Seamless remote traversal of multiple NFSv4 exported file systems

• US 8,392,477 B2
• Filed: 05/09/2008
• Issued: 03/05/2013
• Est. Priority Date: 11/18/2004
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Brown, William Boyd, Burnett, Rodney Carlton, Hsiao, Duen-wen
• Primary Examiner(s): Mofiz, Apu
• Assistant Examiner(s): NGUYEN, THU N
• Application Number:
  US12/117,928
• Publication Number:
  US 20080208892A1
• Time in Patent Office: 1,761 Days
• Field of Search: None
• US Class Current: 707/822
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A method for transparently navigating through exported file system namespaces on a server using a single mount. When an exported file system is mounted onto a client, the client creates a file system ID structure for the exported file system, wherein the file system ID structure is populated with unique properties of the exported file system, and wherein the unique properties include a file system ID. The client also creates an internal virtual file system structure for the exported file system ID structure, wherein the internal virtual file system structure includes a virtual file system ID. Once the file system and virtual file system structures are created, the client links the file system objects created within the mount to the file system ID structure until a user moves from one exported file system to a second exported file system and a new file system ID is detected.

Claims

1. A method in a data processing system for seamlessly traversing multiple exported file systems transparently using a single network mount, comprising:

mounting a first exported file system onto a client;

creating a first file system identifier structure for the first exported file system to form a first exported file system identifier structure, wherein the first file system identifier structure is populated with unique properties of the first exported file system, and wherein the unique properties comprise a first file system identifier that identifies the first exported file system and a first virtual file system identifier that identifies a first internal virtual file system structure;

recording parent information in the first exported file system identifier structure, wherein recording the parent information allows the client to service a request to traverse a file namespace backwards to a root of the single network mount, and wherein the recorded parent information in the first exported file system identifier structure includes a pathname to a root of the first exported file system identifier structure;

creating the first internal virtual file system structure for the first exported file system identifier structure, wherein the first internal virtual file system structure comprises a first virtual file system identifier, wherein the first virtual file system identifier is used to uniquely describe objects within a mounted file system and wherein the first virtual file system identifier allows for distinguishing objects in different server file systems encountered on the client; and

linking file system objects created within the single network mount to the first file system identifier structure until a second file system identifier of a second of the exported file systems is encountered.

2. The method of claim 1, further comprising:

responsive to a determination that the client has moved from the first exported file system to a second exported file system, creating a second exported file system identifier structure for the second exported file system, wherein the second file system identifier structure is populated with unique properties of the second exported file system, and wherein the unique properties comprise a second file system identifier that identifies the second exported file system and a second virtual file system identifier that identifies a second internal virtual file system structure;

creating the second internal virtual file system structure for the second file system identifier structure, wherein the second internal virtual file system structure comprises the second virtual file system identifier; and

linking file system objects created within the mount to the second file system identifier structure until a file system identifier of an exported file system other than the second exported file system is encountered.

3. The method of claim 2, wherein the second file system identifier structure inherits all user tunable properties from the first file system identifier structure.

4. The method of claim 3, wherein the user tunable properties include access control information.

5. The method of claim 3, wherein the user tunable properties are selectively controlled on a per file system identifier structure basis using path names to objects within the file system identifier structure.

6. The method of claim 1, wherein the first virtual file system identifier is used to uniquely describe objects within the network mount, and wherein a server provides the first file system identifier to the client to inform the client which exported file is currently in use.

7. The method of claim 1, wherein the recorded parent information in the first file system identifier structure includes a pathname to the first file system identifier structure'"'"'s root.

8. A system for seamlessly traversing multiple exported file systems transparently using a single network mount, comprising:

a bus system;

a communications unit connected to the bus, wherein data is sent and received using the communications unit;

a memory connected to the bus system, wherein a set of instructions are located in the memory; and

a processor unit connected to the bus system, wherein the processor unit executes the set of instructions, wherein the set of instructions mounts a first exported file system onto a client;

creates a first file system identifier structure for the first exported file system to form a first exported file system identifier structure, wherein the first file system identifier structure is populated with unique properties of the first exported file system, and wherein the unique properties comprise a first file system identifier that identifies the first exported file system and a first virtual file system identifier that identifies a first internal virtual file system structure;

records parent information in the first file system identifier structure, wherein recording the parent information allows the client to service a request to traverse a file namespace backwards to a root of the single network mount, and wherein the recorded parent information in the first exported file system identifier structure includes a pathname to a root of the first exported file system identifier structure;

creates the first internal virtual file system structure for the first file system identifier structure, wherein the first internal virtual file system structure comprises the first virtual file system identifier, wherein the first virtual file system identifier is used to uniquely describe objects within a mounted file system, and wherein the first virtual file system identifier allows for distinguishing objects in different server file systems encountered on the client; and

links file system objects created within the single network mount to the first file system identifier structure until a second file system identifier of a second of the exported file systems is encountered.

