Abstract:
A recording device control apparatus includes a reception unit operable to receive transfer requests and a transfer request specification unit operable to perform transfer criterion judgment processing and same-area judgment processing. When a targeted transfer request fulfills a condition of a negative judgment result in both processes, the apparatus specifies the related data of a targeted transfer request as a transfer target. The same-area judgment process is for judging whether or not a transfer request that has area information identical to area information included in the targeted transfer request was received before the targeted transfer request was received. Furthermore, the apparatus includes a transfer unit operable to transfer the data specified by the transfer request specification unit. By transferring data to the same area in the order specified by the transfer specification unit, inconsistencies are avoided in the data in the recording device control apparatus.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is the National Stage of International Application No. PCT/JP2004/018915, filed on Dec. 17, 2004. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a recording device control apparatus, and in particular to a technique for controlling transfer of data based on transfer requests successively issued by application programs (hereinafter called “applications”) to transfer data to a single recording device. 
     2. Description of the Related Art 
     Digital recorders of recent times are capable of processing a plurality of read and write requests with respect to one recording device. 
     Take for example a case in which television program data is recorded to a hard disk at the same time as data recorded on a DVD (Digital Versatile Disc) is dubbed to the same hard disk. When the file system receives respective write requests from the recording application and the dubbing application, write processing is performed in the following way. 
     The file system, which holds management information such as file data location information and free-block information, sends file data and management information write requests to the device driver so that synchronization of data and management information written to the hard disk can be achieved. 
     The device driver writes recording and dubbing data and data of management information to the hard disk in the order requested by the file system. 
     In this way, even if respective management information of the recording data and the dubbing data is recorded to the same area, inconsistencies in the management information and the like can be avoided as long as the data is written to the device driver in the order sent from file system. 
     However, the following problem may occur when writing the recording data. Because the television program data is sent and written to the buffer at a fixed transmission bit rate, if there is a delay in writing from the buffer to the hard disk, the buffer capacity may become full with television program data and recording thereof may fail. In view of this problem, a control apparatus has been disclosed for prioritively writing data relating to write requests for recording, where writing to the hard disk cannot be delayed (see Japanese Laid Open Patent Application No. H10-275059, for example). 
     BRIEF SUMMARY OF THE INVENTION 
     Problem to be Solved by the Present Invention 
     However, when this control apparatus is used, inconsistencies may occur in data of the management information or the like because the device driver does not write data to the hard disk in the order received from the file system. 
     Effects of the Invention 
     The present invention has a purpose of providing a recording device control apparatus that controls transfer of data relating to transfer requests so that inconsistencies are avoided in data of management information and the like when a transfer order is changed in order to transfer specific data according to priority. 
     The stated object is achieved by a recording device control apparatus that successively receives transfer requests and controls transfer of data relating to the transfer requests to and from a recording device, each transfer request includes (i) area information that shows an area that is a transfer destination or a transfer source in the recording device and (ii) type information for specifying a transfer data type. The recording device control apparatus includes a reception unit operable to receive the transfer requests, and a transfer request specification unit operable to perform transfer criterion judgment processing and same-area judgment processing with respect to each of specification target requests which are received transfer requests whose related data has not been transferred. The transfer request specification unit is also operable, when a targeted transfer request fulfills a condition of a negative judgment result in both of the processing, specify the related data of the targeted transfer request as a transfer target. The transfer criterion judgment processing is for judging whether or not the targeted transfer request is a transfer-withhold target, based on a predetermined transfer criterion that defines a transfer order for the targeted transfer request and one or more transfer requests having different type information to the targeted transfer request, and the same-area judgment processing is for judging whether or not a transfer request that has area information identical to area information included in the targeted transfer request was received before the targeted transfer request was received. Moreover, the recording device control apparatus includes a transfer unit operable to transfer the data specified by the transfer request specification unit. 
     According to the stated structure, for example, in a recording device control apparatus that records file management information in a specific area in the recording device, when the file system receives a transfer request for dubbing data and a transfer request for recording or the like of which transfer of data cannot be delayed, the file system reads the management information in the recording device to the memory, determines the write location of the recording and dubbing data and successively updates the management information in the memory recording device. The control apparatus also sends each write request to the device driver such that synchronization of the data and management information is achieved in the recording device. 
     The device driver is able to write, according to priority, the recording data according to transfer criterion judgment processing, and write the management information so that it is in the order that it was sent by the file system according to the same-area judgment processing. This prevents management information that was updated later by the file system from being overwritten with management information that was updated earlier. Furthermore, when transfer requests are issued for writing data to and reading data from a same sector, reading of data from a sector to which data has not yet been written can be prevented. 
