JPS5985559A - File control system - Google Patents

Abstract

PURPOSE:To always have a correct replacement by replacing the record address information of each journal file only in a monopolized period by a file controller which monopolizes temporarily a corresponding disk device. CONSTITUTION:A file controller 2A decides a connection state display register to a device 5-K for example and then controls a disk switch device 4 to connect the 5-K to the side of the controller 2A and to obtain a monopolized state if the 5-K is idle. Then the disk device number designated by the contents of a disk address field DAD is supplied to a memory control part 23A, and an access is given to a shared memory device 3. Then the record address information which indicates the store position of a journal file of the device 5-K is read out and stored in a record register. At the same time, an arithmetic part 24A replaces said address information so that the next store position is indicated for the journal file and then stores it to the original address of a device 3 via the part 23A.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a file control system for an information processing apparatus.

(Prior art) Generally, when operating a data file system, a journal file is provided separately from the data file in order to always be able to recover even if a failure occurs, and the data file is updated. Each time a change occurs, information indicating the updated contents is recorded in this journal file.

Each time new information (hereinafter referred to as journal data) to be recorded in this journal file is generated.

This prayer journal data is stored in the next recording address area of the journal file so that it does not overlap with previously recorded journal data, and is kept as a record one after another.

Now, multiple information processing devices that are loosely coupled to each other (multiple information processing devices each controlled by an independent O8 (operation system)) share a data file, and therefore In the case where corresponding journal files are shared and multiple information processing devices generate journal data without permission and attempt to record it in the journal file, conventionally, when multiple information processing devices generate journal data without permission and attempt to record it in the journal file, data is stored between or below the multiple information processing devices. A means of communication is provided between multiple file control devices located in the computer, so that journal data from each information processing device is recorded one after another in a new area of the journal file in the correct order without overlapping each other. must be controlled so that

(Object of the Invention) An object of the present invention is to provide a file control system that allows recording of journal data in a journal file in the above-mentioned case by a simple means without providing a special communication means. It is in.

(Structure of the Invention) The file control system of the present invention provides for a plurality of files that are multiple-connected to the plurality of information processing apparatuses so that the plurality of loosely coupled information processing apparatuses share or exclusively access the plurality of files. A system including a control device and a plurality of disk devices that store the files and are commonly accessed by the plurality of file control devices, the system comprising: a control device; A shared memory device shared by the plurality of file control devices for storage and an input/output command containing information specifying the number of the disk device from the information processing device is received and decoded to store ghost information. a data control means for controlling data exchange between a processing device and a designated disk device; a memory control means for accessing the shared memory device;
the plurality of file control devices, the plurality of file control devices including a calculation means for calculating next recording address information of the same journal file from the recording address information of the journal file read through the t1lJ control means; a switching means for selectively switching and connecting the plurality of disk devices; when the information processing device issues a journal file write command, one selected file control device is included in this command; Only when the switching means temporarily monopolizes the disk device specified by the information specifying the number of the disk device, the journal file recording address information in the shared memory device is transferred to the memory control means. Accordingly, the data control section is used to record and write the supplied journal data, and the memory control means and the calculation means are used to write the journal specified by this write command in the shared memory device η. The recording address information of a file is updated to the next recording address information of the same journal file, thereby eliminating conflict in access to the recording address information of the same journal file in the shared memory device.

(Example of the invention) Next, the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, one embodiment of the present invention includes information processing devices IA and IB (hereinafter referred to as CPUIA and IB), file control devices 2A and 2B, a shared memory device 3, a disk switching device 4, and a disk device 5- 1 to s-N.

Further, each file control device has two similar configurations and 2Bi, CPU interfaces 21A and 21B, and data control units 22A and 22B.

It includes memory control units 23A and 23B, calculation units 24A and 24B, and disk interfaces 25A and 25B.

