Reducing read operations and branches in file system policy checks

• US 10,642,784 B2
• Filed: 09/15/2016
• Issued: 05/05/2020
• Est. Priority Date: 09/15/2016
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hasegawa, Tohru, Itagaki, Hiroshi, Matsui, Sosuke, Mitsuma, Shinsuke, Miyamura, Tsuyoshi, Yamamoto, Noriko
• Primary Examiner(s): Shanmugasundaram, Kannan
• Application Number:
  US15/266,757
• Publication Number:
  US 20180075043A1
• Time in Patent Office: 1,328 Days
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 16/122 using management policies backup systems G06F11/1446; file migration policies for HSM systems G06F16/185
• 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 16/16 File or folder operations, e.g. details of user interfaces specifically adapted to file systems
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database

Abstract

A method to identify data elements conforming to a policy includes receiving a request to identify data elements in an input set of data elements that conform to one or more requested policies. According to the method, policy output information describing data elements that conform to a requested policy are saved in association with the requested policy. In response to receiving a subsequent request to identify data elements in a subsequent set of data elements that conform to the requested policy, the method includes outputting the saved policy output information based on the policy output information having been saved in association with the requested policy. A computer program product and a system, configured with processors and a memory that can store saved policy information, can implement the method.

Claims

1. A computer-implemented method for identifying a set of files, conforming to a policy, the method comprising:

receiving, by at least one processor, a first request to determine files, included in a first snapshot of a file system that conform to a first policy attribute, wherein the first policy attribute is included in an input policy, wherein the first request includes a request to determine files included in the first snapshot of the file system that conform to a second policy attribute, and wherein the second policy attribute is included in the input policy;

determining, by the at least one processor, in response to the first request, that policy output information for the first policy attribute is not saved in a storage device;

identifying, by the at least one processor, in response to determining that policy output information for the first policy attribute is not saved in the storage device, a first subset of files, included in the first snapshot of the file system, that conform to the first policy attribute;

identifying, by the at least one processor, in response to the first request a third subset of files, included in the first snapshot of the file system, that conform to the second policy attribute, wherein the first subset of files conform to the first policy attribute based on respective file type attributes of files in the first subset of files matching a first file type, and wherein the third subset of files conform to the second policy attribute based on respective modification date attributes of the third subset of files being greater than a first date;

saving, by the at least one processor, first policy output information descriptive of the first subset of files, and third policy output information comprising information descriptive of files included in the third subset of files;

receiving, by the at least one processor, a subsequent request to determine files, included in a subsequent snapshot of the file system, that conform to the first policy attribute;

determining, by the at least one processor, based on the first policy output information, a difference set comprising files included in the subsequent snapshot that are not included in the first snapshot;

identifying, by the at least one processor, a second subset of files, included in the difference set, that conform to the first policy attribute;

generating second policy output information descriptive of files included in the second subset of files; and

outputting, by the at least one processor, the first policy output information merged with the second policy output information.

2. The method of claim 1, wherein the method further comprises including, by the at least one processor, the first policy attribute in a saved policy set.

3. The method of claim 2, wherein the at least one processor including the first policy attribute in the saved policy set is based on the first policy attribute not included in the saved policy set and a setting, wherein the setting denotes to include the first policy attribute in the saved policy set.

4. The method of claim 1, wherein the method further comprises:

identifying a common policy attribute, wherein the common policy attribute is a policy attribute included in each of a first policy and a second policy, and wherein the first and the second policy are included in the input policy;

combining a check for the common policy attribute included in the first policy with a check for the common policy attribute included in the second policy, wherein the combining reduces the computation required for the at least one processor to determine a fourth subset of files, included in the first snapshot of the file system, that conform to the first policy and the second policy.

5. The method of claim 1, wherein each of the files included in the first subset of files and the second subset of files comprises a file component included in the file system.

