Metadirectory namespace and method for use of the same

• US 7,386,546 B1
• Filed: 07/09/2002
• Issued: 06/10/2008
• Est. Priority Date: 07/09/2002
• Status: Expired due to Term

• Current Assignee: NetApp, Inc.
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Santry, Douglas J., Chen, Raymond C.
• Primary Examiner(s): AL HASHEMI, SANA A
• Application Number:
  US10/191,705
• Time in Patent Office: 2,163 Days
• Field of Search: 707100-1041, 707/9, 707/1, 707/5, 709/214, 709/204, 713/153
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access
• CPC Class Codes: Y10S 707/99936 Pattern matching access
• 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 707/99945 Object-oriented database structure processing

Abstract

A metadirectory namespace is provided for storing files and directories “hidden” from one or more user-accessible namespaces. The metadirectory namespace is a separate, parallel namespace that coexists with other user-accessible namespaces in a storage operating system. Files and directories may be identified as being stored in a metadirectory based on their location or based on their associated flags. The metadirectory namespace may be selectively exported only to clients, users and applications given special file access permissions.

Claims

1. A method for accessing files and directories, comprising:

making a file access request for a file or directory;

determining whether the requested file or directory is stored in a separate metadirectory namespace that is independent of one or more user-accessible namespaces; and

in response to determining the requested file or directory is stored in the metadirectory namespace, processing the file access request upon determining an originator of the file access request is permitted to access the requested file or directory, wherein a series of ordered entries corresponding to discrete client messages requesting file transactions are stored in an NVRAM log (NVLOG) to provide fault-tolerant backup of data stored in both the metadirectory namespace and in the one or more user-accessible namespaces, whereby a predetermined designation in an entry of the NVLOG identifies a file access request for data stored in the metadirectory namespace.

2. The method according to claim 1, wherein the requested file or directory comprises at least one of configuration information, system information or support information for one or more processes running in a storage operating system.

3. The method according to claim 1, wherein the metadirectory namespace is implemented by a file server.

4. The method according to claim 1, wherein one or more flag bits are used to determine whether the requested file or directory is stored in the metadirectory namespace.

5. The method according to claim 1, wherein a storage operating system associates separate libraries of function calls with the metadirectory namespace and the one or more user-accessible namespaces operable within the storage operating system.

6. The method according to claim 3, wherein the file server is a filer comprising one or more storage volumes within a storage operating system.

7. The method according to claim 5, wherein the storage operating system determines the originator of the file access request is permitted to access a file or directory in the metadirectory namespace when the originator uses a file access call contained in the library of function calls associated with the metadirectory namespace.

8. The method according to claim 6, wherein the metadirectory namespace is implemented in the one or more storage volumes within the storage operating system.

9. The method according to claim 8, wherein each inode in the one or more storage volumes comprises at least one flag bit indicating whether the inode is included in the metadirectory namespace.

10. A storage operating system comprising one or more user-accessible file systems and at least one metadirectory namespace, further comprising:

means for receiving a file access request for a file or directory;

means for determining whether the requested file or directory is stored in the at least one metadirectory namespace that is separate from the one or more user-accessible file systems; and

means for processing the file access request upon determining an originator of the file access request is permitted to access a requested file or directory stored in the at least one metadirectory namespace, wherein a series of ordered entries corresponding to discrete client messages requesting file transactions are stored in an NVRAM log (NVLOG) to provide fault-tolerant backup of data stored in both the at least one metadirectory namespace and in the one or more user-accessible namespaces, whereby a predetermined designation in an entry of the NVLOG identifies a file access request for data stored in the at least one metadirectory namespace.

11. The storage operating system according to claim 10, wherein the requested file or directory comprises at least one of configuration information, system information or support information for one or more processes running in the storage operating system.

12. The storage operating system according to claim 10, wherein one or more flag bits are used to determine whether the requested file or directory is stored in the at least one metadirectory namespace.

13. The storage operating system according to claim 10, wherein the storage operating system associates separate libraries of function calls with the at least one metadirectory namespace and the one or more user-accessible namespaces.

14. The storage operating system according to claim 13, wherein the storage operating system determines the originator of the file access request is permitted to access a file or directory in the at least one metadirectory namespace when the originator uses a file access call contained in the library of function calls associated with the at least one metadirectory namespace.