Now, CPUIA and CPUI B operate in a loosely coupled state, and therefore generally execute different processes. Also, file control it 2 A,! The near aisle control unit 2B has a similar configuration, and under normal conditions both units operate separately, but if a failure occurs in one of them, only the remaining unit is switched on and the CPUIA and CPtJI
The configuration is such that there is no problem in processing B. Therefore, the CPUIA can access the disk devices 5-1 to 5-H via the two file control devices,
In addition, the disk device 5--via the file control device 2B
1 to 5-N can also be accessed. Similarly, C.P.
The UIB can also access the disk devices 5-1 to 5-N through either the file control unit fit2A or fit2B. In this way, the file control device 2A,
2B is multiple connected to CPUIA and 1B.

Now, when inputting and outputting data to and from the disk devices 5-1 to 5-N, the CPU
The format of the command issued by B) is the disk address field DAD, as shown in FIG.

It consists of a file access command field FAC and a data field DTP.

This disk address field DAT) Kid, the disk &15~1 to which input/output is to be performed according to this command.
Numbers (device addresses) from 5 to 5-N are specified.

The file access command field FAC indicates whether this is an input/output to a data file or a journal file, and if it is an input/output to a data file, the address in the disk where the input/output should be performed (i.e., cylinder number, head number,
(record number) and information indicating whether to write or read. Data field D for writing
A TP is further added to specify the data for the code to be written here.

On the other hand, when writing to a journal file,
The internal disk address is not given by the CPU 1, but by reading the contents of the shared memory device 3.

In other words, as mentioned above, writing journal data is always stored and recorded in a new area of the journal file, but the recording address information that indicates the current storage recording position of the journal file is stored in the shared memory. Each journal file number (in this embodiment, it is assumed that the journal file number is uniquely determined when the disk device number is determined) in the device 3 is stored at a different predetermined non-memory address. Therefore, C
When a write command to a journal file is issued from the PUI, this recording address information is accessed by accessing the shared memory device 3 using the disk device number specified in the disk address field DAD of this command. It is possible to obtain the address within the disk where the read journal data (the contents of the data field DTP of this command) should be stored and recorded.

As will be described later, once one piece of journal data is stored and recorded in a designated journal file, the recording address information of this journal file stored in the shared memory device 3 specifies the next storage location. In this way, storage records for the journal file are made in new areas one after another without overlapping journal data Vζ.

Next, the operation of this embodiment when, for example, a command to write to a specific journal file is issued from the CPUIA will be described.

CP 'U I A is a file control device with 2 people or 2
The CPU interface 21A or 21B of B selects the file control device on one side that is currently in an idle state, and issues a journal file write command having the format shown in FIG. 2 described above. In this case, even if the two file control devices and 2B are both in an idle state, one of them is always selected and the same command is issued to both file control devices 2A and 2B in parallel. This is controlled on the CPUIA side to ensure that this does not occur. Also, the file control device selected in this way is exclusively selected by this CPUIA until the execution of this command is completed, and does not accept any commands from the CPUIB side (CI).
It is controlled by the U interface 21A''!!take 21B.

Now, let us assume that the file control unit [2A] is selected in response to a command to write to this journal file from CPUxA-.

The contents of the disk address field DAD and file access command field F'AC of this command are
When the data is transferred and stored from the UIA to the data control unit 22A via the CPU interface 21A of the two file control devices, the control unit 22A decodes the contents of this file access command field FAC and determines that this is a write command for the journal file. .

When this is identified, the data control unit 22A sends the disk device number specified by the disk address field DAD of this command in the disk switching device 4 via the disk interface 25A (for example, 5- ) is currently idle.

Disk switching - ¥: (4 has each disk installed & 5-1 to 5
A connection status display register (not shown) is provided for -N, which indicates whether the corresponding disk device is currently idle (not connected to either side) or whether two file control devices It is possible to identify whether it is connected to the file control device 2B side or the file control device 2B side. Furthermore, when the execution of one input/output command for a certain disk device 5-M is completed, the connection to that disk device 5-M is released, and as a result, the connection status display register for this device 5-M will display idle. is controlled by.