6. A computer program product for identifying a set of files conforming to a policy, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by an at least one processor to cause the at least one processor to:

receive a first request to determine files, included in a first snapshot of a file system that conform to a first policy attribute, wherein the first policy attribute is included in an input policy wherein the first request includes a request to determine files included in the first snapshot of the file system that conform to a second policy attribute, and wherein the second policy attribute is included in the input policy;

determine, in response to the first request, that policy output information for the first policy attribute is not saved in a storage device;

identify, in response to determining that policy output information for the first policy attribute is not saved in the storage device, a first subset of files, included in the first snapshot of the file system, that conform to the first policy attribute;

identify, by the at least one processor, in response to the first request a third subset of files, included in the first snapshot of the file system, that conform to the second policy attribute, wherein the first subset of files conform to the first policy attribute based on respective file type attributes of files in the first subset of files matching a first file type, and wherein the third subset of files conform to the second policy attribute based on respective modification date attributes of the third subset of files being greater than a first date;

save first policy output information descriptive of the first subset of files, and third policy output information comprising information descriptive of files included in the third subset of files;

receive a subsequent request to determine files, included in a subsequent snapshot of the file system, that conform to the first policy attribute;

determine, based on the first policy output information, a difference set comprising files included in the subsequent snapshot that are not included in the first snapshot;

identify a second subset of files, included in the difference set, that conform to the first policy attribute;

generate second policy output information descriptive of files included in the second subset of files; and

output, the first policy output information merged with the second policy output information.

7. The computer program product of claim 6, wherein the program instructions further cause the at least one processor to include the first policy attribute in a saved policy set.

8. The computer program product of claim 7, wherein the program instructions cause the at least one processor to include the first policy attribute in the saved policy set based on the first policy attribute not included in the saved policy set and an indication, wherein the indication denotes to include the first policy attribute in the saved policy set.

9. The computer program product of claim 6, wherein the program instructions cause the at least one processor to:

identify a common policy attribute, wherein the common policy attribute is a policy attribute included in each of a first policy and a second policy, and wherein the first and the second policy are included in the input policy;

combine a check for the common policy attribute included in the first policy with a check for the common policy attribute included in the second policy, wherein the combining reduces the computation required for the at least one processor to determine a fourth subset of files, included in the first snapshot of the file system, that conform to the first policy and the second policy.

10. The computer program product of claim 6, wherein each of the files included in the first subset of files and the second subset of files comprises a file component included in the file system.

11. A computing system for identifying a set of files conforming to a policy, the computing system comprising:

a memory configured to store policy output information; and

at least one processor coupled to the memory, wherein the at least one processor is configured to;

receive a first request to determine files, included in a first snapshot of a file system that conform to a first policy attribute, wherein the first policy attribute is included in an input policy, wherein the first request includes a request to determine files included in the first snapshot of the file system that conform to a second policy attribute, and wherein the second policy attribute is included in the input policy;

determine, in response to the first request, that policy output information for the first policy attribute is not saved in a storage device;

identify, in response to determining that policy output information for the first policy attribute is not saved in the storage device, a first subset of files, included in the first snapshot of the file system, that conform to the first policy attribute;

identify, by the at least one processor, in response to the first request a third subset of files, included in the first snapshot of the file system, that conform to the second policy attribute, wherein the first subset of files conform to the first policy attribute based on respective file type attributes of files in the first subset of files matching a first file type, and wherein the third subset of files conform to the second policy attribute based on respective modification date attributes of the third subset of files being greater than a first date;

save first policy output information descriptive of the first subset of files, and third policy output information comprising information descriptive of files included in the third subset of files;

receive a subsequent request to determine files, included in a subsequent snapshot of the file system, that conform to the first policy attribute;

determine, based on the first policy output information, a difference set comprising files included in the subsequent snapshot that are not included in the first snapshot;

identify a second subset of files, included in the difference set, that conform to the first policy attribute;

generate second policy output information descriptive of files included in the second subset of files; and

output, the first policy output information merged with the second policy output information.

12. The system of claim 11, wherein a first and a second policy are included in the input policy, and wherein the at least one processor is further configured to:

identify a common policy attribute, wherein the common policy attribute is a policy attribute included in each of a first policy and a second policy, and wherein the first and the second policy are included in the input policy;

combine a check for the common policy attribute included in the first policy with a check for the common policy attribute included in the second policy, wherein the combining reduces the computation required for the at least one processor to determine a fourth subset of files, included in the first snapshot of the file system, that conform to the first policy and the second policy.

13. The system of claim 11, wherein the at least one processor is further configured to include the first policy attribute in the saved policy set based on the first policy attribute not included in the saved policy set and an indication, wherein the indication denotes to include the first policy attribute in the saved policy set.

14. The system of claim 11, wherein each of the files included in the first subset of files and the second subset of files comprises a file component included in the file system.