JP4424282B2 - File management apparatus, file management method, and program - Google Patents

Description

  The present invention relates to a file management technique capable of recovering a deleted file, and more particularly to a file management technique that enables a deleted file that is highly likely to be requested for recovery by a user to be recovered with high probability.

  Conventionally, when deleting a file created on a storage device such as a magnetic disk device, the file management information of the file requested to be deleted (including information indicating the data area to which the file is allocated) is deleted. Generally, the data area allocated to the file is released. In this method, since the data area allocated to the file requested to be deleted is immediately released, the data area can be used effectively. However, even if it is necessary to recover the deleted file, there is a problem that there is a high possibility that the file cannot be recovered because the data is overwritten.

Therefore, an identifier indicating whether or not the file has been deleted is included in the file management information, and when there is a deletion request, only the identifier in the corresponding file management information is updated to indicate that it has been deleted. Thus, a technique has been proposed in which the data area is not released, and when there is a recovery request, the identifier in the corresponding file management information is updated to one indicating non-deletion (for example, Patent Documents 1 and 2). ). In order to achieve the purpose of recovering the deleted file, it is better not to release the data area allocated to the file whose identifier has been deleted, but doing so will prevent effective use of the data area. In Patent Documents 1 and 2, when a data area is insufficient at the time of file creation, the data areas assigned to the files with the oldest deletion date and time are released in order.
JP-A-6-348555 Japanese Patent Laid-Open No. 7-334397

  In general, most of the files that are requested to be recovered are those that have not been deleted for a long time, so they can be recovered by the user by releasing them in order from the data area assigned to the files with the oldest deletion date and time. Increases the probability of recovering the requested file. However, in the conventional techniques described in Patent Documents 1 and 2, if the data area is insufficient at the time of file creation, the data area that is necessary for creating the file can be allocated to the deleted file without restriction until the data area can be secured. Because the data area that was previously released is released, there is a high possibility that recovery will be requested, and the data area assigned to the deleted file that has not passed the deletion date and time has also been released, making it impossible to recover. There is a problem of becoming.

(Object of invention)
Therefore, an object of the present invention is to enable recovery of a deleted file that is highly likely to be requested for recovery by a user with a high probability.

The first file management apparatus according to the present invention is:
A data area where files are stored;
A warranty period storage unit for storing a warranty period for the deleted file;
A protection period storage unit that stores a protection period longer than the warranty period for the deleted file;
When creating a file, an unused area in the data area to which the file has not yet been assigned and a protection period elapsed area assigned to the deleted file that has passed the protection period from the deletion date and time are transferred to the file. If the area to be allocated is secured and the area necessary for creating the file cannot be secured only with the unused area and the protection period elapsed area, the warranty period has passed since the deletion date and time, The area allocated to the file is secured from the area during the protection period allocated to the deleted file that has not passed the protection period, and if the area necessary for creating the file still cannot be secured, it is secured And an area securing means for failure.

A second file management apparatus according to the present invention is the first file management apparatus,
When the area securing unit secures an area to be allocated to the file from the protection period area, the area securing unit secures the area in order from the area allocated to the deleted file with the oldest deletion date and time.

The third file management apparatus according to the present invention is:
A data area composed of a plurality of blocks and storing files;
A warranty period storage unit for storing a warranty period for the deleted file;
A protection period storage unit that stores a protection period longer than the warranty period for the deleted file;
When creating a file, an unused block in the data area to which the file has not yet been assigned and a protection period elapsed block assigned to the deleted file that has passed the protection period from the deletion date and time are changed to the file. If the block to be allocated is secured and the block necessary for creating the file cannot be secured only with the unused block and the protection period elapsed block, the warranty period has passed since the deletion date, The block allocated to the file is secured from the blocks during the protection period allocated to the deleted file that has not passed the protection period, and if the block necessary for creating the file still cannot be secured, the block is secured And an area securing means for failure.

A fourth file management apparatus according to the present invention is the third file management apparatus,
When the area securing means secures a block to be assigned to the file from a block during the protection period, the area securing means secures the block in order from the block to which the deleted file having the oldest deletion date is assigned.

A fifth file management apparatus according to the present invention is the fourth file management apparatus,
Block management information for each block in the data area, including an identifier indicating whether or not the block is allocated to a file in use, and the date and time when the file allocated to the block is deleted A data area management unit storing block management information, and
The area securing means is configured to recognize an unused block, a protection period elapsed block, and a protection period block based on block management information stored in the data area management unit.

