File system having inverted hierarchical structure

• US 20070005615A1
• Filed: 07/01/2005
• Published: 01/04/2007
• Est. Priority Date: 07/01/2005
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: 8758271 Canada Inc. (Blackberry Limited)
• Inventors: Dodge, Dan
• Granted Patent: US 8,959,125 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/1865 Transactional file systems

Abstract

A computer system that improves upon the traditional file system hierarchy is disclosed. The computer system includes a processor and a persistent data storage device that is accessible by the processor. The system also may include file system software that is executed by the processor. The file system software may operate to organize the files of the persistent data storage device into a plurality of records that are contained in a metafile. Within the metafile, the files and directories of the file system may be organized in an inverted hierarchical structure. In the inverted hierarchical structure, records corresponding to child files and child directories of a parent directory may directly point to a record in the metafile that corresponds to the parent directory. In one implementation of the file system, individual records of the metafile may be each addressable by a file identifier. Each of the individual records, in turn, may include a parent identifier that corresponds to the file identifier of its parent directory record.

Claims

1. A computer system comprising:

a processor;

a persistent data storage device accessible by the processor;

at least one metafile accessible by the processor, the metafile having a plurality of records that correspond to files on the persistent data storage device and to directory containers for the files,

where the individual records of the plurality of records are each addressable by a file identifier, the individual records include a parent identifier, and the parent identifier of a given record corresponds to the file identifier of a parent directory record for the given record.

2. A computer system as claimed in claim 1 in which each of the plurality of records has a fixed length.

3. A computer system as claimed in claim 1 in which each record of the plurality of records further comprises an extended record identifier, where the extended record identifier for a given record corresponds to a file identifier of an extended record in the metafile, and the extended record contains further information pertaining to the file or directory represented by the given record.

4. A computer system as claimed in claim 3 in which the extended record further comprises a plurality of ASCII characters that correspond to a long name of a file or directory represented by the extended record.

5. A computer system as claimed in claim 3 in which the parent identifier of a given extended record corresponds to the file identifier of a record having an extended record identifier addressing the given record.

6. A computer system as claimed in claim 1 in which each of the plurality of record entries further comprises a plurality of ASCII characters that correspond to a short name of a file or directory represented by the record.

7. A computer system as claimed in claim 1 in which each of the plurality of record entries further comprises:

a mode field containing information on the type of file corresponding to the record;

an access time field containing information on the time that the file corresponding to the record was last accessed; and

a modified time field containing information on the time that the file corresponding to the record was last modified.

9. A computer system comprising:

a processor;

a persistent data storage device accessible by the processor;

file system software executed by the processor, where the file system software operates to organize the files of the persistent data storage device into a plurality of records contained in at least one metafile, and the file system software organizes the files and directories in the metafile in an inverted hierarchical structure in which records corresponding to child files and child directories of a parent directory point directly to a record in the metafile that corresponds to the parent directory.

10. A computer system as claimed in claim 9 in which each of the plurality of records has a fixed length.

11. A computer system as claimed in claim 9 in which each record of the plurality of records further comprises:

an extended record identifier, where the extended record identifier for a given record corresponds to a file identifier of an extended record in the metafile, and the extended record contains further information that pertains to the file or directory represented by the given record.

12. A computer system as claimed in claim 11 in which the extended record further comprises a plurality of ASCII characters corresponding to a long name of a file or directory represented by the extended record.

13. A computer system as claimed in claim 11 where the parent identifier of a given extended record corresponds to the file identifier of a record having an extended record identifier addressing the given record.

14. A computer system as claimed in claim 9 where each of the plurality of record entries further comprises a plurality of ASCII characters corresponding to a short name of a file or directory represented by the record.

15. A computer system as claimed in claim 9 where each of the plurality of record entries further comprises:

a mode field containing information on the type of file corresponding to the record;

an access time field containing information on the time that the file corresponding to the record was last accessed; and

a modified time field containing information on the time that the file corresponding to the record was last modified.