file to non-volatile memory media and rendering an update of file size to the TFAT storage medium; and receiving a request to locate data in a non-volatile memory having a TFAT file management system, selecting a sector of the memory to parse to locate the data, determining when the selected sector is a first sector of a directory or subdirectory of the memory and when determining reveals that the selected sector is a first sector, skipping reading data from the selected sector. The concepts also include flushing a cache and synchronizing FATs.

Claims

1. One or more computer readable media having stored thereon a plurality of instructions that, when executed by one or more processors, causes the one or more processors to locate data on a storage medium such that the one or more processors perform acts including:

receiving a request to locate data in a non-volatile memory having a TFAT file management system;

selecting a sector of the memory to parse to locate the data;

determining when the selected sector is a first sector of a directory or subdirectory of the memory; and

when determining reveals that the selected sector is a first sector, skipping reading data from the selected sector.

2. The computer readable media of claim 1, wherein the instructions to cause the one or more processors to locate data comprise instructions to locate data stored in a solid state non-volatile memory.

3. The computer readable media of claim 1, wherein, when determining reveals the selected sector is not a first sector, reading information from the selected sector to compare to search criteria.

4. The computer readable media of claim 1, wherein, when determining reveals that the selected sector is a first sector, selecting another sector and iterating determining when the another selected sector is a first sector of a directory or subdirectory of the memory;

and

when determining reveals that the another selected sector is a first sector, skipping reading data from the selected sector.

5. The computer readable media of claim 1, further comprising, when determining reveals that the selected sector is a first sector, incrementing to another sector.

6. A process performed at least in part by a computer, the process comprising:

receiving a request to locate data in a non-volatile memory having a TFAT file management system;

selecting a sector of the non-volatile memory to parse to locate the data;

determining if the selected sector is a first sector of a directory or subdirectory of the non-volatile memory; and

when determining reveals that the selected sector is a first sector, skipping reading data from the selected sector.

7. The process of claim 6, further comprising locating the data within the non-volatile memory.

8. The process of claim 6, further comprising reading information from the selected sector to compare to search criteria when the determining reveals that the selected sector is not a first sector.

9. The process of claim 6, wherein:

when the determining reveals that the selected sector is a first sector, selecting another sector and determining if the another sector is a first sector of a directory or subdirectory of the memory; and

when the determining reveals that the another sector is a first sector, skipping reading data from the another sector.

10. The process of claim 6, further comprising incrementing to another sector when the determining reveals that the selected sector is a first sector.

11. The process of claim 10, further comprising:

reading information from the another sector to compare to search criteria; and

returning a message when the comparison reveals that the data has been located within the another sector.

12. The process of claim 10, further comprising determining if the another sector is a last sector to be searched.

13. The process of claim 12, further comprising returning a message in accordance with determining that the another sector is the last sector be searched.

14. A system configured to:

receive a request to locate data within a non-volatile memory having a TFAT file management system;

select a sector of the non-volatile memory to parse to locate the data;

determine if the selected sector is a first sector of a directory or subdirectory of the non-volatile memory and, when the determination reveals that the selected sector is a first sector, skip reading data from the selected sector.

15. The system of claim 14, the system further configured to locate the data within the non-volatile memory.

16. The system of claim 14, the system further configured to:

read information from the selected sector; and

compare the information to search criteria to determine if the data is located within the selected sector.

17. The system of claim 14, the system further configured to:

select another sector of the non-volatile memory in response to determining that the selected sector is a first sector;

determine if the another sector is a first sector of a directory or subdirectory of the non-volatile memory; and

skip reading data from the another sector in response to determining that the another sector is a first sector.

18. The system of claim 17, the system further configured to:

read information from the another sector in response to determining that the another sector is not a first sector;

compare the information to search criteria; and

returning a message when the comparison reveals that the data has been located within the another sector.

19. The system of claim 17, the system further configured to determine if the another sector is a last sector to be searched.

20. The system of claim 19, the system further configured to return a message in accordance with determining that the another sector is the last sector be searched.