JP2004213089A - File system management method, file system management program and recording/reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a file system management method, a file system management program and a recording/reproducing device that can efficiently use a recording medium while maintaining the high reliability of recorded information. <P>SOLUTION: When the number of updates in an FE 301 on which management information about a particular directory is recorded reaches a given value, the FE 301 is shifted to an FE 306 in the other position on a recording medium. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a file system management method for managing a file system used for managing data recorded on an optical disk, for example.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an information recording / reproducing apparatus that records and updates information in an arbitrary recording area on a recording medium using a readable and writable recording medium such as a hard disk or a magneto-optical disk and reads information from the recording medium has been widely used. ing. In such a recording medium, when the recorded information is no longer needed, the unnecessary area is deleted so that the recording area where the information is recorded can be used for recording other information. It can be reused as an area.
[0003]
In the information recording / reproducing apparatus as described above, it is common to use a file system in order to enhance the convenience of information access. By using a file system, recorded information can be managed as a file, and by constructing a directory hierarchy, recorded information can be easily managed. Examples of the file system include a widely spread FAT (File Allocation Table) system and a UDF (Universal Disk Format) system of OSTA (Optical Storage Technology Association) introduced in DVD (Digital Versatile Disc) and the like. .
[0004]
When a file system is introduced, management including identification information (for example, a file name) for specifying the actual data, position information on the recording medium where the actual data is recorded, and the like, in addition to the actual data recorded on the recording medium, are provided. Information is also recorded on the recording medium.
[0005]
[Patent Document 1]
JP-A-8-315360 (published November 29, 1996)
[0006]
[Problems to be solved by the invention]
However, in the above-described conventional configuration, there are many file systems in which the information length of the management information is not limited in order to increase versatility, and there are cases where such a high function is not required in an actual use scene. Specifically, in the conventional file system, the entity of the file and the management information are separately recorded, so that even if the recording position of the entity of the file is divided into a plurality of locations, it can be managed. However, when the number of divisions exceeds a predetermined number, it becomes necessary to extend the management information.
[0007]
Further, since the number of files or directories included in the directory is not limited, it is necessary to include a means for analyzing unlimited management information in the configuration of the file system driver.
[0008]
Further, in the above-described conventional configuration, a large variation often occurs in the number of recording updates in each recording area. For example, since data that is frequently updated is recorded in a certain recording area, the number of times of recording update is extremely large, while data that is hardly updated is recorded in another recording area. As a result, a situation in which the number of record updates is extremely small frequently occurs. Therefore, when a recording medium having a limited number of rewritable times is adopted as a recording medium, there are many recording areas that are pulled by the recording area where the number of times of record renewal is large and still have a margin for the number of rewritable times. Even in such a case, it may be determined that the rewriting of the recording medium has become impossible. That is, there is a problem that the period during which the user can use the recording medium may be shortened.
[0009]
Specifically, in the conventional file system, the file entity and the management information are separately recorded, and when the directory structure is moved, the file entity is not changed and only the management information is updated. May be done. On the other hand, even when the file entity is updated, the management information is updated if the area for recording the file entity is changed. Further, since additional information such as the update date and time is recorded in the management information, the file is often updated by updating the file entity even if the area for recording the file entity is not changed. .
[0010]
To cope with such a problem, a method has been proposed in which the number of overwrites of the medium is recorded in a predetermined area of the medium and overwriting is prohibited when the number of overwrites exceeds the predetermined number of times (see, for example, Patent Document 1). 1). However, this method merely discloses a method of prohibiting writing to a medium when the number of overwrites is equal to or more than a predetermined value. That is, the structure of the file system in the medium is not considered at all, and only the overwriting is prohibited, and no alternative is provided, and this is not a fundamental solution.
[0011]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a file system that enables efficient use of a recording medium while maintaining high reliability of recorded information. A management method, a file system management program, and a recording / reproducing device are provided.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a file system management method according to the present invention provides a method for storing information recorded on a recording medium in which information is written and read out from a file corresponding to actual data, and / or A file system management method executed by a file system management unit that manages a file system recorded as a combined directory, wherein the file and / or the directory and the management information of the file and / or the directory are stored in the storage medium. And performing different processing in accordance with the number of updates of files and / or directories managed by the management information, based on the contents recorded in the management information.
[0013]
In the above method, in a file system managed by recording a file and / or a directory and management information of the file and / or the directory on a recording medium, based on the content recorded in the management information, Different processing is performed according to the number of updates of the file and / or directory managed by the management information. Therefore, for example, in the case of a recording medium having a limited number of rewritable times, when the number of rewritable times has reached or approached in a specific area, for example, updating is prohibited or a warning is issued. It is possible to take measures.
[0014]
In the file system management method according to the present invention, in the above method, the file system management means may estimate the number of updates based on the size of the management information.
[0015]
When the number of updates of the management information increases, the size of the managed data tends to increase due to an increase in the number of divisions of the managed data. Therefore, according to the above method, it is possible to estimate the number of updates of the management information without adding specific information to the management information.
[0016]
Further, in the file system management method according to the present invention, in the above method, the file system management means estimates the number of updates based on the creation time information and the update time information recorded in the management information. It may be.
[0017]
In most cases, the management information includes creation time information and update time information. Here, by taking the difference between the creation time and the update time, it is possible to specify the period in which the management information exists, and it is possible to estimate the number of updates based on this time. Become. That is, according to the above method, it is possible to estimate the number of updates of the management information based on the information originally included in the management information.
[0018]
Further, in the file system management method according to the present invention, in the above method, the file system management means may estimate the number of updates based on an update counter recorded in the management information.
[0019]
As described above, by estimating the number of updates based on the update counter recorded in the management information, it is possible to more accurately recognize the number of updates.
Also, in the file system management method according to the present invention, in the above method, the management information may include update number information of the management information, and the file system management unit may determine that the update number is a predetermined number. A method of detecting that the value has exceeded the value may be used.
[0020]
In the above method, in a file system managed by recording a file and / or a directory and management information of the file and / or the directory on a recording medium, the management information includes an update count information of the management information. It is supposed to be. Then, it is detected that the number of updates indicated by the update number information has become a predetermined value or more. Here, by setting the predetermined value based on the number of rewritable times of the recording medium, it is possible to prevent the update from being performed, for example, exceeding the number of rewritable times, thereby lowering the reliability of the recording state. Can be prevented.
[0021]
Further, in the above method, the update of the management information is restricted. Therefore, even if the update of the specific management information is restricted, the update condition is not restricted for the other recording areas. Unless it has reached, it will be possible to update. Therefore, it is possible to fully use the rewritable number over the entire recording area of the recording medium, so that the utilization efficiency of the recording medium can be improved.
