JPH0322152A - File restoring system - Google Patents

Abstract

PURPOSE:To easily restore a file only just after the file is deleted by saving the file control information of the file, which is designated to be deleted, to a common system area, afterwards, deleting the file control information and restoring the saved file control information from the common system area. CONSTITUTION:In response to a file deleting command, a file deletion processing part 8 deletes the corresponding entry of a directory part and a data block control table 3 to be pointed from the entry. In such a case, however, the data block control table 3 is saved to a save area 7 in a common system area 6. In response to a file restoring command, a file restorage processing part 9 restores the entry of the directory part 2 and the data block control table 3 saved in the save area 7. Thus, only just after the file is deleted according to the file deleting command, the file can be easily restored.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a file management method in a data processing system. In particular, regarding method 2 that enables file restoration immediately after a file is deleted by a file deletion command, the purpose of this method is to easily restore a file immediately after deletion by a file deletion command in file management. After saving the file management information of the file specified for deletion to the system common area in response to the command. Performs processing to delete file management information, and in response to a file restoration command, restores the saved file management information of the file specified for restoration from the system common area and restores the file. [Industrial Application Field] The present invention relates to a file management method in a data processing system, and particularly to a method that enables file restoration immediately after a file is deleted using a file deletion command. [Conventional technology] In data processing systems, file management is performed using the file management function of the operating system. With this file management function, when a file deletion command is issued, the process of deleting the file management information of the specified file is performed. Therefore, the same file cannot be accessed after that. [Problem to be solved by the invention] Generally, when a user issues a file deletion command to delete a file. Immediately afterwards, it is often discovered that the file specification was incorrect or that the file should have been saved. Restoring deleted files in such cases requires a great deal of effort, if not impossible, and is extremely difficult in practice. Figure 4 shows a conventional example of restoration processing in such a case. The user is. Immediately after deleting the file in step ■, if it is determined that it is necessary to restore the file in step #, restore the entry in the directory section by patch processing in step #, then dump all the data block of the file device in step This method searches for each data block belonging to the deleted file and restores the data block management table while taking into account the order in the file.

The purpose of the present invention is to easily restore a file immediately after it is deleted using a file deletion command in file management. [Means for Solving the Problems] The present invention uses the file management function of an operating system. When a file is deleted using the file deletion command. What is deleted is not the original data block. When executing a file deletion command by focusing on file management information such as data block management tables and directory entries. If the file management information of the specified file is saved and deleted, and the data block area of the main body is not used to store data of other files. This restores the saved file management information and makes it accessible. Figure 1 is. It is a principle diagram of the present invention.

In Figure 1, 1 is . A file device used to store file data.

2 is the directory part. It has a pointer for referring to the data block management table (described later) of each file from the file name of each file stored in file device l. 3 is a data block management table, which manages, for each file, the physical location of data blocks (described later) that belong to that file.
4 is a data block, and the required number of blocks are allocated from free blocks depending on the size of the file.
In the illustrated example, there are three data blocks (
1, 2, and 3) are associated with one file by the data block management table 3.

5 is a main memory.

6 is the system common area. 7 is a save area for the data block management table 3.

8 is. This is a file deletion processing section. It is implemented as part of the file management function of the operating system or as firmware, and responds to a file deletion command by deleting the corresponding entry in the directory section 2 and the data block management table 3 pointed to by that entry. At this time, the data block management table 3 is saved to the save area 7 of the system common area 6.

Reference numeral 9 denotes a file restoration processing section, which is configured as part of the file management function of the operating system or as firmware, and restores entries in the directory section in response to a file restoration command. The data block management table saved in the save nod area 7 is also restored. [Operation] The process of restoring a file after file deletion using the file restoring method of the present invention will be explained with reference to FIG.

■ When a user issues a file deletion command. File deletion processing is performed in the same way as in the conventional system, but data block management table saving processing is also added.

■ The user decides whether it is necessary to restore the deleted file. If restoration is necessary, issue a file restoration command. ■ When a file restoration command is issued. Restores the directory entry from the specified file name. Also, the process of restoring the saved data backup management table is performed. The data blocks of the original file are now available.

However, if the data block area is allocated as a free area to a file for other processing immediately after file deletion, 9 restoration is not performed. because. This is because file management does not allow data block management tables of different files to point to the same data block. (Embodiment) Figure 3 shows the processing flow of the file deletion command and file restoration command according to the embodiment of the present invention.In this embodiment, the existing OS is not changed and the new processing function of the present invention is implemented in one patch process. and be called by the newly defined command.

Figure 3 (a) is. This is a processing flow of a file deletion command.

The file deletion command issued by the user is a newly defined command, and may be a patch command (procedure command). This file deletion command calls the corresponding data block management table saving program. In this process, the file name of the file to be deleted is linked and the data block management table is saved to the system common area. Next, issue an existing file deletion command defined by the OS. As a result, the existing file management mg of the OS is called, and the entry in the directory section of the relevant file and the data broker management table are deleted.

FIG. 3(b) is a processing flow of the file restoration command. This file restoration command is also a newly defined command, and when this file restoration command is issued, the corresponding data block management table restoration program is called.

Restores the directory part using the file name specified as a parameter. Furthermore, it searches for the data block management table saved in the system common area, copies it to the OS management control area, and restores it.

〔Effect of the invention〕

According to the present invention, it is possible to easily restore files that have been deleted due to accidental manipulation or misunderstanding. Development and processing efficiency is improved, and file guarantees are improved.

[Brief explanation of drawings]

Figure 1 is a principle diagram of the present invention, Figure 2 is a processing flow diagram of the present invention, and Figure 3 is a command processing flow diagram according to an embodiment of the present invention. FIG. 4 is a process flow diagram of a conventional example of file restoration. In Figure 1, l: File device. 2: Directory section 3: Data block management table, 4: Data block 5: Main memory. 6: System common area, 7: Backup area, 8: File deletion processing unit 9: File restoration processing unit.

Claims (1)

[Claims] In a data processing system, in response to a file deletion command, file management information of a file specified for deletion is saved to a system common area, and then the file management information is deleted, and the file is restored. A file restoration method characterized in that, in response to a command, the saved file management information of a file designated for restoration is restored from a system common area to perform file restoration.