A sixth file management apparatus according to the present invention is the fifth file management apparatus,
There is provided a guarantee period / protection period setting means for storing the inputted guarantee period in the guarantee period storage unit and storing the inputted protection period in the protection period storage unit.

A first file management method according to the present invention includes:
A file management apparatus having a data area for storing a file, a guarantee period storage unit for storing a guarantee period for a deleted file, and a protection period storage unit for storing a protection period longer than the guarantee period for the deleted file In
When creating a file, an unused area in the data area to which the file has not yet been assigned and a protection period elapsed area assigned to the deleted file that has passed the protection period from the deletion date and time are transferred to the file. If the area to be allocated is secured and the area necessary for creating the file cannot be secured only with the unused area and the protection period elapsed area, the warranty period has passed since the deletion date and time, The area allocated to the file is secured from the area during the protection period allocated to the deleted file that has not passed the protection period, and if the area necessary for creating the file still cannot be secured, it is secured It is characterized by failure.

A second file management method according to the present invention is the first file management method,
When securing the area to be allocated to the file from the protection period area, the area is allocated in order from the area allocated to the deleted file with the oldest deletion date and time.

The first program according to the present invention is:
A computer having a data area for storing a file, a guarantee period storage unit for storing a guarantee period for a deleted file, and a protection period storage unit for storing a protection period longer than the guarantee period for the deleted file;
When creating a file, an unused area in the data area to which the file has not yet been assigned and a protection period elapsed area assigned to the deleted file that has passed the protection period from the deletion date and time are transferred to the file. If the area to be allocated is secured and the area necessary for creating the file cannot be secured only with the unused area and the protection period elapsed area, the warranty period has passed since the deletion date and time, The area allocated to the file is secured from the area during the protection period allocated to the deleted file that has not passed the protection period, and if the area necessary for creating the file still cannot be secured, it is secured It functions as an area securing means for failure.

The second program according to the present invention is the first program,
When the area securing unit secures an area to be allocated to the file from the protection period area, the area securing unit secures the area in order from the area allocated to the deleted file with the oldest deletion date and time.

[Action]
When creating a file, the area securing means starts from the unused area in the data area where the file has not yet been allocated and the protection period elapsed area assigned to the deleted file whose protection period has elapsed from the deletion date and time. Reserve an area to allocate to the file. If the unused area and the protection period elapsed area alone could not secure the area required to create the file, the warranty period has passed since the deletion date, but the protection period has not passed. An area to be allocated to the file is secured from the area during the protection period allocated to the deleted file. If the area necessary for creating the file still cannot be secured, the area securing means sets the securing failure.

  According to the present invention, it is possible to recover a deleted file that is highly likely to be requested for recovery by a user with a high probability. The reason for this is that when allocating a data area to a newly created file, the area allocation process is performed for the unused area, the protection period elapsed area, and the protection period in progress area, and the file has not passed the time since the deletion. This is because the area during the guarantee period to which is assigned is provided with area securing means for excluding the area allocation process. In other words, even if the data area is insufficient when creating a file, an area to which a file that is likely to be requested for recovery by the user is allocated (an area allocated to a file for which the warranty period has not elapsed since deletion) ) Is excluded from the area allocation processing target, it is possible to recover with high probability a deleted file that is highly likely to be requested for recovery by the user.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of First Embodiment]
FIG. 1 is a block diagram showing a configuration example of a first embodiment of a file management apparatus according to the present invention. Referring to FIG. 1, a file management device 1 is connected to a storage device 2 such as a magnetic disk device and a host device 3 such as a computer. An input unit 4 and a display unit 5 are connected to the host device 3.

  The storage device 2 includes a file management unit 20, a data area management unit 30, a data area 40, a guarantee period storage unit 50, and a protection period storage unit 60.

  As shown in FIG. 2, file management information 21 of the created file is stored in the file management unit 20. The file management information 21 includes an identifier 22 indicating whether the file is a deleted file, date / time information 23 indicating the creation date / time or deletion date / time of the file, and position information 24 indicating a block 41 on the data area 40 to which the file is allocated. Contains. Further, the file management unit 20 also stores special file management information 26 indicating the deleted file directory entry 45 on the data area 40.

