JP2004355640A - File management method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent data other than the desired data written in a predetermined area, without performing segmentation of partitions by a logical file system. <P>SOLUTION: By writing an empty area of the area as a dummy data in each of the areas, and by constituting the dummy data so that only special applications or special files can overwrite the dummy data concerned, segmentations and size changes in a plurality of areas are facilitated by dividing a recording medium into a plurality of areas. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a file management method and apparatus that divides a recording medium into a plurality of areas and uses them when writing files from a plurality of applications to one recording medium.

  The fact that there is a general-purpose disk medium that can be commonly used in different platforms such as PC applications and AV applications has a great merit for users. For example, a disc recorded by an AV disc recorder can be accessed by a disc drive connected to a PC, and vice versa.This means that AV data recorded by an AV disc recorder can be accessed and edited on a PC. Means that the edited result can be easily reproduced by an AV disc recorder or the like. It is also conceivable that AV data is recorded on a single disk, application software for a PC is inserted, and shared between an AV application and a PC application.

  However, the characteristics of data recorded for AV use and data recorded for PC use are different. For example, when reproducing AV data recorded on a disk, the AV data must be read from the disk and displayed on a display at a fixed time. If the display cannot be performed at a fixed time, it means that the reproduction screen is interrupted and the reproduction screen becomes strange, which is not acceptable.

  Since the disk medium has excellent random access properties, even a series of data does not need to be continuously arranged on the disk, and the data is divided and recorded by effectively using the free space on the disk. It does not matter. For example, in the case of a PC application, even if a text data file is recorded on the disc in a divided manner, seeks and track jumps occur at each break point when reading that file, and during that time data reading from the disc is not performed. There is no functional problem at all, as it takes a little longer to read data as compared to the case where data is interrupted and data can be read continuously.

  However, in the case of AV applications, as described above, if the data to be reproduced is divided and recorded on the disc, data reading is interrupted at each division point, which may cause a problem. Generally, AV data read from a disk is temporarily stored to a certain extent in a buffer memory, and even if an interruption in data reading such as seek or track jump occurs, the data stored in the buffer memory can be used to immediately supplement the data. This prevents the playback screen from being interrupted. However, the interruption of the playback screen by the buffer memory cannot be absorbed when seeks or track jumps occur frequently. Therefore, when recording AV data on a disk, continuous recording of data without seeking or track jump in which data reading is interrupted is desired.

  Here, considering that one disk is used for both the AV purpose and the PC purpose, there arises a request to record data for each purpose in different areas. This is because when data for a PC whose data size is much smaller than that of AV data is recorded in a random manner on the disk area where the AV data for which data This is a factor that hinders continuous recording, and in some cases, may hinder recording and reproduction of AV data.

  Further, even for AV applications, data to be recorded includes not only AV data but also various types of data such as management information files for reproducing them and still images. Since data having different properties are recorded even for the same use, there is a demand to manage the data in different areas according to the type of data to be recorded. For example, 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 itself, and an area for recording a still image can be considered.

  Conventionally, there is the following method for dividing one disk into a plurality of areas for use. First, there is a partition function of the logical file system in terms 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.

  In the example shown in FIG. 16, the disk is divided into three partitions, partition 1, partition 2, and partition 3.

  As a second method, when the partition function is not used, it is conceivable that the areas for AV use and PC use are not managed by the logical file system but are managed as management information of the application layer at the implementation level. For example, by recording a management information file in which the position information of each area is recorded on a disc and reading the file, the position information of the area can be grasped. In the example shown in FIG. The location information of the areas 1, 2, and 3 is recorded in a file called DAT. Therefore, AREA. Only the application that can interpret the file called DAT can grasp 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.

  Third, for the purpose of reserving an area for recording one file or data, a dummy file may be created as if the area was used without actually recording data. The files to be recorded in the area shown in FIG. DAT, DUMMY2. DAT, DUMMY3. This is secured by three dummy files called DAT.

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

  In the above-described first method, areas for AV use and PC use can be divided by the partition function, and dedicated areas can be provided. However, partitions are generally created by deciding the number and size of partitions when the disk is initialized, and it is not easy to change the partition configuration during use. This is because each partition generally has an independent logical address, management information of free space, etc., so when changing the configuration, it is necessary to reconfigure a lot of management information. It is. At the time of initialization, the user must decide how much space to reserve for each of AV and PC applications. However, it is conceivable that one of the areas may become insufficient during the use process.