     Furthermore, the recording device control apparatus may have, in the recording device, a management area for storing management information that is for managing data locations in the recording device. The transfer request specification unit may further perform request judgment processing which is for, when the targeted transfer request is a transfer request with respect to the management area, judging whether or not a transfer request having identical type information to the targeted transfer request was received before the targeted transfer request was received. When the targeted transfer request fulfills the condition and, in addition, a judgment result of the request judgment processing is negative, the transfer request specification unit may specify transfer data relating to the transfer request as data to be transferred. 
     According to the stated structure, for example, if management information for recording files and management information for dubbing files is stored in a same area, the management information is updated in the order in which it was issued by the file system. This prevents management information that should be updated later from being updated before management information that should be updated earlier, and management information that should be updated later from being overwritten with management information that should be updated earlier. Furthermore, since management information is not written before recording and dubbing data relating to the management information, inconsistencies such as files being unable to be recognized by the file system are prevented. 
     Furthermore, the transfer request specification unit may further perform specification exclusion processing when the targeted transfer request, having fulfilled the condition and the judgment result of the request judgment processing being negative, is with respect to management information. Moreover, when a transfer request that has not been transferred and, with respect to the management area, was received after the targeted transfer request was received, the specification exclusion process is for excluding the targeted transfer request from being a specification target request without specifying the targeted transfer request as a transfer target. 
     According to the stated structure, for example, if management information for recording data and dubbing data are stored in a same management area in the recording device, when the device driver receives write requests for recording and dubbing data and write requests for a plurality of pieces of management information, part of the contents of earlier management information among the write requests for management information are duplicated in the management information for which the write request was received last. For this reason, if recording data and dubbing data relating to the management information received last are transferred before the management information received last, the time required to write the management information can be reduced by omitting transfer of the duplicated part of the management information and processing the management information write request received last. 
     Furthermore, the reception unit may further receive an omission instruction that instructs that transfer of redundant management information is to be omitted, and the transfer request specification unit may perform the specification exclusion processing only when the reception unit has received the omission instruction. 
     According to the stated structure, for example, only when the file system issues an instruction to omit processing of a write request whose management information is a duplicate of management information of another write request, the device driver can omit processing of the write request with the duplicate management information. 
     Therefore, when placing importance on data integrity, all management information update requests issued from the file system are processed unless an instruction for omission of processing of a management information write request is sent to the device driver, and, the possibility that data that has already been written will be rendered useless if a power cut or the like occurs is low. 
     Furthermore, the predetermined criterion may be predetermined priority levels that show a transfer order for transfer data according to the type information, and the transfer criterion judgment processing may be for judging that the targeted transfer request is a transfer-withhold target when a priority level of a transfer request that includes different type information to the type information of the processing-target transfer request is higher than the priority level of the processing-target transfer request. 
     According to the stated structure, transfer priority levels can be determined in advance according to the types of the data to be transferred, and the device driver can transfer data to the recording device in the order from the data relating to transfer requests having high priority. 
     Furthermore, the present invention is a recording device control apparatus that successively receives transfer requests and controls transfer of data relating to the transfer requests to and from a recording device. Each transfer request includes (i) area information that indicates an area that is a transfer destination or a transfer source in the recording device, and (ii) type information for specifying a type of transfer data. The recording device control apparatus includes a reception unit operable to receive the transfer requests and a transfer request specification unit operable to perform transfer criterion judgment processing, management information judgment processing, and request judgment processing with respect to each of specification target requests which are received transfer requests whose related data has not been transferred. When a targeted transfer request fulfills a condition of a negative judgment result in all of the processing, the transfer request specification unit specifies the related data of the targeted transfer request as a transfer target, the transfer criterion judgment processing being for judging whether or not the targeted transfer request is a transfer-withhold target, based on a predetermined transfer criterion that defines a transfer order for the target transfer request and one or more transfer requests having different type information to the targeted transfer request. The management information judgment processing is for, when the targeted transfer request is a transfer request for management information, judging whether or not a transfer request for transferring management information was received before the targeted transfer request was received, and the request judgment processing being for judging whether or not a transfer request having identical type information to the targeted transfer request was received before the targeted transfer request was received. Moreover, the recording device control apparatus includes a transfer unit operable to transfer the data specified by the transfer request specification unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a structural diagram of a recording device control apparatus  1  relating to a first embodiment of the present invention; 
         FIG. 2  shows an example of a transfer request list held by a queue management unit  120 ; 
         FIGS. 3A to 3C  show examples of structure and content of a management information table; 
         FIGS. 4A and 4B  show examples of structure and content of priority level information and a transfer request table; and 
         FIG. 5  is a flowchart showing transfer request determination processing by a transfer request determination unit  130 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following describes a recording device control apparatus relating to a first embodiment of the present invention. 
