JP4480592B2 - File system - Google Patents

Description

  The present invention relates to a file system. In particular, data having a large amount of information such as data handled by digital broadcasting adopting the MPEG2 transport stream format and data handled by a disk medium equipped with the MPEG2 program stream format can be converted in real time. Relates to a file system for a recording / playback apparatus to be processed in the above.

  In recent years, information processing devices such as high-performance CPUs, memories, and large-capacity recording media have become available at low prices. In addition, standards for various devices such as digital broadcasting, DVD, and BD are prescribed, and many multimedia devices capable of processing large-capacity digital AV data have been commercialized.

  A management device called a file system is used to write or read such digitized AV data on a recording medium. With this device, it is possible to manage the area of the recording medium by ascertaining the area in the recording medium, such as which area is in use or unused, and which area belongs to which file. It is carried out.

  In a general file system, recording medium area management is performed using three types of tables: an area management table, an unused area management table, and a file management table, which will be described later.

  This area management table divides the area of the recording medium into blocks of a predetermined size and indicates whether each block is used as an area for storing any data. The management table is recorded on a recording medium, read from the recording medium, and operated on the working memory.

  FIG. 12 shows an example of an area management table in a conventional general file system.

  As shown in the figure, the conventional area management table only has a “use flag” indicating whether or not the block is used, and information indicating which of the files configured on the recording medium belongs to. Often does not have. Note that the area management table shown in FIG. 12 indicates that the logical blocks 10 to 13 and the logical blocks 20 to 24 are in use in any file, and the other logical blocks are unused. Yes.

  The conventional general file system is provided with area management means as means for operating the area management table as shown in FIG.

  On the other hand, the conventional general file system also includes a file management table, which is a table configured for each file.

  FIG. 13 shows an example of a file management table in a conventional general file system.

  The file management table shown in the figure belongs to which file belongs to which file in which order among the areas indicated by the “usage flag” in the area management table (FIG. 12). It is a table for indicating.

  This file management table is operated on the memory and recorded / read out on the recording medium. For example, in the file management table shown in FIG. 13, information from the top four blocks indicates the area from logical block 10 to logical block 13 on the area management table, and the next five blocks of information are from logical block 20 to logical block The area up to block 24 is shown. If 1 logical block = 512 Kbytes, the position of 3 Mbytes from the top of the area is 3M [bytes] ÷ 512 K [bytes] = 6. You can see that it is located.

A general file system includes file management means as means for operating the file management table. The unused area management table is a table that is listed so that it is easy to search for an area determined to be unused in the area management table, and is often configured on a memory.

  FIG. 14 shows an example of an unused area management table corresponding to FIGS.

  The unused area shown in the figure is an area from logical block 0 to logical block 9, logical block 14 to logical block 19, and logical block 25 to logical block 29. These areas are from any file. Are not used, and each area is managed as a continuous area by a list in which the top logical block and the number of logical blocks are described. Specifically, it is managed as three lists (head, number of blocks) = (0, 10), (14, 6), (25, 5).

  A general file system includes unused area management means as means for operating this unused area management table. Although these management means are general, there are differences in management methods for each file system, and different file systems are often used depending on the respective applications. This is because special methods are required to access different file systems.

  For this reason, as a method for allowing different file systems to coexist on one recording medium, a method of managing them divided into partitions is adopted.

  In this method, an area range for each file system is determined in advance on a recording medium. For example, in the world of a PC, a WINDOWS (registered trademark) file system and a UNIX (registered trademark) file system are set to one. It is used when coexisting on two recording media.

  However, in this conventional method, since the area for each file system is divided in advance, even if there is a space on one file system, the other file system cannot use the area.

Therefore, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-243096), a recording medium is divided into a plurality of areas, and dummy data is written into unused areas for each area, and specific data is specified for the dummy data. Proposals have been made to make it easier to divide and resize a plurality of areas by configuring so that only applications or specific files can be overwritten.
JP 2001-243096 A

  By the way, as described above, the conventional file system employs a method of managing different file systems by dividing them as a method for allowing different file systems to coexist on one recording medium. However, the area for each file system is divided in advance. For this reason, there is a problem that even if there is a space on one file system, the other file system cannot use the area.

  In general, since different file systems have different management methods, when each area on the recording medium is configured by a different file system, one unused area is used by another file system. There was a problem that it was impossible.

  In the method disclosed in Patent Document 1, since the unused area is used for writing dummy data, it cannot be used by another file system unless the dummy data is released.

  For this reason, in the present invention, in a system in which a plurality of file systems share a storage medium, an area that has not been used in any one file system is divided into another file without partitioning the recording medium. It is an object of the present invention to provide a file system for a recording / playback apparatus that can be assigned to a file of the system.

  In order to solve the above problems, a file system according to the present invention has the following features.

The present invention relates to a file system comprising at least a recording medium and a plurality of file systems having recording / reproduction control means for recording / reproducing file data on the recording medium.
Wherein a lower level file system cormorants line recording and reproduction of data directly to the recording medium managing recording medium, the lower file system, a plurality of upper file system that handles as one virtual recording medium and, with a,
The lower-level file system divides the recording medium into a plurality of logical blocks, and manages a first area management table that stores information indicating that the logical blocks are used as areas for storing data. Area management means, first file management means for managing a first file management table for storing information relating to files recorded in a used area on the recording medium, and the logical block for storing data Unused area management means for managing an unused area management table for storing information indicating that the area is unused, the first area management table, the first file management table, and the unused area management table Recording / reproduction control means for directly recording / reproducing data on / from the recording medium based on the information of
The upper file system regards the lower file system as one virtual recording medium, divides the virtual recording medium into a plurality of logical blocks, and uses the logical blocks as areas for storing data. Second area management means for managing a second area management table for storing information indicating the information, and second file management for storing information relating to files recorded in the used area on the virtual recording medium Second file management means for managing the table; conversion means for converting a file recording / reading operation to the virtual storage medium into a file recording / reading operation to the storage medium by the lower-level file system; Logical block area information recorded in the second area management table and a file recorded in the first file management table A comparison means for detecting a mismatch between the two areas by comparing the area information, and when a mismatch is detected in the two areas by the comparison means, It is characterized in that the area is opened and aligned .

