JPH02197938A - Restoring system for draw type optical disk directory - Google Patents

Abstract

PURPOSE:To prevent the increase of the set-up time at and after the next time by rebuilding a directory corresponding to the lost directory for each directory block via a file header and reregistering the rebuilt directory into another unused area when a directory is partly lost. CONSTITUTION:When a directory is partly lost, a directory corresponding to the lost directory is rebuilt at and after a file header for each directory block. Then the rebuilt directory is reregistered into another unused area of a directory area of an optical disk. Thus it is possible to give the subsequent accesses to the lost directory without deteriorating the processing speed by using the rebuilt directory.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a write-once optical disc directory recovery method, and particularly to a write-once optical disc directory recovery method suitable for maintaining a stable access processing speed to a write-once optical disc when a part of the directory is destroyed. This relates to a directory recovery method.

[Conventional technology]

Conventionally, a large amount of text/image information has been input page by page using a scanner and stored on a write-once optical disk. There is a file management system for write-once optical discs that stores a directory on the optical disc for searching file headers at high speed and performs high-speed file searches using this directory.

Although the quality of write-once optical disk media used in such systems has improved considerably in recent years, it is difficult to eliminate defective sectors. In addition to congenital defects that occur during the manufacturing of the medium, these defective sectors include acquired defects in which sectors that were normal when data was written become unreadable due to aging, scratches, or the like. Among these, congenital defects are a small problem because they can be avoided during data writing, but acquired defects that make written data unreadable are a major problem. As a remedy for this acquired defect, CRC (Cyclic
c Redundancy Check), ECC
A method of attaching an error correction code such as (Error Correcting Code) to data is generally used, thereby reducing the error rate. but,
Error correction codes cannot save all cases, so if important administrative data such as a directory indicating the data layout on an optical disk medium is lost,
If recovery processing is not performed, all files contained in the missing sector will become inaccessible. Directory recovery processing in this case is performed by reading all file headers included in the directory and performing directory reconstruction processing.

An example of related directory management technology is Japanese Patent Application No. 1982-204111 previously filed by the present applicant.

[Problem to be solved by the invention]

The conventional recovery process described above is performed by reading all file headers included in the directory and rebuilding the directory. However, if this process is required each time before using the medium, There was a problem in that it took too long for the medium to become usable. In addition, in the above-mentioned file management system for write-once optical discs, it is possible to duplicate important management data (for example, directories), but even with duplication, directories may be lost and files may become inaccessible. there is a possibility.

The purpose of the present invention is to solve such conventional problems, and to provide a file management system for write-once optical discs, which increases the setup time from the next time on an optical disc medium that has a missing directory on the disc that cannot be recovered by hardware. An object of the present invention is to provide a write-once type optical disk directory recovery method that can prevent such problems.

(Means for Solving the Problems) In order to achieve the above object, the write-once optical disk directory recovery method of the present invention includes a file header area storing a file header having a map of records managed in file units, and a In a file management system for a write-once optical disc that manages files on a write-once optical disc that has a directory area that stores a directory for high-speed header searching and a data area that stores file data, the directory area is a write-once optical disc. The directory is divided into directory blocks of the same size as the sector unit, which is the minimum unit for writing/reading on an optical disk, and if part of the above directory is lost, the directory corresponding to the directory that is lost in directory blocks from the above file header. The feature is that the reconstructed directory is re-registered in another unused area of the directory area.

[Effect]

In the present invention, when a part of a directory is lost, the directory corresponding to the lost directory is reconstructed in directory block units from the file header,
By re-registering the reconstructed directory in another unused area of the directory area on the optical disk, the directory lost from subsequent accesses can be accessed without reducing processing speed by using the reconstructed directory. .

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram of a file management system for a write-once optical disc to which the present invention is applied.

21st i! In i, 1 is a CPU that controls the entire system, 2 is a system bus for data transfer between each device,
3 is a console for operator interaction with this system; 4 is a system disk controller; 5 is a program that controls this system; a system disk (for example, a magnetic disk device) in which data is stored; 6 is a memory; 7 is a This is an interface for optical discs. 10 is an optical disk control device, which connects the CP via an interface bus 9.
It is connected to the optical disc interface 7 on the UI side.

Reference numeral 11 denotes an optical disk drive device that drives a write-once optical disk medium. In addition, 8 is the host system,
12 is called an optical disk system. Reference numeral 13 denotes a communication interface, which is used for receiving data to be stored on an optical disc (medium) and transmitting data to output the optical disc data. When the present host system 8 inputs and outputs optical disc data, a scanner interface for data input and a printer interface for data output are required in place of the communication interface 13.