Now, by determining the connection status display register for the disk device 5-K, if it is identified that this is idle (if not, wait until it becomes idle), the file control device The two people control the disk switching device 4, connect the disk device [5-K] to the file control device on the side of the two people, and place it in an exclusive state.

Next, the data control section 22A supplies the disk device number specified by the contents of the disk address field DAD of the command to the memory control section 23A, and sends it to the shared memory device 23A.
By accessing , the recording address information indicating the storage position of the journal file in the disk device 5- is read out, and this value is stored in the recording address register (not shown) provided in the data control unit 22A. Store in. At the same time, the read address information is updated in the calculation unit 24A so as to indicate the next storage location of this journal file.

This is stored again at the original address of the shared memory device 3 (that is, the memory address corresponding to the disk device 5-K) via the memory control unit 23A.

As a result, the disk device 5-1 (
This means that the recording address information of the journal file has been updated to indicate the next storage location.

Now, the data control unit 22A determines the contents of data field 1) T F of this journal file write command transferred from the CPUIA via the CPU interface 21A. , is stored in the storage location indicated by the recording address information obtained as described above in the currently connected disk device 5-.

When this storage is completed, the connection of the disk switching device 4 to the disk device 5-K is released, and the above-mentioned connection status display register for this disk device 5-1 is set to idle.

As is clear from the above explanation, the recording address information of each journal file stored in the shared memory device 3 is stored within the period of exclusive use by the file control device that temporarily monopolizes the corresponding disk device. Since the file is updated only in the shared memory device 3, update conflicts from other file control devices sharing the shared memory device 3 can be eliminated, and correct updates are always performed.

Note that in the above embodiment, the number of loosely coupled information processing devices and the number of file control devices connected thereto were each two, but this is just an example; It is clear that the invention can be applied.

(Effects of the Invention) As described above, by using the present invention, it is possible to use a shared memory device without providing special communication means between a plurality of loosely coupled information processing devices or between a plurality of file control devices. It is possible to provide a file control system that updates recording address information of journal files by eliminating conflicts with each other, thereby enabling correct storage and recording of the next shared journal file.

This has the effect of omitting troublesome communication means between devices for recording the p1 journal file.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is a diagram for explaining the format of a file input/output command given from the information processing device used in this embodiment. In the figure, IA, IB... Information processing equipment (C
PU), 2A, 2B...File control device,
3... Shared memory device, 4... Disk switching device, 5-1 to 5-N... Disk device, 21A, 21B... CPU interface,
22A, 22B... Data control section, 23A, 2
3B...Memory control unit, 24A, 24B...
...Arithmetic unit, 25 A, , 25 B...
disk interface. T'<77 ktL 17 DAD FACDTF Australia 2”W

Claims (1)

[Claims] In order for a plurality of loosely coupled information processing devices to share and exclusively access a plurality of files, a plurality of file control devices and a plurality of file control devices connected to the plurality of information processing devices in multiple ways store the files. and a plurality of disk devices commonly accessed by the plurality of file control devices, the plurality of disk devices for storing recording address information of a journal file shared by the plurality of information processing devices. A shared memory device shared by a file control device, and an input/output command containing information specifying the number of the disk device from the information processing device, decoded, and designated as the information processing device. A data control means for controlling data exchange with a disk device, a memory control means for accessing the shared memory device, and the same from recording address information of the journal file read through the memory control means. the plurality of file control devices including calculation means for calculating next recording address information of a journal file; and switching means for selectively switching and connecting the plurality of file control devices and the plurality of disk devices. When the information processing device issues a journal file '1 command, the selected one of the file control devices switches the specified disk device using information specifying the number of the disk device included in this command. The means uses the memory control means to read journal file recording address information in the shared memory device only when the shared memory device is temporarily occupied, and accordingly records and writes the supplied journal data using the data control section. At the same time, the memory control means and the calculation means are used to update the recording address information of the journal file specified by this writing command in the shared memory device to the next recording address information of the same journal file. 2. A file control system, wherein contention in access to recording address information of the same journal file in the shared memory device is eliminated.