JPH0336640A - Control system for record storing space - Google Patents

Abstract

PURPOSE:To improve speed for processing by providing a space control table to express the using state of spaces in respective extents and a semaphore to execute the exclusive control of these space control tables. CONSTITUTION:An n-th extent is generated in a file 1. At first, the exclusive control is executed to the n-th extent as the increased extent by using the semaphore in a space control table exclusive control table 4 for the n-th extent so that the n-th extend can be in an uncompleted state and can not be used from the other process. The n-th extent is added to the file 1 and the increase processing of the file 1 is executed. Then, the information of the n-th extent are added to a file control record 6 and further, formating the n-th extent. The top space of the n-th extent is defined as the space control table and written to an Rm record. Thus, since the record can be updated and erased for the unit of the extent constituting the file, the addition processing of the new extent can be executed simultaneously, with the addition, update and deletion of the record in the existent extent.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a file management method, and in particular, a record storage space control method having a single stage for managing record storage space in a file in units of file extents. Regarding.

[Prior Art] In a file management system, a group of records that have a logical relationship and become meaningless when divided is generally called a member. When multiple members are stored and managed in one file, is used separately for a directory part and a data part. The records of the members are sequentially stored in the data section, and the names of the members and information indicating where in the data section the records of the members are stored are stored in the directory section.

Conventional technology for managing files configured in this way is
When reading a member record in a file, the directory part is searched using the name of the member as a key, the position of the member record is found, and the record is read. Also, when updating a member, the data writes the member's record to the free space in the directory section, updates the member's record position information in the directory section, and
The file is managed by freeing up the area in the data section that was occupied by the member record before the update. In order to manage the file as described above, this conventional technology generally searches for free space in the data section and frees up space occupied by records that are no longer needed. A space management book is used to manage the space.

A space management list generally consists of a bitmap that stores whether each block in a file is in use or free. When adding, updating, or deleting members in a file, refer to the block usage information in the space management list.
Members are updated. At this time, even if multiple processes request to add, update, or delete members at the same time, it is necessary to prevent double allocation of free space within the file.
Update processing must be performed exclusively.

Generally, expanding the data section of a file to increase the amount of data that can be stored in the file also needs to be done by adding information managed in the space management book. An update occurs. For this reason, file expansion and incremental processing must be performed mutually exclusively with space management list update processing, similar to member addition, update, and deletion processing.

As described above, in the conventional technology, processing that must be performed exclusively is performed by exclusively controlling the entire file. However, in this conventional method, if a request to update or delete a member that can be updated within the existing space of a file is issued during file space expansion processing, the request is made to wait until the file space expansion is completed. For this reason, the above-mentioned conventional technology cannot perform addition, update, or deletion processing of members and expansion of file space at the same time.

In particular, since file space expansion processing requires more processing time than other processes, the above-mentioned conventional technology reduces processing efficiency by making other processes wait while file space expansion processing is in progress. This resulted in a significant decrease in .

Incidentally, as a conventional technique related to this type of file management, for example, a technique described in Japanese Patent Application Laid-Open No. 58-50043 is known.

[Problems to be Solved by the Invention] In the prior art, when expanding the record storage space in a file, in order to exclusively control the entire file, updating and deleting records in the existing file is performed as record storage space expansion processing. It is not possible to perform these processes simultaneously, which has the problem of reducing processing efficiency.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to make it possible to update and delete records in units of extents constituting a file. Record storage that allows records in an extent to be added, updated, and deleted simultaneously, and records in a file to be added, updated, and deleted in parallel from multiple processes in different extents. The purpose is to provide a space control method.

[Means for Solving the Problems] According to the present invention, the above object is to have a space management book indicating the usage status of space in the extent for each extent constituting a file, and to have a space management book for each extent. This is achieved by providing a number of semaphores corresponding to the space management list so that exclusive control can be applied, thereby making it possible to independently perform record storage space update processing in units of extents.

[Operation] File space incremental processing uses a semaphore that corresponds to the space management list of the extent to be allocated, takes exclusive control of the extent to be allocated, then allocates the extent, places the space management list at the beginning of it, and then It will be done. Such exclusive control can prevent access to the incremental extent until the incremental processing is completed.

In this case, since exclusive control has never been applied to the space management list of existing extents, it is possible to add, update, and delete records within the range of existing extents in parallel.

[Embodiment] Hereinafter, an example of the record storage space control method according to the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram showing a processing outline of an embodiment of the present invention, and FIGS. 2, 3, and 4 are flowcharts of various processes explaining the operation of an embodiment of the present invention.

In Figure 1, 1 is a file, 2 is an extent that makes up the file, 3 is a space management book located at the beginning of the extent, 4 is a space management book exclusive control table, 5
is a volume catalog (hereinafter referred to as VT○C), 6 is a file management record, 7 is a record storage space control program, and 8 is a directory section.

In one embodiment of the present invention shown in FIG. 1, file l is composed of a plurality of continuous areas called extents 2 on the medium. Extent 2 that constitutes file 1 is a table VTO on the medium called a volume catalog.
It is managed using file management record 6 stored in C5.

This extent 2 becomes the minimum unit when allocating or incrementing a file. The file l further includes a directory section 8, which is used to manage where member records are stored in the file.