[0022]
That is, according to the above-described method, it is possible to provide a file system management method that enables efficient use of a recording medium while maintaining high reliability of recorded information.
[0023]
Further, in the file system management method according to the present invention, in the above-mentioned method, the file system management means may be configured such that, when the number of updates is equal to or more than a predetermined value, the file and / or the file managed by the management information A method may be used in which the user is notified that the number of times the directory has been updated is equal to or greater than a predetermined value.
[0024]
According to the above method, since the user can know that the number of updates for a specific file and / or directory has reached a predetermined value or more, the user can evaluate the reliability of the file and / or directory. Becomes possible. In this case, the user may perform processing such as copying a file and / or directory with low reliability to another recording area, thereby extremely reducing reliability and losing data. Such a situation can be avoided. In addition, since only the files and / or directories recorded in the low-reliability area need be copied, the entire rewriting life of the entire recording medium can be fully used, and the efficiency of the recording medium can be reduced. You can use it.
[0025]
Further, in the file system management method according to the present invention, in the above method, the file system management means may include the limited number of updates and the number of updates in management information for managing the current applicable file and / or applicable directory. May be presented to the user.
[0026]
According to the above method, the user can grasp the relationship between the limited number of updates and the number of updates in the management information for managing the current file and / or directory. It is possible to recognize how much more the directory can update. Therefore, by recognizing such information, the user can determine how to update each file and / or directory in the future.
[0027]
Further, in the file system management method according to the present invention, in the above method, the file system management means may determine a recording position of the management information on a recording medium when the update count is equal to or greater than a predetermined value. A method of changing and updating may be used.
[0028]
According to the above method, when the number of updates in the specific management information is equal to or more than a predetermined value, the position where the management information is recorded is moved and updated. The later management information is in a state where there is room for the limit condition of the number of updates. That is, it is possible to update management information whose update count is equal to or more than a predetermined value without lowering the reliability of the recorded information.
[0029]
Further, in the file system management method according to the present invention, in the above method, the file system management means may determine a recording position of the management information on a recording medium when the update count is equal to or greater than a predetermined value. File identification for specifying a file contained in a directory managed by the management information and / or a recording position of the data managed by the management information on a recording medium, and / or performing a change and an update. A method of changing the recording position of the information on the recording medium may be used.
[0030]
According to the above method, when the number of updates in the specific management information becomes equal to or more than a predetermined value, the recording position of the managed data and / or file identification information is moved together with the management information. . Here, when the number of updates of the management information is equal to or more than a predetermined value, the number of updates of the data and / or file identification information managed by this management information is also close to the limit of the number of updates. It is expected that. That is, according to the above-described method, not only the management information in which the number of updates is directly counted, but also data and / or file identification information expected to be close to the limit of the number of updates is recorded. It is possible to maintain high reliability of the information.
[0031]
Further, in the file system management method according to the present invention, in the above method, the file system management unit may secure an area for recording specific management information and files and / or directories managed by the specific management information in advance. Alternatively, the recording position of the management information and the file and / or directory may be moved within the secured area.
[0032]
According to the above-described method, for example, an area for recording a file and / or a directory in which the number of updates can be predicted to be large can be reserved in advance in consideration of the movement of the recording position. Therefore, the reliability of the specific management information and the files and / or directories managed by the specific management information can be guaranteed for a long time.
[0033]
In the file system management method according to the present invention, in the above method, the file system management means may set an upper limit on the size of the management information.
[0034]
Conventionally, there is no limit on the size of the management information, and the management information has become infinitely large due to a large number of updates. In this case, for example, when searching for a file, processing such as loading the management information into a memory and performing a search in this memory is performed, but the size of the management information is not limited. However, the capacity of the memory has to be relatively large to allow a margin. When the capacity of the memory is small, the process of sequentially reading the management information into the memory and checking the contents is repeated, which causes a problem of delaying the processing time.
[0035]
On the other hand, according to the above method, in a file system managed by recording a file and / or a directory and management information of the file and / or the directory on a recording medium, an upper limit is imposed on the size of the management information. Is provided, the capacity of the memory may be set according to this upper limit. Therefore, it is only necessary to prepare a memory having a minimum necessary capacity, and it is possible to reduce the apparatus cost of an apparatus for recording and reproducing the recording medium managed by the above method.
[0036]
Further, in the file system management method according to the present invention, in the above method, the file system management means may set a limit on the number of files and / or directories managed by one management information on a recording medium. It may be.
[0037]
The management information includes position information of files and / or directories managed by the management information. Here, when the managed file and / or directory is divided and recorded in a plurality of recording areas, the position information on each divided area is included in the management information. That is, as the number of divided files and / or directories increases, the size of the management information increases in proportion thereto. On the other hand, in the above method, the number of divisions of files and / or directories managed by one management information on the recording medium is limited, so that the size of the management information is set within a predetermined size. can do.
[0038]
Further, in the file system management method according to the present invention, in the above method, the file system management means may be configured so that the management information for managing the directory includes file identification information for specifying a file included in the directory. The file system management unit may be configured to limit the size of the file identification information group managed by one management information.
[0039]
When searching for a file in a certain directory, the file identification information group included in the directory is loaded into the memory, and the search is performed on the memory. Here, if the file identification information is added without being reproduced, the size of the file identification information group will increase, possibly exceeding the memory capacity.
[0040]
On the other hand, in the above method, the size of the file identification information group managed by one management information is limited. Therefore, it is sufficient to set the minimum necessary memory capacity based on this restriction, and it is possible to reduce the apparatus cost of the apparatus for recording and reproducing the recording medium managed by the above method. .
[0041]
Further, in the file system management method according to the present invention, in the above method, when the size of the management information is equal to or more than an upper limit value, the file system management unit may execute a file and / or a file managed by the management information. Alternatively, a method may be used in which the user is informed that updating of the directory is restricted.
[0042]
According to the above-described method, the user can know that the update of a specific file and / or directory is restricted, and thus performs a process such as copying the file or directory to another location. Thus, this can be dealt with.
[0043]
Further, in the file system management method according to the present invention, in the above method, the file system management means may include an upper limit of the size of the management information and a management information size for managing the current corresponding file and / or corresponding directory. The relationship may be presented to the user.
[0044]
According to the above method, the user can grasp the relationship between the upper limit of the size of the management information and the size of the management information for managing the current file and / or directory. It is possible to recognize how much the directory can be updated. Therefore, by recognizing such information, the user can determine how to update each file and / or directory in the future.