  As shown in FIG. 2, block management information 31 corresponding to each block 41 of the data area 40 is stored in the data area management unit 30. The arrangement order of the block management information 31 in the data area management unit 30 corresponds to the arrangement order of the blocks 41 in the data area 40. The block management information 31 includes an identifier 32 indicating whether or not the corresponding block 41 is empty, and date and time information 33 indicating the date and time when the file assigned to the corresponding block 41 was deleted.

  As shown in FIG. 2, the data area 40 includes a plurality of blocks 41. The block 41 is an allocation unit when a data area is allocated to a file. The content recorded in the block 41 matches the file content 21 in the case of a block to which a normal file is assigned, and in the case of a block to which a directory is assigned, the file name 43 of the file in the directory. And a list of file management information numbers 44 corresponding to the files. The data area 40 also includes a block that becomes a deleted file directory entry 45, and the deleted file directory entry 45 is registered with the file name of the deleted file and the file management information number of the deleted file associated with each other. Is done.

  The guarantee period storage unit 50 stores a guarantee period 51, and the protection period storage unit 60 stores a protection period 61. The guarantee period 51 represents a certain time for guaranteeing that the contents of the file are not changed after the file is deleted. That is, if the file is within the guarantee period 51 after being deleted, it is guaranteed that the contents of the file are exactly the same as before the deletion. The protection period 61 represents a certain time for guaranteeing that the contents of the file are not changed after the file is deleted unless the data area 40 is empty. These two periods must satisfy the relationship of protection period> guarantee period. That is, the protection period needs to be longer than the guarantee period. Further, in the initial state, default values are stored in the warranty period storage unit 50 and the protection period storage unit 60.

  The file management apparatus 1 includes a file creation unit 11, a file deletion unit 12, an area securing unit 13, an area release unit 14, a restoration unit 15, a deleted file reference unit 16, a file name deletion unit 17, a guarantee Period / protection period setting means 18.

  The file creation means 11 has a function of storing the file management information 21 of the file requested to be created in the file management unit 20 and a function of issuing an area securing request including the size of the file requested to be created to the area securing means 13. Have.

  The file deletion unit 12 has a function of changing the identifier 22 in the file management information 21 of the file requested to be deleted to “delete”, or a block of a block allocated to the file requested to be deleted by the area release unit 14 It has a function of issuing a release request including a number.

  The area securing unit 13 secures a block 41 corresponding to the file size for which an area securing request is made, and updates the identifier 32 in the block management information 31 corresponding to the secured block 41 to “reserved” or the secured block 41 Is notified to the file creating means 11.

  Here, the area securing unit 13 secures blocks corresponding to the file size based on the following rules. As shown in FIG. 3, the data area 40 is classified into the following five types (areas) (a) to (e).

(A) An area (unused block) that has not yet been assigned to a file.
(B) Area allocated to the created file (in-use block).
(C) An area allocated to the deleted file and within the guarantee period (block during the guarantee period). That is, a block in which current date and time ≦ deletion date and time + guarantee period.
(D) An area allocated to a deleted file, which is an area for which the guarantee period has elapsed since the deletion date and time but for which the protection period has not elapsed (block during the protection period). That is, a block in which deletion date / time + guarantee period <current date ≦ deletion date + protection period
(E) An area allocated to a deletion file and an area where a protection period has elapsed from the deletion date and time (protection period elapsed block). That is, a block in which deletion date / time + protection period <current date / time.

  The area securing means 13 first secures blocks to be allocated to the file from the unused block (a) and the protection period elapsed block (e). If blocks for the file size still cannot be secured, blocks are secured from the block during the protection period of (d). If the block for the file size still cannot be secured, the area allocation fails. No area is reserved from the block during the guarantee period (c) and the block in use (b).

  The area releasing unit 14 has a function of updating the identifier 32 in the block management information 31 of the block notified from the file deleting unit 12 to “free”.

  The recovery means 15 has a function of updating the identifier 22 in the file management information 21 of the file requested for recovery to “in use”.

  The deleted file reference means 16 sends a list of file names of the deleted files stored in the deleted file directory entry 45 to the higher-level device 3, and stores the contents of the deleted file with the file name designated by the user of the higher-level device 3. It has a function to send to the device 3.

  The file name deleting means 17 sends a list of file names of the deleted files stored in the deleted file directory entry 45 to the higher level device 3, and the file name specified by the user of the higher level device 3 and the corresponding file management information. And delete the number from the deleted file directory entry 45.

