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

• US 8,903,761 B1
• Filed: 05/06/2010
• Issued: 12/02/2014
• Est. Priority Date: 06/20/2005
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Zayas, Edward R., Haynes, Thomas, Gillono, John Francis, Kahn, Andy C., Reddy, Sreelatha S.
• Primary Examiner(s): Hwa, Shyue Jiunn
• Application Number:
  US12/775,059
• Time in Patent Office: 1,671 Days
• US Class Current: 707/602
• 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 retrieving inode to pathname information within a file system, comprising:

requesting, by a user, a primary pathname associated with a data container;

determining, by a processor, whether a primary name data structure within a metadata portion of an inode associated with the data container contains a specific value, the specific value signifies that the file system has not yet identified an appropriate inode to pathname (I2P) mapping information for the inode, wherein the primary name data structure includes a parent directory inode field that contains an inode value that is associated with a parent directory of the data container and a parent directory cookie field that identifies an entry in a directory associated with the parent directory inode;

in response to determining the primary name data structure does not contain the specific value, identifying, by the file system, the primary pathname for the requested data container using information stored in the primary name data structure;

determining whether an option has been selected to display alternate pathnames; and

in response to determining the option has been selected, returning and displaying the primary pathname and one or more alternate pathnames on a display device, wherein an alternate pathname data container stores the one or more alternate pathnames associated with the inode.

2. The method of claim 1 comprising in response to determining the primary name data structure contains the specific value, returning to the user information signifying that the I2P mapping information is not available.

3. The method of claim 1 wherein the option is selected by the user utilizing a graphical user interface.

4. The method of claim 3 wherein the alternate pathname data container is a file organized as a B+ tree.

5. The method of claim 4 wherein the alternate pathname data container allows a full pathname to be determined by walking up parent entries stored in a location in each 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 network adaptor configured to receive a request, from a user, for a primary pathname associated with a data container; and

a processor executing a file system the file system configured to;

determine whether a primary name data structure within a metadata portion of an inode associated with the data container contains a specific value, the specific value signifies that the file system has not yet identified an appropriate inode to pathname (I2P) mapping information for an inode, wherein the primary name data structure includes a parent directory inode field that contains an inode value that is associated with a parent directory of the data container and a parent directory cookie field that identifies an entry in a directory associated with the parent directory inode,

identify the primary pathname for the requested data container using information stored in the primary name data structure,

determine whether an option has been selected to display alternate pathnames, and

return and display the primary pathname and one or more alternate pathnames on a display device in response to determining the option has been selected, wherein an alternate pathname data container stores the one or more alternate pathnames associated with the inode.

9. The system of claim 8 wherein the file system is further configured to return to the user information signifying that the I2P mapping information is not available in response to determining the primary name data structure contains the specific value.

10. The system of claim 8 wherein the option has been selected by the user utilizing a graphical user interface.

11. The system of claim 10 wherein the alternate pathname data container is orgainzed as a B+ tree.

12. The system of claim 11 wherein the alternate pathname data container allows a full pathname to be determined by walking up parent entries stored in a location in each directory.

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 non-transitory computer readable medium containing executable program instructions executed by a processor, comprising:

program instructions that accept requests, by a user, for a primary pathname associated with a data container;

program instructions that determine whether a primary name data structure within a metadata portion of an inode associated with the data container contains a specific value, the specific value signifies that the file system has not yet identified an appropriate inode to pathname (I2P) mapping information for the inode., wherein the primary name data structure includes a parent directory inode field that contains an inode value that is associated with a parent directory of the data container and a parent directory cookie field that identifies an entry in a directory associated with the parent directory inode;

program instructions that identify the primary pathname for the requested data container using information stored in the primary name data structure;

program instructions that determine whether an option has been selected to display alternate pathnames, and

program instructions that return and display the primary pathname and one or more alternate pathnames on a display device in response to determining the option has been selected, wherein an alternate pathname data container stores the one or more alternate pathnames associated with the inode.

16. The non-transitory computer readable medium of claim 15 wherein the alternate pathname data container is a file organized as a B+ tree.

17. An apparatus, having a processor, and configured for retrieving inode to pathname information within a file system, comprising:

means for receiving a request, from a user, for a primary pathname associated with a data container;

means for determining whether a primary name data structure within a metadata portion of an inode associated with the data container contains a specific value, the specific value signifying that the file system has not yet identified an appropriate inode to pathname (I2P) mapping information for an inode, wherein the primary name data structure includes a parent directory inode field that contains an inode value that is associated with a parent directory of the data container and a parent directory cookie field that identifies an entry in a directory associated with the parent directory inode;

means for identifying the primary pathname for the requested data container using information stored in the primary name data structure;

means for determining whether an option has been selected to display alternate pathnames; and

means for returning and displaying the primary pathname and one or more alternate pathnames on a display device in response to determining the option has been selected, wherein an alternate pathname data container stores the one or more alternate pathnames associated with the inode.