JPH05120095A - Disk managing system for operating system - Google Patents

Abstract

PURPOSE:To easily restore a deleted file, and to restore even only a part of the deleted file by letting a disk management file have the additional information of the file. CONSTITUTION:In an operating system provided with the management table 5 for dividing and managing the inside of a disk, two pieces of file identification information 9,10 for identifying the file stored in the disk are prepared in the management table 5, the management of the disk is executed by using these file identification information 9, 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an operating system disk management system.

[0002]

2. Description of the Related Art The internal structure of a general disc is shown in FIG.
It shows in (a). A disc 1 is divided into concentric circles into a track 2, and a disc 1 is divided into sectors into a sector 3.
Is called a cluster 11. A group of a plurality of adjacent sectors 3 is called a cluster 11, and the operating system is a disk 1.
The minimum unit for managing is the cluster 11. However, the number of tracks 2 and the number of sectors 3 of one disk 1 and the number of sectors of one cluster 11 differ depending on the disk 1 and the operating system.

Further, for simplification in the following description, FIG.
As shown in (b), the number of tracks 2 is 3, and the number of sectors 3 is 3.
Is virtually used and the cluster 11 is composed of two sectors. In addition, a serial number is given to each cluster 11, and they are referred to as cluster (1), cluster (2), ... Cluster (12).

A disk management system of a conventional operating system will be described with reference to the schematic diagram of FIG. In this example, it is assumed that the file A is divided into the cluster (2), the cluster (8), and the cluster (9) on the disk 1. The operating system uses the file entry table 4a and the disk management table 5a as information for the operating system to manage the files divided on the disk 1 as one file.

The file entry table 4a has three pieces of information: a file name, whether the file exists, and which cluster the file starts from. The file name is stored in the file name field 6, and when the file valid flag 7 is "1", the file exists,
In the case of "0", it can be known that the file does not exist. Also, it can be seen that the file starts from the cluster indicated by the value of the disk pointer 8. In the case of FIG. 5, the operating system has a file whose file name is "file A" from the information of the file entry table 4a, and this file exists from the cluster (2) to the disk 1
You can know what is stored in.

When reading the contents of a file, the operating system uses the disk management table 5a. When reading "file A" in FIG. 5, the file starts from the cluster (2) of the disk 1 from the information of the file entry table 4a. Next, the disk management table 5a has the number of the succeeding cluster, and when this number becomes "0", it means that one file is completed. In the case of FIG. 5, the cluster (2) is followed by the cluster (8), the cluster (8) is followed by the cluster (9), and the "file A" is generated in the cluster (9).
You can see that is finished.

Next, a method of creating and deleting a file will be described. When creating a file, the operating system checks the file valid flag 7 of the file entry table 4a and searches a free table.
When a vacant table is found, the file name to be created is written in the file name field 6 of the table, and the file valid flag 7 is set to "1". Next, an unused cluster on the disk 1 is searched for, and an unused cluster number is written in the disk management table 5. When the file cannot be filled in one cluster, a plurality of clusters are chained, and "0" which means the end of the file is finally written in the disk management table 5 to complete the creation of the file.

When deleting a file, the file valid flag 7 of the file entry table 4 to be deleted is reset to "0" to delete the file.

Next, a method for recovering the contents of the deleted file when the file is accidentally deleted or when the file is deleted due to some impact or the like will be described with reference to the flowchart of FIG. .. First, the file name to be restored is input in the file name input step 21, and then the disk pointer variable hd- is input in the variable initialization step 22.
Initialize ptr. Next, in the cluster check step 43, it is checked whether the cluster indicated by the variable hd-ptr is used for another file (the details of this step 43 will be described later), and if the cluster is already used, the cluster use determination step 44. The file cannot be restored after being removed with. When the cluster is not used, the disk pointer 11 is acquired in the disk pointer acquisition step 45.
Is determined, and it is determined in the disc pointer determination step 26 whether the extracted disk pointer 11 is 0 or not.
If the disk pointer 11 is 0, it means that all the files have been restored, and the file valid flag 7 is set to "1" in the file valid flag setting step 27, and the process ends. If it is not 0, the file still continues, so the disk pointer updating step 28a advances the disk pointer 11 to the next cluster, and step 43
Return to and repeat the above process.

