JP3607279B2 - File management method and apparatus - Google Patents

Description

  The present invention relates to a file management method and apparatus for dividing a recording medium into a plurality of areas and using the same when writing a file from a plurality of applications on one recording medium.

  The existence of a general-purpose disk medium that can be used in common on different platforms such as PC applications and AV applications has great advantages for users. For example, the fact that a disc recorded with an AV disc recorder can be accessed with a disc drive connected to a PC and vice versa is easy access to AV data recorded with an AV disc recorder and editing. This means that editing results can be easily played back on an AV disc recorder or the like. It is also possible to record AV data on a single disc or put PC application software in a shared manner for AV use and PC use.

  However, the properties of data recorded for AV applications and data recorded for PC applications are different. For example, when reproducing AV data recorded on a disc, the AV data must be read from the disc and displayed on a display at a fixed time. If it cannot be displayed at a fixed time, it means that the playback screen is interrupted and the playback screen becomes strange, which is not allowed.

  Since the disk medium is excellent in random accessibility, even a series of data does not need to be continuously arranged on the disk, and the free space on the disk is used effectively and divided and recorded. It doesn't matter. For example, in the case of PC use, even if the text data file is divided and recorded on the disk, when reading the file, a seek or track jump occurs at each break point, and the data is read from the disk during that period. There is no functional problem at all, as it takes a little time to read data compared to the case where data is read continuously.

  However, in the AV application, as described above, when the data to be reproduced is divided and recorded on the disc, the reading of the data is interrupted at each dividing point, which may cause a problem. In general, AV data read from the disk is once stored in the buffer memory to some extent, and even if data read interruption such as seek or track jump occurs, it can be immediately compensated by supplementing with data stored in the buffer memory. The playback screen is prevented from being interrupted. However, the interruption of the playback screen by the buffer memory cannot be dealt with when a seek or track jump occurs in a complicated manner. Therefore, when AV data is recorded on a disc, it is desired to continuously record data without causing a seek or a track jump in which data reading is interrupted.

  Here, considering that one disk is shared between AV and PC applications, there is a demand for recording data for each application in different areas. This is because, when compared to AV data in a disc area where AV data for which data is to be continuously recorded is recorded, data for PC use with a much smaller amount of data is randomly recorded. This is because it is a factor that hinders continuous recording, and in some cases, it may interfere with recording and reproduction of AV data.

  Even for AV applications, the data to be recorded is not only AV data but also various types of data such as a management information file for reproducing them and still images. Since data having different properties are recorded even in the same application, there is a demand for managing areas separately according to the type of data to be recorded. For example, an area for recording management information of a logical file system, an area for recording management information for reproducing AV data, an area for recording AV data itself, and an area for recording still images can be considered.

  In order to use one disk divided into a plurality of areas, conventionally, there are the following methods. First, the partition function of the logical file system exists in the sense of clearly dividing the area. For example, by defining partitions for AV use and PC use, it is possible to provide dedicated areas for each.

  The example shown in FIG. 16 shows a state where the disk is divided into partition 1, partition 2, and partition 3.

  As a second method, when the partition function is not used, it is conceivable to manage the area as management information of the application layer at the mounting level without managing the areas for AV use and PC use by the logical file system. For example, a management information file in which position information of each area is recorded is recorded on a disk, and the position information of the area can be grasped by reading the file. In the example shown in FIG. Position information of area 1, area 2, and area 3 is recorded in a file called DAT. Therefore, AREA. Only applications that can interpret DAT files can understand the range of the area.

  Unlike the first method described above, the areas 1 to 3 here are constituted by one partition on the logical file system, and are divided into areas therein.

  Thirdly, it is also possible to create a dummy file as if the area was used without actually recording data, for the purpose of reserving an area for recording one file or data. Each of the files recorded in the area shown in FIG. DAT, DUMMY2. DAT, DUMMY3. It is secured by three dummy files called DAT.

  Thus, as dummy data, data of the same size as data recorded in advance is written, and when writing a file of a predetermined data type, the dummy data is deleted, and the file is written at that position, Files can be written continuously for each data type.