  As mentioned above, it is not easy to change the partition size etc., for example, even if there is free space in the PC use area, it will no longer be available when the AV use area is full AV data cannot be recorded, and the disc cannot be used effectively. Also, in the same AV application, the area for recording management information of the logical file system, the area for recording management information for reproducing AV data, the area for recording AV data, and the area for recording still images. In some cases, it is desirable to manage data in multiple areas, and if these areas are managed in partitions, the number of partitions is large, and if one partition is full, the disk will be empty. Even so, there is a problem that the possibility of no longer being able to record data or the like increases accordingly.

  As in the second method, when the area is not managed by the partition function provided by the logical file system but is managed as management information of the application layer at the implementation level, the area is assumed to be managed by the application. The management information in which the location information of this area is recorded has no meaning for a non-application. Since the reserved areas are not reserved at the logical file system level, there is no problem if the disk is used only by the expected application, but if the disk is accessed by an unexpected application, the area is allocated. Since it cannot be recognized, unexpected data may be recorded in the secured area, which is problematic.

  Also, 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, when it is desired to secure a continuous area for recording management information, the size and number of files to be recorded in the future are predicted, and the area is secured by recording a dummy file of the same size and number. Must. Therefore, the dummy file is basically created with the assumed maximum size of the file. If the file to be actually written is smaller than the size of the dummy file, there is a problem that much waste occurs.

  In the area 1 shown in FIG. 18, assuming that the size of each of the written files is 1M, a dummy file having a size of 1M is created. When writing a 0.8M file, first, 0.8M data is written to the position of the first dummy file (DUMMY1.DAT), and then, when 0.9M data is written, the next dummy file is written. Since the data is written at the position of the file (DUMMY2.DAT), a useless portion of 0.1 M is generated. Further, when the size of a file to be written cannot be predicted (the maximum size cannot be expected), there is a problem that it cannot be handled.

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

  The present invention relates to a recording apparatus including a recording medium and recording control means for managing input and output of data to and from the recording medium. When a file is written in the area, the above problem is solved by writing the file on a dummy file in the area and updating the size of the dummy file to the size of the free area in the area. Things.

  According to the present invention, by creating a dummy file so as to manage the unused portion in the secured continuous area, the area is treated as being completely used for applications other than the application that uses this area. In addition, it is possible to prevent data from being written.

  Also, for an application that specifies a dummy file, by obtaining the file size and position information of the dummy file, it is possible to easily grasp the size and position of an unused portion in the secured area, and Files can be easily created and updated.

  When an application that can understand the dummy file is implemented by a plurality of manufacturers or the like, the size of the continuous area to be secured is not always the same. Also in this case, the unused portion can be grasped only by referring to the information of the dummy file, so that compatibility between manufacturers can be obtained.

  Also, since the partition function, which is a function of the logical file system, is not used, the size of the area can be changed only by simple processing such as updating the dummy file, compared to changing the size of the partition. It becomes possible. When it is necessary to know the range of the secured continuous area, the last area of the continuous area or both the top and bottom logical blocks are managed in a dummy file as necessary, so that the continuous area can be easily managed. Can be grasped.

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

  FIG. 1 shows the configuration of a general disk device. The data input / output unit 1 captures a video signal input from a camera or the like and outputs reproduced data to a monitor or the like. The data processing unit 2 is a processing unit that performs, for example, signal processing for encoding and 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 at the time of reproduction, controls the disc 6 to read data from the target location on the disc. And stored in the memory 3. Each processing unit is controlled by the system control unit 4.

  In such a disk device, when it is desired to divide and manage a disk area, a partition function in a logical file system is generally used. However, as described above, once a partition is partitioned, it is not easy to change the size of the partition or to connect a certain partition to another partition to increase the size. 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. It is assumed that an area for recording certain information is defined in the created partition. Because the partition function is not used and the UDF, which is a general-purpose file system, is used, there is no logical file system level management information for managing a plurality of areas in one partition. The key here is that a disk can be used on multiple platforms. For example, it is conceivable to access a disc recorded for AV use with a drive of a PC. Therefore, it is not enough 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 securing it even if there is access from PC applications etc. This means that writing to the specified area must be suppressed. In order to realize this, the reserved area must have data already recorded and viewed as being used when viewed from the logical file system.