[0045]
Further, the file system management method according to the present invention can be suitably used in a file system conforming to the Universal Disk Format.
[0046]
A file system management program according to the present invention causes a computer to execute the file system management method according to the present invention.
[0047]
By causing the computer to execute the program, the file system management method can be provided to the user.
[0048]
Further, the recording / reproducing apparatus according to the present invention is a recording / reproducing apparatus for performing information writing and / or reading processing on a recording medium on which information is written and / or read, wherein the recording / reproducing apparatus performs writing and / or reading on the recording medium. And / or when reading, the file system management method according to the present invention is used.
[0049]
According to the above configuration, as described above, the recording medium can be efficiently used while maintaining the reliability of the recorded information at a high level, and the apparatus cost can be reduced. .
[0050]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention will be described below with reference to FIGS.
[0051]
(Device configuration)
FIG. 13 is a block diagram illustrating a schematic configuration example of the recording / reproducing apparatus 1 according to the present embodiment. As shown in FIG. 1, the recording / reproducing apparatus 1 is an apparatus for recording and reproducing information on and from a recording medium 2, and includes a device driver 3, a file system driver (file system management means) 4, an application program 5, a display The configuration includes a unit 6 and an operation unit 7.
[0052]
As the recording medium 2, for example, an optical disk such as a DVD-R or a DVD-RAM is assumed. However, the recording medium 2 is not limited to this, and information can be read and information can be written. Any recording medium may be used. Although a disk-shaped recording medium is shown in the figure, a recording medium using a semiconductor such as an EEPROM (Electrically Erasable / Programmable Read Only Memory) may be used.
[0053]
The device driver 3 is a driver that controls mechanical and / or electrical operations when reading / writing information from / to the recording medium 2. For example, when the recording medium 2 is an optical disk, the device driver 3 corresponds to a driver that defines processing of a control unit that controls operations of an optical pickup and a magnetic pickup used for recording and reproduction.
[0054]
The file system driver 4 is a driver that performs processing for defining how to manage files when reading and writing information from and to the recording medium 2. The file system driver 4 is realized by a computer executing a program describing the content to be processed. This program is stored in a storage device (for example, ROM or RAM) (not shown) provided in the recording / reproducing apparatus 1, and is read and executed when necessary. Further, the program for realizing the file system driver 4 may be capable of being externally input via a recording medium or input via a communication line.
[0055]
The application program 5 is a program that performs actual processing when performing a recording / reproducing operation on the recording medium 2. Then, the content of the processing performed by the application program 5 is appropriately displayed on the display unit 6 and presented to the user. Further, an operation input from the user is input to the application program 5 via the operation unit 7, and the corresponding processing is performed by the application program 5.
[0056]
In the above configuration, the recording / reproducing apparatus 1 has a configuration including the display unit 6, the operation unit 7, and the application program 5. However, the configuration is not limited to this. For example, a configuration realized by a PC (Personal Computer) may be used. In this case, the recording / reproducing apparatus 1 is an apparatus that functions as a recording medium drive that performs only a recording / reproducing operation on the recording medium 2.
[0057]
(File system)
Hereinafter, a file system management method according to an embodiment of the present invention will be described. First, a UDF (Universal Disk Format), which is a file system used for a DVD (Digital Versatile Disc) or the like, will be briefly described.
[0058]
In the UDF file system, a recording area on a recording medium is divided into units called sectors, and a logical sector number LSN (Logical Sector Number) from 0 to the last logical sector is assigned to the sector. The recording area is secured as one or more areas called partitions.
[0059]
In the partition area, a logical block number LBN (Logical Block Number) from 0 to the last logical block number is allocated in sector units from the first sector. In this partition area, real data of files and their management information, and furthermore, directory management information are recorded.
[0060]
Each management information is stored in a structure called a descriptor for each application. All descriptors have an identifier field called Descriptor Tag at the beginning of the structure, and the type of the descriptor is determined by this.
[0061]
FIG. 8 shows an example of the structure in the partition. In this example, a state in which one directory having three elements and one file are recorded on the recording medium 801 is shown. The directory includes FE (File Entry) (management information) 802 and one or more (three in this example) FIDs (File Identifier Descriptors) (file identification information) 803, 804, and 805. In the FE 802, directory management information and information for managing the recording areas of the FIDs 803, 804, and 805 are recorded. The FIDs 803, 804, and 805 include management information of files or directories included in the directory. Of these, the FID 805 is information for managing the recording area of the FE 806. The file includes an FE 806 and actual data 807. In the FE 806, file management information and information for managing the recording area of the actual data 807 are recorded.
[0062]
(Descriptor structure)
Next, the FE structural standard will be described. FIG. 9 shows the structure standard of the FE. In the figure, the BP column shows the absolute position (unit: byte) from the beginning of the logical block, the Length column shows the length of each field, and the Name column shows Indicates the name of each field.
[0063]
The Descriptor Tag field records information indicating what kind of descriptor the Descriptor is. In this case, a Tag indicating the FE is recorded. In the ICB Tag field, internal attribute information of the FE is recorded. The Uid and Gid fields record the user ID and group ID of the administrator, respectively. In the Permissions field, file or directory access permission information is recorded. The number of references to this FE is recorded in the File Link Count field. In the Information Length field, the file size or the size of the FID information sequence is recorded. The Logical Blocks Recorded field records the number of logical blocks in which information managed by the FE is recorded. In the Access Date and Time field, the time when this FE was accessed is recorded. The FE update time is recorded in the Modification Date and Time field.
[0064]
The Attribute Date and Time field records the time when the FE attribute field was updated. The recording position of the extended information ICB is recorded in the Extended Attribute ICB field. The Implementation Identifier field is used depending on the implementation. In the Unique ID, an ID unique to the FE is recorded. In the Length of Extended Attributes field, the size of the Extended Attributes field is recorded. In the Length of Allocation Descriptors field, the size of the Allocation Descriptors field for recording Allocation Descriptors is recorded. Note that the Record Format field, Record Display Attributes field, Record Length field, and Checkpoint field are not used in UDF.
[0065]
In the Allocation Descriptors field provided in the FE, recording area information of data managed by the FE is recorded. There are a plurality of types of Allocation Descriptor (AD) depending on the application. In the UDF standard, the Short Allocation Descriptor type is used. FIG. 10 shows the structure standard of the Short Allocation Descriptor.
