Alexander N Mathews

20230027230, Jan 26, 2023

Jul 23, 2021

17/384260

- Hopkinton MA, US
Ahsan Rashid - Edison NJ, US
Soumyadeep Sen - Summit NJ, US
Marc A. De Souter - Wayne NJ, US
Morgan A. Clark - South Orange NJ, US
Alexander S. Mathews - Morganville NJ, US

G06F 16/11
G06F 16/188
G06F 16/17
G06F 16/16

The technology described herein efficiently determines whether a real inode is shared among views, or owned. In-memory data structures include a view snapshot generation counter that is increased as a snapshot that generates a view is created, and an inode total weight. An in-memory virtual inode cache dataset for a filesystem object associated with the view is instantiated with the value of snapshot generation counter, sharing-related data based on the inode mapping file entry for the object, and an inode access weight. To determine whether the inode is shared (and needs to be split), such as on a write to the object, the in-memory data is evaluated. The real inode is shared if the generation counters are unequal, if the sharing-related data indicates sharing at an intermediate indirect block level, or indicates sharing at the inode level and the inode access weight is less than the inode total weight.

20210034266, Feb 4, 2021

Aug 1, 2019

16/529182

- Hopkinton MA, US
Bijaya Nanda - Edison NJ, US
Dixitkumar Vishnubhai Patel - Monroe NJ, US
Alexander S. Mathews - Morganville NJ, US
Soumyadeep Sen - Highland Park NJ, US

G06F 3/06
G06F 12/06
G06F 11/14

A method, computer program product, and computer system for maintaining a back pointer from a physical layer block (PLB) to a virtual layer block (VLB) in a multi-level hierarchical file system. A generation number may be maintained in the VLB, wherein the generation number may indicate when data is moved from the PLB to another PLB. An object may be reconstructed in the multi-level hierarchical file system based upon, at least in part, at least one of the back pointer and the generation number.

20200349032, Nov 5, 2020

Apr 30, 2019

16/399028

- Hopkinton MA, US
Dixitkumar Patel - Monroe NJ, US
Soumyadeep Sen - Highland Park NJ, US
Rohit K. Chawla - Scotch Plains NJ, US
Alexander S. Mathews - Morganville NJ, US

G06F 11/14
G06F 11/30
G06F 11/08
G06F 12/1009

A technique for repairing an indirect addressing structure of a file system damaged by corruption of a mid-level mapping (MID) page includes scanning selected leaf pages to identify leaf pages associated with the corrupted MID page, then recreating the MID page by recreating pointers to the identified leaf pages. The scanning includes (1) based on an association of groups of leaf pages with corresponding sets of families of storage objects, scanning the leaf pages of only those groups of leaf pages associated with the family of storage objects for the corrupted MID page. The scanning further includes (2) performing a two-pass process including first identifying all leaf pages for the logical offset range of the corrupted MID page and then pruning those identified leaf pages that are reachable via non-corrupted MID pages, yielding the leaf pages for the corrupted MID page only, usable to recreate the corrupted MID page.

20190236002, Aug 1, 2019

Jan 30, 2018

15/883701

- Hopkinton MA, US
Ahsan Rashid - Edison NJ, US
Kumari Bijayalaxmi Nanda - Edison NJ, US
Alexander S. Mathews - Morganville NJ, US

G06F 12/02
G06F 12/0891

An in-line (or foreground) approach to obtaining contiguous ranges of free space in a file system of a data storage system that can select windows having blocks suitable for relocation at a time when one or more blocks within the respective windows are freed or de-allocated. By providing the in-line or foreground approach to obtaining contiguous ranges of free space in a file system, a more efficient determination of windows having blocks suitable for relocation can be achieved, thereby conserving processing resources of the data storage system.