Further, the present invention is a file system comprising at least a recording medium and a plurality of file systems having recording / reproduction control means for recording / reproducing file data on the recording medium.
A lower file system that manages the recording medium and directly records / reproduces data to / from the recording medium, and a plurality of upper file systems that handle the lower file system as one virtual recording medium, A file system arbitration processing unit that mediates between the plurality of upper file systems and the lower file system, and arbitrates operations from the plurality of upper file systems to the lower file system;
The lower-level file system divides the recording medium into a plurality of logical blocks, and manages a first area management table that stores information indicating that the logical blocks are used as areas for storing data. Area management means, first file management means for managing a first file management table for storing information relating to files recorded in a used area on the recording medium, and the logical block for storing data Unused area management means for managing an unused area management table for storing information indicating that the area is unused, the first area management table, the first file management table, and the unused area management table Recording / reproduction control means for directly recording / reproducing data on / from the recording medium based on the information of
The upper file system regards the lower file system as one virtual recording medium, divides the virtual recording medium into a plurality of logical blocks, and uses the logical blocks as areas for storing data. Second area management means for managing a second area management table for storing information indicating the information, and second file management for storing information relating to files recorded in the used area on the virtual recording medium Second file management means for managing the table; conversion means for converting a file recording / reading operation to the virtual storage medium into a file recording / reading operation to the storage medium by the lower-level file system; A plurality of operations for managing recording / reading operations to / from the virtual storage medium by the first file management means of the lower-level file system Comprising conversion means for converting the recording and reading operations to a file, and
The file system arbitration processing means causes the lower file system to execute an execution command from the upper file system if the lower file system is not being executed when there is an execution command from the upper file system, If the lower file system is being executed, based on the priority included in the execution instruction from the upper file system, the priority included in the execution instruction being executed, the priority included in the new execution instruction, , The lower priority file system is executed by the lower-level file system, the lower-priority execution instruction is temporarily stored, and the lower-priority execution is executed after the higher-priority execution is completed. and executes the instructions.

Further, the first file management table includes a first block number of the logical blocks allocated to each file recorded on the recording medium, and stores the number of consecutive blocks, in the middle of each of the file area of the file it is characterized in that there is a case where unallocated blocks exist.

Furthermore, the first file management table indicates, for each file recorded on the recording medium, the logical block number from the head of the file data area, the number of logical blocks, and whether or not the area is usable. is a record, wherein the kite invalid flag indicating.

Furthermore, the prior SL information recorded in the first file area management table provided in the first file management means, it is characterized in that recorded in the file area of the storage medium.

  As described above, according to the file system of the present invention, the system configuration is divided into at least two or more higher-level file systems and lower-level file systems. To provide a file system in which an upper file system can coexist on one recording medium, and an area that is no longer needed in any one upper file system can be reused in another upper file system. it can.

  In addition, since conversion means for converting operations on files in the upper file system into operations on a plurality of files in the lower file system is provided, it is not necessary to have an area management table and an unused area management table on the upper file system. Therefore, it is possible to share an unused area among a plurality of upper file systems.

  In addition, since the conversion means for converting the operation on the upper file system into the operation on a plurality of files on the lower file system is provided, the upper file system treats the file on the lower file system as if it were a recording medium. Can be operated. In addition, when an area is released or registered in the area management table in the upper file system, the file in the lower file system, which is the corresponding area, is deleted and created so that it can be created between multiple upper file systems. The unused area on the recording medium can be shared.

  In addition, the upper file system manages the files belonging to the lower file system as virtual recording media, thereby leaving a configuration in which the area management table and the file management table are retained on the upper file system. The unused area of the lower file system can be shared between file systems.

  The file management table indicating the files managed by the lower file system includes a logical block number from the head of the file area for each file, the number of logical blocks, and an invalid flag indicating whether or not the area is usable. By managing the recorded list table and referring to it appropriately, for example, it becomes possible to create a file with a hollow structure having no area in the middle of the file area, and the upper file system belongs to the lower file system. When operating a file as a virtual recording medium, for example, when releasing an area from this virtual recording medium, the area is released without rewriting the area management table or file management table recorded in the file. can do.

  Further, according to the file system of the present invention, since the file system arbitration processing means for arbitrating operations on the lower file system from a plurality of upper file systems is provided, for example, one of the upper file systems needs real-time characteristics. AV data access, and when the other higher-level file system is access to PC data (that is, data that needs to be read correctly even after retrying), the arbitration by this arbitration processing means A file system that can give priority to access can be provided.

  Also, file system operations can be performed by comparing the area management table managed on the upper file system with the area management table managed on the lower file system for the upper file system area used on the lower file system. It is possible to detect a flaw between file systems when the power is turned off due to a power failure or the like.

  Also, compare the upper file system area used on the lower file system with the area management table managed on the upper file system and the file management table managed on the lower file system. If there is no error, a means for matching is provided. For example, during operation of the file system, even if a flaw occurs between the upper file system and the used area of the lower file system due to a power failure, etc. This trap can be restored.

  Furthermore, the first file management table managed by the lower file system is recorded with a logical block number from the head of the file data area, the number of logical blocks, and an invalid flag indicating whether or not the area is usable. By writing this into the recording medium as a list table format, it will not disappear from the CPU storage area due to, for example, turning on / off the power supply. It is possible to realize a file system that can be shared stably.