  The file management apparatus 1 can be realized by a computer, and when realized by a computer, for example, the following is performed. A disk, semiconductor memory, or other recording medium on which a program for causing the computer to function as the file management apparatus 1 is prepared is prepared, and the computer is caused to read the program. The computer controls its own operation according to the read program, so that the file creation means 11, the file deletion means 12, the area securing means 13, the area release means 14, the recovery means 15, and the deleted file reference means 16 are stored on the computer. The file name deleting unit 17 and the guarantee period / protection period setting unit 18 are realized.

[Description of Operation of First Embodiment]
Next, the operation of the present embodiment will be described in detail.

[Operation when creating a file]
First, the operation when creating a file will be described. When a file creation request including a file name and a file size is sent from the host device 3, the file creation means 11 in the file management device 1 has an identifier 22 = "in use", as shown in the flowchart of FIG. The file management information 21 with date / time information 23 = “current date / time” is created and registered in the file management unit 20 (step S41). At this time, nothing is set in the position information 24.

  Thereafter, the file creating unit 11 issues an area securing request including the size of the file requested to be created to the region securing unit 13. Thereby, the area securing unit 13 executes the area securing process (step S42).

  5 and 6 are flowcharts showing an example of the area securing process performed by the area securing unit 13. When the area securing request is passed from the file creating unit 11, the area securing unit 13, as shown in the flowchart of FIG. 5, of the block management information 31 stored in the data region management unit 30 is the first block management information. Attention is paid to 31 (step S51). Thereafter, the area securing unit 13 checks whether or not the block management information 31 being noticed is a block corresponding to an unused block or a protection period elapsed block (steps S53 to S55). That is, the block management information 31 with the identifier 32 = “free” and the date / time information 33 = “NULL” (the block management information 31 in which both steps S53 and S54 are YES) is the block management information corresponding to the unused block. 31. Further, the block management information 31 in which the identifier 32 = “free”, date / time information 33 ≠ “NULL”, and the deletion date / time indicated by the date / time information 33 has passed the protection period (YES in step S53, NO in step S54). , Step S55 is YES), it is determined that the block management information 31 is assigned to the protection period elapsed block.

  If the block management information 31 of interest does not correspond to an unused block or a protection period elapsed block (when step S53 is NO or when step S55 is NO), Pay attention to the next block management information 31 (step S51).

  On the other hand, when the noticed block management information corresponds to an unused block or a protection period result block, the identifier of the noticed block management information 31 is changed to “reserved” (step S56). ). Thereafter, the area securing unit 13 checks whether or not the block 41 having a file size or larger included in the area securing request has been secured (step S57).

  If the block 41 larger than the file size can be secured (YES in step S57), the block numbers of all the secured blocks 41 are notified to the file creation unit 11 of the request source (step S58), and the process is performed. finish. On the other hand, when the block 41 larger than the file size cannot be secured (NO in step S57), attention is paid to the next block management information 31 (step S51), and processing similar to that described above is performed.

  If all the block management information 31 stored in the data area management unit 30 is noticed and the block 41 larger than the file size cannot be secured (NO in step S52), the area securing unit 13 The process shown in the flowchart of FIG. That is, if the block 41 larger than the file size cannot be secured only from the unused block and the protection period result block, the processing shown in the flowchart of FIG. 6 is executed.

  Referring to FIG. 6, the area securing unit 13 first pays attention to the block management information 31 at the head of the block management information 31 stored in the data area management unit 30 (step S61), and the block management information 31 is protected. It is checked whether the block corresponds to the block during the period (steps S63 and S64). That is, when the identifier 32 = “free” and the deletion date / time indicated by the date / time information 33 is the one in which the guarantee period has passed but the protection period has not passed, the block management information being noticed is It is determined that the block corresponds to the block during the protection period.

  When the block management information 31 being noticed does not correspond to the block during the protection period (NO in step S63 or step S64), the area securing unit 13 pays attention to the next block (step S61). On the other hand, if the block management information 31 being noticed corresponds to a block during the protection period (both steps S63 and S64 are YES), the identifier 32 of the block management information 31 being noticed is “reserved”. After the change to (step S65), it is checked whether or not the block 41 larger than the file size has been secured (step S66).

