JPS63213042A - Method for extending file area - Google Patents

Abstract

PURPOSE:To quickly extend a file area by copying the control information on a file area before it is extended and a data area to a new file area without destruction the contents of said control information and data area. CONSTITUTION:A file area 1a is extended to a control information area 2a and a data area 3a. The old data area 3a is copied to a new data area 3b by copying successively the contents of the area 3a to an area right after the area 3a (an area right after an address X3), for example, in the area 3b. When the contents of the area 3a are all copied to the area 3b in said process, an idle area 4 and an idle area 5 (a part of the area 3a) are produced in the area 3b as shown in a figure (c). Then the necessary processes are carried out to copy the area 2a to a new control information area 2b and an idle block is processed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for expanding a file area on a storage medium such as a magnetic disk medium.

[Conventional technology]

One known method for managing files stored on storage media such as magnetic disk media is to manage files as a list of fixed-length blocks, but expanding the file area containing such files is known. In this case, the conventional method was to first save the file to another auxiliary storage device, expand the original file area, and then read and register the file from the auxiliary storage device to which it was saved.

[Problem that the invention seeks to solve]

Therefore, there are disadvantages in that a separate auxiliary storage device is required for saving and restoring files, and that the process of saving and restoring files takes time and effort.

The present invention solves these conventional drawbacks, and its purpose is to provide an expansion method that can quickly expand a file area on a storage medium without saving or restoring it to another storage medium. It is in.

[Means for solving problems]

In order to achieve the above object, the present invention divides a file area on a storage medium into a data area and a management information area, each of which is used by dividing it into fixed-length blocks, and stores the file entity within the data area. It is stored in multiple data blocks and its addresses are managed in management blocks in the management information area, and free data blocks in the data area and free management blocks in the management information area are managed in a chain structure. In a file system in which specific blocks in the management information area point to data blocks and free management blocks, after creating a new file area by expanding the file area on the storage medium on the same storage medium as the storage medium. , Copy at least one of the management information area and data area of the file area before expansion to the new file area without destroying the management information area and data area before copying, and then use the free space created in the new file area. The file area is expanded by updating the management information regarding the block and the address information in the currently used management block in the new management information area.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram of one embodiment of the present invention, in which figure (al indicates the file area 1a before expansion). The created file area 1a is composed of a management information area 2a and a data area 3a, where the management information area 2a is located from addresses X1 to X2 on the magnetic disk medium DK, and the data area 3a is located from addresses X2 to X3. are doing.

FIG. 2 is an internal configuration diagram of the file area 1a.

As shown in the figure, the data area 3a includes a large number of fixed-length data blocks D1 to D9, and the management information area 2a includes a large number of management blocks M1 to M3, as well as empty management blocks in the management information area 2a. It includes a header block H1 of the list and a header block H2 of the free data block list in the data area 3a. FIG. 2(a) shows an initial state in which no files are stored in the file area 1a, and all management blocks M1 to M1 in the management information area 2a are stored in the file area 1a.
M3 is in an empty state, and a pointer value such as a relative address value pointing to the first management block M1 is stored in the header block H1, and the remaining empty management blocks M2 . M3 is chained by the pointer value in each management block and managed as a list. Similarly, all data blocks D1 to D9 in the data area 3a are also free, and the pointer value of the first data block D1 is stored in the header block H2, and the remaining free data is stored in order from the first data block D1. Blocks D2 to D9 are chained by pointer values in each data block and managed as a list.

In the initial state as shown in FIG. 2(a), when creating a file, the hesoda block H1 of the management information area 2a
with reference to one free management block (management block M
1) is selected, and the empty management block list is updated as shown in FIG. 2 (bl) by changing the pointer value of the header block H1.

Then, file management information such as the identification name (file name) of the file to be created, the address of the first data block D1, and the data block length of the file is stored in the management block M1. The data block is used, the header block H2 is updated after the file is created, and the free data block list is updated as shown in FIG. 2 (tel).

Now, when the number of files to be stored in the file area 1a increases, or when a large file is created, the current capacity of the file area 1a becomes insufficient.
The file area 1a is expanded.

FIG. 1 (bl) is a file area 1 after expanding the file area 1a in FIG. 1(a) on the same magnetic disk medium DK.
In this example, the file area 1a is divided into a management information area 2b from addresses X4 to X5 and an address X.
File area 1 with data area 3b from 5 to X6
The case of extension to b is shown.

The present invention extends the file area 1a to the management information area 2a.
An example of the procedure for the expansion process of this embodiment is shown in FIG. 3. The method of this embodiment will be explained below with reference to each figure. Note that from now on, the file area 1a will be referred to as the old file area, the management information area 2a as the old management information area, the data area 3a as the old data area, the file area 1b as the new file area, and the management information area 2b as the new management information area, data area. 3b will be called the new data area.