[Overview]
Hereinafter, embodiments of the file system of the present invention will be described in the order of [first embodiment] to [fourth embodiment]. Before that, an outline of the file system of the present invention will be described.

In the file system of the present invention, whole is constituted by a multilayer structure of upper file system and the underlying file system, the upper file system comprises a second file management unit and a second region managing means, mainly upper file The file management table and the area management table in the system are managed . The lower file system includes a first file management means, a first area management means, and an unused area management means , mainly in the lower file system. performing a file management table, the management and the area management table, the management of the unused area management table.

  The upper file system is composed of two or more file systems each having different characteristics.

In this higher-level file system, internal file management tables such as file creation and file writing and extension of area management tables and partial deletion of file area management tables such as file creation via API (application interface) held by itself are deleted. And operations such as deleting files.

In addition, when it is necessary to secure an area, this upper file system verifies whether the lower file system can secure the area. When the area can be secured, the internal file management table and the area management table are changed, and this is returned to the application via the API.

Further, when it is necessary for the upper file system to release the area, the file management table and the area management table in the upper file system are changed, and the area is returned to the lower file system.

  In this case, as a method for realizing the upper file system, a method of converting one file on the upper file system into a plurality of files on the lower file system can be considered.

  Further, in this case, as a method for realizing the upper file system, a method for operating a plurality of files in the lower file system as if they were one recording area is possible.

  FIG. 11 is an explanatory diagram showing a correspondence relationship between files on the upper file system (file systems A and B) and files on the lower file system.

  The file (file A1) of the upper file system A is converted into a plurality of files (file C1, file C2) on the lower file system, for example, as shown in FIG.

  The upper file system A shown in FIG. 11 is a virtual file system that operates files in the lower file system, and operations on the upper file system are converted into operations on the lower file system on the virtual file system.

  The file A1 operated in the upper file system is divided into a plurality of files in the lower file system, that is, mapped to the file C1 and the file C2. The operation on the file A1 is converted into an operation on either the file C1 or the file C2 converted by the upper file system A.

  For example, the operation of deleting the file A1 is converted into an operation of deleting the files C1 and C2 of the lower file system on the virtual file system A.

  According to such a method, all file operations in the upper file system are converted into operations to the lower file system, and use and unused of the area on the recording medium are managed by the lower file system. After erasing the file A1, it becomes possible for another higher-level file system to secure a free space generated by this erasure.

  Further, as another method of realizing the upper file system, it is possible to operate as if it is one recording area by connecting recording areas of a plurality of files in the lower file system.

  For example, the recording area of the upper file system B shown in FIG. 11 is handled as one virtual recording medium of the lower file system. Hereinafter, this virtual recording medium is referred to as a “recording medium image file”.

The upper file system B is a file system capable of performing area management and file management, and operates a file on the lower file system on the “recording medium image file”.

  That is, all operations on the recording medium in the upper file system B are converted into operations on the file on the lower file system.

  As an example, a case will be described in which the upper file system B accesses the lower file system as a virtual recording medium such as an HDD.

  All accesses in the upper file system B are accesses to the HDD sector. The sector of the HDD is generally 1 sector = 512 bytes. In the upper file system B, the access to the HDD is converted into an operation for the recording medium image file.

  When the upper file system B needs to read / write a sector on the HDD, the upper file system B converts the read / write to a file on the lower file system. For example, reading / writing with respect to the sector x of the recording medium image file of the upper file system B is converted into reading / writing from the 512 × x byte from the top of the file of the lower file system. As a result, the file on the lower file system can be manipulated as if it were a recording medium such as an HDD.

  However, in this method, when an intermediate area in the recording medium image file becomes unnecessary for the upper file system, it cannot be used as an unused area of the lower file system.

  Therefore, the present invention solves this by using the following two methods.

  The first is a method of configuring a recording medium image file configured on the lower file system as a plurality of fixed-length files, and the other is the concept of a hollow file on the lower file system. It is a method to do.

  First, a method for configuring a recording medium image file operated by the upper file system as a plurality of fixed-length files existing on the lower file system will be described.

  The files 0 to 3 and the files 8 to 12 shown in FIG. 2 are files on a lower file system each divided by a size of 512 Kbytes, and each file corresponds to which position from the beginning of the file area. An ID indicating whether to do it is given. As shown in FIG. 2, the plurality of files consist of 4 blocks of 2 Mbytes with the 0th byte as the first byte from the beginning of the area (imaginary area to be imaged) of the recording medium image file, and the beginning of the area. Are composed of 5 blocks of 2.5 Mbytes with the 4 Mbytes as the first byte.

  For example, file 0 constitutes 512 Kbytes with the first byte from the beginning of the area of the recording medium image file as seen from the upper file system as the first byte, and file 10 is the 4.5 Mbyte from the beginning of the data area. Are 512 Kbytes starting from the first byte. Files 4 to 7 are nonexistent files.

  The host file system accesses these files as if they were recording media. For this reason, the upper file system configures an area management table and a file management table managed by the upper file system in the recording medium image file, and manages other areas as logical blocks managed by the upper file system. . The host file system accesses these data by converting the sector offset from the head of the area into an address.

  For example, when accessing the 4095th sector from the head of the area, it is 4095 × 512 = 2096640 bytes on the recording medium image file, which corresponds to 511 Kbytes of file 3 on the lower file system.

  When there is no corresponding file on the lower file system, this indicates that the area is not allocated as viewed from the upper file system. For example, 2M bytes from the 2M byte on the area of the recording medium image file indicate that the area is not secured for the upper file system. Only writing is possible in such an area. However, it is necessary to create a file by a lower file system before writing. In addition, when there is a write request to a location where no area exists in the file, the lower-level file system secures the area and writes to that location.

