JPH07319636A - Controller for storing data of magnetic disk - Google Patents

Abstract

PURPOSE:To prevent delay at the time of file access by eliminating seek delay. CONSTITUTION:A B/M (bit map) file generating means 3 generates an in-cylinder successive sector B/M file from an alternative sector B/M file showing alternation processing is performed owing to a sector defect as to the respective sectors of magnetic disks 7 and 8 and an use-state B/M file showing whether or not the respective sectors are in use. The file shows sectors which are neither alternative nor in use and other sectors, cylinder by cylinder. When a packet read-in means 2 reading in a file generation request packet, a storage area setting means 4 sets an area wherein sectors that are neither alternative nor in use succeeding in the same cylinder as a file storage area by referring to the in- cylinder successive sector B/M file. Consequently, the file storage area includes neither alternative sectors nor a part extending over plural cylinders.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk data storage control device for allocating storage areas when storing data on a magnetic disk.

[0002]

2. Description of the Related Art A defective sector inevitably occurs on a magnetic disk. The generated defective sector is skipped during formatting, and the defective sector generated after formatting is replaced with another sector by a specific command. In this way, even if a defective sector occurs midway and the area of the magnetic disk becomes physically discontinuous, it can be treated as a logically continuous area having no defect.

FIG. 9 is an explanatory diagram of the sector skip processing and the skip sector list. As shown in FIG. 9, for example, when there are defects in the physical sector numbers 5 and 8 and these sectors are defective sectors, the defective sectors are skipped during the formatting of the disk and the logical sector numbers are skipped. Attach. Then, the physical sector number of the skipped sector is written in the skip sector lists 7b and 8b so that it can be known which sector has been skipped.

FIG. 10 is an explanatory diagram of the alternate sector processing and the alternate sector list. After the start of use of the magnetic disk, when a defect occurs in any of the sectors, or when a defect is about to occur, the replacement process of the defective sector is performed by the reassign command. As shown in FIG. 10, for example, when a defect occurs in the sectors with physical sector numbers 3 and 7, the sectors with physical sector numbers 90 and 91 are used as their replacement sectors, and logical sector numbers 3 and 7 are assigned to them. Then, the physical sector numbers of the defective sector and the replacement sector are written in the replacement sector lists 7a and 8a so that which sector is replaced by which sector is known.

When data is stored on a magnetic disk in which defective sectors have been skipped or sectors have been changed in this way, first, the sector usage status is checked in order of logical sector number to find an unused area. In this way, the storage area is allocated to the found unused area and the data is stored. At that time, in the conventional case, the area setting is performed regardless of the presence or absence of the defective sector in the area.

Prior art documents relating to such a data storage control device for a magnetic disk include, for example, JP-A-62-209774 and JP-A-63-8165.
8 and JP-A-62-93727.

[0007]

[Problems to be Solved by the Invention]

(Problem) However, the above-mentioned conventional technique has a problem that a delay such as a seek delay occurs when a bad sector is accessed or a file is accessed across a physical cylinder. there were.

(Explanation of Problems) As shown in FIG. 11A, the replacement sector B of the defective sector A on the cylinder S ₁ is
Consider the case where they are on different cylinders S ₂ . In such a case, when attempting to access the defective sector A, the header is once moved from the cylinder S _{1 being} accessed to the cylinder S ₂ where the alternate sector B is located, the alternate sector B is accessed, and then the original sector is restored again. The header will be moved to the cylinder S ₁ . Therefore, a delay occurs due to the seek delay.

In order to eliminate such seek delay,
As shown in FIG. 11B, it is conceivable to provide the alternate sector D of the defective sector C in the same cylinder S ₃ . However, even in such a case, if the tracks are different, it takes time to switch the heads, and a delay occurs even if it is not the same as in the case of FIG.

