System and method for performing file lookups based on tags

• US 7,228,299 B1
• Filed: 05/02/2003
• Issued: 06/05/2007
• Est. Priority Date: 05/02/2003
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Veritas Operating Corporation (Gen Digital Inc.)
• Inventors: Harmer, Craig K., Vajgel, Peter, Abraham, Sara
• Primary Examiner(s): Rones; Charles
• Assistant Examiner(s): LEWIS, ALICIA M
• Application Number:
  US10/428,543
• Time in Patent Office: 1,495 Days
• Field of Search: None
• US Class Current: 707/741
• CPC Class Codes: G06F 16/148 File search processing
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A method for performing file lookups based on tags indicative of file characteristics may involve: a file system storing an association between a tag and a file, where the tag is indicative of a characteristic of the file; the file system storing an additional association between the tag and an additional file that also has the characteristic; the file system searching for files having the tag; and in response to searching, the file system returning identifiers of both files associated with the tag. The returned identifiers may include the files'"'"' pathnames or inode identifiers of the files'"'"' inodes.

Claims

1. A computer-implemented method, comprising:

a file system storing an association between a tag and a file included within the file system, wherein the tag is indicative of a characteristic of the file, wherein the association is stored in a data structure that indicates an inode identifier of an inode stored by the file system for the file, wherein the inode comprises a pointer to one or more blocks of physical storage in which data of the file is stored;

the file system storing an additional association between the tag and an additional file included within the file system, wherein the additional file also has the characteristic;

the file system searching for and identifying files having the tag;

in response to said searching for and identifying, the file system returning an identifier of the file and an identifier of the additional file.

2. The method of claim 1, further comprising an application generating the tag to indicate one or more of:

a file size of the file, a file type of the file, an owner of the file, contents of the file, an access characteristic of the file, and a handle used to identify each replicated copy of the file.

3. The method of claim 1, wherein said storing the association between the tag and the file comprises storing the tag in an extended attribute of the inode, wherein the extended attribute comprises an array of one or more entries stored in an inode table by the file system, wherein the inode table includes the inode.

4. The method of claim 3, further comprising storing each of a plurality of tags in the extended attribute, wherein each of the plurality of tags is indicative of a different characteristic of the file.

5. The method of claim 1, wherein at least one file within the file system does not have a stored association with any tags.

6. The method of claim 1, further comprising:

in response to a query, the file system returning all tags for which an association with the file is stored.

7. The method of claim 1, wherein the data structure comprises an index, the method further comprising:

the file system storing the association between the tag and the file by storing the tag and the inode identifier in an entry in the index;

the file system storing the additional association between the tag and the additional file by storing the tag and an additional inode identifier of an additional inode associated with the additional file in an additional entry in the index;

wherein said searching comprises the file system searching the index for entries that include the tag.

8. The method of claim 7, further comprising:

the file system storing another association between a different tag and the file by storing the different tag and the inode identifier in a different entry in the index than the entry containing the tag and the inode identifier of the file, wherein the different tag is indicative of a different characteristic of the file.

9. The method of claim 1, wherein the identifier of the file is a pathname of the file.

10. The method of claim 1, further comprising the file system maintaining a different index for each of a plurality of applications that generate tags for files, wherein each different index stores associations between files and tags generated by a respective one of the plurality of applications.

11. The method of claim 1, further comprising the file system updating the association between the file and the tag in response to the file being renamed or deleted.

12. The method of claim 1, further comprising:

the file system storing each of a plurality of associations between a file and a tag in a respective entry in an index; and

the file system verifying the index in response to a system crash.

13. The method of claim 1, further comprising:

an application generating the tag in response to the file having the characteristic;

the application providing the tag and an indication of the file to the file system via a file system interface; and

the file system storing the association between the file and the tag in response to receiving the tag and the indication of the file via the file system interface.

14. The method of claim 13, further comprising the application accessing a file change log and responsively generating one or more tags for each of a plurality of files included in the file change log.

15. A system, comprising:

a processor; and

a memory coupled to the processor and storing program instructions executable by the processor to implement a file system, wherein the file system maintains an index comprising;

a plurality of entries, wherein each entry of the plurality of entries stores an indication of a file and a tag indicative of a characteristic of the file, wherein the indication of the file comprises an inode identifier of an inode stored by the file system for the file, wherein the inode comprises a pointer to one or more blocks of physical storage in which data of the file is stored;

wherein the file system is configured to search the index for each entry storing the tag and, in response to identifying an entry storing the tag, to return an identifier of a respective file indicated in each entry storing the tag;

wherein more than one of the plurality of entries store the tag, and wherein an indication of a different file is stored in at least some of the more than one of the plurality of entries that store the tag.

16. The system of claim 15, wherein the memory is configured to store additional program instructions executable by the processor to implement an application, wherein the application is configured to generate the tag to indicate one or more of:

a file size of the file, a file type of the file, an owner of the file, contents of the file, an access characteristic of the file, and a handle used to identify each replicated copy of the file.

17. The system of claim 15, wherein in response to a query from an application, the file system is configured to return all tags associated with a particular file.

18. A tangible, computer accessible storage medium storing program instructions implementing a file system, wherein the program instructions implementing the file system are computer executable to:

store an association between a tag and a file included within the file system, wherein the tag is indicative of a characteristic of the file, wherein the association is stored in a data structure that indicates an inode identifier of an inode stored by the file system for the file, wherein the inode comprises a pointer to one or more blocks of physical storage in which data of the file is stored;

store an additional association between the tag and an additional file included within the file system, wherein the additional file also has the characteristic;

search for and identify files having the tag;

in response to searching for and identifying files having the tag, return an identifier of the file and an identifier of the additional file.

19. A computer-implemented method, comprising:

a file system storing an association between a tag and a file included within the file system, wherein the tag is indicative of a characteristic of the file, wherein the association is stored in a data structure that indicates an inode identifier of an inode stored by the file system for the file, wherein the inode comprises a pointer to one or more blocks of physical storage in which data of the file is stored;

the file system storing an additional association between an additional tag and the file, wherein the additional tag is indicative of an additional characteristic of the file;

the file system returning an identifier of the file in response to searching for and identifying files having the tag;

the file system returning an identifier of the file in response to searching for and identifying files having the additional tag.

20. The method of claim 19, further comprising:

the file system storing an additional association between the tag and an additional file included within the file system, wherein the additional file also has the characteristic;

wherein the file system returns an identifier of the file and an identifier of the additional file in response to searching for and identifying files having the tag.