  When it is desired to release a specific area of the lower file system from the upper file system, a file in the area to be released is designated from the upper file system, and the lower file system deletes the file. At this time, a file having a larger number than the deleted file is not prepended. This is because the position of the file on the lower file system from the head corresponds to a sector which is area management in the higher file system.

  The following describes a method for using the concept of a hollow file on a lower file system.

  FIG. 5 is an explanatory diagram for explaining the concept of a missing file.

  The file shown in the figure is a file on a lower-level file system in which logical blocks are divided every 512 Kbytes, and includes 4 blocks of 2 Mbytes starting with the 0th byte or more from the beginning, and 2.5M of 4 Mbytes or more from the beginning. This is a file in which 5 blocks of bytes are secured. In this file, 2 Mbytes from 2 Mbytes to less than 4 Mbytes from the beginning are areas where no area is secured. Although only writing to this area is possible, it is necessary to secure the area by the lower file system before writing. The area can be secured by instructing the lower file system in advance by the upper file system.

  If there is an instruction to write to a location where no area exists in the file, the lower-level file system secures the area and then writes to the location. When the upper file system wants to release a specific area of the lower file system, the upper file system specifies the offset and size of the area to be released to the lower file system. The specified area is deleted from the file management area on the lower file system, and the corresponding area is registered in the unused area management table. At this time, the lower file system updates the file management area without leading the area behind the deleted area. This treatment is as described above. That is, since the offset address from the top of the file on the lower file system corresponds to a sector that is area management in the upper file system, the area management table of the upper file system is rewritten when the offset deviates. This is because the necessity arises.

  By using a missing file in file management on the lower file system, the interface with the upper file system can be retained as an image of the recording medium, so control such as area management and file management in the higher file system can be diverted. Thus, the recording medium can be shared with other upper file systems.

  In the present invention, in order to compare and collate the area management table of the upper file system and the file management table of the lower file system, a flag that is operated when the power is turned on / off is provided. The upper file system detects the mismatch (不) between the two management tables and recovers them.

  This flag is set to FALSE when the entire file system is correctly started when the power is on, and set to TRUE when all operations on the entire file system are normally completed when the power is off. .

  In general, an operation on a recording medium requires reading and writing of AV data that requires the operation to be completed within a certain time (that is, real-time performance), and usually requires accuracy even if the access time is somewhat delayed. Broadly divided into data reading and writing. In particular, when reading / writing AV data, the amount of access is large, so if the processing does not end within a certain time after the request is transmitted, the amount of memory in the buffer for buffering AV data is large. Is required.

  However, if the file system is requested to read and write normal data, the AV data buffer may fail. In particular, when there are a plurality of upper file systems, for example, one upper file system may be requested to read / write AV data, and the other upper file system may be requested to read / write normal data. . In order to solve this problem, by providing file system arbitration means, even when one upper file system requests read / write to normal data, the other upper file system can read / write AV data. To be able to do.

Hereinafter, the best embodiment of the subtitle of the present invention will be described in detail in the order of [First Embodiment] to [Fourth Embodiment] with reference to the drawings.
[First Embodiment]
FIG. 1 is a configuration diagram showing the overall configuration of the file system according to the first embodiment of the present invention.

  In the figure, the file system according to the present embodiment is connected to a recording processing unit A (101), a reproduction processing unit A (102), a recording processing unit A (101), and a reproduction processing unit A (102). Upper file system A (103), recording processing unit B (104), reproduction processing unit B (105), upper file system B connected to recording processing unit B (104) and reproduction processing unit B (105) (106), the lower file system 107 having the upper file system A (103) and the upper file system B (106) as the upper file system, and the video from the reproduction processing unit A (102) and the reproduction processing unit B (105) A display processing unit 108 for displaying the audio data output and a recording medium 109 as a real storage medium operated by the lower-level file system 107 are configured.

  In this embodiment, the recording processing unit A (101) and the reproduction processing unit A (102), and the recording processing unit B (104) and the reproduction processing unit B (105) are two types of recording / reproducing processes having different recording methods. Part. For example, one side records and reproduces in the MPEG2-TS (transport stream) format through the digital broadcast tuner, and the other uses the MPEG2 encoder to record and reproduce analog broadcast in the MPEG2-PS (program stream) format. It may be what performs.

  By the way, recording digital broadcasts in MPEG2-TS format means that you can view multiplexed data broadcasts when copying to a D-VHS device or playing back from a recording medium through an IEEE1394 connection. There are benefits. Since the MPEG2-PS format is also a recording format adopted by DVD, there is an advantage that it can be copied to DVD without re-encoding.

  In this embodiment, the recording processing unit A (101), the reproduction processing unit A (102), and the upper file system A (103) process MPEG2-TS, and the recording processing unit B (104) and reproduction processing. The part B (105) and the upper file system B (106) are assumed to process MPEG2-PS, and the recording medium 109 is assumed to be an HDD (hard disk).

  The recording processing unit A (101) records the MPEG2-TS obtained from the digital broadcast on the recording medium 109 via the upper file system A (103). The upper file system A (103) records on the shared recording medium 109 via the lower file system 107.

  The reproduction processing unit A (102) reads out the recording data composed of the MPEG2-TS stream recorded by the recording processing unit A (101) from the recording medium 109 via the higher-level file system A (103), decodes it. Then, the video data is sent to the display processing unit 108.

  The recording processing unit B (104) encodes the audio / video data obtained from the analog broadcast in MPEG2, converts it into the MPEG2-PS format, and records it on the recording medium 109 via the upper file system B (106). To do. The upper file system B (106) records on the shared recording medium 109 via the lower file system 107.