  In the first method described above, areas for AV use and PC use can be divided by partition functions, and dedicated areas can be provided. However, in general, partitions are created by determining the number and size of partitions when initializing a disk, and it is not easy to change the partition configuration during use. This is because each partition usually has an independent logical address, free space management information, etc., so when changing the configuration, it is necessary to reconfigure a lot of management information. It is. In addition, the user must decide how much space to reserve for AV and PC applications at initialization. However, it is possible that either area will become insufficient in the course of use.

  As mentioned above, it is not easy to change the size of the partition. For example, even if free space remains in the PC use area, when the AV use area is full, it is more than that. AV data cannot be recorded, and the disk cannot be used effectively, which is problematic. Also, in the same AV application, it is said to be an area for recording management information of the logical file system, an area for recording management information for reproducing AV data, an area for recording AV data, and an area for recording still images. In some cases, it is desirable to manage these areas by dividing them into multiple areas. If these areas are managed by partitions, the number of partitions is large, so when one partition becomes full, the disk is free. Even if this is the case, there is a problem that the possibility that data or the like cannot be recorded further increases.

  As in the second method, if the area is not managed by the partition function provided by the logical file system, but managed as management information of the application layer at the implementation level, it is assumed that the area is managed by the application. For non-applications, the management information in which the position information of this area is recorded has no meaning. Each reserved area is not reserved at the logical file system level, so there is no problem if the disk is used only by the assumed application, but if accessed from an unexpected application, the area will be Since it cannot be recognized, there is a possibility that unexpected data may be recorded in the reserved area.

  Further, as in the third method, it is possible to secure an area by using a dummy file to reserve an area for recording one file or data. In this method, for example, if you want to secure a continuous area for recording management information, predict the size and number of files to be recorded in the future, and secure the area by recording dummy files of the same size and number. Must. Therefore, basically, the dummy file is created with the assumed maximum size of the file, and when the actually written file is smaller than the size of the dummy file, there is a problem that a lot of waste occurs.

  In the area 1 shown in FIG. 18, assuming that the size of each file to be written is 1M, a dummy file having a size of 1M is created. When a 0.8M file is written here, first, 0.8M data is written at the position of the first dummy file (DUMMY1.DAT), and then 0.9M data is written, the next dummy file is written. Since it is written at the position of the file (DUMMY2.DAT), a wasteful portion of 0.1M is generated. In addition, there is a problem that it is impossible to cope with the case where the size of the file to be written cannot be predicted (the maximum size cannot be expected).

  Accordingly, the present invention solves the problems in the above three methods, and it is possible to prevent data other than desired data from being written in a predetermined area without partitioning by a logical file system. It becomes.

  The present invention relates to a recording apparatus comprising a recording medium and a recording control means for managing input / output of data to / from the recording medium, and at least one area is secured in the recording medium, and each empty area is a dummy file. If the file is written to the area, the file is written on the dummy file in the area, and the size of the dummy file is updated to the size of the empty area in the area to solve the above problem. Is.

  According to the present invention, by creating a dummy file so as to manage the unused portion in the secured continuous area, this area is treated as being used by all but the application that uses this area. Thus, it is possible to suppress data from being written.

  For applications that specify dummy files, it is possible to easily grasp the size and position of unused locations in the secured area by acquiring the file size and location information of the dummy file. Files can be created and updated easily.

  In addition, when an application that can understand the dummy file is installed by a plurality of manufacturers or the like, the size of the continuous area to be secured is not necessarily the same. Even in this case, the unused part can be grasped only by referring to the information of the dummy file, so that compatibility between manufacturers can be achieved.

  In addition, since the partition function that is a function of the logical file system is not used, the size of the area can be changed by simple processing such as updating a dummy file, compared to changing the size of the partition. It becomes possible. If it is necessary to know the range of the contiguous area secured, the contiguous area can be easily managed by managing the last logical block or both top and bottom logical blocks with a dummy file as necessary. It becomes possible to grasp the range.

  Hereinafter, embodiments of the region management method of the present invention will be described in detail with reference to the drawings. The present embodiment assumes a portable video camera, a video deck, an external storage device connected to a PC, or the like using a disk for AV recording / reproduction as a disk device. The disk medium is preferably a removable disk, but it may be a stationary type such as a hard disk. Also, for convenience of explanation, UDF (Universal Disk Format), which is an OSTA (Optical Storage Technology Association) standard, is assumed as a logical file system used for a disk, but other general-purpose logical file systems may be used.