  Therefore, in the present invention, in order to secure a continuous area for recording an arbitrary number of specific information, a dummy file is created in a form in which data is not recorded and an unused portion in the area is managed. Shall be. In other words, it is as if data on the disk managed by the dummy file is written in an unused portion in the area.

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

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

  When a directory is defined, the File Entry that manages the directory manages the recording position of the 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. In the File Entry, attribute information such as date and position information of data on the disk managed by the file (File Entry) or, in the case of a directory, directory information (a set of File Identifier Descriptor) is recorded. Manage location information. In this way, by following the File Entry and the File Identifier Descriptor, it is possible to grasp the directory hierarchy. 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 one example of the area reservation by the dummy file, in FIG. 2, areas 1, 2, and 3 are defined as continuous areas for recording an arbitrary number of specific information, and a file FILE1. DAT, FILE2. DAT, FILE3. This shows how DAT is recorded. On an actual disk, FILE1. FE (File Entry) which is management information of UDF 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, area 1.

  Position information on the disk is managed by a set of Allocation Descriptors indicating the starting logical block number and the number of logical blocks. In other words, if the data managed by one file (File Entry) is recorded continuously on the disc, the Allocation Descriptor is one. Will be managed.

  FILE1. FILE2. DAT, FILE3. The FE (File Entry) corresponding to the DAT and the actual data corresponding to the FE are recorded in a continuous area where the data is secured. Here, a dummy file DUMMY1.COM is placed in an unused portion of the secured continuous area where no data is recorded. Create a DAT. In other words, the dummy file DUMMY1. DATs are created and managed by the FE (File Entry) Allocation Descriptor. Also, for the Space Bitmap Descriptor that manages the free space with the management information of the UDF file system, the dummy file DUMMY1. The part managed by DAT is treated as being used.

  In the use process, for example, FILE2. When DAT is deleted, usually FILE2. The space where the FE (File Entry) corresponding to the DAT and the data were recorded is an unused part by the Space Bitmap Descriptor, and is released. However, in the present invention, as shown in the figure, the deleted part is not released, and the dummy file DUMMY1. Treated as a part managed by DAT. At this time, DUMMY1. Update Allocation Descriptor in FE (File Entry) of DAT, and update DUMMY1. DAT is a file composed of two divisions.

  When creating a dummy file, a name of the dummy file that can be understood by an application using the secured continuous area is defined. In the example of the figure, the dummy file in the secured continuous area is DUMMY1. Defined as DAT. In other words, from an application point of view, this DUMMY1. Understand that DAT is an empty area.

  In this way, by creating a dummy file so as to manage the unused portion in the secured continuous area, this area is always treated as being completely used for applications other than the application that uses this area. No data is written. In addition to suppressing the writing of data from other applications, for applications that specify a dummy file, the size and location of unused parts in an easily secured area can be obtained by obtaining information on the dummy file. There is also an effect that can be grasped. For example, the size of the unused portion can be found by referring to the file size of the dummy file, and the position information can be easily grasped by referring to the Allocation Descriptor in FE (File Entry) of the dummy file. . That is, the dummy file becomes an unused portion in the secured area as it is.

  Further, when an application that can understand the dummy file is implemented by a plurality of manufacturers, the size of the continuous area to be secured between the manufacturers is not always the same. Also in this case, it is possible to grasp the unused portion in the secured area only by referring to the information of the dummy file, so that compatibility between manufacturers can be obtained without specifying the size of the area. . Also, if necessary, the size of the area can be grasped from the information of the file to be recorded in the area and the dummy file.

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

  Here, a process when a file creation request is actually generated will be described. When a file creation request is issued, it is determined in which area the file can be written. For example, as shown in FIG. 2, when an area is divided into an area 1, an area 2, an area 3,..., When an AV application requests a file write, the file is written to the area 1. Suppose This determination is made, for example, for the AV application DUMMY1. This is done by defining it in the AV application itself so that it is written to the DAT location. For example, PC applications other than AV applications are DUMMY1. The data is not written on the DAT, but written on other areas.

  Also, by defining an area (correspondence with dummy data) to be written in each application according to the file type, for example, video data is DUMMY1. Audio data is written on DAT2. 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 a predetermined area.

  Next, a process for creating a file in the area secured by the dummy file after the area to be written is determined will be described in detail with reference to the flowchart shown in FIG.