     &lt;Overview&gt; 
     The recording device control apparatus of the first embodiment records a plurality of pieces of file data to a single recording device, and records management information of recorded files to a specific area of the recording device. This management information is managed by one file system. 
     Furthermore, the file system receives data indicating a request to transfer data (hereinafter referred to as a “transfer request”) from an application, determines which file the data relating to the received transfer request (hereinafter referred to as “transfer target data”) belongs to, designates an area in the recording device that is a transfer destination or a transfer origin, and sends the transfer request to the device driver after attaching priority information which prescribes a transfer order in accordance with the type of the transfer target data. 
     On receiving transfer requests that have priority information attached thereto from the file system, the device driver holds the transfer requests in a queue in the order in which they were received. When transfer requests are held in the queue, the device driver determines a transfer request for transferring data to a designated area in the recording device, and transfers the transfer target data to the recording device. 
     Here, the transfer requests for management information are transfer requests with respect to a same area. A same area may be a management area group in which each sector is a different management area, or may be one sector. In the first embodiment, a case of the management information being stored in one sector is described. 
     &lt;Structure&gt; 
       FIG. 1  is a functional block diagram of a recording device control apparatus  1  of the present invention. 
     The recording device control apparatus  1  is composed of a file system  400 , a transfer control unit  100 , and a recording device  200 . 
     Specifically, the recording device control apparatus  1  is a computer system implemented using a microprocessor, a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk device, and the like. Computer programs are stored in the ROM or the hard disk device. 
     The functions of the units of the recording device control apparatus  1  shown in  FIG. 1  are realized by the microprocessor executing the computer programs. Furthermore, storage of information is implemented using the RAM and the hard disk device. 
     The following describes each unit of the recording device control apparatus  1 . 
     The file system  400  has functions of receiving transfer requests from applications to transfer data to the recording device  400 , and, after adding information to the transfer requests, sending the transfer requests to a request reception unit  110 . Here, the information that the file system  400  adds to each transfer request includes a file handle of transfer target data, an access type such as read or write, a data type showing whether or not the transfer target data is management information, and a sector location in the recording device  200 . 
     The following describes one example of information included in a transfer request when a request to write data to the recording device  200  is received from an application for recording a television program or a dubbing application. 
     The file system  400  determines whether the transfer data is recording data or dubbing data according to the file handle of the command issued from the application. When a write command has been issued by the application, the file system  400  treats this as a write request for recording data or dubbing data, and when a sync command has been issued, the file system  400  treats this as a management information write request for writing management information so that data written to the recording device  200  is recognizable by the file system  400 . The sector location in the recording device  200  for the transfer target data is determined by the file system  400  allocating a sector of a free block based on the management information. 
     A transfer control unit  100  has functions of holding transfer requests received from the file system  400 , determining, from among the held transfer requests, a transfer request for transferring data to the recording device  200 , and transferring the selected transfer target data to the recording device  200 . The transfer control unit  100  includes the request reception unit  110 , a queue management unit  120 , a transfer request determination unit  130 , and a transfer unit  140 . 
     The following describes each unit of the transfer control unit  100 . 
     The request reception unit  110  has the functions of receiving transfer requests from the file system  400 , and sending the received transfer requests to the queue management unit  120  in the received order. 
     The queue management unit  120  has the functions of holding the transfer requests connected in a list structure in the order in which they are received from the request reception unit  110 , and on receiving information of a transfer request that is a transfer target from a request judgment unit  133  (described later), deleting the corresponding transfer request data from the transfer request list. 
     The transfer request determination unit  130  has a function of selecting a transfer target from among transfer requests in the transfer request list in the queue management unit  120 . The determination unit  130  is composed of a transfer criterion judgment unit  131 , a management information judgment unit  132 , and a request judgment unit  133 . The following describes each of these units. 
     The transfer criterion judgment unit  131  has functions of focusing on one of the transfer requests connected to the transfer request list in the queue management unit  120 , judging whether or not the transfer priority level of the file handle of the corresponding transfer target data is higher than the priority level of file handles of other transfer target data connected in the transfer request list in the queue management unit  120 , and sending a result of the judgment to the management information judgment unit  132 . 
     The management information judgment unit  132  has a function of, when the transfer target data being focused on connected in the transfer request list in the queue management unit  120  is management information, judging whether or not a transfer request exists for management information that is before the focus transfer request, and sending a result of the judgment to the request judgment unit  133 . 