  If the block 41 larger than the file size can be secured (YES in step S66), the block numbers of all the secured blocks 41 are notified to the requesting file creation means 11 (step S58 in FIG. 5). On the other hand, when the block 41 larger than the file size cannot be secured (NO in step S66), attention is paid to the next block management information 31 (step S61), and the same process as described above is performed.

  Then, even if the above-described processing is performed on all the block management information 31 stored in the data area management unit 30, the block 41 having a file size or larger cannot be secured (NO in step S62). The securing unit 13 notifies the request source file creation unit 11 of the failure to secure the area (step S67), and ends the process. In other words, if the block 41 larger than the file size cannot be secured from the unused block, the protection period elapsed block, and the block during the protection period, the area securing unit 13 notifies the file creating unit 11 of the area securing failure. .

  When the block number of the block 41 secured from the area securing unit 13 is notified, the request source file creating unit 11 is notified as the position information 24 of the file management information 21 stored in the file management unit 20 in step S41. All block numbers are written (step S43 in FIG. 4). Thereafter, the file creation means 11 adds the file name of the file requested to be created and the number 25 of the file management information 21 stored in the file management unit 20 in step S41 to the block 41 serving as a directory (step S44). End the process. When the area securing unit 13 is notified of the failure to secure the area, the file creating unit 11 notifies the host apparatus 3 to that effect and then ends the process.

[Operation when deleting files]
Next, the operation when deleting a file will be described.

  When a file deletion request including the file name of a file to be deleted is sent from the host apparatus 3, the file deletion means 12 in the file management apparatus 1 is a block 41 that is a directory as shown in the flowchart of FIG. Then, the number 44 registered in association with the file name is acquired, and the file management information 21 with the number 25 matching the number 44 is searched from the file management unit 20 (step S71). Thereafter, the file deletion unit 12 changes the identifier 22 in the found file management information 21 to “delete”, and sets “current date” in the date information 23 as the deletion date (step S72).

  When the processing in step S72 is completed, the file deletion unit 12 includes the block number (one or more cases) set as the position information 24 in the file management information 21 found in step S71. A release request is issued to the area release means 14. Thereby, the area release means 14 executes an area release process (step S73).

  FIG. 8 is a flowchart showing an example of the area release process performed by the area release unit 14. When the area release request including the block number is issued, the area release means 14 searches for all block management information 31 corresponding to the block having the block number specified by the release request (step In S81), the identifier 32 in the found block management information 31 is changed to “free”, and “current date” is set as the deletion date in the date information 33 (step S82). When the processing in step S82 is completed, the area release unit 14 notifies the request source file deletion unit 12 of this fact.

  As a result, the file deleting means 12 moves the file name 43 and the number 44 of the corresponding file stored in the block 41 serving as the directory to the deleted file directory entry 45 (step S74 in FIG. 7), and thereafter the processing is performed. Exit.

[Operation when recovering deleted files]
When the restoration request including the file name of the file to be restored is sent from the host apparatus 3, the restoration means 15 in the file management apparatus 1 starts from the block 41 which is a directory as shown in the flowchart of FIG. The number 44 registered in association with the file name is acquired, and the file management information 21 having the same number 25 as this number 44 is searched from the file management unit 20 (step S91). Thereafter, the recovery means 15 changes the identifier 22 in the found file management information 21 to “in use” and sets “current date” in the date information 23 (step S92).

  Thereafter, the recovery unit 15 searches the data area management unit 30 for block management information 31 (block management information 31 corresponding to the block 41 having the block number indicated by the position information 24) assigned to the file to be recovered. (Step S93), the identifier 32 of the found block management information 31 is changed to “reserved”, and “current date and time” is set in the date and time information 33 (step S94).

[Operation when referencing the deleted file]
Next, the operation when referring to the contents of the deleted file will be described. The user of the host device 3 inputs a delete file reference request to the host device 3 from the input unit 4 when referring to the contents of the deleted file. As a result, the host device 3 issues a delete file reference request to the file management device 1.

  When a deletion file reference request is issued from the higher-level device 3, the deletion file reference means 16 in the file management device 1, as shown in the flowchart of FIG. And a list of the file management information numbers of the file) are sent to the host device 3 (step S101).

  The host device 3 displays a list of file names and file management information numbers sent from the deleted file reference means 16 on the display unit 5, and the user uses the input unit 4 to display the displayed file names. Select the file name of the file you want to refer to. As a result, the host device 3 transmits the selected file name to the file management device 1.