  When a file creation request is issued in step S10, information on the dummy file is obtained in step S11. Specifically, a file name specified as a dummy file refers to a corresponding File Entry, and the file size and position information of the dummy file are grasped from the information. In step S12, it is determined whether or not 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 a file in the reserved 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. In step S13, the file is created in a free space managed by the dummy file.

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

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

  When a file update request accompanied by a change in file size occurs in step S20, it is determined in step S21 whether the size of the file increases or decreases. When the size of the file is reduced, in step S28, the Allocation Descriptor of the File Entry of the file to be reduced is updated to manage the reduced data. In step S29, the file is updated by adding the reduced file location to the Allocation Descriptor of the File Entry of the dummy file, and the process ends. If the size is to be extended, the information of the dummy file is obtained in step S22, and the empty portion in the secured area is grasped. In step S23, a comparison is made between the size of the dummy file, that is, the size of the unused space in the secured area, and the data size to be newly expanded as a file. If the size of the dummy file is larger, that is, if there is a sufficient free space in the secured area, in step S24, data to be expanded to an unused space managed by the dummy file is recorded. 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 ends. 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 for expansion, error processing is performed in step S27 and the processing ends.

  The process for deleting a file existing in the area secured by the dummy file will be described in detail with reference to the flowchart shown in FIG. When a file deletion request is generated in step S30, a file deletion process 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.

  The processing when the area secured by the dummy file becomes insufficient and the size of the area is to be expanded will be described in detail 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 area to be extended adjacent to the area to be extended. If there is, 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 processing shown in FIG. 5 is performed, and the processing ends. In this case, the area to be extended is not continuous with the existing area. If the area must be a continuous area, the processing may be terminated after performing the error processing without performing the continuous area securing processing in step S43. FIG. 11 shows an example of a case where an area in FIG. 10 is extended. In this example, FILE1. DAT, FILE2. DAT, FILE3. This is an example in which the DAT is recorded and the free area is exhausted, and an attempt is made to expand the area using the adjacent area, but another continuous area on the disk is secured because the adjacent area 2 has already been secured. The dummy file in area 1 is DUMMY1. The extension area of area 1 is DUMMY2. Free space is managed by a dummy file called DAT. Here, since the file name is specified, DUMMY2. If a DAT exists, it is possible to know that there is an extended continuous area in a non-adjacent location on the disk. If you want to extend an existing contiguous area and cannot expand continuously because the adjacent location is used, move the adjacent data to another location on the disk, open the area, and expand continuously. May be performed.

  In this way, since the partition function, which is a function of the logical file system, is not used, it is possible to change the size of the area only by updating the dummy file, compared to changing the size of the partition etc. Therefore, it can be performed with much simpler processing.

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

  If the files to be recorded in the continuous area to be secured are determined, it is possible to know the range of the continuous area from the Allocation Descriptor in those File Entry and the information of the dummy file. If the file name to be recorded is not fixed, it is not possible to determine which continuous area is the data recorded from the file name, so the empty space can be grasped by the dummy file. However, 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 head and tail 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 a space managed by the dummy file. Therefore, a total of three logical blocks, that is, two logical blocks and one logical block for recording a dummy file File Entry, are secured in a size desired to be secured as a continuous area.

  Alternatively, as shown in FIG. 13, the head of the continuous area to be reserved must be a File Entry for managing a dummy file, and the last logical block may be reserved as a space managed by the dummy file. Absent. With this configuration, the dummy files DUMMY1. The logical block number that is the smallest logical block number in the Allocation Descriptor of the File Entry that manages the DAT or the logical block number in which the File Entry itself of the dummy file is recorded is the top position of the continuous area secured, and the largest logical block Conversely, the number becomes 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 applications for recording AV data. First, the area is divided into a file system management information area, an application management information area, and a data area for management. The file system management information area contains basic management information in the UDF file system, such as Space Bitmap Descriptor (SBD), File Set Descriptor (FSD), Terminating Descriptor (TD), and File Entry (FE) of a directory defined by the AV application. ) And File Identifier Descriptor (FID), which is pointer information to File Entry that manages files and directories defined in the directory. In the example of this figure, a ROOT directory, an AVMAN directory for recording AV data management information, a File Entry for managing an AVDAT directory for recording AV data, and a File Identifier Descriptor (FID) of a file defined in each directory Is recorded. Then, the dummy file LOGI. DMY manages an unused portion in the file system management information area.