Further, in the conventional one, as shown in FIG.
Different cylinder S_Four, S _FiveFa across
There is a delay due to seek delay when accessing files
Occur. The area to store a file is cylinder S_Four
To cylinder S_FiveIf set across the cylinder
S_FourCylinder S after accessing the last track of_FiveTo
After moving the header, the cylinder S_FiveThe first
You will access the rack. Therefore, the head
There will be a seek delay to move
It The present invention has an object to solve the above problems.
It is the subject.

[0011]

In order to solve the above-mentioned problems, in a data storage control device for a magnetic disk according to a first aspect of the present invention, information indicating a defective physical sector which has been replaced by a replacement physical sector, Based on the information indicating the defective physical sector to which no logical sector number is assigned and the information indicating the usage status of each logical sector, it is determined whether or not each logical sector is a sector that is neither replaced nor used. Bit map file creating means for creating a continuous sector bitmap file, packet reading means for reading a file creation request packet requesting creation of a file in a magnetic disk, and the packet reading means for reading the file creation request packet Then, referring to the continuous sector bitmap file, neither the alternation process nor the use is performed. The area where the sectors are continuous and with that it comprises a storage region setting means for setting as a storage area of the file. In the data storage control device for a magnetic disk according to the second aspect of the present invention, information indicating a defective physical sector that has been subjected to the replacement processing by substituting the replacement physical sector and information indicating a defective physical sector to which a logical sector number is not assigned. And information indicating the usage status of each logical sector,
In-cylinder contiguous sector bitmap file that indicates, for each cylinder, whether or not each logical sector is a sector that has not been replaced or used, based on the information that indicates the correspondence between each cylinder and each physical sector A bit map file creating means for creating a file, a packet reading means for reading a file creation request packet requesting creation of a file in a magnetic disk, and a packet reading means for reading the file creation request packet in the cylinder Referring to the continuous sector bitmap file,
A storage area setting means is provided for setting an area where sectors which are not used for alternation and which are not used in the same cylinder, are set as a storage area for the file.

[0012]

[Operation] In the first aspect of the invention, when the packet reading means reads the file creation request packet, the storage area setting means refers to the continuous sector bitmap file, and consecutive sectors that are not used for alternation or use are consecutive. Area is set as the file storage area. Therefore, the storage area of the file does not include a replacement sector, and when accessing the storage area, the replacement sector is not accessed, so that seek delay hardly occurs.

Further, in the second invention, when the packet reading means reads the file creation request packet, the storage area setting means refers to the in-cylinder continuous sector bitmap file, and neither alternation processing nor use is performed. An area where sectors are consecutive in the same cylinder is set as the file storage area. Therefore, the storage area of the file does not include a replacement sector and a portion that spans different cylinders, and when accessing the storage area, access the replacement sector and span the different cylinders. Since there is no access, seek delay does not occur.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing the schematic arrangement of the first embodiment. In FIG. 1, 1 is a CPU (Central Processing Unit), 2 is a packet reading means, 3 is a bitmap file creating means, 4 is a storage area setting means, 5 is a memory, 6 is a disk controller, 7 and 8 are magnetic disks. The device, 9 is a bus. The CPU 1 performs various processes while controlling various devices connected to the bus 9 including the magnetic disk devices 7 and 8. The memory 5 stores a processing program for the CPU 1 and provides a work area for the CPU 1. The disk controller 6 controls the magnetic disk devices 7 and 8 according to a command from the CPU 1.

The magnetic disk devices 7 and 8 hold their own alternate sector lists 7a and 8a (FIG. 10) and skip sector lists 7b and 8b (FIG. 9). The packet reading means 2 realized by operating the CPU 1 by the processing program stored in the memory 5 reads the file creation request packet into the work area of the memory 5. The bitmap file creating means 3 reads the alternate sector lists 7a and 8a and the skip sector lists 7b and 8b from the magnetic disk devices 7 and 8 and creates various bitmap files described later. Storage area setting means 4
Sets an area for storing files in the magnetic disk devices 7 and 8.