  The reproduction processing unit (B105) reads the recording data composed of the MPEG2-PS stream recorded by the recording processing unit B (104) from the recording medium 109 via the upper file system B (106), decodes it, Video data is sent to the display processing unit 108.

  The display processing unit (108) displays the video / audio data decoded by the reproduction processing unit A (102) or the reproduction processing unit B (105).

  FIG. 2 is an area map showing a correspondence relationship between the recording medium image of the upper file system and the file of the lower file system in the file system according to the first embodiment of the present invention.

The upper file system A (103) accesses a plurality of files of the lower file system 107 as if they were one recording medium. The upper file system A (103) includes second file management means and second area management means. On this recording medium image file, an area management table (second area management table), a file management table, And logical blocks.

  Hereinafter, in the present embodiment, details of the upper file system A (103) will be described (the details of the upper file system B (106) will be described in a second embodiment described later).

  Here, the logical block unit in the upper file system A (103) and the size of one file in the lower file system constituting the recording medium image file are set to 512 Kbytes. Also, it is assumed that the recording medium image file has 1 sector = 512 bytes.

As shown in FIG. 2, the upper file system A (103) (FIG. 1) sets its own area management table and file management table to the area between the 0th sector and the 4095th sector of the recording medium image file. Storing. These pieces of information are actually stored in a file on the lower file system, and the operation on the sector x of the recording medium image file is replaced with the file on the lower file system and its offset by equation (1). .
File number y = (x × 512) ÷ (512 × 1024) AND
Offset byte in file y = MOD ((x × 512)), (512 × 1024))
……… (1)
However, in the equation (1), MOD (A, B) indicates a remainder obtained by dividing A by B. The file number y is an index indicating which file of the lower file corresponds to. The file number y is assigned to the file of the lower file system 107 by assigning a fixed decimal number to the file name as in FILE0008. Can be associated. Further, the offset byte in the file y is an offset from the head of the associated file. Hereinafter, these will be described with specific examples.

  For example, the sector 8193 on the upper file system A103 has the file number y = (8193 × 512) ÷ (512 × 1024) = 8, and the MOD (8913 × 512, 512 × 1024) = 512 bytes from the top. Become.

  Next, a process for deleting a file existing on the upper file system will be described by way of an example.

  FIG. 3 is a flowchart showing an example of processing in the case of deleting a file existing on the higher-level file system in the file system according to the first embodiment of the present invention.

  In the figure, first, deletion of a file on the upper file system A (103) is instructed from an application by an API or the like (step S501). The file to be deleted is identified using a file name, an identifier (ID) associated with the file, or the like.

  Next, the upper file system A (103) searches the file management table of the file corresponding to this identifier, and acquires the file management table (step S502).

  Next, the upper file system A (103) sets the use flag on the area management table to all logical blocks used by the designated file to be deleted in the file management table (step S503). A use state is set (step S504).

  Thereafter, the updated file management table is written in the recording medium image file as that of the recording medium image file (step S505). Further, the updated area management table is written in the recording medium image file as that of the recording medium image file (step S506). The file number and the file offset in the area management table are converted into a storage area on the lower file system 107 by the expression (1).

  Finally, the upper file system A (103) is only used when the unused logical block for one file on the lower file system 107 is all unused on the area management table of the upper file system A103. The corresponding file is deleted (step S507).

  Next, a process for recording a file on the upper file system A (103) will be described with reference to FIG.

  FIG. 4 is a flowchart showing an example of processing when data is recorded in a file on the higher-level file system in the file system according to the first embodiment of the present invention.

  First, data recording to a file in the upper file system A103 is instructed from an application by an API or the like (step S601). The file to be recorded is identified using a file name or an identifier (ID) associated with the file.

  The upper file system A (103) acquires the file management table of the file in the upper file system A (103) corresponding to this identifier (step S602).

  Next, the upper file system A (103) verifies whether or not a logical block is assigned to a position where data for the corresponding file is written (step S603), and if a logical block is not assigned to the position. The process proceeds to step S609. If a logical block is assigned to the position, the process proceeds to step S604.

  In step S604, the upper file system A (103) searches for a logical block with a use flag OFF in its own area management table.

  The area corresponding to the searched logical block may not exist even on the recording medium image file. Therefore, it is verified whether or not a file corresponding to this logical block already exists on the lower file system 107 (step S605). If it does not exist, the logical block is not assigned to the upper file system A (103). Therefore, in this case, since it is necessary to allocate an unused area on the lower file system 107 to the upper file system A (103), the file having the corresponding file number is deleted using the API of the lower file system 107. Create (step S606). At this time, an area of 512 Kbytes is allocated to the corresponding file simultaneously with file creation.

  If it is determined that the file corresponding to the logical block has already been assigned to the lower file system 107, the use flag of the logical block in the area management table of the upper file system A (103) is set to ON ( In step S607), the logical block is registered in the file management table of the file (step S608). At this time, similarly to the processing shown in FIG. 3, the updated file management table and area management table may be written back to a file on the lower file system as a virtual recording medium.

  In step S609, if it is determined that a logical block is assigned to the file, the upper file system A (103) writes the file in the lower file system as a virtual recording medium.

[Second Embodiment]
The configuration of the file system according to the second embodiment of the present invention is the same as the configuration of the file system according to the first embodiment of the present invention. However, in the file system according to the first embodiment of the present invention, Compared to the fact that there is a correspondence between the recording medium image of the upper file system and the file of the lower file system, in the file system according to the present embodiment, the recording medium image of the upper file system and the file data of the lower file system Correspondence exists. In addition, an invalid flag is prepared in the file management table on the lower file system.