[0066]
The size of the information to be referred to is recorded in the Extent Length field. The Extent Position field stores the recording start LBN of the information to be referred to. If the recording area of the real data or FID managed by the FE is divided into a plurality of areas, ADs storing the position information of each division are recorded in this field in the same number as the number of divisions. However, the FE must fit within one logical block. If the number of ADs is large and the FE does not fit in one logical block, the recording area of the AD must be extended using a descriptor called AED (Allocation Extent Descriptor) described below. At this time, the recording area of the AED is designated using the last AD recorded in the FE.
[0067]
FIG. 11 shows the structure standard of the AED. The Previous Allocation Extent Location field is not used in UDF. In the Length of Allocation Descriptors field, the length of the AD information sequence recorded below the AED is recorded. AD that does not fit into the FE is recorded following the AED.
[0068]
FIG. 12 shows the structure standard of the FID. The RBP column indicates the position where each field is recorded (relative position with the beginning of the descriptor being 0). The Length column indicates the length of each field. The column shows the name of each field.
[0069]
The Descriptor Tag field records information indicating what kind of descriptor the Descriptor is. In this case, a Tag indicating the FID is recorded. 1 is recorded in the File Version Number field. In the File Characteristics field, attribute information of a file or a directory managed by the FE managing the FID is recorded. In the Length of File Identifier field, the size of a File Identifier field described later is recorded. In the ICB field, recording area information of the corresponding FE is recorded. In the Length of Implementation Use field, the size of an Implementation Use field described later is recorded. The Implementation Use field is an implementation-dependent field. A file name or a directory name is recorded in the File Identifier field. The FID having such a configuration is continuously recorded in an area managed by the FE.
[0070]
A plurality of FIDs can be recorded continuously, and are managed as one-dimensional byte strings like actual data of a file, and division is recognized. However, since the head of the FID is 4-byte aligned, a value 0 of 0 to 3 bytes is padded at the rear end so that the entire length of one FID is a multiple of 4 bytes.
[0071]
(File system management method)
Hereinafter, a specific example of the file system management method according to the present embodiment will be described. First, as a first and a second embodiment, an example of a file system management method for simplifying the configuration of a file system will be described.
[0072]
(First embodiment)
As a first embodiment, a function-limited UDF driver as a file system management method that does not use an AED structure will be described. Assuming that the length of the Extended Attributes field of the information included in the FE is 0, the portion excluding the Allocation Descriptors field is 176 bytes as shown in FIG. Assuming that the sector size is 2048 bytes, the Allocation Descriptors field has a maximum of 2048-176 = 1873 bytes. Since the Short Allocation Descriptor has a size of 8 bytes as shown in FIG. 10, the largest Allocation Descriptors field contains 187 Short Allocation Descriptors = 1872/8.
[0073]
Therefore, in the UDF driver according to the present embodiment, it is assumed that up to 234 divisions are recognized for the recording area of the actual data or FID managed by one FE, but the 235th division is not created. When the 234th Allocation Descriptor points to the next AED, it is assumed that the data is read only up to the 233rd division.
[0074]
The flow of the above processing will be described below with reference to the flowchart shown in FIG. First, in step 11 (hereinafter simply referred to as S11), it is determined whether a directory or file update command has been issued. If the update command has not been issued (NO in S11), the process of S11 is repeated. That is, S11 indicates a standby state of the update command.
[0075]
If an update command has been issued (YES in S11), in S12, it is determined whether the number of divisions of the real data or FID managed by the FE to be updated by the update is a predetermined value, in the above example, 234 or more. Is determined. If it is determined that the number of divisions is less than the predetermined value (NO in S12), the corresponding FE is updated in S13 according to the update command, and the process returns to S11.
[0076]
On the other hand, if it is determined that the number of divisions is equal to or more than the predetermined value (YES in S12), the update command is rejected in S14, and the update is prohibited. Here, the user may be appropriately notified that the update cannot be performed. Thereafter, the flow returns to S11 to return to the standby state for the update command.
[0077]
According to the UDF driver as described above, since the AED structure is not used for the FE recorded on the recording medium, the file system driver 4 is provided with an analysis module for analyzing the AED structure. There is no need to implement it. Therefore, the simplification of the file system driver 4 can be achieved, so that the burden of design and development of the file system driver 4 can be reduced. Can be reduced.
[0078]
When the AED structure is used, the information about the FE is expected to be endlessly large. However, by not using the AED structure as described above, the size of the information about the FE is reduced. It is possible to reduce the value to a predetermined value or less. Therefore, the capacity of the memory for loading the information about the FE can be reduced, and the hardware configuration for realizing the UDF driver can be simplified.
[0079]
Note that, in the above description, up to 234 divisions are permitted for the recording area of the actual data or FID managed by one FE. However, the number of divisions is not limited. What is necessary is just to set suitably according to a state.
[0080]
(Second embodiment)
As a second embodiment, a UDF driver that limits the length of the FID information sequence included in one directory will be described. The FID is variable-length information, and its index information is not prepared. Therefore, in order to read out a specific FID, it is necessary to sequentially search from the top of the FID information sequence recorded as a set of FIDs.
[0081]
The FID information sequence can be divided and recorded like the actual data of the file. Therefore, in order to search for a specific FID, a memory sufficient for loading all the FID information strings considered to include the FID is secured, and the FID is searched in the memory or the FID is sequentially loaded. Then, it is necessary to check each time.
[0082]
Therefore, the UDF driver according to the present embodiment is designed so that an upper limit is set for the length of the FID information sequence, and a FID having an information sequence exceeding the upper limit cannot be added. For example, the upper limit of the length of the FID information sequence is one sector. The size of the FID whose file name is defined by an identifier of 8 characters, a period, an extension of 3 characters, and a termination code of 13 bytes is 84 bytes. Note that the size of the FID is assumed to be Length of File Identifier = 13 and Length of Implementation Use = 32. In this state, the size of the FID is 83 bytes in total, but is 4 bytes for alignment. Is added, so that the size of the FID is 84 bytes.
[0083]
Here, assuming that the sector size of one sector is 2048 bytes, if the FIDs have the same length, about 24 FIDs can be included in one sector. Here, since the first FID is determined to indicate the parent directory, the upper limit is about 23 files and directories included in one directory, if one is estimated.
[0084]
The flow of the above processing will be described below with reference to the flowchart shown in FIG. First, in S21, it is determined whether an FID addition command has been issued. If the addition command has not been issued (NO in S21), the process of S21 is repeated. That is, S21 indicates a standby state of the FID addition command.
[0085]
If the addition command has been issued (YES in S21), it is determined in S22 whether the length of the FID information sequence in the corresponding directory is equal to or larger than a predetermined value by adding the FID. If it is determined that the length of the FID information string is less than the predetermined value (NO in S22), FID addition processing is performed in S23, and the process returns to S21.