  A configuration of a general disk device is shown in FIG. The data input / output unit 1 captures a video signal input from a camera or the like, and outputs data to be reproduced to a monitor or the like. The data processing unit 2 is a processing unit that performs, for example, signal processing for encoding or decoding an MPEG code, and the processed data is stored in the memory 3. When recording data, the disc control unit 5 controls the disc 6 to record data at a target location on the disc, and during playback, the disc 6 is controlled to read data from the target location on the disc. Stored in memory 3. Each processing unit is controlled by the system control unit 4.

  In such a disk device, in order to divide and manage a disk area, it is common to use a partition function in a logical file system. However, as described above, once a partition is partitioned, it is not easy to change the size of the partition or to expand the size by linking one partition with another partition. In this embodiment, since the area is not divided by the partition function, one partition is created so as to manage the entire user area of the disk as shown in FIG. An area for recording certain information shall be defined in the created partition. Since the partition function is not used and UDF, which is a general-purpose file system, is used, there is no logical file system level management information for managing multiple areas in one partition. The key here is the possibility of using one disk on multiple platforms. For example, it is possible to access a disc recorded for AV use with a PC drive. Therefore, it is not sufficient to secure an area with information that can be understood only by a specific application such as an AV application. In other words, defining an area for recording certain information means not only managing the recording area according to the type of data in AV applications, but also ensuring access even if there is access from a PC application etc. This means that writing to the specified area must be suppressed. In order to realize this, when the reserved area is viewed from the logical file system, data must already be recorded and viewed as being used.

  Therefore, in the present invention, in order to secure a continuous area for recording any number of specific information, a dummy file is created in such a manner as to manage an unused part in which no data is recorded in the area. Shall. That is, it is as if data on the disk managed by the dummy file is written in the unused portion in the area.

  The UDF is divided into volume level management information and file system level management information. Here, related file system level management information will be briefly described. In a partition defined by volume level management information, a Space Bitmap Descriptor that manages free space, a File Set Descriptor that includes pointer information to the basic information of the directory structure in the partition and the File Entry that manages the ROOT directory A Terminating Descriptor indicating that the Set Descriptor has ended, and a File Entry in the ROOT directory are basically recorded as management information at the file system level.

  Space Bitmap Descriptor assigns 1 bit to all logical blocks managed in a partition, and determines whether the corresponding logical block is used or not based on 0 or 1 bit information. It is. The logical block here is a minimum access unit in the file system, and logical block numbers are added to each logical block in ascending order in the UDF partition.

  When a directory is defined, a File Entry for managing the directory manages a recording position of a set of File Identifier Descriptors corresponding to the files and directories included in the directory. The File Identifier Descriptor stores address information in which File Entry corresponding to file and directory names and attribute information is recorded. File Entry records attribute information such as date and data location information on the disk managed by this file (File Entry), or directory information (a set of File Identifier Descriptors) in the case of a directory. Manage location information. In this way, the directory hierarchy can be grasped by following the File Entry and File Identifier Descriptor. These pieces of information are management information of the UDF file system, and are usually used only by the device driver and are usually invisible to the user. FIG. 4 shows the relationship between File Entry and File Identifier Descriptor for expressing the directory hierarchy in UDF.

  As an example of securing the area by the dummy file, FIG. 2 defines areas 1, 2, and 3 as continuous areas for recording any number of specific information, and files FILE1. DAT, FILE2. DAT, FILE3. This shows how DAT is recorded. In the actual disk, FILE1. FE (File Entry) which is UDF management information corresponding to DAT and File1 which is data itself are recorded. In this example, a File Identifier Descriptor including pointer information to FE (File Entry), which is file management information, is not shown as being recorded in, for example, the area 1.

  The location information on the disk is managed by a set of Allocation Descriptors indicating the start logical block number and the number of logical blocks. In other words, if the data managed by one file (File Entry) is continuously recorded on the disk, the Allocation Descriptor is divided into two, and if the data is divided into two, the file is allocated by two Allocation Descriptors. Will manage location information.

  FILE1. Like DAT, FILE2. DAT, FILE3. FE (File Entry) corresponding to DAT and actual data corresponding to DAT are recorded in a continuous area. Here, the dummy file DUMMY1. Create a DAT. In other words, the dummy file DUMMY1. DAT is created and managed by FE (File Entry) Allocation Descriptor. The dummy file DUMMY1.Space is also used for the Space Bitmap Descriptor that manages the free space with the management information of the UDF file system. The part managed by DAT is treated as being used.

