Versioned File System with Global Lock

• US 20160154817A1
• Filed: 06/10/2015
• Published: 06/02/2016
• Est. Priority Date: 11/28/2014
• Status: Active Grant

• Current Assignee: Nasuni Corporation
• Original Assignee: Nasuni Corporation
• Inventors: Mason, Jr., Robert S., Shaw, David M., Baughman, Kevin W., Lacasse, Christopher S., McDonald, Matthew M., Neufeld, Russell A., Saxena, Akshay K.
• Granted Patent: US 10,311,153 B2
• Time in Patent Office: Days
• 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: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067

Abstract

A versioned file system comprising network accessible storage is provided. Aspects of the system include globally locking files or groups of files so as to better control the stored files in the file system and to avoid problems associated with simultaneous remote access or conflicting multiple access requests for the same files. A method for operating, creating and using the global locks is also disclosed. A multiprotocol global lock can be provided for filing nodes that have multiple network protocols for generating local lock requests.

Claims

1. A method of locking a shared file stored in a network-attached file system (NAS), the method comprising:

intercepting a local lock request initiated by a user of a local file system, the local lock request for write access to the shared file;

translating the local lock request having a first local protocol to a global lock request having a common protocol;

sending the global lock request to a central lock server; and

receiving a global lock for the shared file if the central lock server determines that the global lock is available.

2. The method of claim 1, wherein the first local protocol is Network File System (NFS).

3. The method of claim 1, wherein the first local protocol is Server Message Block (SMB) or Common Internet File System (CIFS).

4. The method of claim 2, further comprising:

intercepting a second local lock request initiated by a second user of a second local file system, the second local lock request for write access to the shared file, the second local lock request having a second local protocol, the second local protocol comprising Server Message Block (SMB) or Common Internet File System (CIFS);

translating the second local lock request having the second local protocol to a second global lock request having the common protocol;

sending the second global lock request to the central lock server; and

receiving a multiprotocol global lock for the shared file if the central lock server determines that the multiprotocol global lock is available.

5. The method of claim 1, further comprising creating a snapshot of a most recent version of the shared file.

6. The method of claim 5, further comprising marking a parent directory of the shared file as modified.

7. The method of claim 1, further comprising merging a file data for the shared file in a local cache prior to locking a file path of the shared file.

8. The method of claim 7, further comprising determining whether a network file data stored in a server is newer than a local file data stored in the local cache.

9. The method of claim 8, further comprising, prior to releasing the global lock, discarding the network file data if the local file data of the shared file is newer than the network file data of the shared file.

10. The method of claim 9, further comprising discarding the network file data if a lock_write_version of the shared file is less than a lock_push_version of the shared file.

11. The method of claim 9, further comprising merging the local file data with the network file data if a lock_write_version is greater than a lock_push_version.

12. The method of claim 1, further comprising temporarily storing a local lock release request in a local lock cache.

13. The method of claim 12, further comprising reestablishing the global lock if a second local lock request is generated while the local lock release is stored in the local cache.

14. The method of claim 13, further comprising resetting an existing lock mode of the global lock if the new lock mode for the second lock request is different than the existing lock mode.

15. The method of claim 14, wherein the reset lock mode is inclusive of an existing access level of the existing lock mode and a new access level of the new lock mode.

16. The method of claim 14, wherein the reset lock mode is inclusive of an existing share level of the existing lock mode and a new share level of the new lock mode.

17. The method of claim 12, further comprising:

translating the local lock release to a global lock release having the common protocol; and

sending the global lock release to the central lock server.

18. The method of claim 1, further comprising updating a central lock database with an identity of the shared file associated with the global lock released by the global lock server.

19. The method of claim 1, further comprising determining whether a requested lock mode is available.

20. The method of claim 19, wherein the requested lock mode includes an exclusive write access or a shared write access.

21. The method of claim 19, further comprising determining if the requested lock mode is compatible with an existing lock mode for an existing global lock on the shared file.

22. The method of claim 21, wherein determining if the requested lock mode is compatible with an existing lock mode comprises comparing the first local protocol associated with the global lock request with a second local protocol associated with the existing global lock.

23. The method of claim 1, further comprising storing a new file request on the central lock server.

24. The method of claim 23, further comprising polling the central lock server for new files or new objects that have not been merged into the NAS.

25. The method of claim 23, further comprising merging a new file generated by the new file request into the NAS.

26. The method of claim 1, further comprising promoting the local lock request to a write lock that allows read-only access to others users of the NAS.

27. The method of claim 1, further comprising honoring an access flag and a shared access flag associated with the local lock request.

28. The method of claim 1, further comprising initiating a lock peek when the user opens the shared file.

29. The method of claim 28, wherein the lock peek comprises retrieving at least one of a file handle, a handle version, a first handle, and a lock push version.

30. The method of claim 29, wherein the lock peek is retrieved from a local lock cache.

31. The method of claim 29, wherein the lock peek is retrieved from the central lock server.

32. The method of claim 31, further comprising temporarily storing information retrieved from the lock peek in a local lock cache.

33. A method for managing locks in a shared network-attached file system, the method comprising:

receiving a first global lock request from a first node, the first global lock request comprising a first local protocol of a first local lock request generated by the first node;

providing a global lock to the first node;

receiving a second global lock request from a second node, the second global lock request comprising a second local protocol of a second local lock request generated by the second node, wherein the first protocol is different than the second protocol; and

providing a multiprotocol global lock to the second node if the multiprotocol global lock is compatible with the first local protocol and the second local protocol.

34. The method of claim 33 wherein the first local protocol is Network File System (NFS).

35. The method of claim 33 wherein the first local protocol is Server Message Block (SMB) or Common Internet File System (CIFS).

36. The method of claim 35 wherein the second local protocol is Network File System (NFS).

37. An apparatus for managing file locks in a shared network-attached file system, the apparatus comprising:

a first server comprising a processor, a network interface, a file system agent, and a lock daemon;

wherein the first server is in communication with a central lock server and a cloud-based storage via the network interface,

wherein the lock daemon is configured to translate a local lock request for a shared file in the shared network-attached file system to a global lock request, the local lock request having a first protocol, the global lock request having a common protocol, and

wherein the file system agent is configured to create and export to the cloud-based storage one or more structured data representations of a local file system to generate a version of the shared network-attached file system.

38. An apparatus associated with multiple filer entities, at least one of which creates and exports to a cloud data store one or more structured data representations comprising a shared versioned file system, the shared versioned file system accessible to each file entity, wherein filer entities do not interact with one another, comprising:

a processor;

a computer memory storing computer program instructions executed by the processor to;

(a) intercept a local lock request initiated by the filer entity, the local lock request for write access to a shared file in the shared versioned file system;

(b) translate the local lock request having a first local protocol to a global lock request having a common protocol;

(c) transmit the global lock request to a central lock server; and

(d) receive a global lock for the shared file if the central lock server determines that the global lock is available.