     The request judgment unit  133  has a function of sending, to the transfer unit  140 , information showing the focus transfer request, when no transfer request that has a file handle identical to the transfer target data of the focus transfer request is before the focus transfer request in the transfer request list of the queue management unit  120 . 
     The transfer unit  140  has functions of receiving information of the transfer request that is the transfer target from the request judgment unit  140 , and transferring, to the recording device  200 , the transfer target data of the transfer target, the transfer target data including information showing the transfer destination. 
     The recording device  200  is a recording medium such as a hard disk or a DVD. 
     &lt;Data&gt; 
       FIG. 2  shows an example of a transfer request list held by the queue management unit  120 . 
     The transfer request list is read by the transfer request determination unit  130 , and updated by the queue management unit  120  when a transfer request has been selected to be a transfer target. 
     A head  500  is a head pointer. The transfer requests are connected according to a list structure in the order indicated by arrows  601  to  605 . Each transfer request is composed of a file handle, a data type, an access type, and so on. 
     Here, data type F shows file data and M shows management information. Access type W shows a write. This data corresponds to transfer requests in a transfer request table  60  in  FIG. 4B  (described later). 
     Furthermore, the transfer request for management information having an identifier  3  is a write request to write management information relating to transfer target data having an identifier  1  when a sync command of a file handle A was issued. The transfer request for management information having an identifier  5  is management information when a sync command of a file handle A was issued, to which has been added management information relating to transfer target data having identifiers  2  and  4 , respectively. 
     The following describes  FIGS. 3A ,  3 B, and  3 C. 
       FIGS. 3A ,  3 B, and  3 C each show management information stored in the recording device  200 . 
     The management information is composed of free block information made up of i nodes  21  and usage states  24 , i node information that corresponds i nodes and sectors  23 , and free block information made up of blocks  22  in the recording device and usage states  24 . 
     Here, the file system  400  corresponds files in the recording device  200  with i nodes that are a data structure holding control information relating to files, and is able to uniquely identify each file by the corresponding i node. 
     Furthermore, the management information is read to the memory by the file system  400  when a transfer request has been issued by the application, and the transfer unit  140  updates the management information in the recording device  200 . 
     In each of  FIGS. 3A ,  3 B, and  3 C, i nodes  21  are i node numbers in correspondence with files recorded in the recording device  200 , the file system  400  managing i nodes  1  to N. The usage states  24  express whether or not i node numbers and block numbers are in use, expressing that an i node number or block number is in use, and 1 expressing that an i node number or block number is not in use. Sector locations  23  show sector locations in the recording device  200  where data of a file corresponding to an i node  21  is stored. 
     The following describes the data in each of  FIGS. 3A ,  3 B, and  3   c.    
       FIG. 3A  shows data of management information before the file system  400  determines the sector location of the transfer target data of the transfer request list shown in  FIG. 2 . 
     On receiving, from the application, a transfer request connected in the transfer request list of  FIG. 2  before the sector location of the transfer target data is determined, the file system  400  reads the management information  20  shown in  FIG. 3A . When a file does not exist for transfer target data, the file system  400  determines an i node based on the free i node information in  FIG. 3A , determines a transfer destination block for the transfer target data based on the free block information, determines the sector location of the transfer destination based on the i node information, and updates the management information in the memory. 
       FIG. 3B  shows management information when a piece of transfer target data having an identifier  3  in the transfer request list in  FIG. 2  is written to the recording device  200 . 
     As described with respect to  FIG. 2 , the management information that is the transfer target information having the identifier  3  relates to the transfer target data having the identifier  1  of the file handle A.  FIG. 3B  shows where the transfer target data having the identifier  1  is stored in the recording device  200 . The i node showing the identifier  1  of the file handle A is N 1 , the block in which the piece of transfer target data having the identifier  1  is stored is K 1 , and the transfer target data having the identifier  1  is written in the sector  100 . 
     The following describes  FIG. 3C . 
       FIG. 3C  shows management information when the piece of target data having the identifier  5  in the transfer request list in  FIG. 2  is written to the recording device  200 . 
     As with  FIG. 3B , the management information that is the transfer target data of the identifier  5  relates to the transfer data having the identifier  2  and the transfer data having the identifier  4  of the file handle B, and  FIG. 3C  is the management information of  FIG. 3B  to which information storing the transfer target data information having the identifiers  2  and  4  has been added. 
     The i node that shows the file handle B of the identifiers  2  and  4  is N 2 , the block in which the transfer target data of the identifiers  2  and  4  is stored is K 2 , and these transfer target data are stored in sectors  200  and  201 , respectively. 
     The following describes  FIGS. 4A and 4B . 
       FIG. 4A  shows an example of the structure and content of a priority level information table  50 . As shown in  FIG. 4A , the priority level information table  50  is composed of file handles  51  and priority levels  52 , and is set depending on the transfer target data. 