  Further, in the process of use, for example, FILE2. When DAT is deleted, it is usually FILE2. The location where FE (File Entry) and data corresponding to DAT were recorded is an unused portion by the Space Bitmap Descriptor and is released. However, in the present invention, the deleted file DUMMY1. Treat as a part managed by DAT. At this time, DUMMY1. Update Allocation Descriptor in FE (File Entry) of DAT, and DUMMY1. DAT will be a file consisting of two divisions.

  When creating a dummy file, the name of the dummy file that can be understood by the application using the secured continuous area is defined. In the example in the figure, the dummy file in the secured continuous area is DUMMY1. Defined as DAT. In other words, from a certain application, this DUMMY1. We understand that DAT is a free space.

  In this way, by always creating a dummy file so that unused parts in the secured continuous area are managed, this area is always treated as being used by all but the application that uses this area. Data is never written. In addition to suppressing the writing of data from other applications, the size and position of the unused part in the area that is easily secured by acquiring dummy file information for applications that specify dummy files. There is also an effect that can be grasped. For example, the size of the unused part can be found by referring to the file size of the dummy file, and the location information can be easily grasped by referring to the Allocation Descriptor in the FE (File Entry) of the dummy file. . That is, the dummy file is used as it is in the reserved area.

  In addition, when an application that can understand the dummy file is installed by a plurality of manufacturers, the size of the continuous area to be secured is not necessarily the same between the manufacturers. Even in this case, it is possible to grasp the unused portion in the reserved area simply by referring to the information of the dummy file, so that compatibility between manufacturers can be achieved without specifying the size of the area. . In addition, the size of the area can be grasped from the information of the file to be recorded in the area and the dummy file as necessary.

  Here, details of a process for securing a continuous area of a predetermined size for newly recording specific information will be described with reference to the flowchart shown in FIG. When a request to secure a continuous area is generated in step S1, a free area on the disk is grasped by referring to Space Bitmap information which is management information of the UDF logical file system in step S2. If the continuous area to be secured cannot be secured at an arbitrary location on the disk in step S3, error processing is performed in step S5 and the process is terminated. If the continuous area to be secured can be secured at an arbitrary location on the disk in step S3, a dummy file is created in step S4 so as to manage the secured continuous area, and the process ends. Specifically, a File Identifier Descriptor that is pointer information to the File Entry of the dummy file is added to the directory information of the directory where the dummy file is created, and the File Entry that manages the location information and attribute information of the dummy file data is added. Record. At this time, the start logical block number and the number of logical blocks, which are the location information of the reserved area, are recorded in the Allocation Descriptor in the File Entry.

  Here, processing when a file creation request is actually generated will be described. When there is a file creation request, it is determined in which area the file can be written. For example, as shown in FIG. 2, when an area 1, area 2, area 3,... Is divided and an AV application makes a file write request, it is associated with writing to area 1. Suppose that For example, the AV application is DUMMY1. This is done by defining the AV application itself so that it is written at the DAT location. For example, PC applications other than AV applications are DUMMY1. It is not written on DAT, but written to other areas.

  Also, by defining an area (corresponding to dummy data) to be written in each application according to the file type, for example, video data is DUMMY1. The audio data is DUMMY2. It is also possible to control to write on DAT.

  That is, a predetermined application can be written in a predetermined area, or a file of a predetermined type can be written in the predetermined area.

  Next, details of processing when a file is created in an area secured by a dummy file after the area to be written is determined will be described with reference to the flowchart shown in FIG.

  When a file creation request occurs in step S10, dummy file information is acquired in step S11. Specifically, referring to the corresponding File Entry from the file name defined as the dummy file, the file size and position information of the dummy file are grasped from the information. In step S12, it is determined whether the file size of the dummy file, that is, the free size in the secured area is larger than the size of the file to be created. If the size of the dummy file is smaller than the size of the file to be created, there is no space for creating the file in the secured area, so an error process is performed in step S15, and the process ends. If the size of the dummy file is larger than the size of the file to be created in step S12, the file can be created in the reserved area. Therefore, in step S13, the file is created in the empty part managed by the dummy file.