  The application management information area is an area where AV application management information such as management information for reproducing AV data is recorded. In this area, AVINFO1. DAT and AVINFO2. The DAT is recorded, and the corresponding File Entry and the actual data are recorded on the disc. Similarly 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, the disk appears as a directory hierarchy as shown in FIG.

  In the data area, AV1. DAT and AV2. DAT is recorded, and corresponding File Entry and its substance are recorded on the disc. In the example of this figure, as for the data area, the area of the data area is not secured by the dummy file, but the area may be secured by defining the dummy file as needed.

  As described above, the unused portion of the file system management information area is stored in the dummy file LOGI. Unused portions of the application management information area are managed by the dummy file APPL. It is managed by DMY, and is treated as managing the free area of the corresponding area for the AV application using these 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 the files were recorded with no free space. This is equivalent to securing an area. Therefore, no data is written in these areas.

  At this time, since it is difficult to delete the management information of the directory and AV data used by the AV application from the PC application, write protection may be set as an attribute of these files and directories. That is, the PC application can only write to the free area of the data area. In addition, since it is not necessary to delete the dummy file itself, a write prohibition attribute may be set similarly. In addition, the dummy file may have a hidden file attribute set so as to be invisible from the PC application. 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 managing the free space. Things are also possible.

FIG. 1 is a block diagram illustrating a configuration of a disk device according to an embodiment of the present invention. FIG. 9 is an explanatory diagram showing a state where an area is secured by a dummy file in the embodiment of the area management method of the present invention. It is an explanatory view showing a situation of a dummy file when a file is deleted in an embodiment of an area management method of the present invention. FIG. 6 is an explanatory diagram showing a relationship of UDF management information in the embodiment of the area management method of the present invention. 6 is a flowchart illustrating a flow of a process for securing a continuous area in the embodiment of the area management method of the present invention. 9 is a flowchart showing a flow of processing when creating a file in a continuous area secured in the embodiment of the area management method of the present invention. 9 is a flowchart showing a flow of processing when there is an update accompanied by a change in the size of a file in a continuous area secured in the embodiment of the area management method of the present invention. 9 is a flowchart showing a flow of processing when deleting a file in a continuous area secured in the embodiment of the area management method of the present invention. 9 is a flowchart showing a flow of processing when expanding a continuous area secured in the embodiment of the area management method of the present invention. It is an explanatory view showing an example at the time of expanding the continuous area secured in the embodiment of the area management method of the present invention. FIG. 11 is an explanatory diagram showing a state where a dummy file in an area always manages the last logical block in the embodiment of the area management method of the present invention. FIG. 9 is an explanatory diagram showing a state in which a dummy file in an area always manages the first and last logical blocks in the embodiment of the area management method of the present invention. FIG. 11 is an explanatory diagram showing a state where a dummy file in an area always manages the last logical block and a file entry of the dummy file is arranged in a first logical block in the embodiment of the area management method of the present invention. It is explanatory drawing which shows the example of actual application in embodiment of the area management method of this invention. FIG. 13 is an explanatory diagram showing a directory hierarchy of the example of FIG. 12 in the embodiment of the area management method of the present invention. FIG. 11 is an explanatory diagram of how a partition is secured in a conventional technique. FIG. 11 is an explanatory diagram of a state of securing an area using a file for recording position information of the area in the related art. FIG. 11 is an explanatory diagram of a state in which an area is secured by a dummy file in file units in the related art.

Explanation of reference numerals

Reference Signs List 1 data input / output unit 2 data processing unit 3 memory 4 system control unit 5 disk control unit 6 disk

Claims (5)

In a recording apparatus including a recording medium and recording control means for managing input / output of data to / from the recording medium, a file which secures at least one or more areas in the recording medium and manages a free area of each area with a dummy file. Management method,
A file management method for writing a file in the area, writing the file on a dummy file in the area, and updating the size of the dummy file to the size of a free area in the area.   The file management method according to claim 1, wherein each of the dummy files can be written only by a predetermined application.   3. The file management method according to claim 1, wherein each of the dummy files can be written only in a predetermined file type.   4. The file management method according to claim 1, wherein the last end of each area is always constituted by a dummy block.   5. The file management method according to claim 1, wherein a leading end and a trailing end of each area are always constituted by dummy blocks.

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