     Here, each file handle  51  is information expressing a file belonging to data relating to a transfer request issued by the application. 
     Each priority level  52  shows the priority level of a write to the recording device  200 . The file system  400  processes according to priority write requests of data whose file handle has a priority level with a high numeric value. 
     Furthermore,  FIG. 4B  shows an example of the structure and contents of a transfer request table  60 . The transfer requests correspond to the transfer requests connected in the transfer request list shown in  FIG. 2 . 
     As shown in  FIG. 4B , the transfer request table  60  is composed of identifiers  61 , file handles  62 , data types  63 , access types  64 , sector locations  65 , memory locations  66 , and sizes  67 . The file system  400  determines the sector location of the transfer destination or transfer origin of the transfer target data and sends this information to the request reception unit  110 , and the information is read by the transfer request determination unit  130 . 
     Each identifier  61  is information showing an identity of a transfer request. 
     Each file handle  62  is information showing a file of data relating to a transfer request, and when the data relating to the transfer request is management information, the file handle  62  is a file handle belonging to an i node. 
     Each data type  63  shows whether a piece of transfer target data is management information or is file data other than management information. 
     Each access type  64  shows a type of access to the recording device  200 . For example, the access type  64  is “read” in the case of a read command being sent from the application, and “write” in the case of a write command being sent from the application. 
     Each sector location  65  shows a sector location in the recording device  200 . When the access type  64  of a transfer request is “write”, data relating to the transfer is recorded in the sector location, and when the access type  64  is “read”, data is read from the sector location. 
     Note that the file system  400  pre-determines that management information relating to file data of file handles A and B are all to be stored in a sector  500  of the recording device  200 . 
     Each memory location  66  shows an address location in the memory of the recording device control apparatus  1 . When the access type  64  of a transfer request is “write”, data in the memory location  66  is written to the recording device  200 , and when the access type  64  is “read”, data is read from the memory location  66 . 
     Each size  67  shows the size of data relating to a transfer request. 
     &lt;Operations&gt; 
     The file system  400  receives write command and sync command transfer requests issued by the application, determines the file handle, the data type and the access type of each transfer request, reads the management information in the recording device  200  to the memory to determine the sector of transfer target data based on the management information, and sends transfer requests ( FIG. 4B ) that include information of the transfer request memory location and the transfer target data size, to the request reception unit  110  in the order in which they were received from the application. 
     The request reception unit  110  sends the transfer requests to the queue management unit  120  in the order they were received from the file system  400 , and the queue management unit  120  connects the transfer requests to the transfer request list ( FIG. 2 ) in the order in which they were received. 
       FIG. 5  shows the flow of operations for the transfer request determination unit  130 , which is the characteristic part of the present invention, to set a transfer request connected to the aforementioned transfer request list as a transfer target, and for the transfer unit  140  to transfer the transfer target data to the recording device  200 . 
     Note that the cycle of the operations is determined according to control demands for transferring data according to priority. For instance, if high priority data must be transmitted in a fixed period, the operations for the transfer requests that have been sent from the file system  400  and are being held by the queue management unit  120  are performed in that fixed period. 
     The following describes the flow shown in the drawing. 
     First, on receiving transfer requests from the file system  400 , the request reception unit  110  sends the transfer requests to the queue management unit  120  in the order in which they were received. The queue management unit  120  receives the transfer requests sent from the request reception unit  110 , and holds the transfer request list in which the transfer requests are connected by pointers. 
     The transfer request determination unit  130  focuses on the transfer request held at the head of the transfer request list in the queue management unit  120  (step S 01 ). 
     The transfer criterion judgment unit  131  reads the transfer request table  60 , and judges whether or not any transfer requests in the transfer request list in the queue management unit  120  have a different file handle compared to the file handle  62  of the transfer request focused on at step S 01  (hereinafter called the “focus transfer request”) (step S 02 ). 
     When the transfer criterion judgment unit  131  judges in the affirmative (step S 02 :Y), the transfer criterion judgment unit  131  reads the priority level table  50  ( FIG. 4A ), and judges whether the transfer request or requests that have the different file handle have higher transfer priority than the focus transfer request (step S 03 ). 
     When the transfer criterion judgment unit  131  judges that the file handle of the focus transfer request has higher priority at step S 03  (step S 03 :N), the transfer criterion judgment unit  131  sends information showing the judgment result to the management information judgment unit  132 . 
     Next, the file management information judgment unit  132  reads the data type  63  from the transfer request table  60 , and judges whether or not the focus transfer request is a management information transfer request (step S 05 ). 
