Uniform name space referrals with location independence

• US 20050149528A1
• Filed: 03/09/2005
• Published: 07/07/2005
• Est. Priority Date: 07/30/2002
• Status: Active Grant

• Current Assignee: Boaz Shmueli, Craig F. Everhart, Owen T. Anderson
• Original Assignee: Boaz Shmueli, Craig F. Everhart, Owen T. Anderson
• Inventors: Shmueli, Boaz, Everhart, Craig F., Anderson, Owen T.
• Granted Patent: US 7,774,364 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

Improved techniques are disclosed for accessing content in file systems, allowing file system clients to realize advantages of file system referrals even though a file access protocol used by the client is not specifically adapted for referral objects. (For example, the client may have a legacy file system protocol or a proprietary file system protocol which does not support referrals.) These advantages include a uniform name space view of content in a network file system, and an ability to locate content in a (nearly) seamless and transparent manner, even though the content may be dynamically moved from one location to another or replicated in different locations. A file system server returns a symbolic link in place of a referral, and an automated file mounting process on the client is leveraged to access the content using the link. Built-in crash recovery techniques of the file system client are leveraged to access moved content.

Claims

1. A computer-implemented method of accessing content in file systems, comprising steps of:

receiving, at a first location, a request for a file object;

determining that the requested file object is not stored at the first location but that the first location stores, for the requested file object, a referral to a different location;

creating, responsive to the determining step, a symbolic reference for the requested file object, the symbolic reference comprising an indicator and a key associated with the stored referral; and

returning, as a response to the request, the symbolic reference, whereby a function at a receiver of the response is adapted for using the key, responsive to detecting the indicator in the response, to locate the requested file object.

2. The computer-implemented method according to claim 1, wherein the function at the receiver is an automounter.

3. The computer-implemented method according to claim 1, wherein the function at the receiver is a file locating component.

4. The computer-implemented method according to claim 1, wherein the receiving, determining, creating, and returning steps operate at a file system server and the request is received from a file system client.

5. The computer-implemented method according to claim 1, wherein the requested file object is a file system.

6-15. -15. (canceled)

16. A computer-implemented method of accessing content in file systems, comprising steps of:

requesting a file object from a first location;

receiving, as a response to the request, a symbolic reference for the requested file object, where the symbolic reference was created responsive to a determination that the requested file object is not stored at the first location but that the first location stores, for the requested file object, a referral to a different location;

extracting, from the received symbolic reference, a key associated with the stored referral; and

programmatically locating, using function at the receiver, the requested file object by using the extracted key to retrieve location information for the file object from a key-to-location mapping.

17. The computer-implemented method according to claim 16, wherein the function is an automounter.

18. The computer-implemented method according to claim 16, further comprising the step of mounting the located file object at the receiver.

19. The computer-implemented method according to claim 16, wherein the requesting, receiving, and programmatically locating steps operate at a file system client and the response is received from a file system server.

20-26. -26. (canceled)

27. A computer-implemented system for accessing content in file systems, comprising:

means for receiving, at a first location, a request for a file object;

means for determining that the requested file object is not stored at the first location but that the first location stores, for the requested file object, a referral to a different location;

means for creating, responsive to operation of the means for determining, a symbolic reference for the requested file object, the symbolic reference comprising an indicator and a key associated with the stored referral; and

means for returning, as a response to the request, the symbolic reference, whereby a function at a receiver of the response is adapted for using the key, responsive to detecting the indicator in the response, to locate the requested file object.

37. The computer-implemented system according to claim 27, wherein the function at the receiver is an automounter.

38. The computer-implemented system according to claim 27, wherein the function at the receiver is a file locating component.

39. The computer-implemented system according to claim 27, wherein the means for receiving, determining, creating, and returning operate at a file system server and the request is received from a file system client.

40. The computer-implemented system according to claim 27, wherein the requested file object is a file system.

28-29. -29. (canceled)

30. A computer-implemented system for accessing content in file systems, comprising:

means for requesting a file object from a first location;

means for receiving, as a response to the request, a symbolic reference for the requested file object, where the symbolic reference was created responsive to a determination that the requested file object is not stored at the first location but that the first location stores, for the requested file object, a referral to a different location;

means for extracting, from the received symbolic reference, a key associated with the stored referral; and

means for programmatically locating, using function at the receiver, the requested file object by using the extracted key to retrieve location information for the file object from a key-to-location mapping.

45. The computer-implemented system according to claim 30, wherein the function is an automounter.

46. The computer-implemented system according to claim 30, further comprising means for mounting the located file object at the receiver.

47. The computer-implemented system according to claim 30, wherein the means for requesting, receiving, and programmatically locating operate at a file system client and the response is received from a file system server.

31. (canceled)

32. A computer program product for accessing content in file systems, the computer program product embodied on one or more computer-readable media and comprising:

computer readable program code means for receiving, at a first location, a request for a file object;

computer readable program code means for determining that the requested file object is not stored at the first location but that the first location stores, for the requested file object, a referral to a different location;

computer readable program code means for creating, responsive to operation of the computer readable program code means for determining, a symbolic reference for the requested file object, the symbolic reference comprising an indicator and a key associated with the stored referral; and

computer readable program code means for returning, as a response to the request, the symbolic reference, whereby a function at a receiver of the response is adapted for using the key, responsive to detecting the indicator in the response, to locate the requested file object.

41. The computer program product according to claim 32, wherein the function at the receiver is an automounter.

42. The computer program product according to claim 32, wherein the function at the receiver is a file locating component.

43. The computer program product according to claim 32, wherein the computer readable program code means for receiving, determining, creating, and returning operate at a file system server and the request is received from a file system client.

44. The computer program product according to claim 32, wherein the requested file object is a file system.

33-34. -34. (canceled)

35. A computer program product for accessing content in file systems, the computer program product embodied on one or more computer-readable media and comprising:

computer readable program code means for requesting a file object from a first location;

computer readable program code means for receiving, as a response to the request, a symbolic reference for the requested file object, where the symbolic reference was created responsive to a determination that the requested file object is not stored at the first location but that the first location stores, for the requested file object, a referral to a different location;

computer readable program code means for extracting, from the received symbolic reference, a key associated with the stored referral; and

computer readable program code means for programmatically locating, using function at the receiver, the requested file object by using the extracted key to retrieve location information for the file object from a key-to-location mapping.

48. The computer program product according to claim 35, wherein the function is an automounter.

49. The computer program product according to claim 35, further comprising computer readable program code means for mounting the located file object at the receiver.

50. The computer program product according to claim 35, wherein the computer readable program code means for requesting, receiving, and programmatically locating operate at a file system client and the response is received from a file system server.

36. (canceled)