file system with block sharing

Abstract

To provide operations in which files can be quickly copied or rearranged, file systems allow stored data to be shared between two or more files or within a file. The file system provides operations that allow a section from one file to be copied into a section of another file, or into a different section in the same file, if the sections do not overlap. To support such operations, the file system keeps track of where the stored data for a section of a file is stored, and tracks whether the stored data for a section of a file is shared with any other file or by another portion of the same file. data. A write to a section of a file that references shared stored data invokes a write operation to a new section on the storage device, and the tracked information for the affected section is updated.

Description

Background technique [0001] The file system in a computer is generally the part of the operating system that manages access to data stored in files on one or more storage devices. The file system provides an interface through which other applications can create and manage file system objects, write data to files, and read data from files stored on storage devices. [0002] An operation that may be provided by the file system is copying files. Files may be copied for various purposes. In some instances, the purpose of duplication of a file is to provide a backup copy that is not intended to be modified when the original file is subsequently modified. Another purpose is to provide individually modifiable clones of the original files. [0003] Another operation that may be provided by a file system is rearranging one or more files. For example, data in a file may be arranged in an order that is inefficient for accessing the data. Such rearrangement can be used, for example, ...

AI Technical Summary

Problems solved by technology

For example, the data in the file may be arranged in an order that is inefficient for accessing the data

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