JPH04315232A - Disk device and file managing method therefor - Google Patents

Abstract

PURPOSE:To recover a file as needed even after the file is deleted. CONSTITUTION:A disk device 1 is equipped with file areas 4a-4n, file label areas 2a-2n including file deletion identifier areas 3a-3n, empty reas 6 and empty area managing area 5. When the file is deleted, it is recorded in the file deletion identifier area that the file area is invalid inthe stat of preserving the contents of the file area in an operating system, and it is recorded in the empty area managing area that the deleted file area is the empty area. When recovering the file, the operating system records it in the file deletion identifier area of the file that the file area made invalid is valid, and deletes the record of the empty area deleted in the empty area managing area.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file management method for a disk device.

0002

2. Description of the Related Art Files allocated on a magnetic disk are managed by an operating system using a file label area in which file area specifications are recorded and a free area management area in which free areas are recorded.

FIG. 2 is a layout diagram for explaining an example of each area provided on a conventional magnetic disk. In FIG. 2, reference numeral 1 denotes a magnetic disk installed in a disk device, and the magnetic disk 1 has file areas 4a, 4b, 4
c...4n, and file label areas 2a and 2 for recording labels of files recorded in these file areas.
b, 2c, . . . 2n, a free area 6, and a free area management area 5 for managing this free area. and,
One file label area corresponds to one file area.

[0004] When deleting a file on a magnetic disk, if you instruct the operating system to delete the file, the operating system will:
For example, the file label area 2c of the file to be deleted is initialized. That is, the contents of the label recorded in this file label area 2c are erased. Next, it is recorded in the free space management area 5 that the area of the deleted file is a free space.

[0005]

[Problems to be Solved by the Invention] In the conventional file management method of the disk device described above, when a file is deleted, the operating system initializes the file label area and deletes the file written in the file label area 2c. Since the label is erased, there is a drawback that even if a situation arises where you want to restore a deleted file, the file cannot be recovered.

SUMMARY OF THE INVENTION An object of the present invention is to provide a file management method for a disk device that allows the file to be restored if necessary even if the file is deleted.

[0007]

[Means for Solving the Problems] A first invention provides a disk device having a file area, a file label area, a free area, and a free area management area, in which whether or not a file is deleted in the file label area is determined. Contains a file deletion identifier area indicating the file deletion.

[0008] A second invention is a file management method for the disk device, in which when deleting the file,
The operating system records that the file area is invalid in the file deletion identifier area while preserving the contents of the file area, and also records that the deleted file area is a free area in the free space management area. When recording and restoring the file,
The operating system records that the invalidated file area is valid in a file deletion identifier area of the file, and deletes the record of the deleted free area in the free area management area.

[0009]

Embodiments Examples of the present invention will be described with reference to the drawings.

FIG. 1 is a layout diagram showing an embodiment of the present invention. In FIG. 1, file deletion identifier areas 3a, 3b, 3c...3n are provided in file label areas 2a, 2b, 2c...2n allocated on a magnetic disk 1. The rest is the same as the conventional example shown in FIG.

[0011] Here, when deleting a file allocated on the magnetic disk 1, for example, the file area 4c
If you want to delete a file recorded in , you can instruct the operating system to delete the file.
The operating system changes the content of the file deletion identifier area 3c from "0" to "1" while preserving the content of the file label area 2c of the file to be deleted. In this process, the file label area 2c is invalidated while the contents of the file label area 2c are preserved. Next, the operating system uses the empty file area 4c.
is recorded in the free space management area 5.

Furthermore, when it becomes necessary to restore a deleted file, when the operating system is instructed to restore the file, the operating system deletes the record of the deleted file area 4c from the free space management area 5. Next, the operating system changes the contents of the file deletion identifier area 3c in the file label area 2c from "1" to "0". Through the above processing,
Since the contents of the free space management area 5 and the state of the file label area 2c are the same as before file deletion, the file becomes usable.

Although this embodiment has been described with respect to a magnetic disk, the present invention is not limited thereto, and the present invention is similarly applicable to optical disk devices and electronic disk devices.

[0014]

[Effects of the Invention] As explained above, when deleting a file, the present invention provides a file deletion identifier area in the file label area, and deletes and restores the file simply by rewriting the contents of this file deletion identifier area. , file labels are not deleted, so even if a file has been deleted, if a situation arises where you want to recover it,
This has the effect of allowing file recovery.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating the arrangement of each area of a conventional magnetic disk.

[Explanation of symbols]

1 Magnetic disks 2a to 2n File label areas 3a to 3n
File deletion identifier area 4a to 4n File area 5 Free space management area 6 Free space

Claims (2)

[Claims] 1. A disk device having a file area, a file label area, a free area, and a free area management area, wherein the file label area includes a file deletion identifier area indicating whether or not a file has been deleted. Characteristic disk device. 2. The file management method for a disk device according to claim 1, wherein when deleting the file, the operating system stores the file area in the file deletion identifier area while preserving the contents of the file area. In addition to recording that the deleted file area is invalid, the operating system records in the free space management area that the deleted file area is a free area, and when the file is restored, the operating system uses the file deletion identifier area of the file. A file management method for a disk device, comprising: recording that the invalidated file area is valid, and deleting a record of the deleted free space in the free space management area.