  Specifically, a File Identifier Descriptor that is pointer information to the File Entry that manages the file is added to the directory information of the directory that contains the file to be created, and the File Entry that manages the file data location information and attribute information Record. In step S14, the file entry of the dummy file is updated and the process ends. At this time, update is performed by subtracting the portion assigned to the newly created file from the Allocation Descriptor information in the File Entry.

  Details of processing when an update accompanied by a change in the size of a file existing in an area secured by a dummy file will be described with reference to the flowchart shown in FIG.

  If a file update request accompanied by a file size change occurs in step S20, it is determined in step S21 whether the file size is increased or decreased. When the file size is reduced, in step S28, the Allocation Descriptor of the File Entry of the file to be reduced is updated so as to manage the reduced data. In step S29, the dummy file's File Entry Allocation Descriptor is updated by adding the reduced file location, and the process ends. If the size is to be expanded, the dummy file information is acquired in step S22, and the free space in the secured area is grasped. In step S23, the size of the dummy file, that is, the size of the unused space in the reserved area is compared with the data size newly expanded as a file. If the size of the dummy file is larger, that is, if there is a sufficient space in the reserved area, the data to be expanded in the unused space managed by the dummy file is recorded in step S24. In step S25, the Allocation Descriptor of the File Entry of the expanded file is updated. In step S26, the Allocation Descriptor of the File Entry of the dummy file is updated and the process is terminated. If the size of the data to be expanded is larger than the size of the dummy file in step S23, that is, if there is no remaining free space to be expanded, error processing is performed in step S27 and the processing is terminated.

  Details of the processing for deleting a file existing in the area secured by the dummy file will be described with reference to the flowchart shown in FIG. When a file deletion request is generated in step S30, file deletion processing is performed in step S31. Specifically, the corresponding File Identifier Descriptor is deleted from the directory information of the directory containing the file to be deleted. In step S32, the file entry of the dummy file is updated and the process ends. Specifically, the Allocation Descriptor of the dummy file is updated so as to manage the portion where the deleted file was recorded.

  Details of processing when it is desired to expand the size of the area due to the lack of the area secured by the dummy file will be described with reference to the flowchart shown in FIG.

  When an area expansion request is generated in step S40, the free space of the disk is grasped from the space bitmap in step S41. In step S42, it is determined whether or not there is a continuous region that is desired to be expanded adjacent to the region to be expanded. If it exists, the file entry of the dummy file is updated in step S44 so as to include the extended area. If there is no continuous area to be secured in the adjacent location, the continuous area securing process shown in FIG. 5 is performed and the process is terminated. In this case, the area to be expanded is not continuous with the existing area. If the area needs to be a continuous area, the process may be terminated by performing an error process without performing the continuous area securing process in step S43. An example in which the area in FIG. 10 is expanded is shown. In this example, FILE1. DAT, FILE2. DAT, FILE3. This is an example in which DAT is recorded and there is no free area, and an attempt was made to expand the area using an adjacent location, but another adjacent area on the disc was secured because the adjacent area 2 was already secured. The dummy file for area 1 is DUMMY1. With the file name DAT, the extension area of area 1 is DUMMY2. Free space is managed by a dummy file called DAT. Since the file name is specified here, DUMMY2. When DAT exists, it is possible to grasp that there is an extended continuous area at a non-adjacent location on the disk. Also, if you want to expand an existing continuous area and cannot be expanded continuously because adjacent locations are used, move adjacent data to another location on the disk, and then expand the space continuously. May be performed.

  In this way, since the partition function that is a function of the logical file system is not used, the size of the area can be changed only by updating the dummy file, compared to the case of changing the size of the partition. Therefore, it can be done with much simpler processing.

  Note that when managing empty space with a dummy file in a defined continuous area, a restriction may be imposed that the last logical block of the continuous area must be managed with a dummy file as shown in FIG. That is, the last logical block in the continuous area is always secured as a space managed by the dummy file. Therefore, an extra two logical blocks, one logical block and one logical block for recording a File Entry for managing a dummy file, are secured in the size to be secured as a continuous area. Therefore, dummy file DUMMY1. In the Allocation Descriptor in the File Entry that manages DAT, this is the end of the continuous area secured by the largest logical block number. With this configuration, when the data file is recorded to the end of the continuous area, the boundary of the continuous area can be prevented from being lost, and the boundary of the continuous area can be easily grasped. .

