IP Library Granted Patent US 11,138,185
Granted Patent B1
US 11,138,185 · App. 15/887,068 · Granted Oct 5, 2021

Method, apparatus and computer program product for managing data inconsistencies in file systems

Inventors: Yaming Kuang (Shanghai, CN); Philippe Armangau (Acton, MA); Xiao Hua Fan (Shanghai, CN)
Assignee: EMC IP Holding Company LLC
G06F16/2365G06F11/1469G06F16/185G06F2201/80
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Quick Facts
Patent No.
US 11,138,185
App. No.
15/887,068
Granted
Oct 5, 2021
Kind
B1
Abstract

There is disclosed a technique for managing data inconsistencies in file systems. For example, in one embodiment, the technique comprises detecting a data inconsistency relating to a file system block in a file system. The technique also comprises determining whether the file system block includes a mapping pointer associated with a first type of pattern. The technique further comprises performing recovery in connection with the file system block. The recovery including deciding whether to associate a mapping pointer of the file system block with one of a second type of pattern or a data loss state based on the said determination of whether the file system block includes a mapping pointer associated with a first type of pattern.

Claims (32)

1. A method, comprising:

detecting a data inconsistency relating to a file system block in a file system;

determining whether the file system block includes a mapping pointer associated with a first type of pattern;

tracking whether the mapping pointer is associated with the first type of pattern by using a bitmap to track at least one region of a plurality of regions in a leaf indirect block, wherein each bit of the bitmap is associated with one of the plurality of regions in the leaf indirect block; and

performing recovery in connection with the file system block, wherein recovery is performed on separate regions of the plurality of regions according to the bit associated with the respective region to limit data loss to the respective region, wherein performing recovery includes deciding whether to associate a mapping pointer of the file system block with one of a second type of pattern or a data loss state based on the said determination of whether the file system block includes a mapping pointer associated with a first type of pattern.

2. The method as claimed in claim 1 , wherein the file system is organized as a file system hierarchy of file system blocks.

3. The method as claimed in claim 1 , wherein the file system block describes an indirect data block that includes a set of mapping pointers.

4. The method as claimed in claim 1 , wherein the said determining comprises forming a bitmap for the file system block to track if a first type of pattern is associated with one or more mapping pointers in the file system block.

5. The method as claimed in claim 1 , wherein performing recovery includes deciding to associate a mapping pointer of the file system block with the second type of pattern upon the file system block being determined to include no mapping pointer associated with a first type of pattern.

6. The method as claimed in claim 1 , wherein performing recovery includes deciding to associate a mapping pointer of the file system block with the data loss state upon the file system block being determined to include a mapping pointer associated with a first type of pattern.

7. An apparatus, comprising:

memory; and

processing circuitry coupled to the memory, the memory storing instructions which, when executed by the processing circuitry, cause the processing circuitry to:

detect a data inconsistency relating to a file system block in a file system;

determine whether the file system block includes a mapping pointer associated with a first type of pattern;

tracking whether the mapping pointer is associated with the first type of pattern by using a bitmap to track at least one region of a plurality of regions in a leaf indirect block, wherein each bit of the bitmap is associated with one of the plurality of regions in the leaf indirect block; and

perform recovery in connection with the file system block, wherein recovery is performed on separate regions of the plurality of regions according to the bit associated with the respective region to limit data loss to the respective region, wherein performing recovery includes deciding whether to associate a mapping pointer of the file system block with one of a second type of pattern or a data loss state based on the said determination of whether the file system block includes a mapping pointer associated with a first type of pattern.

8. The apparatus as claimed in claim 7 , wherein the file system is organized as a file system hierarchy of file system blocks.

9. The apparatus as claimed in claim 7 , wherein the file system block describes an indirect data block that includes a set of mapping pointers.

10. The apparatus as claimed in claim 7 , wherein the said determining comprises forming a bitmap for the file system block to track if a first type of pattern is associated with one or more mapping pointers in the file system block.

11. The apparatus as claimed in claim 7 , wherein performing recovery includes deciding to associate a mapping pointer of the file system block with the second type of pattern upon the file system block being determined to include no mapping pointer associated with a first type of pattern.

12. The apparatus as claimed in claim 7 , wherein performing recovery includes deciding to associate a mapping pointer of the file system block with the data loss state upon the file system block being determined to include a mapping pointer associated with a first type of pattern.