[0086]
On the other hand, if it is determined that the length of the FID information string is equal to or greater than the predetermined value (YES in S22), the FID addition command is rejected in S24, and the addition of the FID is prohibited. Here, the user may be appropriately notified that addition is not possible. Thereafter, the process returns to S21 to return to the standby state for the FID addition command.
[0087]
Here, a procedure for loading the directory management information by the file system driver dedicated to the file system will be described with reference to FIG. When the reading (loading) of the directory is started, first, assuming that a necessary memory size is specified, a memory is secured based on the specified memory size (step 1, hereinafter referred to as S1). In this example, it is assumed that memory for two sectors is secured.
[0088]
Next, the FE composed of one sector corresponding to the target directory is loaded into the memory secured in S1 (S2). Here, in order to prevent the FE from being extended by the AED, as described in the first embodiment, the upper limit of the number of divisions of the FID information sequence needs to be less than 235. Since the number of columns is about 23 or less, expansion by the AED is not performed.
[0089]
Next, the FID information sequence of the target directory is loaded into the memory (S3). Here, since the upper limit of the FID information sequence is one sector, one unused sector among the two sectors of memory secured in S1 is used. In the above example, the upper limit of the FID information sequence is set to one sector, but it may be adjusted to an appropriate value depending on the purpose of the file system, the margin of the memory, and the like. After the entire FID information sequence is stored in the memory, a sufficiently high-speed search can be performed by searching the memory for the FID (S4).
[0090]
As described above, by setting an upper limit to the length of the FID information sequence, the size of the memory required for loading the FID information sequence can be suppressed to a predetermined value or less. Further, all of the FID information strings necessary for the search can be loaded into a relatively small-sized memory, and the search can be performed on this memory, so that a high-speed search can be performed.
[0091]
Next, an example of a file system management method for managing the number of rewrites and reducing the probability of occurrence of a read error due to deterioration of a recording medium will be described. First, a UDF driver that counts the number of FE updates will be described as such a file system management method. When the length is changed by updating the FID information sequence or updating the substance of the file, the FE is also updated. Further, in a normal device driver, rewriting is performed in sector units, so that, for example, even when information of some fields in the FE is updated, the entire FE is updated.
[0092]
Therefore, in this embodiment, an update counter is prepared for FEs that are likely to be updated at fixed positions. In this embodiment, an Extended Attributes (EA) field in the FE is used as the update counter. The count value of this update counter corresponds to the update count information.
[0093]
FIG. 15 shows Counter Format as an example of a format recorded in the Extended Attributes field. In the figure, the RBP column shows the position where each field in the EA field is recorded (relative position with the beginning of the descriptor being 0), and the Length column shows the length of each field. In the column of Name, the name of each field is shown, and in the column of Contents, the contents of each field are shown.
[0094]
The Counter Format is composed of 16 bytes, and an ID indicating the Counter Format is recorded in the first 8 bytes. An update counter is provided in the next two bytes as a rewrite counter. This Rewrite Counter is treated as an increment counter starting from 0. The remaining 6 bytes are reserved as a spare area.
[0095]
The Rewrite Counter is incremented each time an edit is added to the FE and updated at the same time. Here, as an example, consider a case where the above counter is installed in the FE of the directory. If a file is added as a directory element and an FID is added to the FID information sequence, the length of the FID information sequence managed by the FE will be rewritten. At this time, the Rewrite Counter value of the Counter Format is simultaneously incremented.
[0096]
As described above, the count is performed each time the FE is edited, so that the counter value indicated by the Rewrite Counter can be used as an index for estimating the deterioration of the area where the FE is recorded. For example, assuming that the rewriting life of the recording medium is N times, when the counter value reaches 90% of N, it can be determined that the reliability of the area where the FE is recorded has become lower. It becomes.
[0097]
There are the following three methods for dealing with the case where the reliability of a certain recording area is determined to be low. A first method is a method of prohibiting updating of a file or directory recorded in a recording area having low reliability. The second method is a method of notifying a user that the reliability of a specific recording area is low. This second method will be described later. The third method is a method of moving the physical recording position of the FE of the file or directory recorded in the recording area with low reliability. In this case, the area where the FE has been recorded and the reliability is low is already severely deteriorated, and it is not desirable to reuse the area. Therefore, after the physical recording position of the FE is moved, the area with low reliability is set as an unusable area, or a dummy file is created and managed as a data area. It is preferable to prevent use.
[0098]
(Third embodiment)
Here, as a third embodiment, a processing procedure in the third method will be described below with reference to FIGS. 3 (a) to 3 (c). First, the state illustrated in FIG. 3A is a state in which the FE 301 manages the FIDs 302, 303, and 304. Here, when the FID is added, the state normally becomes as shown in FIG. That is, the FE 301 is updated to manage the FIDs 302, 303, 304, and 305.
[0099]
On the other hand, when the counter value of the FE 301 is updated and reaches 90% of the rewrite life N, the state shown in FIG. That is, the FE 301 is updated to a new area as the FE 306, and the FIDs 302, 303, 304, and 305 are similarly managed. At this time, the counter value in the FE 306 is reset. Then, the area 301 in which the FE 301 has been recorded is already determined to be an area with low reliability, and is managed as an actual data area of a dummy file managed by the FE 307. Actually, nothing is written in the area 301, but by being managed as a dummy file, it can be prevented from being used for another file or directory.
[0100]
Note that, in the above example, an example has been described in which the reliability is determined to be low when the counter value exceeds 90% of the rewrite life N, but the present invention is not limited to this determination criterion. In the above example, the counter value is used as an index for estimating the area degradation.However, the present invention is not limited to this.For example, the area degradation can be estimated based on the time from the Creation Time. In addition, it is possible to infer from the information amount of the FID information sequence and the number of FIDs. This will be described below.
[0101]
In the case of a general use method, the number of files is small at the start of use, and the number of FIDs included in one directory is small. As the use is repeated, the number of files and the number of FIDs included in one directory increase. In other words, it can be said that the number of updates of the FE is also increasing. As a result, the number of updates can be estimated from the number of FIDs and the length of the FID information sequence without having a counter. Also, the FID has a deleted bit in the File Characteristics field, and the number of FIDs may not decrease even if a file is deleted. In particular, if the file names have different lengths, it is difficult to overwrite the file names, so that even if the file is deleted, the number of FIDs is less likely to decrease. Therefore, it is possible to estimate the number of updates based on the number of FIDs.
[0102]
A method of estimating the number of updates by calculating the difference between the creation time and the update time based on the creation time information and the update time information recorded in the FE is also conceivable.