When reading a record of a member stored in file l, the directory section 8 is searched using the name of the member as a key to find the storage location of the record. The record storage space control program 7 is a program that manages the storage space of records in the file 1, and manages the space of the file l using the space management list 3 installed in the first record of each extent 2. ing. The space management list 3 has information indicating whether each block within the extent 2 is in use or free. The record storage space control program 7 is called in response to addition, deletion, or update of members, or changes in the record storage space due to file increment, and uses the space management list 3 to write records of added or updated members. Determine the space or perform control to free the space occupied by the record of the deleted member. At this time, the record storage space control program 7 uses a space management book exclusive control table 4 to exclusively refer to and update the space management book 3.
A semaphore provided in correspondence to each extent 2 is used.

Various processing operations of an embodiment of the present invention configured as described above will be explained with reference to the flows shown in FIGS. 2 to 4.

First, the operation of file increment processing will be explained with reference to FIG.

(1) Assume that a new nth extent is created in file 19 In this case, first, make sure that the nth extent that will be created from now on is not used by other processes in an incomplete state. Therefore, the n-th extent, which is an incremental extent, is exclusively controlled using the semaphore in the space management book exclusive control table 4 for the n-th extent (step 2).

(2) Add the nth extent to file l, perform file incremental processing, add information about the nth extent to file management record 6, and perform formatting of the nth extent (steps 22 to 24). )
4 (3) The leading space of the n-th extent, which is the incremental extent, is set as the space management list 3, and an Rm record is written (step 25).

(4) Through the above processing, the nth incremental extent
Since the extent is completed, use the semaphore for the nth extent of the space management book exclusive control table 4,
The exclusive control on the n-th extent, that is, on the space management list 3 of this extent, is released (step 26).

Next, the process of deleting records stored in an extent will be explained with reference to FIG.

(1) First, the file management record 6 in the VTOC 5 is imported and it is determined which extent contains the record to be deleted (steps 31 and 32).

(2) Using the semaphore of the extent containing the record to be deleted in the space management book exclusive control table 4,
Exclusively control the extent containing the record to be deleted. (Step 33).

(3> Record deletion is executed by importing the space management list 3 at the head of the extent containing the record to be deleted and making the information corresponding to the record to be deleted unused (steps 34 and 35).

(4) Space management book 3 that has completed the process of step 35
is written to the original location at the beginning of the extent to complete the deletion of the record, and finally, the exclusive control of the extent is released using the corresponding semaphore in the space management book exclusive control table 4 (steps 36 and 37). .

In the processes shown in FIGS. 2 and 3 described above, the extent containing the record to be deleted and the extent to which incremental processing is performed are never the same, and exclusive control of the incremental extent (step 21 in FIG. 2) is performed. Exclusive control of extents containing records to be deleted (step 3 in Figure 3)
3) There is no conflict between the two. Therefore, according to the above-described embodiment of the present invention, it is possible to perform incremental processing and record deletion processing at the same time.

Next, the process of determining the record storage space will be explained with reference to FIG.

(1) In order to search for a space that can store records in existing extents in the order of the extents, first initialize the extent number i to "O", then increment it by 1,
It is confirmed that this extent number i is not larger than the last extent number n of all extents constituting the file 1 (steps 41 to 43).

(2) Exclusive control is applied to this i-th extent in the same manner as in the process described above, and the space management list 3 at the head of the i-th extent is taken in (steps 44 and 45).

(3) Examine the management information in the space management list 3 imported in step 45, and search whether there is free space within the extent (steps 46 and 47).

(4) If a free space is found in step 47, the free space is allocated in the space management list 3 of the i-th extent, and the space management list 3 is written in the first record of the i-th extent (steps 48 and 49).

(5) Exclusive control of the i-th extent is released in the same way as in the above-described process, and the process ends (step 50).

(6) In step 47, if no free space is found in the n-th extent, release the exclusive control of the i-th extent and continue the process from step 42 while incrementing the extent number by 1 until a free space is found, or In step 43, the process is repeated until i becomes larger than n (step 51).

In the process described above, if the requested free space is found in the existing extent, the exclusive control of the extent in this process (step 44 in FIG. 4) will conflict with the exclusive control of the incremental extent (step 21 in FIG. 2). There is no. Therefore, according to the embodiment of the present invention described above, it is possible to simultaneously execute the incremental processing and the processing for determining the record storage space.

Furthermore, according to one embodiment of the present invention, exclusive control is performed for each extent, so requests from multiple processes can be processed in parallel unless they are for the same extent.

[Effects of the Invention] As explained above, according to the present invention, a space management list is provided for each extent constituting a file and represents the space usage status in each extent, and a semaphore is provided for exclusive control of these space management records. By having
Incremental processing of a file and updating of records within the file,
It becomes possible to simultaneously execute deletion processing in parallel. Further, since incremental processing can be performed while using files, processing speed can be increased and the degree of freedom in file system operation can be increased.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a processing outline of an embodiment of the present invention, FIG. 2 is a flowchart showing the flow of incremental allocation processing, and FIG.
FIG. 4 is a flowchart showing the flow of record deletion processing, and FIG. 4 is a flowchart showing the flow of record storage space allocation processing. l...File, 2...Extents that make up the file, 3...Space management book located at the beginning of the extent, 4...Space management book exclusive control Table, 5...VTOC, 6.
... File management record, 7 ... Record storage space control program, 8 ... Directory section. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. In a file control method including a space management list for managing record storage space within a file, for each extent constituting a file, a space management list for managing record storage space within the extent. 1. A record storage space control method, comprising: exclusive control of update processing of the space management list. 2. The record storage space control system according to claim 1, wherein a semaphore is provided for each space management list in order to exclusively control update processing of the space management list. 3. By exclusively controlling the updating process of the space management list, it is possible to add, update, or delete records within the range of existing extents while incrementally processing the record storage space of a file and allocating new extents. Claim 1 characterized in that
The record storage space control method described in item 1 or 2.