13. A computer program product having a non-transitory computer readable medium which stores a set of instructions, the set of instructions, when carried out by processing circuitry, causing the processing circuitry to perform a method of:

detecting a data inconsistency relating to a file system block in a file system;

determining whether the file system block includes a mapping pointer associated with a first type of pattern;

tracking whether the mapping pointer is associated with the first type of pattern by using a bitmap to track at least one region of a plurality of regions in a leaf indirect block, wherein each bit of the bitmap is associated with one of the plurality of regions in the leaf indirect block; and

performing recovery in connection with the file system block, wherein recovery is performed on separate regions of the plurality of regions according to the bit associated with the respective region to limit data loss to the respective region, wherein performing recovery includes deciding whether to associate a mapping pointer of the file system block with one of a second type of pattern or a data loss state based on the said determination of whether the file system block includes a mapping pointer associated with a first type of pattern.

14. The computer program product as claimed in claim 13 , wherein the file system is organized as a file system hierarchy of file system blocks.

15. The computer program product as claimed in claim 13 , wherein the file system block describes an indirect data block that includes a set of mapping pointers.

16. The computer program product as claimed in claim 13 , wherein the said determining comprises forming a bitmap for the file system block to track if a first type of pattern is associated with one or more mapping pointers in the file system block.

17. The computer program product as claimed in claim 13 , wherein performing recovery includes deciding to associate a mapping pointer of the file system block with the second type of pattern upon the file system block being determined to include no mapping pointer associated with a first type of pattern.

18. The computer program product as claimed in claim 13 , wherein performing recovery includes deciding to associate a mapping pointer of the file system block with the data loss state upon the file system block being determined to include a mapping pointer associated with a first type of pattern.

Assignments (8)
RELEASE OF SECURITY INTEREST IN PATENTS PREVIOUSLY RECORDED AT REEL/FRAME (053546/0001) Recorded Jun 23, 2022
From: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
To: DELL MARKETING L.P. (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO CREDANT TECHNOLOGIES, INC.); DELL INTERNATIONAL L.L.C.; DELL PRODUCTS L.P.; DELL USA L.P.; EMC CORPORATION; DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO FORCE10 NETWORKS, INC. AND WYSE TECHNOLOGY L.L.C.); EMC IP HOLDING COMPANY LLC
Reel/Frame 071642/0001 →
RELEASE OF SECURITY INTEREST IN PATENTS PREVIOUSLY RECORDED AT REEL/FRAME (045482/0131) Recorded May 20, 2022
From: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
To: DELL PRODUCTS L.P.; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO WYSE TECHNOLOGY L.L.C.)
Reel/Frame 061749/0924 →
RELEASE OF SECURITY INTEREST AT REEL 045482 FRAME 0395 Recorded Nov 2, 2021
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
To: DELL PRODUCTS L.P.; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; WYSE TECHNOLOGY L.L.C.
Reel/Frame 058298/0314 →
SECURITY AGREEMENT Recorded Apr 22, 2020
From: CREDANT TECHNOLOGIES INC.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL USA L.P.; EMC CORPORATION; FORCE10 NETWORKS, INC.; WYSE TECHNOLOGY L.L.C.; EMC IP HOLDING COMPANY LLC
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.
Reel/Frame 053546/0001 →
SECURITY AGREEMENT Recorded Mar 21, 2019
From: CREDANT TECHNOLOGIES, INC.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL USA L.P.; EMC CORPORATION; FORCE10 NETWORKS, INC.; WYSE TECHNOLOGY L.L.C.; EMC IP HOLDING COMPANY LLC
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.
Reel/Frame 049452/0223 →
PATENT SECURITY AGREEMENT (NOTES) Recorded Mar 1, 2018
From: DELL PRODUCTS L.P.; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; WYSE TECHNOLOGY L.L.C.
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS COLLATERAL AGENT
Reel/Frame 045482/0131 →
PATENT SECURITY AGREEMENT (CREDIT) Recorded Mar 1, 2018
From: DELL PRODUCTS L.P.; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; WYSE TECHNOLOGY L.L.C.
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH, AS COLLATERAL AGENT
Reel/Frame 045482/0395 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 2, 2018
From: KUANG, YAMING; ARMANGAU, PHILIPPE; FAN, XIAO HUA
To: EMC IP HOLDING COMPANY LLC
Reel/Frame 044813/0700 →
Cited By (2)
US 12,254,197 US 12,566,698