[0103]
A method for repeatedly operating the above method for one or a plurality of directories will be described below with reference to FIGS. 4 (a) to 4 (c). First, the state shown in FIG. The FE 401 of the directory manages the FID information strings 402, 403, and 404. At this time, it is assumed that the counter value of the FE 401 is one less than 90% of the rewriting life N.
[0104]
FIG. 4B shows a state in which the FID 405 is added as the next update. First, in the state shown in FIG. 4A, the area where the FE 401 is recorded is a state in which the reliability of the recording medium is reduced. In this case, it is expected that the area where the FID managed by the FE 401 is recorded is updated along with the update of the FE 401. That is, if the number of remaining renewable times of the FE 401 is small, it is expected that the FID managed by the FE 401 also has a small number of remaining renewable times. It cannot be said that there is a certain state.
[0105]
Therefore, as shown in FIG. 4B, the FIDs 402, 403, 404, and the added FID 405 are rewritten to a new area at the same time when the recording position of the FE 401 that has reached the rewriting condition is changed. In this case, the area where the FE or FID is recorded in the state shown in FIG. 4A is secured as the real data area 408 managed by the FE 407 of the dummy file. At this time, the counter value of the FE 401 is reset.
[0106]
Further, it is assumed that the update progresses in the state shown in FIG. Here, as the next update, a state in which the FID 406 is added will be described with reference to FIG. In the state shown in FIG. 4B, it is expected that the area in which the FE 401, FID 402, 403, 404, and 405 are recorded has low reliability. The data is written into the new area, and the state shown in FIG. In the state shown in FIG. 4B, the area where the FE 401, FID 402, 403, 404, and 405 are recorded is managed as the real data area of the dummy file. At this time, the area newly set as the dummy file is combined with the dummy data area in the state shown in FIG.
[0107]
According to the above-described method, it is possible to maintain a high reliability state not only in the FE region where the reliability can be determined based on the counter value but also in the FID region managed by the FE. Therefore, it is possible to guarantee the reliability of a specific directory for a long term.
[0108]
Further, by applying the above method, it is also possible to realize a method of operating in a specific area specialized for one or a plurality of directories. The method will be described below with reference to FIGS. 5 (a) to 5 (c).
[0109]
First, the state shown in FIG. The FE 501 of the directory manages the FID information strings 502, 503, and 504. The real data area 508 of the dummy file is managed by the FE 507 of the dummy file as a reserved area.
[0110]
As in the previous example, when adding the FID 505, if the counter value of the FE 501 reaches the rewrite condition, the FE 501, the FIDs 502, 503, 504, and the added FID 505 are stored in the area reserved as the reserved area 508. Written. At this time, the counter value of the FE 501 is reset, and the reserved area 508 is reduced by the amount used for the recording. The area where these are written, that is, the areas of FE501, FID502, 503, and 504 in FIG. 5A are managed by the FE507 as the first half 509 of the dummy file. This state is the state shown in FIG.
[0111]
If the counter value of the FE 501 reaches the rewriting condition when the FID 506 is added, the FE 501, the FIDs 502, 503, 504, 505, and the added FID 506 are written in the area reserved as the reserved area 508. It is. At this time, the counter value of the FE 501 is reset, and the reserved area 508 is reduced by the amount used for the recording. The area where these are written, that is, the areas of FE501, FID502, 503, 504, and 505 in FIG. 5B are combined with the first half 509 of the dummy file and managed by the FE507. This state is the state shown in FIG.
[0112]
According to the above-described method, an area for recording a specific directory structure that can be expected to increase the number of updates can be reserved in advance in consideration of the movement of the recording position. Therefore, it is possible to guarantee the reliability of a specific directory for a long term.
[0113]
(Fourth embodiment)
As a fourth embodiment, when the reliability of a specific recording area is determined to be low, the above-described second method, that is, when the reliability of a specific FE is determined to be low, Means for clearly indicating this to the user will be described. For example, as shown in FIG. 6, the deterioration prediction of the corresponding FE is displayed on the icons of the directories 601, 602, 603 and the files 604, 605, 606 displayed on the display unit 6 as a GUI (Graphical User Interface). In the form
[0114]
If the reliability is sufficient, the display is such that the meter is closer to “SAFE (safety)” as in the directory 601 and the file 604. If the rewriting life exceeds 90% of N times, the meter is displayed as if it were in the middle between “SAFE (safety)” and “DANGER (danger)” as in the directory 602 and the file 605. If the number of updates is greater than the rewrite lifetime N times, the meter is displayed as if it were closer to “DANGER (danger)” as in the directory 603 or file 606.
[0115]
According to the method as described above, the user can grasp at least the area where the FE is recorded with respect to the deterioration of the recording medium. Therefore, the user can evaluate the reliability of the corresponding directory or file by recognizing the deterioration state of the FE. In this case, for example, by copying a directory or a file with low reliability to another recording area, it is possible to avoid a situation in which the reliability is extremely reduced and data is lost. . Also, since only the directories and files recorded in the low-reliability area need to be copied, the entire rewriting life of the entire recording medium can be completely used, and the recording medium can be efficiently used. Can be used.
[0116]
In the above example, as a means for clearly indicating the reliability of the area, a method of displaying a meter on the icon of a directory or a file is adopted, but the present invention is not limited to this. For example, a method of changing the color or shape of the icon may be used, or a counter value may be displayed as it is. Further, in the above embodiment, the rewriting condition is set to 90%, but it is needless to say that the rewriting condition is not limited to this value, and may be appropriately set in consideration of the characteristics of the recording medium.
[0117]
However, in the above example, the FE counter value is used as a criterion for determining the reliability of the area, but this is based on the premise that the area is an unrecorded area until immediately before the counter is installed. is there.
[0118]
(Fifth embodiment)
Next, as a fifth embodiment, the above-described first method as a method for coping with a case where it is determined that the reliability of a certain recording area is low, that is, the content of the update prohibition process Will be described, and a means for specifying the time limit until the update is prohibited will be described. In this embodiment, it is assumed that up to 234 divisions are allowed for the recording area of the actual data or FID managed by one FE in the first embodiment, but the 235th division is not created. The same applies to the method and the second embodiment in which an upper limit is set for the length of the FID information sequence so that an FID having an information sequence exceeding the upper limit cannot be added. It is possible.
[0119]
For example, as shown in FIG. 7, in a directory or a file displayed as a GUI on the display unit 6, use restriction information of the corresponding FE or information on a margin until the use restriction is specified. Here, as an example, a system management method according to the second embodiment, that is, a case where an upper limit is set for the length of the FID information sequence will be described.
