File cloning across different filesets

• US 8,650,158 B2
• Filed: 09/10/2010
• Issued: 02/11/2014
• Est. Priority Date: 09/10/2010
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Adkins, Janet E., Chang, Joon, Craft, David J., Kumar, Manoj N., Palsule, Ninad S.
• Primary Examiner(s): Fleurantin, Jean B
• Application Number:
  US12/879,882
• Publication Number:
  US 20120066183A1
• Time in Patent Office: 1,250 Days
• Field of Search: 707/639, 707/640, 707/648, 707/649, 707/657, 711/161, 711/162
• US Class Current: 707/649
• CPC Class Codes: G06F 16/11 File system administration, e.g. details of archiving or snapshots file system backup G06F11/14
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/40 of multimedia data, e.g. slideshows comprising image and additional audio data retrieval of still image data G06F16/50; retrieval of audio data G06F16/60; retrieval of video data G06F16/70

Abstract

Embodiments include a computer program product and an apparatus for cloning files across different filesets and maintaining the clone files. After a clone file is created from a file, a write request targeting the clone file can be handled. It is determined that the write request indicates the clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. It is then determined that the data block at a current location cannot be modified. The write request is implemented with respect to the data block at a different location. It is indicated that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

Claims

1. A computer program product for cloning a file across filesets in a clustered file system, the computer program product comprising:

a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to,

determine that a write request indicates a clone file that was cloned from a file in a first fileset, wherein the clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset;

determine a data block of the clone file affected by the write request;

determine that the data block at a current location cannot be modified based on whether the data block and the clone file are part of a same fileset, wherein the computer readable program code being configured to determine that the data block at the current location cannot be modified comprises the computer readable program code being configured to

determine that the data block is not associated with the second fileset;

determine that the data block belongs to a generation different than a generation of the second fileset; and

determine that the data block does not belong to a generation later than a generation of creation of the clone file; and

in response to a determination that the data block at the current location cannot be modified,

implement the write request with respect to the data block at a different location; and

indicate that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

2. The computer program product of claim 1, wherein the computer readable program code is further configured to generate the metadata for the clone file based, at least in part, on metadata of the file in the first fileset in response to a request to clone the file from the first fileset into the second fileset.

3. The computer program product of claim 2, wherein the computer readable program code is further configured to:

cause a snapshot of at least the file in the first fileset to be created in response to the request to clone the file; and

associate the snapshot with the clone file.

4. The computer program product of claim 3, wherein the computer readable program code is further configured to prevent removal or deletion of the snapshot while the clone file is associated with the snapshot.

5. The computer program product of claim 1, wherein the computer readable program code being configured to indicate that the data block at the different location can be modified for subsequent write requests that indicate the clone file comprises the computer readable program code being configured to update metadata of the data block to indicate the second fileset.

6. An apparatus comprising:

a processor;

a network interface operable to receive a file write request; and

a file system clone module operable to,

determine that the file write request indicates a clone file that was cloned from a file in a first fileset, wherein the clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset;

determine a data block of the clone file affected by the file write request;

determine that the data block at a current location cannot be modified based on whether the data block and the clone file are part of a same fileset, wherein the computer readable program code being configured to determine that the data block at the current location cannot be modified comprises the computer readable program code being configured to

determine that the data block is not associated with the second fileset;

determine that the data block belongs to a generation different than a generation of the second fileset; and

determine that the data block does not belong to a generation later than a generation of creation of the clone file; and

in response to a determination that the data block at the current location cannot be modified,

implement the write request with respect to the data block at a different location; and

indicate that the data block at the different location can be modified for subsequent write requests that indicate the clone file.