9. The system of claim 8, wherein the set of instructions further creates a second exported file system identifier structure for the second exported file system in response to a determination that the client has moved from the first exported file system to a second exported file system, wherein the second file system identifier structure is populated with unique properties of the second exported file system, and wherein the unique properties comprise a second file system identifier that identifies the second exported file system and a second virtual file system ID that identifies a second internal virtual file system structure;

creates the second internal virtual file system structure for the second file system identifier structure, wherein the second internal virtual file system structure comprises the second virtual file system identifier; and

links file system objects created within the mount to the second file system identifier structure until a file system identifier of an exported file system other than the second exported file system is encountered.

10. The system of claim 9, wherein the second file system identifier structure inherits all user tunable properties from the first file system identifier structure.

11. The system of claim 10, wherein the user tunable properties include access control information.

12. The system of claim 10, wherein the user tunable properties are selectively controlled on a per file system identifier structure basis using path names to objects within the file system identifier structure.

13. The system of claim 8, wherein the first virtual file system identifier is used to uniquely describe objects within the network mount, and wherein a server provides the first file system identifier to the client to inform the client which exported file is currently in use.

14. The system of claim 8, wherein the recorded parent information in the first file system identifier structure includes a pathname to the first file system identifier structure'"'"'s root.

15. A computer program product in a computer readable storage device for seamlessly traversing multiple exported file systems transparently using a single network mount, comprising:

first instructions for mounting a first exported file system onto a client;

second instructions for creating a first file system identifier structure for the first exported file system, wherein the first file system identifier structure is populated with unique properties of the first exported file system, and wherein the unique properties comprise a first file system identifier that identifies the first exported file system and a first virtual file system identifier that identifies a first internal virtual file system structure;

third instructions for recording parent information in the first file system identifier structure, wherein recording the parent information allows the client to service a request to traverse a file namespace backwards to a root of the single network mount;

fourth instructions for creating the first internal virtual file system structure for the first file system identifier structure, wherein the first internal virtual file system structure includes the first virtual file system identifier, wherein the first virtual file system ID is used to uniquely describe objects within a mounted file system and wherein the first virtual file system identifier allows for distinguishing objects in different server file systems encountered on the client; and

fifth instructions for linking file system objects created within the single network mount to the first file system identifier structure until a second file system identifier of a second of the exported file systems is encountered.

16. The computer program product of claim 15, further comprising:

fifth instructions for creating a second exported file system identifier structure for the second exported file system in response to a determination that the client has moved from the first exported file system to a second exported file system, wherein the second file system identifier structure is populated with unique properties of the second exported file system, and wherein the unique properties comprise a second file system identifier that identifies the second exported file system and a second virtual file system identifier that identifies a second internal virtual file system structure;

sixth instructions for creating the second internal virtual file system structure for the second file system identifier structure, wherein the second internal virtual file system structure includes the second virtual file system identifier; and

seventh instructions for linking file system objects created within the mount to the second file system identifier structure until a file system identifier of an exported file system other than the second exported file system is encountered.

17. The computer program product of claim 16, wherein the second file system identifier structure inherits all user tunable properties from the first file system identifier structure.

18. The computer program product of claim 17, wherein the user tunable properties include access control information.

19. The computer program product of claim 17, wherein the user tunable properties are selectively controlled on a per file system identifier structure basis using path names to objects within the first file system identifier structure.

20. The computer program product of claim 15, wherein the virtual file system identifier is used to uniquely describe objects within the network mount, and wherein a server provides the first file system identifier to the client to inform the client which exported file is currently in use.

21. The computer program product of claim 15, wherein the recorded parent information in the first file system identifier structure includes a pathname to the first file system identifier structure'"'"'s root.

22. A method in a data processing system for navigating through multiple exported file systems transparently using a single network mount, comprising:

mounting a first exported file system onto a client;

creating a first file system identifier structure for the first exported file system, wherein the first file system identifier structure is populated with unique properties of the first exported file system, and wherein the unique properties comprise a first file system identifier that identifies the first exported file system and a first virtual file system identifier that identifies a first internal virtual file system structure;

recording parent information in the first exported file system identifier structure, wherein recording the parent information allows the client to service a request to traverse a file namespace backwards to a root of the single network mount, and wherein the recorded parent information in the first exported file system identifier structure includes a pathname to a root of the first exported file system identifier structure;

linking file system objects created within the single network mount to the first file system identifier structure until a second file system identifier of a second of the exported file systems is encountered;

determining that the client has traversed from a first exported file system into a second exported file system;

responsive to determining that the user has traversed from the first exported file system into the second exported file system, creating a file system identifier structure for the second exported file system, wherein the file system identifier structure is populated with unique properties of the second exported file system, and wherein the unique properties comprise a file system identifier that identifies the second exported file system and a virtual file system identifier that identifies an internal virtual file system structure; and

retrieving file system wide data for each file system identifier of each exported file system, wherein the file system wide data is retrieved by performing operations on an individual file system object associated with a file system identifier.

23. The method of claim 22, wherein the determining step is performed by detecting a change in major and minor device numbers.

24. The method of claim 22, wherein the user on the client is bound by settings provided for each individual file system identifier.