  FIG. 5 is an area map showing the correspondence between the recording medium image of the upper file system and the file data of the lower file system in the file system according to the second embodiment of the present invention.

  A recording medium image file (here, a disk image) shown in the figure is a virtual recording medium image constituted by one file on a lower file system. The upper file system B106 constitutes an area management table, a file management table, and a logical block used in the upper file system on the recording medium image file.

  The file area on the lower file system corresponding to the recording medium image file includes a section to which the area is allocated and a section to which the area is not allocated (missing section).

  FIG. 6 is an area map showing the invalid flag added to the file management table of the lower-level file system. FIG. 6A shows the first configuration, and FIG. 6B shows the second configuration. It is.

  As shown in FIG. 6A, the file management table of the lower level file system includes an invalid flag, a head logical block number, and a list of the number of logical blocks.

  The head logical block number is a value indicating from which area (numbered block area) the area corresponding to the logical block is actually recorded. The number of logical blocks is a value indicating how many blocks are consecutively allocated to the file from the first logical block number. The invalid flag is a flag indicating whether or not the area is an allocated section. If there is an unallocated section in the middle of the file, this invalid flag is set at the corresponding position in the list of the file management table along with the number of logical blocks indicating the length of the unassigned section. Insert.

  FIG. 6A is a file management table of the file shown in FIG. 5, and the size of one logical block is 512 Kbytes.

  In FIG. 6A, the table indicated by the invalid flag = 0, the head logical block number = 10, and the number of logical blocks = 4 indicates the 2 Mbyte area from the head shown in FIG. Further, the table indicated by the invalid flag = 0, the head logical block number = 20, and the number of logical blocks = 5 indicates a 2.5 Mbyte area of 4 Mbytes or more from the top shown in FIG. In FIG. 4, 2 M bytes beyond the 2 M byte from the top are not allocated. As a table indicating this unallocated area, an invalid flag = 1 and the number of logical blocks = 4.

  In each area of this file management table, the offset from the beginning of the file is determined by the sum of the number of logical blocks in the area existing before that area. For example, a 2.5 Mbyte area of 4 Mbytes or more from the beginning exists at a position of (4 + 4) logical block = 8 × 512 Kbytes = 4 Mbytes from the beginning of the file management table.

  FIG. 6B realizes the same function as FIG. 6A by putting an invalid value in the first logical block number instead of the invalid flag. In this case, by inserting −1 in the first logical block number, it is indicated that the corresponding area of the file management table is an unallocated area for the file.

[Third Embodiment]
FIG. 7 is a configuration diagram showing the overall configuration of the file system according to the third embodiment of the present invention.

  In the figure, the file system according to the present embodiment is connected to a recording processing unit A (201), a reproduction processing unit A (202), a recording processing unit A (201), and a reproduction processing unit A (202). Upper file system A (203), recording processing unit B (204), reproduction processing unit B (205), upper file system B connected to recording processing unit B (204) and reproduction processing unit B (205) (206), the file system arbitration processing unit 210 connected to the upper file system A (203) and the upper file system B (206), and the file system arbitration processing unit 210, and the upper file system A (203). And the lower file system 207 having the upper file system B (206) as the upper file system, the reproduction processing unit A (202), and the reproduction A display processing unit 208 for displaying the video and audio data output from the processing section B (205), configured to include a recording medium 209 of the real recording medium subordinate file system 207 operates, the.

  The recording processing unit A (201) and the reproduction processing unit A (202) are processing units that perform the same processing as the recording processing unit A (101) and the reproduction processing unit A (102) described in the first embodiment. The recording processing unit B (204) and the reproduction processing unit B (205) are processing units that perform the same processing as the recording processing unit B (104) and the reproduction processing unit B (105). This is a device that performs the same display as the display processing unit 108.

  The upper file system A (203) is a file system that performs the same processing as the upper file system A (103), but does not directly operate the lower file system 207, but operates through the file system arbitration processing unit 210. .

  The upper file system B (203) is a file system that performs the same processing as the upper file system B (103), but does not directly operate the lower file system 207, but operates the file system arbitration processing unit 210. .

  The file system arbitration processing unit 210 is a processing unit that issues an instruction to the lower file system 207 instructed from the upper file system A (203) and the upper file system B (206).

  FIG. 8 is a block diagram showing one configuration example of the file system arbitration processing unit of the file system according to the third embodiment of the present invention.

  The file system arbitration processing unit 210 shown in the figure includes a message reception unit 801, a control unit 802, a lower file system execution unit 803, and a message storage unit 804.

  In addition, although not shown in the figure, a transmission unit is provided for responding to the results of processing requested to the upper file system A (203) and the upper file system B (206).

  The message receiving unit 801 is a receiving unit for receiving requests from the upper file system A (203) and the upper file system B (206). The message reception unit 801 also receives a notification message when the execution of the lower file system 207 is completed. The message received by the message receiving unit 801 includes data indicating which instruction of the lower file system 207 is executed, data indicating the priority of the instruction, and data indicating which message is instructed by which upper file system. And are included. The lower file system execution unit 803 is a processing unit that actually executes an instruction to the lower file system 207 instructed by the upper file system A (203) or the upper file system B (206). Executed below.

  The message storage unit 804 is a management area for temporarily storing a request with a low processing priority among the operation requests to the lower file system 207 received by the message receiving unit 801, and is controlled by the control unit 802. .

  The control unit 802 is a processing unit that controls the entire file system arbitration processing unit 210.

  Next, the operation of the file system arbitration processing unit 210 will be described.

  FIG. 9 is a flowchart showing the operation of the file system arbitration processing unit of the file system according to the third embodiment of the present invention.

