Methods and apparatus for updating file systems

• US 20040093359A1
• Filed: 11/12/2002
• Published: 05/13/2004
• Est. Priority Date: 11/12/2002
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Sharpe, Edward J., Rai, Sushanth
• Application Number:
  US10/293,097
• Publication Number:
  US 20040093359A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

A file system in a computer is disclosed. The file system is configured to service file access requests between an application program and a first data storage subsystem. The file system includes a first persistent module coupled to receive a first file access request. The first persistent module is associated with the first data storage subsystem. The first file access request pertains to the first data storage subsystem. The file system includes a first transparently unloadable module coupled to the first persistent module to service the first file access request. The first transparently unloadable module is configured to be dynamically unloadable from the computer, wherein the first persistent module includes a blocking arrangement for blocking the first file access request at the first persistent module to allow the first transparently unloadable module to be unloaded without causing an error in the application program. The first persistent module includes memory for storing data necessary to allow the first file access request to be serviced in a manner substantially transparent to the application program after a substitute transparently unloadable module associated with the first data storage subsystem is loaded in place of the first transparently unloadable module.

Claims

1. A computer-implemented method for maintaining a file system, said file system being configured to service file access requests between an application program and a first data storage subsystem, said file system including a first persistent module and a first transparently unloadable module, said first persistent module and said first transparently unloadable module being associated with said first data storage subsystem, comprising:

blocking, using said first persistent module, a first file access request made by said application program to said first data storage subsystem, said blocking including maintaining information pertaining to said first file access request at said first persistent module;

unloading said first transparently unloadable module, said unloading rendering file access functionalities in said transparently unloadable module inaccessible to said first persistent module; and

loading a first substitute transparently unloadable module to render file access functionalities in said first substitute transparently unloadable module accessible to said first persistent module, said first substitute transparently unloadable module being associated with said first data storage subsystem after said loading,

wherein said first file access request made by said application program to said first data storage subsystem does not cause a generation of an error condition with respect to said application program while said first transparently unloadable module is unloaded and wherein said unloading of said first transparently unloadable module and said loading of said substitute transparently unloadable module are made without rebooting a computer associated with said file system.

2. The computer-implemented method of claim 1 wherein further comprising:

servicing said first file access request, employing said first substitute transparently unloadable module and said information pertaining to said first file access request that is maintained by said first persistent module, after said first substitute transparently unloadable module is loaded.

3. The computer-implemented method of claim 1 wherein said file system is part of an operating system of a computer and said first transparently unloadable module is a dynamically linkable module that is linkable by said operating system.

4. The computer-implemented method of claim 3 wherein said operating system is Unix-based.

5. The computer-implemented method of claim 3 wherein said operating system is Windows-based.

6. The computer-implemented method of claim 3 wherein said operating system is Linux-based.

7. The computer-implemented method of claim 3 wherein said first persistent module is disposed in a kernel space of said operating system.

8. The computer-implemented method of claim 3 wherein said first persistent module is disposed in an application space of said operating system.

9. The computer-implemented method of claim 1 further comprising transferring first data from said first transparently unloadable module to said first persistent module prior to said unloading, said first data being associated with a second file access request that is awaiting to be serviced at said first transparently unloadable module, said first data including at least a subset of the information necessary to substantially transparently service said second file access request after said substitute transparently unloadable module is loaded.

10. The computer-implemented method of claim 1 further comprising blocking a second file access request at said first persistent module, said second file access request being made by said application program after said first transparently unloadable module is unloaded but before said substitute transparently loadable module is loaded.

11. In a computer, a file system configured to service file access requests between an application program and a first data storage subsystem, said file system comprising:

a first persistent module coupled to receive a first file access request, said first persistent module being associated with said first data storage subsystem, said first file access request pertains to said first data storage subsystem; and

a first transparently unloadable module coupled to said first persistent module to service said first file access request, said first transparently unloadable module being configured to be dynamically unloadable from said computer, wherein said first persistent module includes a blocking arrangement for blocking said first file access request at said first persistent module to allow said first transparently unloadable module to be unloaded without causing an error in said application program, said first persistent module includes memory for storing data necessary to allow said first file access request to be serviced in a manner substantially transparent to said application program after a substitute transparently unloadable module associated with said first data storage subsystem is loaded in place of said first transparently unloadable module.

12. The file system of claim 11 wherein said computer further includes a virtual file system, said first persistent module being coupled to said virtual file system to receive said first file access request from said virtual file system.

13. The file system of claim 11 wherein said first transparently unloadable module is implemented as a dynamically linkable module that is linkable by an operating system of said computer.

14. The file system of claim 13 wherein said operating system is Unix-based.

15. The file system of claim 13 wherein said first persistent module is disposed in a kernel space of said operating system.

16. The file system of claim 13 wherein said first persistent module is disposed in an application space of said operating system.

17. The file system of claim 11 further comprising an arrangement associated with said first transparently unloadable module for transferring first data from said first transparently unloadable module to said first persistent module prior to unloading said first transparently unloadable module, said first data being associated with a second file access request that is awaiting to be serviced at said first transparently unloadable module, said first data includes at least a subset of the information necessary to substantially transparently service said second file access request after said substitute transparently unloadable module is loaded.

18. A file system in a computer for servicing file access requests between an application program and a first data storage subsystem, comprising:

a first persistent module having means for blocking a first file access request for said first data storage subsystem and means for storing first data associated with said first file access request at said first persistent module; and

a first transparently unloadable module coupled to said first persistent module to service said first file access request, said first transparently unloadable module being configured to be dynamically unloadable from said computer, wherein said means for blocking blocks said first file access request at said first persistent module prior to unloading said first transparently unloadable module to allow said first transparently unloadable module to be unloaded without causing an error in said application program, and wherein said first data includes data necessary to allow said first file access request to be serviced in a manner substantially transparent to said application program after a substitute transparently unloadable module associated with said first data storage subsystem is loaded in place of said first transparently unloadable module.

19. The file system of claim 18 wherein said first transparently unloadable module is implemented as a dynamically linkable module that is linkable by an operating system of said computer.

20. The file system of claim 18 further comprising an arrangement associated with said first transparently unloadable module for transferring second data from said first transparently unloadable module to said first persistent module prior to unloading said first transparently unloadable module, said second data being associated with a second file access request that is awaiting to be serviced at said first transparently unloadable module, said second data includes at least a subset of the information necessary to substantially transparently service said second file access request after said substitute transparently unloadable module is loaded.

21. The file system of claim 18 wherein said first persistent module is disposed in a kernel space of an operating system of said computer.