FILE SYSTEM, AND METHOD FOR STORING AND SEARCHING FOR FILE BY THE SAME

• US 20080155171A1
• Filed: 12/21/2007
• Published: 06/26/2008
• Est. Priority Date: 12/26/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: JEONG, Soon-Yong
• Granted Patent: US 8,099,421 B2
• Time in Patent Office: Days
• US Class Current: 711/101
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31

Abstract

A file system and a method for file storage and file search by the same are provided. All files have unique names in a block-based storage device, such as a hard disk, a flash memory, etc., so that each file is mapped and stored in a one-dimensional storage area. Each file name is matched with a memory block storing data of the corresponding file so that a memory block corresponding to a file name can be found when the file name is input. In addition, through information stored in the found memory block, the data corresponding to the file name can be read from the memory block storing the data or can be stored in a specific memory block.

Claims

1. A file system for storing a file, the file system comprising:

a conversion unit for creating a name of a file to be stored and converting a created file name into memory block information about a specific memory block;

a storage unit including a plurality of memory blocks, which contains a memory block corresponding to the memory block information converted from the file name, and at least one memory block to store data corresponding to the file name; and

a data management unit for selecting memory block corresponding to the memory block information and the at least one memory block to store the data, storing detailed information about the file and information about the at least one memory block selected to store the data in the memory block corresponding to the memory block information, and storing the data corresponding to file name in the at least one memory block selected to store the data.

2. The file system as claimed in claim 1, wherein, when the memory block corresponding to the memory block information is currently unavailable, the data management unit selects another memory block that is available, and stores memory block information about said another memory block in the memory block corresponding to the memory block information, thereby linking the memory block and the memory block information to said another memory block.

3. The file system as claimed in claim 1, wherein, when a storage capacity of the memory block corresponding to the memory block information is too small to store the detailed information about the file and the information about the at least one memory block selected to store the data, the data management unit additionally selects an available memory block, and separately stores the detailed information about the file and the information about the one memory block selected to store the data in the selected memory blocks.

4. The file system as claimed in claim 1, wherein the file name is converted into the memory block information by using a hash function.

5. The file system as claimed in claim 1, wherein the memory block information is stored in a header area of the specific memory block.

6. The file system as claimed in claim 1, wherein the storage unit includes a bitmap block area that contains information about whether each memory block in the storage unit is available.

7. The file system as claimed in claim 6, wherein the data management unit determines if a specific memory block is available by scanning the bitmap block area, and allocates at least one available memory block as a memory block to be used for storing the data corresponding to the file name.

8. The file system as claimed in claim 1, wherein the data management unit reads a file name of a file stored in the storage unit, and when a read file name includes a specific delimiter, the data management unit separates the read file name based on the specific delimiter and determines a group to which the stored file is to belong.

9. A file system for searching for a file, the file system comprising:

a conversion unit for converting a name of a target file into memory block information about a specific memory block;

a storage unit including a plurality of memory blocks, which contains a memory block corresponding to the memory block information, and at least one memory block storing data corresponding to the target file;

a data management unit for selecting the memory block corresponding to the memory block information, and when a selected memory block has stored detailed information about the target file and memory block information about the at least one memory block having stored the data corresponding to the target file, reading the data corresponding to the target file from the at least one memory block having stored the data; and

an output unit for outputting the read data.

10. The file system as claimed in claim 9, wherein, when the selected memory block has stored detailed information about a specific file and memory block information about at least one memory block having stored data corresponding to the specific file, the data management unit extracts a name of the specific file from the detailed information about the specific file, and compares an extracted file name with the name of the target file, thereby determining if the selected memory block corresponds to a memory block containing information about the target file.

11. The file system as claimed in claim 9, wherein, when the selected memory block has not stored the detailed information about the target file and the memory block information about the at least one memory block having stored the data corresponding to the target file, the data management unit extracts memory block information about another memory block from a header of the selected memory block, and selects a memory block according to extracted memory block information.

12. The file system as claimed in claim 10, wherein the data management unit selects another memory block that is linked with the selected memory block through a doubly-linked list.

13. The file system as claimed in claim 9, wherein the file name is converted into the memory block information by using a hash function.

14. The file system as claimed in claim 9, wherein the memory block information is stored in a header of the specific memory block.

15. The file system as claimed in claim 9, wherein the storage unit includes a bitmap block area that contains information about whether each memory block in the storage unit is available.

16. A method for storing a newly-created file in a file system, the method comprising:

a name creation step of creating a name of the newly-created file;

a conversion step of converting the name of the file into information about a specific memory block;

a selection step of selecting a memory block corresponding to converted memory block information and checking if a selected memory block is available;

a data block number calculation step of calculating a number of memory blocks required to store data corresponding to the file name when the selected memory block is available;

a data block selection step of selecting as many currently available memory blocks as the number of memory blocks obtained through the calculation as data blocks;

an information storage step of storing detailed information about the file and memory block information about the currently-selected data blocks in the selected memory block; and

a data storage step of storing the data of the file in memory blocks selected as the data blocks.

17. The method as claimed in claim 16, wherein the selection step comprises:

an another-block selection step of additionally selecting another block that is available when it is determined that the selected memory block is unavailable as a result of the availability check; and

a link step of linking the selected memory block and an additionally-selected memory block.

18. The method as claimed in claim 16, wherein, in the information-storage step, memory block information about the data blocks are stored as a data block list having a form of indexes.

19. The method as claimed in claim 16, further comprising:

a file name read step of reading the file name of the newly-created file;

a delimiter-separation step of separating the file name according to a specific delimiter when the file name contains the specific delimiter; and

a group-determination step of determining a group to which the file is to belong according to the file name separated by the specific delimiter.

20. The method as claimed in claim 16, wherein, in the conversion step, the file name is converted into the information about the specific memory block by using a hash function.

21. A method for searching for a target file in a file system, the method comprising:

a conversion step of, when a name of a target file is input, converting an input file name into memory block information about a specific memory block;

a memory-block-selection step of selecting a memory block corresponding to the memory block information obtained through the conversion;

a file-block-determination step of determining if a selected memory block has stored detailed information about a specific file and information about data blocks corresponding to the specific file;

a name-extraction step of extracting a name of the specific file from the selected memory block when the selected memory block has stored detailed information about the specific file and information about data blocks corresponding to the specific file;

a comparison step of comparing an extracted file name with a name of the target file;

a data-block-information-extraction step of extracting information about data blocks from the selected memory block when it is determined that the extracted file name is the same as the name of the target file as a result of the comparison; and

a data-read step of reading data corresponding to the target file from memory blocks corresponding to extracted data block information.

22. The method as claimed in claim 21, wherein the file-block determination step comprises:

a block-extraction step of extracting memory block information about another memory block from a header of the selected memory block when the selected memory block has not stored the detailed information about the specific file and the information about the data blocks corresponding to the specific file; and

an extraction-selection step of selecting said another memory block corresponding to the extracted memory block information.

23. The method as claimed in claim 21, wherein, in the conversion step, the file name is converted into the information about the specific memory block by using a hash function.