  In the following, referring to FIGS. 7 and 8, using the flowchart shown in FIG. 9, first, when normal processing (normal priority processing) in the file system arbitration processing unit 210 is performed, or a lower file system The operation when a lower priority command is received during the execution of the command to 207 will be described.

  First, the file system arbitration processing unit 210 waits for an access request to the lower file system 207 from the upper file system A (203) or the upper file system B (206) (step S701).

  Next, the control unit 802 of the file system arbitration processing unit 210 verifies whether or not the message received by the message receiving unit 801 is an access request from any one of the upper file systems (step S702). If the message is an access request from any of the upper file systems, the process proceeds to step S703, and the received message is not any access request of the upper file system (here, it is assumed that the execution is completed). If YES, the process moves to step S708.

  In step S703, the control unit 802 verifies whether the lower file system 207 is being executed based on the received message. If the lower file system 207 is being executed, the process proceeds to step S705, where the lower file system 207 If not, the process moves to step S704.

  In step S704, under the control of the control unit 802, the lower file system execution unit 803 executes the instruction of the lower file system 207 corresponding to the received message, and returns to step S701 (in step S701, the upper file system A (203) or the next access request from the upper file system B (206) or the completion of the execution of the executed lower file system 207).

  In step S705, the control unit 802 verifies whether the access request has a higher priority than the access request being executed. Here, as described above, whether the access request has a normal priority, Alternatively, since a command having a lower priority is received during the execution of the command to the lower file system 207, the process proceeds to step S706.

  In step S706, the control unit 802 stores the received message in the message storage unit 804, and returns to step S701 (in step S701, the next file from the upper file system A (203) and the upper file system B (206)). Wait for the access request or completion of execution of the executed lower file system 207).

  In step S708, the higher-level file system that has requested the command is notified from the transmission unit (not shown) that the execution has been completed. Thereafter, it is verified whether there is a pending instruction in the message storage unit 804 (step S709). If there is a pending instruction, the process proceeds to step S710, and if there is no pending instruction, the step is performed. The process returns to S701 (in step S701, the next access request from the upper file system A (203) or the upper file system B (206) or the completion of execution of the executed lower file system 207 is waited).

  In step S710, the highest priority message is acquired from the instructions pending in the message storage unit 804, and the process proceeds to step S704.

  Next, an operation when a higher priority command is received during command execution to the lower file system 207 will be described.

  The operation in this case is the same as the above-described normal processing up to step S705, but the determination result in step S705 is different from the above-described processing. Therefore, the processing after step S705 will be described below.

  In step S705, the control unit 802 compares the priority of the message received this time with the instruction currently being executed. In this case, since the priority of the message received this time is higher, the process proceeds to step S707.

  In step S707, the lower file system execution unit 803 interrupts the instruction of the currently executed lower file system, and the control unit 802 stores the interrupted instruction in the message storage unit 804 as a hold instruction (step S707). After that, the process proceeds to step S704 described above.

  The once interrupted message is executed at the end of execution of a high priority instruction. In step S701, when a response to the end of execution of the instruction is received from the lower file system 207, the process proceeds to the above-described step S708 by the verification in the subsequent step S702 (notified to the upper file system that issued the instruction). ).

[Fourth Embodiment]
The overall configuration of the file system according to the fourth embodiment of the present invention is the same as the overall configuration of the file system according to the first embodiment of the present invention (FIG. 1), but the lower file system 107 (FIG. 1). Includes a cutoff flag (not shown) whose logical value is operated when the power is turned on / off. This shut-off flag is set to FALSE by the lower file system 107 when the entire file system is correctly started when the power is turned on, and lower when all operations on the entire file system are normally completed when the power is turned off. Set to TRUE by the file system 107.

  The upper file system (one of the upper file system A (103) and the lower file system B (106)) refers to the logical value of this blocking flag, and the upper file system A (103) and the lower file system B ( 106), it is determined whether or not to perform an operation of detecting a wrinkle.

  FIG. 10 is a flowchart showing an operation example in the case where a flaw with a lower file system is detected and a flaw between file systems is matched in the file system according to the fourth embodiment of the present invention.

  Hereinafter, with reference to FIG. 1, an operation example in the case where a conflict with the lower file system 107 is detected and a conflict between file systems is matched will be described using the flowchart shown in FIG. 10.

  First, the upper file system (either the upper file system A (103) or the lower file system B (106)) acquires the logical value of the above-described shut-off flag when the power is turned on (step S1401). ).

  Next, the upper file system verifies the logical value of the cutoff flag (step S1402), and if the logical value of the cutoff flag is TRUE, the process immediately ends, assuming that the power is correctly turned off. If the logical value of the blocking flag is FALSE, there is a possibility that a defect exists between the upper file system and the lower file system 107, and the process advances to step S1403.

  In step S1403, the upper file system acquires its own area management table.

  Next, the upper file system acquires a file management table on the lower file system 107 corresponding to its own recording medium image file (step S1404).

  Next, the upper file system compares the areas of the two tables (step S1405).

  Subsequently, the upper file system verifies the comparison result (step S1406), and immediately ends the process if the areas match. Also, if the areas do not match, it is assumed that there is a trap between itself and the lower file system 107, and the areas that are wasted in each table are released to align the two tables. (Step S1407), the process ends.

  It should be noted that at least a part of the processing of each component of the file system according to the present invention is executed by computer control, and the above processing is performed by a computer according to the procedure shown in the flowcharts of FIGS. The program to be executed may be distributed after being stored in a computer-readable recording medium such as a semiconductor memory, a CD-ROM, or a magnetic tape. A computer including at least a microcomputer, a personal computer, and a general-purpose computer may read the program from the recording medium and execute the program.