[0120]
In FIG. 7, the icon indicating the directory 701 has an X mark as a mark indicating that the length of the FID information string has reached the limit and the element, that is, the FID cannot be added. In FIG. 7, the icon indicating the directory 702 is indicated by the numeral 3 as a mark indicating that about three more elements can be added to this directory. Here, the reason that the number of elements that can be added is "approximately" three is that the length of the FID changes depending on the file name of the file to be added. In FIG. 7, the icon indicating the file 703 is indicated by the numeral 5 as a mark indicating that the file can be edited five more times.
[0121]
By grasping the above information, the user can refrain from updating, for example, copying a directory or a file to which there is no margin for the use limit, copying the directory or file to a directory having the margin for use, Processing such as moving a file can be performed. Therefore, it is possible to efficiently use all the recording areas in the recording medium.
[0122]
Note that, in the above example, the information about the elements that can be added is indicated by the X mark and the number, but the present invention is not limited to this, and a graph or the like may be used, for example.
[0123]
In each of the above embodiments, an example in which a UDF is assumed as a file system has been described. However, the present invention is not limited to this. If the file system has the same configuration, the same processing is performed, and the same operation and effect are obtained. It is possible to get.
[0124]
【The invention's effect】
As described above, according to the file system management method of the present invention, information recorded on a recording medium on which information is written and read is stored as a file corresponding to actual data and / or a directory in which the files are put together. A file system management method executed by a file system management means for managing a file system to be recorded, wherein the file and / or the directory and management information of the file and / or the directory are recorded on the recording medium. In this method, based on the contents recorded in the management information, a different process is performed according to the number of updates of the file and / or directory managed by the management information.
[0125]
Thus, for example, in the case of a recording medium having a limited number of rewritable times, when the number of rewritable times has reached or approached in a specific area, for example, updating is prohibited or a warning is issued. This makes it possible to take appropriate measures.
[0126]
Further, in the file system management method according to the present invention, the file system management means may estimate the number of updates based on the size of the management information.
[0127]
Thereby, in addition to the effect of the above-described method, there is an effect that the number of updates of the management information can be estimated without adding specific information to the management information.
[0128]
In the file system management method according to the present invention, the file system management means may estimate the number of updates based on creation time information and update time information recorded in the management information.
[0129]
Thereby, in addition to the effect of the above method, there is an effect that the number of updates of the management information can be estimated based on information originally included in the management information.
[0130]
In the file system management method according to the present invention, the file system management means may estimate the number of updates based on an update counter recorded in the management information.
[0131]
Accordingly, in addition to the effect of the above method, by estimating the number of updates based on the update counter recorded in the management information, the number of updates can be more accurately recognized.
[0132]
Further, in the file system management method according to the present invention, the management information may include update count information of the management information, and the file system management unit may determine that the update count is equal to or greater than a predetermined value. May be detected.
[0133]
Accordingly, in addition to the effect of the above method, by setting the predetermined value based on the number of rewritable times of the recording medium, it is possible to prevent the update from being performed, for example, exceeding the number of rewritable times. Thus, it is possible to prevent the reliability of the recording state from being lowered.
[0134]
Further, in the file system management method according to the present invention, the file system management means may be configured such that, when the number of updates is equal to or more than a predetermined value, the number of updates of the file and / or directory managed by the management information is reduced. A method of presenting to the user that the value has become equal to or more than the predetermined value may be used.
[0135]
This makes it possible to evaluate the reliability of the file and / or directory in addition to the effect of the above method, so that the entire rewriting life of the recording medium can be fully used, and the recording medium can be efficiently used. This has the effect that it can be used for
[0136]
Also, in the file system management method according to the present invention, the file system management means may notify the user of a relationship between the limited number of updates and the number of updates in management information for managing the current applicable file and / or applicable directory. Alternatively, a method of presenting the information may be used.
[0137]
This allows the user to recognize how much more each file and / or directory can be updated, in addition to the effect of the method described above, so that the user can select each file and / or directory. This makes it possible to determine how to update the data in the future.
[0138]
Further, in the file system management method according to the present invention, the file system management means updates the update by changing the recording position of the management information on the recording medium when the update count becomes a predetermined value or more. The method may be performed.
[0139]
Thereby, in addition to the effect of the above-described method, it is possible to update the management information whose update count is equal to or more than a predetermined value without lowering the reliability of the recorded information. It has the effect of becoming.
[0140]
Further, in the file system management method according to the present invention, the file system management means updates the update by changing the recording position of the management information on the recording medium when the update count becomes a predetermined value or more. Performing, on the recording medium, the recording position of the data managed by the management information on the recording medium and / or the file identification information for specifying the file included in the directory managed by the management information. Alternatively, a method of changing the recording position in the above may be used.
[0141]
Accordingly, in addition to the effect of the above method, not only the management information in which the number of updates is directly counted, but also data and / or file identification information expected to be close to the limit of the number of updates. This has the effect that the reliability of the recorded information can be maintained high.
[0142]
Further, in the file system management method according to the present invention, the file system management means reserves in advance an area for recording specific management information and files and / or directories managed by the specific management information. The recording position of the management information and the file and / or the directory may be moved within the area where the management information is recorded.
[0143]
As a result, in addition to the effect of the above-described method, there is an effect that it is possible to guarantee the reliability of the specific management information and the files and / or directories managed by the specific management information for a long term.
[0144]
In the file system management method according to the present invention, the file system management means may set an upper limit on the size of the management information.
[0145]
As a result, the memory capacity may be set according to the upper limit. Therefore, it is only necessary to prepare a memory having a minimum necessary capacity, and it is possible to reduce the cost of the apparatus for recording and reproducing the recording medium managed by the above method.
[0146]
Further, in the file system management method according to the present invention, the file system management means may set a limit on the number of files and / or directories managed by one management information on a recording medium.
[0147]
Thereby, in addition to the effect of the above method, the number of divisions of files and / or directories managed by one management information on the recording medium is limited, so that the size of the management information is within a predetermined size. This has the effect of being able to be set to
[0148]
Also, in the file system management method according to the present invention, the file system management means manages the file identification information for specifying a file included in the directory, wherein the management information for managing the directory is managed. The file system management means may set a limit on the size of the file identification information group managed by one management information.
[0149]
Thus, in addition to the effect of the above method, the minimum necessary memory capacity may be set based on the restriction. Therefore, the apparatus for recording and reproducing the recording medium managed by the above method This has the effect that the cost of the device can be reduced.