     When the management information judgment unit  132  judges in the negative at step S 05  (step S 05 :N), the management information judgment unit  132  sends information showing the judgment result to the request judgment unit  133 . 
     On receiving a negative judgment result from the management information judgment unit  132 , the request judgment unit  133  judges whether any transfer requests that are connected to the queue management unit  120  before the focus transfer request have the same file handle as the focus transfer request (step S 08 ). 
     When the request judgment unit  133  judges in the negative at step S 08  (step S 08 :N), the request judgment unit  133  sends information showing the focus transfer request, to the queue management unit  120  and the transfer unit  140 . On receiving the information, if the data of the transfer request relating to the received information is management information, the transfer unit  140  reads the data of the management information stored in the memory location  66  and having the corresponding identifier  61  from the transfer request table  60 , and updates the management information of the designated sector location in the recording device  200  (step S 10 ). The queue management unit  120  deletes, from the transfer request list, the transfer request relating to the information received from the request judgment unit  133 , and updates the transfer request list (step S 11 ). 
     Furthermore, when the transfer criterion judgment unit  131  judges in the negative at step S 02  (step S 02 :N), the transfer criterion judgment unit  131  sends information showing the judgment result to the management information judgment unit  132 , and operations move to step S 05 . 
     Furthermore, when the transfer criterion judgment unit  131  judges at step S 03  that the file handle of the focus transfer request has lower priority (step S 03 :N), transfer of the focus transfer request is withheld, the transfer request following the focus transfer request is then focused on (step S 04 ), and step S 02  is performed with respect to the transfer request that is now being focused on. 
     Furthermore, at step S 05 , when the management information judgment unit  132  judges that the transfer target data of the focus transfer request is management information (step S 05 :Y), the management information judgment unit  132  judges whether or not there are any transfer requests connected before the focus transfer request in the queue management unit  120  whose data relating to transfer is management information (step S 06 ). 
     When the management information judgment unit  132  judges in the negative at step S 06  (step S 06 :N), the management information judgment unit  132  sends information showing the judgment result to the request judgment unit  133 , and step S 08  is performed. Furthermore, when the management information judgment unit  132  judges in the affirmative at step S 06  (step S 06 :Y), the management information judgment unit  132  focuses on the closest transfer request, to the focus transfer request, that is for management information (step S 07 ), and step S 06  is performed. 
     Furthermore, when the request judgment unit  133  judges in the affirmative at step S 08  (step S 08 :Y), the request judgment unit  133  focuses on transfer request closest to the focus transfer request (step S 09 ), and step S 08  is performed. 
     Next, the transfer request determination unit  130  repeatedly performs the described processing (step S 01  to step S 11 ), with respect to the transfer requests held in the queue management unit  120 , until no transfer requests remain connected in the transfer list of the queue management unit  120 . 
     &lt;Operation Example&gt; 
     The following describes operations of the transfer request determination unit  130  and the transfer unit  140  using the example in  FIG. 2  following the described operations ( FIG. 5 ), and with use of  FIG. 3  and  FIG. 4 . 
     At step S 01  of  FIG. 5 , the transfer request determination unit  130  focuses on the transfer request shown by the head  500 . 
     The transfer criterion judgment unit  131  judges whether or not there are any transfer requests having a file handle that is different than the file handle A in the transfer request list in the queue management unit  120  (step S 02 ). 
     On judging that there are transfer requests having a file handle B in the transfer request list ( FIG. 2 ) (step S 02 :Y), the transfer criterion judgment unit  131  reads the priority level table  50  ( FIG. 4A ), judges that the transfer requests having the file handle B have higher priority (step S 03 :Y), and focuses on the transfer request  520  having the identifier  2  that follows the transfer request  510  having the identifier  1  (step S 04 ). 
     As above, the transfer criterion judgment unit  131  performs the judgments of step S 02  and step S 03  for the transfer request  520  that has the identifier  2  (step S 02 :Y, step S 03 :N), and sends information showing the judgment results to the management information judgment unit  132 . 
     Next, the management information judgment unit  132  reads the transfer request table  60  ( FIG. 4B ), judges that the data type  63  of the transfer request  520  having the identifier  2  is file data (step S 05 :N), and sends information showing the result of the judgment to the request judgment unit  133 . 
     On judging that there are no transfer requests having the file handle B before the transfer request having the identifier  2  in the transfer request list (step S 08 :N), the request judgment unit  133  sends the judgment result and the transfer request  520  that has the identifier  2  to the queue management unit  120  and the transfer unit unit  140 . 
     The transfer unit  140  reads the file data of the transfer request  520  having the identifier  2  from the memory location  66  based on the transfer request table  60 , and transfers the file data to the recording device  200  to be stored in the sector location  200  in the recording device  200 . 