The alternate sector bit map file 5a in the memory 5, as shown in FIG.
“1” and “0” indicate whether or not each logical sector of the magnetic disk devices 7 and 8 which has been created based on the alternate sector lists 7a and 8a read from 8 is subjected to the alternate processing. As shown in FIG. 2, the usage status bitmap file 5b indicates by "1" and "0" whether or not data is written and used in each logical sector of the magnetic disk devices 7 and 8. . Further, as shown in FIG. 2, the continuous sector bitmap file 5c is created by taking the logical sum of the alternate sector bitmap file 5a and the usage status bitmap file 5b, and the alternate processing is performed for each logical sector. Indicates whether or not it is unused.

In this embodiment, when the packet reading means 2 reads the file creation request packet, the storage area setting means 4 refers to the continuous sector bit map file 5c and is not subjected to alternation processing, and An area in which unused sectors are continuous is set as a storage area for the file.

FIG. 3 is a flowchart showing a procedure for creating a continuous sector bitmap file. Step 1 ... Read the alternate sector lists 7a, 8a from the magnetic disk devices 7, 8. Step 2 ... Read the skip sector lists 7b and 8b from the magnetic disk devices 7 and 8. Step 3 ... Read data for one sector from the read alternate sector lists 7a, 8a. Step 4 ... Read skip sector list 7b, 8
The difference between the physical sector number and the logical sector number is obtained by referring to b. Step 5 ... In consideration of the difference between the physical sector number and the logical sector number, "1" is set to the logical sector corresponding to the physical sector number in the alternate sector lists 7a and 8a.

Step 6 ... Alternate sector list 7a, 8a
It is determined whether or not all the sectors have been completed, and if not completed, the process returns to step 3. Step 7 ... Upon completion, the creation of the alternate sector bitmap file 5a is completed. Step 8 ... Read the usage status bitmap file 5b of the magnetic disk devices 7 and 8 into the work area. Step 9 ... Performs a logical sum operation of the alternate sector bitmap file 5a and the usage status bitmap file 5b. Step 10 ... As a result, creation of the continuous sector bitmap file 5c is completed.

Next, the storage area setting process of the first embodiment will be described. FIG. 4 is a flowchart showing the storage area setting process of the first embodiment. Step 1 ... The packet reading means 2 reads the file creation request packet from the outside or from another area in the memory 5 into the work area. Step 2 ... It is determined whether or not the high speed mode is designated for the read packet.

Step 3: If specified, the continuous sector bitmap file 5c is used. Step 4: As an allocating process, the storage area setting unit 4 refers to the continuous sector bitmap file 5c, and an area where "0" is continuous, that is, a sector which has not been subjected to alternation processing and is unused. A continuous area is set as the storage area of the file. After setting, "1" is put in the area of the continuous sector bitmap file 5c to update the file. Step 5 ... In preparation for the next file creation, "1" is put in the portion corresponding to the above area in the usage status bitmap file 5b, and the file is updated.

Step 6 ... If the high speed mode is not designated in Step 2, the usage status bitmap file 5b is used. Step 7: The storage area setting means 4 refers to the usage status bitmap file 5b and refers to an area where "0" s are continuous, that is, an area where unused sectors are continuous, the storage area of the file. Set as. After setting, "1" is put in the area in the usage status bitmap file 5b to update the file. Step 8 ... In preparation for the next file creation, "1" is put in the portion corresponding to the above area in the continuous sector bitmap file 5c, and the file is updated.

As described above, according to this embodiment, when a file that needs to be written or read without delay is created, the high speed mode is specified in the file creation request packet. A file storage area is set using the continuous sector bitmap file 5c. Therefore, an area not including the sector subjected to the alternation processing is accessed, and the processing is performed at high speed. On the other hand, when a normal file is created, the normal mode is specified in the file creation request packet to set the file storage area using the usage status bitmap file 5b. Therefore, the area including the sector subjected to the alternation process is also used, and the processing speed may be slowed down, but the area of the magnetic disk can be effectively used.

