System and method for maintaining mappings from data containers to their parent directories

• US 20060288026A1
• Filed: 06/20/2005
• Published: 12/21/2006
• Est. Priority Date: 06/20/2005
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Reddy, Sreelatha S., Kahn, Andy C., Haynes, Thomas, Gillono, John Francis, Zayas, Edward R.
• Granted Patent: US 7,739,318 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A system and method maintains mappings from data containers to their parent directories within a file system of a storage system. Each inode is modified to include a primary name data structure comprising a parent directory inode and a parent directory cookie value. The parent directory cookie value identifies a particular directory entry within a specified block of a directory identified by parent directory inode. An alternate name file is utilized to store alternate names, such as those associated with hard links.

Claims

1. A method for maintaining a mapping from a data container to a parent directory within a file system of a storage system, the method comprising the steps of:

providing a primary name data structure within an inode associated with the data container, the primary name data structure identifying a primary name associated with the inode; and

providing an alternate name data container storing zero or more alternate names associated with the inode.

2. The method of claim 1 wherein the primary name data structure comprises a parent directory inode field and a parent directory cookie field.

3. The method of claim 2 wherein the parent directory cookie field identifies a specified directory entry within a specified directory block of a directory identified by the parent directory inode field.

4. The method of claim 1 wherein the alternate name data container comprises a file organized as B+ tree.

5. The method of claim 1 wherein the alternate name data container is stored within a hidden metadata directory.

6. The method of claim 1 wherein the data container comprises a file.

7. The method of claim 1 wherein the data container comprises a virtual disk.

8. A system for maintaining a mapping from a data container to a parent directory, the system comprising:

a computer implementing a file system, the file system adapted to store a primary name data structure in an inode associated with the data container.

9. The system of claim 8 wherein the primary name data structure comprises a parent directory inode field and a parent directory cookie field.

10. The system of claim 9 wherein the parent directory cookie field identifies a specified directory entry within a specified directory block of a directory identified by the parent directory inode field.

11. The system of claim 8 wherein the file system is further adapted to manage an alternative name data container.

12. The system of claim 11 wherein the alternative name data container comprises a file organized as a B+ tree.

13. The system of claim 8 wherein the data container comprises a file.

14. The system of claim 8 wherein the data container comprises a virtual disk.

15. A method for maintaining a mapping from a data container to a parent directory within a file system of a storage system, the method comprising the steps of:

creating a new name associated with the data container;

determining whether the created name is a primary name associated with the data container;

in response to determining that the created name is the primary name associated with the data container, setting a primary name data structure in the inode associated with the data container; and

in response to determining that the created name is not the primary name associated with the data container, creating an alternate name entry in an alternate name data container.

16. The method of claim 15 wherein the primary name data structure comprises a parent directory inode field and a parent directory cookie field

17. The method of claim 16 wherein the parent directory cookie field identifies a specified directory entry within a specified directory block of a directory identified by the parent directory inode field.

18. A system for maintaining a mapping from a data container to a parent directory within a file system of a storage system, the system comprising:

means for creating a new name associated with the data container;

means for determining whether the created name is a primary name associated with the data container;

in response to determining that the created name is the primary name associated with the data container, means for setting a primary name data structure in the inode associated with the data container; and

in response to determining that the created name is not the primary name associated with the data container, means for creating an alternate name entry in an alternate name data container.

19. The system of claim 18 wherein the alternate name data container comprises a file organized as B+ tree.

20. A computer readable medium for maintaining a mapping from a data container to a parent directory within a file system of a storage system, the computer readable medium including program instructions for performing the steps of:

providing a primary name data structure within an inode associated with the data container, the primary name data structure identifying a primary name associated with the inode; and

providing an alternate name data container storing zero or more alternate names associated with the inode.