Cluster check step 4 in FIG.
Details of No. 3 will be described with reference to FIG. First, in the cluster check step 50, the number of the cluster whose usage status is to be checked is input, and this value is used in the cluster determination step 60.

In the variable creation step 51, the array cruste
Create r []. The number of clusters on disk 1 is now 12
Since the number is set to 12, the number of elements of the array cruster [] is set to 12. Array c in variable initialization step 52
Clear all elements of ruster [] to 0. From the next search start step 53, processing is started from the top table of the file entry table 4. File valid flag 7
If the file validity flag is "0" and the file is not valid, the process proceeds to the final table determination step 59.

On the other hand, when the file is valid, the array set step 56 sets 1 in the array cluster [] corresponding to the current value of the disk pointer 8. Next, in the disk pointer value determination step 58, it is determined whether or not the disk pointer 8 is "0", and if it is not 0, the disk pointer 8 is updated in the disk pointer update step 63.
The pointer is updated to the next disk pointer 8 indicated by the value of. If this is 0, it is checked in the final table determination step 59 whether the file entry table 4 is at the end, and if there is any remaining, the disk management table update step 64 advances the disk management table by 1 and the above processing is performed. repeat. If there is no table, in the cluster use determination step 60, the element of the array cruster [] corresponding to the cluster number whose usage status is to be checked is determined. If the element of the array cluster [] is "1", this cluster ends with a return value indicating that it is used by another file (abnormal end step 62). On the contrary, when the element of the array cluster [] is 0, this cluster ends with the unused value as a return value (normal end step 61).

[0013]

The above-mentioned conventional method for managing the disk 1 only manages the pointers to the clusters of the disk, so that a file may be deleted by mistake or some kind of impact may occur. If the disk pointer is destroyed by, to recover all the contents of the lost file, follow the disk management table 5 to find the chain of clusters, making sure that the cluster is not used by any other file. Disk management table 5
There was a problem that it was difficult to restore the file, and it was not possible to restore only a part of the file when the file could not be restored.

An object of the present invention is to solve the above problems and to provide a disk management system of an operating system which makes it possible to easily restore a file even if the disk pointer is accidentally deleted or destroyed. To provide.

[0015]

According to the structure of the present invention, in a disk management system of an operating system having a management table for dividing and managing the inside of the disk, the disk is stored in the management table. A file identification information section for identifying a file is provided, and means for managing the disk using the file identification information is provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram for explaining the first embodiment of the present invention, and FIG. 2 is a flow chart for explaining the file restoration method of this embodiment. In this embodiment, a file ID storage area 10 is provided for the operating system to manage the disk 1, and a file I is stored in the file entry table 4 and the disk management table 5.
D9 is provided. The file identification information in the management table 5 includes the file ID storage area 10 and the file ID 9
Equivalent to.

Next, a method of using the file ID storage area 10 and the file ID 9 will be described. The file ID storage area 10 and the file ID 9 have file identification information existing on the disk 1 to facilitate file management.

First, a method of creating and deleting a file will be described. When creating a file, the operating system uses the file valid flag 7 in the file entry table 4.
And search for unused tables. When an unused table is found, the file name to be created is written in the file name field 6 of that table, the file valid flag 7 is set to "1", and the file ID 9 of the file entry table 4 is stored in the file ID storage area 10. A value (“7” in the example of the figure) is written, and the value of the file ID storage area 10 is incremented.

Next, an unused cluster on the disk 1 is searched for, the unused cluster number is written in the disk management table 5, and the file ID of the file entry table 4 is written as the file ID 9 ("7" in the example of the figure). ). If the file cannot be filled in one cluster, a plurality of clusters are chained and finally "0" which means the end of the file is stored in the disk management table 5.
Finish writing the file by writing.

When deleting a file, the file valid flag 7 of the file entry table 4 to be deleted is reset to "0" as in the conventional case, and the file is deleted.

Next, a method of restoring a deleted or destroyed file will be described. The flowchart of FIG. 2 is a method of restoring all the deleted files. As a condition to restore all files, all the disk pointers 8 of the files to be restored must be saved,
If even one of the dispointers 8 is used for another file, it is not possible to completely restore all of the files.