(Second Embodiment) FIG. 5 is a block diagram showing the schematic arrangement of the second embodiment. The reference numerals correspond to those in FIG. In this embodiment, the continuous sector bitmap file 5c and the skip sector lists 7b, 8
b and cylinder zone data 7c and 8c,
An in-cylinder continuous sector bitmap file 5d is created. And using it, it has not been replaced,
In addition, an area where unused sectors are continuous in the same cylinder is set as the storage area of the file.

FIG. 6 is an explanatory diagram of an in-cylinder continuous sector bitmap file. As described above, the in-cylinder continuous sector bitmap file 5d includes the continuous sector bitmap file 5c and the skip sector list 7
b, 8b and cylinder zone data 7c, 8c. Among them, regarding the continuous sector bitmap file 5c and the skip sector lists 7b and 8b,
Already explained. The cylinder zone data 7c and 8c show the range of the physical sector number contained in each cylinder of each zone of the magnetic disk device, as shown in FIG.

The in-cylinder continuous sector bit map file 5d uses the skip sector lists 7b and 8b to associate the physical sector number with the logical sector number, and the continuous sector bit map file 5c to the cylinder zone data 7c, 8c is used to divide the record into cylinder units. Then, the cylinder number, the maximum number of consecutive sectors in each cylinder, etc. are added to it.

FIG. 7 is a flowchart showing the procedure for creating the in-cylinder continuous sector bitmap file. Since steps 1 to 10 are the same as those in FIG. 3,
The description is omitted here. Step 11 ... Read the cylinder zone data 7c, 8c from the magnetic disk devices 7, 8. Step 12 ... The cylinder zone data 7c and 8c and the skip sector lists 7b and 8b read in Step 2
With reference to, the continuous sector bitmap file 5c created in step 10 is divided into records in cylinder units. Step 13 ... Adds the cylinder number and the maximum number of consecutive sectors, and the cylinder consecutive sector bitmap file 5d
Complete the creation of.

Next, the storage area setting process of the second embodiment will be described. FIG. 8 is a flowchart showing the storage area setting process of the second embodiment. Step 1 ... The packet reading means 2 reads the file creation request packet received from the outside or in the memory 5 into the work area. Step 2 ... It is determined whether the read packet specifies the normal mode, the high speed mode, or the ultra-high speed mode.

Step 3 ... If the normal mode is designated, the usage status bitmap file 5b is used. Step 4 ... As an allocating process, the storage area setting means 4 refers to the usage status bitmap file 5b, and determines an area where “0” is continuous, that is, an area where unused sectors are continuous. Set as a file storage area. After setting, "1" is put in the area in the usage status bitmap file 5b to update the file. Step 5: In preparation for the next file creation, "1" is put in a portion of the continuous sector bitmap file 5c corresponding to the storage area, and the file is updated. Step 6 ... In the in-cylinder continuous sector bitmap file 5d, "1" is put in the location corresponding to the storage area, and the file is updated.

Step 7 ... If the high speed mode is designated in Step 2, the continuous sector bitmap file 5c
To use. Step 8: As an allocating process, the storage area setting means 4 refers to the continuous sector bitmap file 5c, and an area in which "0" is continuous, that is, a sector that has not been subjected to alternation processing and is unused A continuous area is set as the storage area of the file. After setting, "1" is put in the area of the continuous sector bitmap file 5c to update the file. Step 9 ... In preparation for the next file creation, "1" is put in a portion of the usage status bitmap file 5b corresponding to the storage area, and the file is updated. Step 10 ... Put "1" in the portion corresponding to the storage area in the in-cylinder continuous sector bitmap file 5d and update the file.

Step 11 ... If the ultra high speed mode is designated in Step 2, the in-cylinder continuous sector bitmap file 5d is used. Step 12: As an allocating process, the storage area setting means 4 refers to the in-cylinder continuous sector bitmap file 5d, and an area where "0" is continuous, that is, is not subjected to alternation processing and is unused. An area where a certain sector is continuous and does not straddle between cylinders,
Set as a storage area for the above files. Once set,
"1" is put in the area in the in-cylinder continuous sector bitmap file 5d to update the file. Step 13 ... In preparation for the next file creation, "1" is put in a portion of the usage status bitmap file 5b corresponding to the storage area, and the file is updated. Step 14 ... In the continuous sector bitmap file 5c, "1" is put in a portion corresponding to the storage area, and the file is updated.

