Infrastructure for performing file operations by a database server

• US 7,627,574 B2
• Filed: 12/16/2004
• Issued: 12/01/2009
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Sedlar, Eric, Jain, Namit, Idicula, Sam, Agarwal, Nipun, Pannala, Syam
• Primary Examiner(s): Mofiz; Apu M
• Assistant Examiner(s): Le; Hung D
• Application Number:
  US11/014,354
• Publication Number:
  US 20060136376A1
• Time in Patent Office: 1,811 Days
• Field of Search: 707/8, 707/9, 707/10, 707/100, 710/36, 710/200, 711/151, 711/152, 711/167, 715/229, 715/733, 717/170, 718/102
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99939 Privileged access

Abstract

A method and apparatus for processing a file system operation at a database server is provided. A request to perform a file system operation on a resource stored in a database is received at a database system. The request may be implemented using the NFS protocol. The request may include state identification data that identifies state information associated with the request. State information associated with the request is retrieved within the database system based on the state identification data. State information is information that describes the operational state of the requestor for a particular file. The request is then processed based, at least in part, on the state identification. File system operations may be processed a database management system to access any data, such as a file, relational data, and object-relational data.

Claims

1. A machine-implemented method, comprising the steps of:

a database server receiving a request from a requestor to perform a file system operation defined by a file system protocol on a resource, wherein said request includes state identification data;

said database server retrieving, using a lookup mechanism in said database server, state information associated with said request, wherein said state information specifies an operational state of the resource, wherein said operational state reflects one or more stateful operations previously performed on said resource by the requestor;

wherein said lookup mechanism comprises certain data that associates said state identification data with said state information;

wherein using said lookup mechanism comprises using said certain data and said state identification data to lookup said state information;

said database server processing said request based, at least in part, on said state information;

in response to processing said request, updating the state information in the lookup mechanism to specify an updated operational state of the resource after the file system operation has been performed on the resource and creating a second state identification data that identifies the updated state information and that is associated with the requestor, wherein the updated operational state also reflects said one or more stateful operations previously performed on said resource by the requestor; and

transmitting said second state identification data to said requestor.

2. The method of claim 1, wherein said step of retrieving said state information associated with said request comprises:

using said state identification data as a key value in said lookup mechanism to retrieve said state information.

3. The method of claim 2, wherein said lookup mechanism is one member selected from the group consisting of:

a b-tree and a hash table.

4. The method of claim 1, wherein said updated state information specifies a file opened by said requestor in response to processing said request.

5. The method of claim 1, wherein said updated state information specifies a new lock on a file granted to said requestor in response to processing said request, wherein said updated state information specifies any locks previously granted to said requestor.

6. The method of claim 5, wherein said new lock covers a specified byte range of said file, wherein said specified byte range does not span all of said file.

7. The method of claim 1, wherein said request is a second request, and the method further comprises the steps of:

prior to receiving said second request, receiving, at said database server, a first request to establish a client identifier for a requestor; and

transmitting said client identifier to said requestor, wherein

said second request comprises said client identifier.

8. The method of claim 1, wherein said request identifies a particular requestor, and the method further comprises the step of:

prior to said step of retrieving said state information associated with said request, determining whether a requestor that issued the request is actually the particular requestor that is identified in the request.

9. The method of claim 1, wherein said request is issued by a requestor, and the method further comprises the step of:

prior to performing a particular operation requested by said request, determining if said requestor has a permission level sufficient to perform said particular operation.

10. The method of claim 1, wherein said request is issued by a requestor, and wherein said step of updating the state information comprises the step of:

updating requestor data, maintained at said database server, to specify said requestor, wherein said requestor data identifies requestors registered to issue file system operations.

11. The method of claim 1, wherein said request is issued by a requestor, wherein said file system operation is an operation to open a file, and wherein said step of updating the state information comprises the step of:

updating file data, maintained at said database server, to reflect that said requestor has opened said file.

12. The method of claim 1, wherein said request is issued by a requestor, wherein said file system operation is an operation to lock a portion of a file, and wherein said step of updating the state information comprises the step of:

updating lock data, maintained at said database server, to reflect said portion of said file which said requestor has locked.

13. The method of claim 1, wherein the updated state information includes data specifying information about a client or requestor involved in one or more stateful operations performed on said resource, said information including one or more of:

a client identifier, a requestor identifier, an association of a client to a requestor, a time of a last communication from the client or requestor, and a list of files that are open for the client or requestor.