  If the file to be recorded in the continuous area to be secured is determined, it is possible to grasp the range of the continuous area from the information of Allocation Descriptor and dummy file in those File Entry. If the file name to be recorded is not determined, it is impossible to determine which continuous area the data is recorded from the file name, so it is possible to grasp the free space by the dummy file. The range of the secured continuous area cannot be grasped. Therefore, in such a case, as shown in FIG. 12, a restriction may be imposed that the top and bottom logical blocks of the continuous area must be managed by a dummy file. That is, the first and last logical blocks in the continuous area are always secured as space managed by the dummy file. Therefore, a total of three logical blocks, two logical blocks and one logical block for recording the dummy file File Entry, are secured in the size to be secured as a continuous area.

  Alternatively, as shown in FIG. 13, the head of the continuous area to be secured must be a File Entry for managing a dummy file, and the last logical block may be secured as a space managed by the dummy file. Absent. With this configuration, the dummy file DUMMY1. The smallest logical block number in the Allocation Descriptor of the File Entry managing the DAT or the logical block number in which the dummy file's File Entry itself is recorded is the start position of the continuous area, and the largest logical block On the contrary, the number is the last position of the continuous area, and the range of the managed continuous area can be easily grasped.

  Here, an actual application example of the present invention will be described with reference to FIG. This figure shows an example of area management in AV usage for recording AV data. First, it is assumed that a file system management information area, an application management information area, and a data area are divided and managed as areas. In the file system management information area, the basic management information in the UDF file system, Space Bitmap Descriptor (SBD), File Set Descriptor (FSD), Terminating Descriptor (TD) and File Entry (FE ) And a file identifier descriptor (FID) that is pointer information to a file entry that manages a file or directory defined in the directory. In the example in this figure, the ROOT directory, the AVMAN directory that records AV data management information, the File Entry that manages the AVDAT directory that records AV data, and the File Identifier Descriptor (FID) of the files defined in each directory A set of is recorded. And dummy file LOGI. DMY manages unused parts in the file system management information area.

  The application management information area is an area in which AV application management information such as management information for reproducing AV data is recorded. This area contains AVINFO1.AV, which is AV data management information. DAT and AVINFO2. DAT is recorded, and the corresponding file entry and data entity are recorded on the disc. Similar to the file system management information area, the dummy file APPL. DMY manages unused parts in the application management information area. When a user accesses a disk having such a configuration, it will appear as a directory hierarchy as shown in FIG.

  In the data area, AV1. DAT and AV2. DAT is recorded, and the corresponding File Entry and its entity are recorded on the disc. In the example of this figure, regarding the data area, the area of the data area is not secured by the dummy file, but the dummy file may be defined as necessary to secure the area.

  In this way, the unused part of the file system management information area is the dummy file LOGI. It is managed by DMY, and the unused part of the application management information area is a dummy file APPL. It is managed by DMY, and for an AV application that uses these areas, it is treated as managing free areas of the corresponding areas. For example, when a disk in such a situation is accessed by a disk drive connected to a PC, the file system management information area and the application management information area are handled as if files were recorded with no free space. Therefore, it is equivalent to securing the area. Therefore, data is not written to these areas.

  At this time, since it is not necessary to delete the management information of the directory and AV data used in the AV application from the PC application, write prohibition may be set as the attribute of these files and directories. In other words, the PC application can write only to the empty area of the data area. Further, since it is naturally not necessary to delete the dummy file itself, the write prohibition attribute may be set in the same manner. In order to hide the dummy file from the PC application, a hidden file attribute may be set. If the dummy file is deleted by mistake, the dummy file is reconstructed from the management information of the logical file system of the currently defined file or directory and the information of the Space Bitmap Descriptor that manages the free space. Things are also possible.