[0150]
Further, in the file system management method according to the present invention, when the size of the management information is equal to or more than the upper limit, the file system management unit updates the file and / or directory managed by the management information. A method of presenting the restriction to the user may be used.
[0151]
As a result, in addition to the effect of the above-described method, there is an effect that, for example, by performing processing such as copying the file or directory to another location, it is possible to cope with this.
[0152]
Also, in the file system management method according to the present invention, the file system management means may notify the user of a relationship between an upper limit of the size of the management information and a management information size for managing the current applicable file and / or applicable directory. May be presented.
[0153]
Thereby, in addition to the effect of the above-described method, it is possible to recognize how much each file and / or directory can be updated. Accordingly, by recognizing such information, the user can determine how to update each file and / or directory in the future.
[0154]
A file system management program according to the present invention causes a computer to execute the file system management method according to the present invention.
[0155]
Accordingly, there is an effect that the file system management method can be provided to the user by causing the computer to execute the program.
[0156]
Further, the recording / reproducing apparatus according to the present invention is a recording / reproducing apparatus for performing information writing and / or reading processing on a recording medium on which information is written and / or read, wherein the recording / reproducing apparatus performs writing and / or reading on the recording medium. And / or When reading, the file system management method according to the present invention is used.
[0157]
As a result, the recording medium can be used efficiently while maintaining the reliability of the recorded information at a high level, and the cost of the apparatus can be reduced.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating a flow of processing performed by a UDF driver having a limited function as a file system management method that does not use an AED structure.
FIG. 2 is a flowchart showing a flow of processing performed by a UDF driver having a limited function as a file system management method for setting an upper limit on the length of an FID information sequence.
FIGS. 3A to 3C are diagrams for explaining the flow of an example of processing of a file system management method according to an embodiment of the present invention.
FIGS. 4A to 4C are diagrams for explaining the flow of another example of the processing of the file system management method according to the embodiment of the present invention.
FIGS. 5A to 5C are diagrams for explaining the flow of still another example of the processing of the file system management method according to the embodiment of the present invention.
FIG. 6 is a diagram illustrating a GUI as a means for clearly indicating to a user when the reliability of a specific FE is determined to be low.
FIG. 7 is a view showing a GUI as a means for specifying use restriction information of the FE or information relating to a margin before use restriction.
FIG. 8 is a diagram illustrating an example of a structure in a partition in a recording area of a recording medium.
FIG. 9 is a diagram showing a structural standard of an FE.
FIG. 10 is a diagram showing a structure standard of a Short Allocation Descriptor.
FIG. 11 is a diagram showing a structural standard of an AED.
FIG. 12 is a diagram showing a structure standard of FID.
FIG. 13 is a block diagram illustrating a schematic configuration example of a recording / reproducing apparatus according to the embodiment.
FIG. 14 is a flowchart showing a procedure for loading directory management information by a file system driver based on the file system management method.
FIG. 15 is a diagram illustrating a Counter Format as a format example recorded in an Extended Attributes field.
[Explanation of symbols]
1 Recording and playback device
2 Recording media
3 Device driver
4 File system driver (file system management means)
5 Application programs
6 Display
7 Operation section

Claims (21)

A file executed by a file system management means for managing a file corresponding to actual data and / or a file system for recording the information recorded on a recording medium on which information is written and read as a directory in which the files are collected. A system management method,
The file and / or the directory and management information of the file and / or the directory are recorded on the recording medium,
A file system management method, wherein different processes are performed based on the contents recorded in the management information according to the number of updates of a file and / or directory managed by the management information. 2. The file system management method according to claim 1, wherein the file system management means estimates the number of updates based on a size of the management information. 2. The file system management method according to claim 1, wherein the file system management means estimates the number of updates based on creation time information and update time information recorded in the management information. 2. The file system management method according to claim 1, wherein the file system management means estimates the number of updates based on an update counter recorded in the management information. When the number of updates is equal to or greater than a predetermined value, the file system management means informs the user that the number of updates of the file and / or directory managed by the management information has exceeded a predetermined value. The file system management method according to any one of claims 1 to 4, wherein the file system management method is presented. 6. The file system management means according to claim 5, wherein a relationship between the limited number of updates and the number of updates in management information for managing the current applicable file and / or applicable directory is presented to the user. The file system management method described. 2. The file according to claim 1, wherein the file system management means updates the recording position of the management information on a recording medium when the number of updates is equal to or greater than a predetermined value. System management method. When the number of updates is equal to or more than a predetermined value, the file system management means changes the recording position of the management information on the recording medium to perform the update, and updates the data managed by the management information. The recording position on the recording medium and / or the recording position on the recording medium of the file identification information for specifying the file included in the directory managed by the management information is changed. The file system management method according to claim 7. The file system management means reserves in advance an area for recording specific management information and data and / or file identification information managed by the specific management information, and within the secured area, the management information, 9. The file system management method according to claim 8, wherein a recording position of data and / or file identification information is moved. 2. The file system management method according to claim 1, wherein the file system management means sets an upper limit on the size of the management information. 11. The file system management method according to claim 10, wherein said file system management means limits the number of files and / or directories managed by one management information on a recording medium. The file system management means is assumed that the management information for managing the directory manages file identification information for specifying a file included in the directory,
11. The file system management method according to claim 10, wherein said file system management means limits a size of said file identification information group managed by one management information. When the size of the management information is equal to or larger than the upper limit value, the file system management unit presents to the user that updating of files and / or directories managed by the management information is restricted. 13. The file system management method according to claim 10, 11, or 12. 14. The file system management unit according to claim 13, wherein a relationship between an upper limit of the size of the management information and a management information size for managing a current corresponding file and / or corresponding directory is presented to a user. File system management method. 15. The file system management method according to claim 1, wherein the management information is FE in Universal Disk Format. 3. The file system management method according to claim 2, wherein the management information is an FE in the Universal Disk Format, and the size of the management information is obtained by the number of ADs included in the FE. 3. The file system management method according to claim 2, wherein the management information is FE in Universal Disk Format, and the size of the management information is obtained by the number of FIDs in a FID information sequence managed by the FE. . 12. The file system management method according to claim 11, wherein the management information is FE in Universal Disk Format, and the number of ADs and / or AEDs managed by the FE is limited. 13. The file system management method according to claim 8, wherein the management information is FE in Universal Disk Format, and the file identification information is FID in Universal Disk Format. A file system management program for causing a computer to execute the file system management method according to claim 1. In a recording / reproducing apparatus for performing information writing and / or reading processing on a recording medium on which information is written and / or read,
20. A recording / reproducing apparatus using the file system management method according to claim 1 when writing and / or reading data from / to the recording medium.

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