14. The method of claim 1, wherein the updated state information includes data specifying information about an open file, said information including one or more of:

a file handle, a number of file-based locks on the open file, a type of a file-based lock on the open file, a requestor that opened the open file, a requestor having a lock on an open file, data indicating whether the file was opened for reading or for writing, data indicating whether the open file has been modified, and data indicating whether reading or writing has been denied to any requestor other than the requestor which opened the open file.

15. The method of claim 1, wherein the updated state information includes data specifying one or more locks granted on said resource.

16. A computer-readable storage medium storing one or more sequences of instruction which, when executed by one or more processors, cause:

a database server receiving a request from a requestor to perform a file system operation defined by a file system protocol on a resource, wherein said request includes state identification data;

said database server retrieving, using a lookup mechanism in said database server;

state information associated with said request, wherein said state information specifies an operational state of the resource, wherein said operational state reflects one or more stateful operations previously performed on said resource by the requestor;

wherein said lookup mechanism comprises certain data that associates said state identification data with said state information;

wherein using said lookup mechanism comprises using said certain data and said state identification data to lookup said state information;

said database server processing said request based, at least in part, on said state information;

in response to processing said request, updating the state information in the lookup mechanism to specify an updated operational state of the resource after the file system operation has been performed on the resource and creating a second state identification data that identifies the updated state information and that is associated with the requestor, wherein the updated state information operational state also speeif4es-reflects said one or more stateful operations previously performed on said resource by the requestor; and

transmitting said second state identification data to said requestor.

17. The computer-readable storage medium of claim 16, wherein retrieving said state information associated with said request comprises:

using said state identification data as a key value in said lookup mechanism to retrieve said state information.

18. The computer-readable storage medium of claim 17, wherein said lookup mechanism is one member selected from the group consisting of:

a b-tree and a hash table.

19. The computer-readable storage medium of claim 16, wherein said updated state information specifies a file opened by said requestor in response to processing said request.

20. The computer-readable storage medium of claim 16, wherein said updated state information specifies a new lock on a file granted to said requestor in response to processing said request, wherein said updated state information specifies any locks previously granted to said requestor.

21. The computer-readable storage medium of claim 20, wherein said new lock covers a specified byte range of said file, wherein said specified byte range does not span all of said file.

22. The computer-readable storage medium of claim 16, wherein said request is a second request, and the method further comprises the steps of:

prior to receiving said second request, receiving, at said database server, a first request to establish a client identifier for a requestor; and

transmitting said client identifier to said requestor, wherein said second request comprises said client identifier.

23. The computer-readable storage medium of claim 16, wherein said request identifies a particular requestor, and the method further comprises the step of:

prior to said step of retrieving said state information associated with said request, determining whether a requestor that issued the request is actually the particular requestor that is identified in the request.

24. The computer-readable storage medium of claim 16, wherein said request is issued by a requestor, and the method further comprises the step of:

prior to performing a particular operation requested by said request, determining if said requestor has a permission level sufficient to perform said particular operation.

25. The computer-readable storage medium of claim 16, wherein said request is issued by a requestor, and wherein updating the state information further comprises the step of:

updating requestor data, maintained at said database server, to specify said requestor, wherein said requestor data identifies requestors registered to issue file system operations.

26. The computer-readable storage medium of claim 16, wherein said request is issued by a requestor, wherein said file system operation is an operation to open a file, and wherein said step of updating the state information further comprises the step of:

updating file data, maintained at said database server, to reflect that said requestor has opened said file.

27. The computer-readable storage medium of claim 16, wherein said request is issued by a requestor, wherein said file system operation is an operation to lock a portion of a file, and wherein said step of updating the state information further comprises the step of:

updating lock data, maintained at said database server, to reflect said portion of said file which said requestor has locked.

28. The computer-readable storage medium of claim 16, wherein the updated state information includes data specifying information about a client or requestor involved in one or more stateful operations performed on said resource, said information including one or more of:

a client identifier, a requestor identifier, an association of a client to a requestor, a time of a last communication from the client or requestor, and a list of files that are open for the client or requestor.

29. The computer-readable storage medium of claim 16, wherein the updated state information includes data specifying information about an open file, said information including one or more of:

a file handle, a number of file-based locks on the open file, a type of a file-based lock on the open file, a requestor that opened the open file, a requestor having a lock on an open file, data indicating whether the file was opened for reading or for writing, data indicating whether the open file has been modified, and data indicating whether reading or writing has been denied to any requestor other than the requestor which opened the open file.

30. The computer-readable storage medium of claim 16, wherein the updated state information includes data specifying one or more locks granted on said resource.