1 is a block diagram illustrating a configuration of a disk device according to an embodiment of the present invention. It is explanatory drawing which shows a mode that the area | region is ensured with the dummy file in embodiment of the area | region management method of this invention. It is explanatory drawing which shows the mode of a dummy file when the file is deleted in embodiment of the area | region management method of this invention. It is explanatory drawing which shows the relationship of UDF management information in embodiment of the area | region management method of this invention. It is a flowchart which shows the flow of the process which ensures a continuous area | region in embodiment of the area | region management method of this invention. It is a flowchart which shows the flow of a process at the time of creating a file in the continuous area ensured in embodiment of the area | region management method of this invention. It is a flowchart which shows the flow of a process when there exists an update accompanying the change of the size of the file in the continuous area secured in embodiment of the area | region management method of this invention. It is a flowchart which shows the flow of a process at the time of deleting the file in the continuous area secured in embodiment of the area | region management method of this invention. It is a flowchart which shows the flow of a process at the time of expanding the continuous area secured in embodiment of the area | region management method of this invention. It is explanatory drawing which shows the example at the time of expanding the continuous area secured in embodiment of the area | region management method of this invention. It is explanatory drawing which shows a mode that the dummy file in an area | region always manages the last logical block in embodiment of the area | region management method of this invention. It is explanatory drawing which shows a mode that the dummy file in an area | region always manages the head and the last logical block in embodiment of the area | region management method of this invention. It is explanatory drawing which shows a mode that the dummy file in an area | region manages the last logical block in the embodiment of the area | region management method of this invention, and the file entry of a dummy file is arrange | positioned at the first logical block. It is explanatory drawing which shows the actual example of application in embodiment of the area | region management method of this invention. It is explanatory drawing which shows the directory hierarchy of the example of FIG. 12 in embodiment of the area | region management method of this invention. It is explanatory drawing of the mode of the area reservation by the partition in a prior art. It is explanatory drawing of the mode of the area ensuring by the file which records the positional infomation on the area | region in a prior art. It is explanatory drawing of the mode of the area ensuring by the dummy file in a file unit in a prior art.

Explanation of symbols

1 Data Input / Output Unit 2 Data Processing Unit 3 Memory 4 System Control Unit 5 Disk Control Unit 6 Disk

Claims (13)

A file management method for securing a data area for storing actual data to be recorded on a recording medium and an area for storing management information related to the actual data, and managing the data as a file,
Securing a first area for storing first management information relating to first actual data in the recording medium;
Setting an unused area in the first area as a dummy file;
Writing a first management information in the dummy file when a write request for the first management information occurs;
Reducing the dummy file by subtracting the area allocated to the first management information from the dummy file area;
A file management method characterized by comprising: A file management method for securing a data area for storing actual data to be recorded on a recording medium and an area for storing management information related to the actual data, and managing the data as a file,
Securing a first area for storing first management information relating to first actual data in the recording medium;
Setting an unused area in the first area as a dummy file;
When deleting the first management information in the first area, expanding the dummy file by including an area allocated to the management information to be deleted in the dummy file;
A file management method characterized by comprising: The file management method according to claim 1 or 2, wherein the first management information is application management information for reproducing the first actual data. The first management information is application management information for reproducing the first actual data and file system management information for managing a directory hierarchy of a file of the application management information. The file management method described. The file management method according to claim 1, wherein the first management information is file system management information for managing a directory hierarchy of the first actual data file .   3. The file management method according to claim 1, wherein file management information of the dummy file exists in the first area. A step of comparing the size of the dummy file with the size of the first management information having the write request when a write request for the first management information is generated;
Extending the dummy file by including an unused area adjacent to the first area in the dummy file when the size of the dummy file necessary for writing the first management information is insufficient; ,
The file management method according to claim 1 or 2, characterized by comprising: A step of comparing the size of the dummy file with the size of the first management information having the write request when a write request for the first management information is generated;
A step of setting a non-adjacent unused area of the first area as a non-adjacent dummy file when the size of the dummy file necessary for writing the first management information is insufficient.
3. The file management method according to claim 1, wherein a file name associated with the dummy file is defined as a file name of the non-adjacent dummy file. It said adjacent unused space, the file management method of claim 7 wherein the real data or adjacent to the dummy file is already recorded, characterized in that it is created by moving the management information.
  The file management method according to claim 1, wherein a rear end of the first area is always configured by the dummy file.   The file management method according to claim 1, wherein a leading end and a trailing end of the first area are always configured by the dummy file.   A file management apparatus for executing the file management method according to claim 1.   A file management apparatus for executing the file management method according to claim 2.

Images