According to this embodiment, in a real-time system or the like, when a delay is not allowed at the time of writing or reading data to or from the magnetic disk devices 7 and 8, the cylinder is specified by designating the ultra high speed mode in the file creation request packet. The file storage area is set using the inner continuous sector bitmap file 5d. Therefore, at the time of data writing and reading, an area which does not include the sector subjected to the alternation processing and which does not include the portion extending between different cylinders is accessed, and the processing without delay is guaranteed.

[0033]

As described above, according to the data storage control device of the magnetic disk of the present invention, the file storage area does not include a replacement sector, and when the storage area is accessed, the replacement sector is accessed. Because there is nothing to do
Almost no seek delay occurs. Further, when the in-cylinder continuous sector bitmap file is used when setting the storage area, the storage area of the file is accessed without including the alternate sector and the portion extending between different cylinders. At this time, since the alternate sector is not accessed and the access is not performed across different cylinders, the seek delay does not occur. Therefore, the access time can be predicted, and if applied to a real-time system in which system timing is important, its reliability can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment.

FIG. 2 is a diagram showing a method of creating a continuous sector bitmap file.

FIG. 3 is a flowchart showing a procedure for creating a continuous sector bitmap file.

FIG. 4 is a flowchart showing a storage area setting process of the first embodiment.

FIG. 5 is a block diagram showing a schematic configuration of a second embodiment.

FIG. 6 is an explanatory diagram of an in-cylinder continuous sector bitmap file.

FIG. 7 is a flowchart showing a procedure for creating a continuous sector bitmap file in a cylinder.

FIG. 8 is a flowchart showing a storage area setting process of the second embodiment.

FIG. 9 is an explanatory diagram of sector skip processing and a skip sector list.

FIG. 10 is an explanatory diagram of a replacement sector process and a replacement sector list.

FIG. 11 is a diagram for explaining the reason why a delay occurs at the time of access in the conventional technique.

[Explanation of symbols]

1 ... CPU, 2 ... Packet reading means, 3 ... Bitmap file creating means, 4 ... Storage area setting means, 5 ... Memory, 6 ... Disk controller, 7, 8 ... Magnetic disk device

Claims (2)

[Claims] 1. Information indicating a defective physical sector that has been replaced by replacement with a replacement physical sector, information indicating a defective physical sector to which a logical sector number is not assigned, and the usage status of each logical sector. Based on information and
Bit map file creating means for creating a continuous sector bitmap file indicating whether or not each logical sector is a sector that has not been replaced or used, and a file creation request for creating a file in a magnetic disk Packet reading means for reading a packet, and when the packet reading means reads the file creation request packet, the continuous sector bitmap file is referred to, and an area in which sectors that are neither alternated nor used are contiguous A data storage control device for a magnetic disk, comprising storage area setting means for setting a storage area for the file. 2. Information indicating a defective physical sector that has been replaced by replacement with a replacement physical sector, information indicating a defective physical sector to which a logical sector number is not assigned, and the usage status of each logical sector. Based on the information and the information indicating the correspondence between each cylinder and each physical sector,
Bit map file creating means for creating an in-cylinder continuous sector bit map file that indicates for each cylinder whether or not each logical sector is a sector that has not been replaced or used, and file creation in a magnetic disk And a packet reading means for reading a file creation request packet for requesting a file creation request packet, and when the packet reading means reads the file creation request packet, it refers to the in-cylinder continuous sector bitmap file, and neither replacement processing nor use is performed. A data storage control device for a magnetic disk, comprising: storage area setting means for setting an area where sectors are consecutive in the same cylinder as a storage area for the file.