Flash-based file saving method and system

Abstract

The invention provides a Flash-based file saving method and system. The method comprises the following steps: acquiring a filename of a to-be-saved file, and judging whether the filename exists in a valid file address index list established according to a head Flash address of a valid file in a memory; if yes, applying to write the to-be-saved file into an idle Flash storage space so as to form afirst new file, enabling a head source file address field of the first new file to point to a Flash address of a source file, and marking the source file as a deletion state, so as to modify the file;and if not, applying to write the to-be-saved file into an idle Flash storage space so as to form a second new file, and preserving a head source file address field of the second new file, so as to newly build a file. According to the method, address links of same-name files can be stored in the Flash, so that the outage protection is realized, and the wear balancing effect is achieved.

Description

technical field [0001] The invention relates to the technical field of Flash storage, in particular to a method and system for saving files based on Flash. Background technique [0002] With the advancement of science and technology, all kinds of intelligent hardware are developing very rapidly. These devices need to have storage capabilities to record device configuration information, device operating status, etc.; at the same time, because Flash memory has high reliability, high storage The advantages of price, non-volatility, and easy erasing and writing have replaced traditional EPROM and EEPROM, and have been widely used in embedded systems. Flash memory can be divided into several blocks, and each block is composed of several pages. The erasing operation of Flash is performed in units of blocks, while the read and write operations are performed in units of pages. Flash memory must first erase the target block before performing a write operation. At the same time, due...

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Problems solved by technology

At the same time, due to the uncertainty of the power supply, if a power failure occurs while data is being recorded, the data in the Flash file system may be lost, and even the system may be damaged and cause serious consequences such as failure to start.

[0003] Therefore, in the current typical Flash file system, such as the second version (jffs2: journaling flash file system version 2) file system of the Linux system, although the power-off data can be protected, it will take up a lot of memory. The Flash space is used for the log management of the file system. After an abnormal power failure, it will take a long time to restore the data when it is restarted, and the efficiency is very low; When writing data, the Flash will be written twice in full amount. However, the double backup method not only takes a long time to erase and write, but also causes the problem that the life of the Flash is reduced because the Flash is erased and written from a fixed starting position each time.

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