In a file management system with such a configuration, when searching for an image file, the directory on the optical disk medium is used to quickly search for the file header, and the image data is searched based on the obtained file header to find the necessary image file. The image data is then displayed on the display section of the console 3.

FIG. 3 is a diagram showing the directory structure of this embodiment. This shows an example of area division (layout) on an optical disc medium (hereinafter referred to as media).

The volume label area shown in the media layout stores the volume label for identifying the media, the file header area stores a file header with a map of records managed in file units, and the data area stores the file header. Records addressed by the record map are stored.

As shown in FIG. 3, the directory area is divided into directory blocks of the same size as the sector unit, which is the minimum unit for writing and reading optical discs, and the directory block is further divided into block headers and M directory entries. Become.

In the block header, a block ID, which is a number that is sequential from the beginning of each directory block and is unique in the medium, and a start address and an end address of a group of file headers included in the block are stored in the block header. An example of this is shown in FIG.

Each directory entry corresponds to one file,
The specified file is sorted within the range of the file header group indicated by the block header so that it can be searched quickly, and the file header is addressed by this entry. Note that the file header is written to the file generation class.

FIG. 1 is a flowchart of a write-once optical disc directory recovery process showing an embodiment of the present invention. this is,
This figure shows a processing flow when setting up media using the CPU of FIG. 2. The operation of this embodiment will be described below according to the processing flow shown in FIG. Furthermore, the process of making a certain medium available for use will hereinafter be referred to as mounting.

First, in the mounting process, the directory on the media is loaded into the memory 6 or the magnetic disk device 5 (step 101) to speed up access, but during the process, a directory block with an unrecoverable media error was detected. When (step 102, 1
03), the corresponding block in the loading destination table is made vacant, and the block ID of the media error block is held (step 104). If there is no media error (step 103), a directory block is set in the loading destination table corresponding to the block ID (step 105). At this time, if the block in the loading directory is smaller than the previous one, the block is a recovery block, so it is set at the original position in the loading destination table and the media error block ID is deleted from the retention list.

After performing the above processing up to the current last block in the directory area (step 102), if the media error block ID remains (step 106), it is an unrecovered directory block, so the recovery process (see Figure 6 below) ) (step 107). Subsequently, another mounting process is executed (step 108), and the process ends.

FIG. 6 is a detailed flowchart of the directory block recovery process in FIG. 1. The process will be explained below according to the processing flow shown in FIG.

First, the start file header address and end file header address of the block are determined from the start file header address and end file header address of the block headers in the blocks before and after the block (step 601). Next, read the file header from the start file header address (step 60).
2). Step 6: Create a directory entry corresponding to the file header based on the information on the file header.
04), set it on the loading destination table.

The above processing is executed up to the end file header address (step 603). Next, the block ID, start file header address, and end file header address are set in the loading destination block header (step 605), and the created (reconstructed) directory block is then added to the directory area on the media. An example of this is shown in FIG. 5, in which the data is written in an unused area of the file and re-registered (step 606).

In this way, in this embodiment, when a part of a directory is lost, the directory corresponding to the lost directory is reconstructed in directory block units from the file header, and the reconstructed directory is transferred to the other directory areas. By re-registering the directory in an unused area, there is no need to perform recovery processing every time, and directories lost in subsequent accesses can be accessed without reducing processing speed by using the reconstructed directory.

〔Effect of the invention〕

As explained above, according to the present invention, in a file management system for a write-once optical disc, it is possible to prevent an increase in setup time from the next time on an optical disc medium in which a missing directory that cannot be recovered by hardware exists on the disc. become.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of a directory recovery process showing an embodiment of the present invention, FIG. 2 is a configuration diagram of a file management system for a write-once optical disc to which the present invention is applied, and FIG. 3 is a directory configuration in an embodiment of the present invention. Figure 4 showing
5 is a diagram showing a format example of a directory area and a file header area, FIG. 5 is a diagram showing a directory block re-registration state, and FIG. 6 is a detailed flowchart of the directory block recovery process in FIG. 1. 1: cPU, 2 system bus, 3: console, 4 system disk controller, 5 system disk, 6: memory, 7: optical disk interface, 8;
host system, 9: interface bus, 10: optical disc control device, 11: optical disc drive device, 12: optical disc system. 13: Communication interface. Pet 1

Claims (1)

[Claims] (1) A file header area that stores a file header with a map of records managed on a file-by-file basis, a directory area that stores a directory for quickly searching the file header, and a data area that stores file data. In a file management system for a write-once optical disc that manages files on a write-once optical disc having If part of the directory is lost, the directory corresponding to the lost directory is reconstructed in directory block units from the above file header, and the reconstructed directory is re-registered in another unused area of the above directory area. A write-once optical disc directory recovery method characterized by the following.