Method and device for achieving copy-on-write file system

Abstract

The embodiment of the invention discloses a method and device for achieving a copy-on-write file system. The method includes the steps of searching an internal storage for first meta-data with dirt data identification, setting the lock identification of the first meta-data, distributing a new disk space for dirt data corresponding to the first meta-data, brushing the dirt data downwards to the new disk space, writing the first meta-data in a meta-data file adjacent to the position of the new disk space, writing second meta-data, corresponding to the dirt data, in a block map file, and brushing the dirt data downwards to the new disk space. By means of the method of not directly conducting modification on existing disk data, it is ensured that a file system is in the consistent state all the time, the meta-data are written in the meta-data file, and the unnecessary disk seeking time is shortened.

Description

technical field [0001] The invention relates to the fields of storage and file systems, and more specifically, to a method and device for realizing a copy-on-write file system. Background technique [0002] When the ordinary linux file system modifies the data, it will modify the original data on the disk. If the system crashes during the modification process, such as a power failure, the data will be damaged, resulting in the inconsistency of the file system. When the Linux file system writes data, the head will go back and forth between the inode data and data data stored in the fixed area of ​​​​the disk for multiple operations, which increases the unnecessary disk seeks for this "read-modify-write" process. time. [0003] Therefore, how to ensure that the file system is in a consistent state at all times and reduce unnecessary disk seek time is a problem that needs to be solved now. Contents of the invention [0004] The object of the present invention is to provide ...

AI Technical Summary

Problems solved by technology

[0002] When modifying data, the ordinary Linux file system will modify the original data on the disk. If the system crashes during the modification process, such as a power failure, the data will be damaged, resulting in inconsistency of the file system.

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