In this embodiment, as shown in FIG. 3, first, the old data area 3
A is copied to the new data area 3b (step S
l). As shown in FIG. 1 (C1), this transfers the contents of the old data area 3a to the old data area 3a in the new data area 3b.
This is done by sequentially copying to the area immediately after (the area immediately after address X3). With this process, the new data area 3b
When all the contents of the old data area 3a have been copied to t in the same figure,
As shown in c+, a free area 4 (originally a free area) and a free area 5 (a part of the old data area 3a) are created in the new data area 3b.

Next, as shown in step S2 in FIG. 3, the old management information area 2a is copied to the new management information area 2b. This is done by sequentially copying the contents of the old management information area 2a from the beginning of the new management information area 2b, as shown in FIG. 1(d). When this copying process is completed, a free area 6 (which was a part of the old management information area 2a and the old data area 3a) is created in the new management information area 2b as shown in the figure (d+).

Next, the management information block in use in the new management information area 2b is updated (step S3).

This is, for example, the distance D (D= (X3 −(X4+α), α・
. . size of the old management information area 2a). Note that the pointer values of the data blocks D1 to D6 in use in FIG.

Finally, as shown in step S4 in FIG. 3, free block management processing is performed. This is divided into management of free data blocks in the new data area 3b and management of free management information blocks in the new management information area 2b, and the following processing is performed for each.

[Free data block management processing] The pointer value in the free data block management header block H2 in the new management information area 2b is corrected by the distance IID between the old management information area 2a and the old data area 3a,
All the free data blocks in the newly created free area 4.5 in the new data area 3b are connected in a chain, and the first free data block is the last free data block that originally existed in the old data area 3a. Connect to.

[Free management information block management processing] If the pointer value in the free management information block management header block H1 in the new management information area 2b is not a relative value and needs to be changed, it is updated to match the new management information area 2b. At the same time, all the free management blocks in the newly generated free area 6 in the new management information area 2b are connected in a chain, and the first free management block is replaced with the free management block that originally existed in the old management information area 2a. Tie it to the end.

This completes the process of expanding the old file area 1a to the new file area 1b.

As described above, according to this embodiment, the file area 1a is
It can be expanded on the same magnetic disk medium DK without saving it to a magnetic disk medium other than the magnetic disk medium DK on which it is formed, and expansion can be done by copying the file area once. can be carried out promptly.

In the embodiment shown in FIG. 1, the old data area 3a is copied and then the old management information area 2a is copied, but in the case of FIG. 1, the copying order may be reversed.

FIG. 4 is an explanatory diagram of another embodiment of the present invention, showing a case where the old management information area 2a is copied before the old data area 3a is copied. As shown in the figure fat, the old management information area 2a
is located at addresses XIO to Xll of the magnetic disk medium DK, and when the old management information area 2a is destroyed by copying the old data area 3a to the new data area 3b as shown in FIG. The management information area 2a is copied to the new management information area 2b, and then the old data area 3a is copied to the new data area 3b.

FIGS. 5 and 6 are explanatory diagrams of still another embodiment of the present invention. As shown in FIG. 5, both the start address of the old management information area 2a and the start address of the new management information area 2b are X20.
If they are equal, the process of copying the old management information area 2a to the new management information area 2b can be omitted. In addition, as shown in FIG. 6, the address range (X30-'X31) of the old data area 3a is
If it is included in the address range (X32 to X33) of the new data area 3b, the process of copying the old data area 3a to the new data area 3b can be omitted.

〔Effect of the invention〕

As described above, the present invention creates a new file area by expanding a file area on a storage medium on the same storage medium, and creates at least one of the management information area and the data area of the file area before expansion. is copied to the new file area without destroying the management information area and data area before copying, and then the management information regarding free blocks generated in the new file area and the management blocks in use in the new management information area are copied. Address information can be updated, and the file area can be expanded without using auxiliary storage for backup and recovery.Also, since the file area only needs to be copied once, the file area can be expanded quickly. There are some effects that can be achieved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, FIG. 2 is an internal configuration diagram of a file area 1a, FIG. 3 is a flowchart showing a processing procedure of an embodiment of the present invention, and FIGS. 4 to 6 The figures are explanatory diagrams of other different embodiments of the present invention. In the figure, 1a...file area before expansion, 1b...
...File area after expansion, 2a, 2b...Management information area, 3a, 3b...Data area, 4-6...Free space, DK...Magnetic disk medium, M1-M3...
Management block, D1 to D9...Data block, Hl
・・・Hesodapurosoku of free space management block list, H2
...The list of free data blocks.

Claims (1)

[Claims] A file area on a storage medium is divided into a data area and a management information area, each of which is divided into fixed-length blocks, and the file entity is divided into multiple data blocks in the data area. The address is managed in a management block in the management information area, and free data blocks in the data area and free management blocks in the management information area are managed in a chain structure, and the first free data block and free management are In a file system in which a block is pointed to by a specific block in the management information area, after creating a new file area on the same storage medium by expanding the file area on the storage medium, the file area before expansion is created. Copying at least one of the management information area and data area to the new file area without destroying the management information area and data area before copying, and then copying management information regarding free blocks generated in the new file area, A method for expanding a file area, characterized in that the file area is expanded by updating address information in a currently used management block in a new management information area.