     The queue management unit  120  deletes the transfer request  520  having the identifier  2  from the transfer request list, and updates the transfer request list so that the pointer  511  of the transfer request  510  having the identifier  1  indicates the transfer request  530  having the identifier  3  (step S 11 ). 
     Next, the transfer criterion judgment unit  131  performs the described judgment in order starting from the transfer request  510  that is indicated by the head  500 , the transfer request  540  having the identifier  4  consequently becoming the focus request. 
     The management information judgment unit  132  and the request judgment unit  133  perform the judgments from step S 05  to step S 08  with respect to the transfer request  540  having the identifier  4 . The request judgment unit  133  determines the transfer request  540  to be the transfer target (step S 05 :N, step S 08 :N), and the transfer unit  140  transfers the related transfer target data to the sector  201  of the recording device  200  (step S 10 ). 
     The queue management unit  120  deletes the transfer request having the identifier  4  from the transfer request list, and updates the list so that the pointer  531  of the transfer request  530  having the identifier  3  indicates the transfer request  550  having the identifier  5  (step S 11 ). 
     Once again, the transfer criterion judgment unit  131  performs the judgments at step S 02  to step S 03  in order from the transfer request  510  having the identifier  1 , and focuses on the transfer request  550  having the identifier  5 . 
     The management information judgment unit  132  reads the transfer request table  60 , and judges that the data type  63  of the transfer request  550  having the identifier  5  is management information, and that the transfer request  530  having the identifier  3  and whose data type  63  is management information is before the transfer request  550  having the identifier  5  in the transfer request list (step S 02 :Y, step S 03 :Y, step S 02 :Y, step S 03 :N, step S 05 :Y, step S 06 :Y, step S 06 :N, and step S 08 :N). 
     The management information judgment unit  132  focuses on the transfer request  530  having the identifier  3  (step S 07 ), judges that there are no management information transfer requests before the transfer request  530  (step S 06 :N), and sends information showing the judgment result to the request judgment unit  133 . 
     The request judgment unit  133  reads the transfer request table  60 , judges that the transfer request  510  having the file handle A is before the transfer request  530  having the identifier  3  in the transfer request list (step S 08 :Y), and focuses on the transfer request  510  having the identifier  1  (step S 09 ). Furthermore, the request judgment unit  133  judges that there are no transfer requests having the file handle A before the transfer request  510  having the identifier  1  (step S 08 :N), and sends information showing the transfer request  510  having the identifier  1  to the transfer unit  140  and the queue management unit  120 . The transfer unit  140  and the queue management unit  120  perform step S 10  and step S 11 . 
     As a result of the described processing, the transfer request having the identifier  3  and the identifier  5  are in a state of being connected in the transfer request list of the queue management unit  140 , and when step S 01  to step S 08  are performed with respect to these transfer requests, the transfer request having the identifier  3  becomes the transfer target (step S 02 :N, step S 05 :Y, step S 06 :Y, and step S 08 :N). 
     The transfer unit  140  transfers the management information stored in the memory location  66  of the identifier  3  in the transfer request table  60  ( FIG. 4B ) to the sector location  500  in the recording device  200  (step S 10 ). As a result of the transfer, the data of the management information in the recording device  200  changes from that in  FIG. 3A  to that in  FIG. 3B . Furthermore, the queue management unit  120  deletes the transfer request  530  from the transfer request list ( FIG. 2 ) to update the transfer request list (step S 11 ). 
     Steps S 01  to S 08  are performed in the same way with respect to the transfer request having the identifier  5 , and when the transfer unit  140  transfers the management information that is the transfer target data to the sector location  500  in the recording device  200 , the management information in the recording device  200  changes from that in  FIG. 3B  to that in  FIG. 3C . 
     As a result of processing the transfer requests in the transfer request list of  FIG. 2  in this way, transfers are made in the following order: identifier  2 , identifier  4 , identifier  1 , identifier  3 , identifier  5 . 
     &lt;Supplementary Remarks&gt; 
     Although the recording device control apparatus relating to the present invention has been described based on the first embodiment, modifications such as the following may be made, and the present invention is not limited to the recording device control apparatus shown in the described first embodiment. 
     (1) In the first embodiment, the free i node information, the inode information and the free block information, which are management information, are described as being stored in continuous areas in the same sector. However, in other embodiments, it is possible to store the pieces of information in the same sector but not in continuous areas, or in different sectors. 