First, in the file name input step 21, the file name to be restored is input. In the next variable initialization step 22, if the file name to be restored remains in the file entry step 4, the disk pointer 11 is extracted from the file entry table 4 and the variable hd-p
Store in tr. Next, in the variable initialization step 23, the variable f
Substitute the file ID 9 of the file to be restored for ile-id. Next, in the file ID acquisition step 24, the file ID 9 is extracted from the disk management table 5 indicated by the disk pointer 9 of hd-ptr. In the file ID determination step 25, it is determined whether the retrieved file ID 9 is equal to the file ID of the file to be restored. If this is not the case, the cluster cannot be restored and the process ends because the cluster is being used by another file.

If the file IDs are the same, it is judged in the disk pointer judgment step 26 whether the disk pointer 11 is "0".

When the disk pointer 11 is "0", it means that the restoration of all the files has been completed, so the file valid flag is set in the file valid flag setting step 27, and the process is terminated. If the disk pointer 11 is not "0", there is still a file remaining.
In the disk pointer update step 28, the variable hd-pt
r is updated according to the value of the disk pointer 11, and the process returns to step 24 to repeat the above processing.

FIG. 3 is a flow chart for explaining the second embodiment of the present invention. The configuration of this embodiment is similar to that of FIG.
The method of using the file ID 9 and the method of creating and deleting the file are the same as in the previous embodiment. In the first embodiment,
If the disk pointer 8 of the file to be restored is not completely left, the file cannot be restored, and only part of the file cannot be restored. However, in this embodiment, when the disk pointer 8 of the file to be restored is not completely left, only a part of the file can be restored.

This restoration method will be described with reference to FIG. First, in the file name input step 21, the file name to be restored is input, and in the next variable initialization step 22a, hd-pt
When r1 is the head of the disk management table 5 and the file name to be restored remains in the file entry step 4, the disk pointer 11 is extracted from the file entry table 4 and stored in the variable hd-ptr2. In the next variable initialization step 23, the variable file-id
Substitute the file ID 9 of the file to be restored to.

Further, in the disk management table end judgment step 34, it is judged whether or not all the disk management tables 5 have been searched, and if completed, the processing is ended. File ID
At decision step 35, the variable file-id and the current hd
-It is determined whether the file ID 9 of the disk management table 5 indicated by the disk management pointer 11 of ptr1 is the same. If they are not equal, the variable hd-ptr1 is incremented by 1 in the hd-ptr1 updating step 39, and the processing is repeated. If they are equal to each other, the data in this cluster is the data of the file to be restored, so that the processes in and after step 34 are performed so as to recognize it as a file.

In step 36 of setting the disk pointer 11, the disk pointer 11 of hd-ptr1 is set to "0". Next, in a pointer connection step 37, hd-ptr
A chain is made by substituting the value of hd-ptr1 into the disk pointer 11 of 2. Next, in the hd-ptr2 updating step 38, hd-ptr2 is set to hd-ptr1, and the process proceeds to step 39 to repeat the processing.

[0029]

As described above, according to the present invention, by adding the additional information of the file to the disk management table, the deleted file can be easily restored, and only a part of the deleted file can be restored. The effect is that it can be revived.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a disc for explaining an embodiment of the present invention.

FIG. 2 is a flowchart illustrating the file restoration method of FIG.

FIG. 3 is a flowchart illustrating a method for restoring part of the file in FIG.

4A and 4B are a schematic diagram showing a part of the disk configuration and an array diagram showing the arrangement of the clusters.

FIG. 5 is a schematic configuration diagram of a conventional disc.

FIG. 6 is a flowchart illustrating the file restoration method of FIG.

FIG. 7 is a foot chart of the cluster check step of FIG.

[Explanation of symbols]

1 disk 2 tracks 3 sectors 4, 4a file entry table 5, 5a disk management table 6 file name field 7 file valid flag 8 disk pointer 9 file ID 10 file ID storage area 11 clusters 21, 22, 22a, 23-27, 34 ~ 39 processing steps 43-45, 50-62 processing steps

Claims (1)

[Claims] 1. In a disk management system of an operating system having a management table for dividing and managing the inside of the disk, a file identification information section for identifying a file stored in the disk in the management table. And a means for managing the disk by using the file identification information.