It is a block diagram which shows the whole structure of the file system which concerns on the 1st Embodiment of this invention. 4 is an area map showing a correspondence relationship between a recording medium image of a higher-level file system and files of a lower-level file system in the file system according to the first embodiment of the present invention. It is a flowchart which shows an example of the process in the case of deleting the file which exists on a high-order file system in the file system which concerns on the 1st Embodiment of this invention. 5 is a flowchart showing an example of processing when data is recorded in a file on a higher-level file system in the file system according to the first embodiment of the present invention. It is explanatory drawing for demonstrating the concept of an omission file. It is an area | region map which shows the invalid flag added to the file management table of a low-order file system, (a) shows the 1st structure, (b) shows the 2nd structure. It is a block diagram which shows the whole structure of the file system which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows one structural example of the file system arbitration process part of the file system which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the file system arbitration process part of the file system which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the operation example in the case where the flaw with a low-order file system is detected and the wrinkles between file systems are matched in the file system which concerns on the 4th Embodiment of this invention. It is explanatory drawing which shows the correspondence of the file on a high-order file system, and the file on a low-order file system. An example of the area management table in the conventional general file system is shown. It is an area management table provided in a conventional general file system. 12 shows an example of an unused area management table corresponding to FIGS.

Explanation of symbols

101, 201 Recording processing unit A
102, 202 Playback processing unit A
103, 203 Host file system A
104, 204 Recording processing unit B
105, 205 Playback processing section B
106,206 Host file system B
107, 207 Lower file system 108, 208 Display processing unit 109, 209 Recording medium 210 File system arbitration processing unit 801 Message reception unit 802 Control unit 803 Lower file system execution unit 804 Message storage unit

Claims (5)

In a file system comprising at least a recording medium and a plurality of file systems having recording / reproduction control means for recording / reproducing file data on the recording medium,
And the lower level file system cormorants line recording and reproduction of data directly to the recording medium to manage the recording medium,
A plurality of upper file systems that handle the lower file system as one virtual recording medium;
Equipped with a,
The lower file system is
First area management means for managing a first area management table for storing information indicating that the recording medium is divided into a plurality of logical blocks and the logical blocks are used as areas for storing data;
First file management means for managing a first file management table for storing information relating to files recorded in a used area on the recording medium;
Unused area management means for managing an unused area management table for storing information indicating that the logical block is unused as an area for storing data;
Recording / reproduction control means for directly recording / reproducing data on / from the recording medium based on the information of the first area management table, the first file management table, and the unused area management table;
With
The upper file system is
The lower-level file system is regarded as one virtual recording medium, the virtual recording medium is divided into a plurality of logical blocks, and information indicating that the logical block is used as an area for storing data is stored. Second area management means for managing the second area management table;
Second file management means for managing a second file management table for storing information relating to files recorded in a used area on the virtual recording medium;
Conversion means for converting a file recording / reading operation to / from the virtual storage medium into a file recording / reading operation to / from the storage medium by the lower file system;
Comparison that detects mismatch between the two areas by comparing the area information of the logical block recorded in the second area management table with the area information of the file recorded in the first file management table. Means,
With
2. A file system according to claim 1, wherein when a mismatch is detected between the two areas by the comparing means, the areas of the mismatch between the two tables are opened and aligned . In a file system comprising at least a recording medium and a plurality of file systems having recording / reproduction control means for recording / reproducing file data on the recording medium,
A lower file system that manages the recording medium and directly records and reproduces data on the recording medium; and
A plurality of upper file systems that handle the lower file system as one virtual recording medium;
A file system arbitration processing unit that intervenes between the plurality of upper file systems and the lower file system, and arbitrates operations from the plurality of upper file systems to the lower file system;
With
The lower file system is
First area management means for managing a first area management table for storing information indicating that the recording medium is divided into a plurality of logical blocks and the logical blocks are used as areas for storing data;
First file management means for managing a first file management table for storing information relating to files recorded in a used area on the recording medium;
Unused area management means for managing an unused area management table for storing information indicating that the logical block is unused as an area for storing data;
Recording / reproduction control means for directly recording / reproducing data on / from the recording medium based on the information of the first area management table, the first file management table, and the unused area management table;
With
The upper file system is
The lower-level file system is regarded as one virtual recording medium, the virtual recording medium is divided into a plurality of logical blocks, and information indicating that the logical block is used as an area for storing data is stored. Second area management means for managing the second area management table;
Second file management means for managing a second file management table for storing information relating to files recorded in a used area on the virtual recording medium;
Conversion means for converting a file recording / reading operation to / from the virtual storage medium into a file recording / reading operation to / from the storage medium by the lower file system;
Conversion means for converting a recording / reading operation to the virtual storage medium into a recording / reading operation to a plurality of files managed by the first file management means of the lower file system;
With
The file system arbitration processing means includes:
When there is an execution instruction from the upper file system, if the lower file system is not being executed, the lower file system is caused to execute an execution instruction from the upper file system,
If the lower file system is being executed, based on the priority included in the execution instruction from the upper file system, the priority included in the execution instruction being executed, the priority included in the new execution instruction, , The lower priority file system is executed by the lower-level file system, the lower-priority execution instruction is temporarily stored, and the lower-priority execution is executed after the higher-priority execution is completed. A file system characterized by executing instructions . The first file management table stores the head block number of the logical blocks allocated to each file recorded on the recording medium, and a number of continuous blocks, unallocated in the middle of each of the file area of the file file system of claim 1 or 2, characterized in that when there is the block is present. The first file management table is invalid for each file recorded on the recording medium, indicating the logical block number from the head of the file data area, the number of logical blocks, and whether or not the area can be used. The file system according to claim 1 or 2 , wherein a flag is recorded . 5. The information recorded in the first file area management table provided in the first file management unit is recorded in a file area of the storage medium. File system.

Images