     In such a case, on receiving a sync command from the application, the file system  400  sends, to the request reception unit  110 , a write request that designates a write location of the free block information, the i node information and the free i node information, and the queue management unit  120  connects a transfer request for management information that includes this information to the transfer request list. When transferring the management information, the transfer unit  140  transfers the information included in the transfer request to the respective sectors in order of the free block information, the i node information, and the free i node information. 
     (2) In the first embodiment, a description is given only of a case in which data recorded in the same area is management data, and at step S 05  a judgment is made as to whether the focus transfer request is for management information. However, in other embodiments, this judgment is not limited to being made with respect to management information, and may be a judgment for determining whether or not there is a transfer request with respect to the same area before the focus transfer request. In this case, if there is a transfer request with respect to the same area, the focus is moved to the closest transfer request to the focus transfer request. This can be applied to cases in which management information is stored in the same area as described in the first embodiment, and to cases in which writing and reading are performed with respect to the same area. 
     (3) In the first embodiment, management information transfer requests are described as belonging to file handles of sync commands issued by the application. However, in other embodiments, the file system may judge in advance whether or not the file handle of the management information is A or B, or another file handle. When this is the case, the file system provides a link from the management information transfer request to the transfer request of file data having an identical file handle to the file handle of sync command issued for the management information transfer request. For example, when all pieces of management information belong to the file handle B, the request judgment unit  133  may judge whether or not there is a file data transfer request that is linked to the management information, and if there is a linked transfer request, transfer the data of the transfer request to which the link is made. 
     Furthermore, it is not necessary for the management information transfer request to belong to either of the file handles. When this is the case, management information transfer requests may all be treated as transfer requests that do not have file handles, and when the management information is transferred when transfer processing is performed in accordance with the priority levels, the management information transfer requests are processed in the order in which they were issued by the file system. 
     (4) In the first embodiment, in the case of the transfer request list in  FIG. 2  for example, the management information having the identifier  3  is transferred before the management information having the identifier  5 . However, when transfer target data having the identifier  1 , which is before the transfer request having the identifier  5 , is transferred, transfer of the management information having the identifier  3  may be omitted because the information relating to the file data having the identifier  1  is also included in the management information having the identifier  5 . In this case, the queue management unit  120  deletes the transfer request for the management information having the identifier  3  from the transfer request list, and does not send the transfer request having the identifier  3  to the transfer unit  140 . 
     (5) In the first embodiment, according to a sync command issued with predetermined time intervals by the application, the transfer requests thereof are treated as management information write requests. However, in other embodiments, management information write requests may be received according to write commands. Alternatively, when a close command is issued, this may be treated as a management information write request. 
     (6) In the first embodiment, the transfer control unit  100  determines a transfer target transfer request from among transfer requests received from the file system  400 . However, in other embodiments the file system  400  may determine a transfer order by judging based on a transfer criterion shown in the flow in  FIG. 5 , and send the transfer requests to the transfer unit  140  in determined order, and the transfer unit  140  may transfer the data relating to the received transfer requests to the recoding device  200  in the received order. 
     (7) In the first embodiment, the priority levels for transfer are determined based on the file handles to which the transfer target data belongs. However, in other embodiments, the priority levels for transfer may be determined according to the application that issues the transfer requests. In this case, when issuing a transfer request, the application may attach information showing which application issued the transfer request and transfer this to the file system. This enables the file system to determine which application issued each transfer request. 
     Furthermore, requests to be transferred according to priority may be determined dynamically according to combinations of information such as priority level, request time and size. Suppose for instance that, among the transfer requests of the file handles A and B, the priority level and transfer bit rate of A is higher than B, and the transfer request time of B is earlier than the transfer request time of A. Here, when the transfer bit rate of A is maintained even if the transfer data of B is transferred before the transfer data of A, priority is given to the transfer request of B whose transfer request time is earlier than A. 
     (8) In the first embodiment, only write requests to the recording device are described. However, the invention may be applied to transfer requests for either writing or reading of data. 
     (9) In the first embodiment, the transfer request determination unit  130  judges whether or not transfer requests are transfer targets, in order from the head transfer request connected in the list structure in the queue management unit  120 . However, in other embodiments, the judgment may be made starting from any transfer request held in the queue management unit  120 . 
     (10) Furthermore, in the first embodiment, the queue management unit  120  connects transfer requests in a list structure. However, in other embodiments, the queue management unit  120  may hold the transfer requests in another structure such as an array. 
     (11) The present invention may be a computer-readable recording medium on which a computer program is recorded, such as a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, or a DVD-RAM. Furthermore, the present invention may be the aforementioned computer program conveyed over an electric communication network, a wired or wireless communication network, or a network of which the Internet is representative. 
     The recording device control apparatus of the present invention may be used in a hard disk recorder, a DVD recorder, or the like.