  When the file name is sent from the host device 3, the deleted file reference means 16 in the file management device 1 first registers the file management information registered in association with the file name from the block 41 that is a directory. 21 is obtained, and the file management information 21 with the number 25 that matches the number 44 is searched from the file management unit 20 (step S102). Thereafter, the deleted file reference means 16 sends the block contents (file contents) indicated by the position information 24 of the found file management information 21 to the higher-level device 3 (step S103). Thereby, the host device 3 displays the contents of the transmitted block on the display unit 5.

[Operation when deleting file name]
Next, an operation for deleting a pair of a file name stored in the deleted file directory entry 45 and a file management information number will be described.

  When the user of the higher level apparatus 3 wants to delete the file name and the file management information number stored in the deleted file directory entry 45, the user inputs a file name deletion request from the input unit 4 to the higher level apparatus 3. As a result, the host device 3 issues a file name deletion request to the file management device 1.

  When a file name deletion request is sent from the host device 3, the file name deletion means 17 in the file management device 1, as shown in the flowchart of FIG. 11, shows the contents of the deleted file directory entry 45 (file name and file management). A list of information numbers) is sent to the host device 3 (step S111).

  Accordingly, the host device 3 displays a list of file names and file management information numbers on the display unit 5, and the user selects a file name to be deleted using the input unit 4. The host device 3 transmits the selected file name to the file management device 1.

  As a result, the file name deleting means 17 deletes the file name selected by the user from the deleted file directory entry 45 and the number of the file management information paired therewith (step S112).

[Operation during warranty period and protection period setting]
When setting the guarantee period and the protection period, the user inputs a guarantee period / protection period setting request from the input unit 4 to the host device 3. As a result, the host apparatus 3 issues a guarantee period / protection period setting request to the file management apparatus 1.

  When a guarantee period / protection period setting request is issued, the guarantee period / protection period setting means 18 in the file management apparatus 1 sets the guarantee period / protection period to the host apparatus 3 as shown in the flowchart of FIG. The screen 181 is sent (step S121).

  Upon receiving the guarantee period / protection period setting screen 181, the host device 3 displays it on the display unit 5. FIG. 13 is a diagram showing an example of a warranty period / protection period setting screen, which includes a guarantee period input field 182, a protection period input field 183, and a decision button 184. When the user inputs the guarantee period and the protection period in the input fields 182 and 183, the user operates the determination button 184. As a result, the upper level apparatus 3 transmits the guarantee period and the protection period input in the input fields 182 and 183 to the file management apparatus 1.

  The guarantee period / protection period setting means 18 in the file management apparatus 1 guarantees the guarantee period and the protection period when the guarantee period and protection period sent from the host apparatus 3 satisfy the relationship of guarantee period <protection period. It stores in the period storage unit 50 and the protection period storage unit 60 (step S122). On the other hand, if the relationship of guarantee period <protection period is not satisfied, a message indicating that the guarantee period <protection period needs to be set, and a guarantee period / protection period setting screen 181 are displayed. Send to 3. The user performs the above-described operation again using the retransmitted guarantee period / protection period setting screen 181.

[Effect of the first embodiment]
According to the present embodiment, it is possible to recover with high probability a deleted file that is highly likely to be requested for recovery by the user. The reason for this is that when allocating an area to a newly created file, an area allocation process is performed for unused blocks, protection period elapsed blocks, and blocks during protection period, and files that have not passed too long after deletion are deleted. This is because the allocated block during the guarantee period includes the area securing means 13 to be excluded from the area allocation process. In other words, even if the data area is insufficient at the time of file creation, a block to which a file that is likely to be requested for recovery by the user is assigned (a block assigned to a file for which the warranty period has not elapsed since deletion) ) Is excluded from the area allocation processing target, it is possible to recover with high probability a deleted file that is highly likely to be requested for recovery by the user.

  Furthermore, according to the present embodiment, the user can set the guarantee period and the protection period in accordance with the operation state of the system. The reason is that a guarantee period / protection period setting means 18 is provided.

[Second Embodiment]
Next, a second embodiment of the file management apparatus according to the present invention will be described. The present embodiment is characterized in that when a block to be allocated to a file is secured from among the blocks during the protection period, the block is allocated in order from the block allocated to the file with the oldest deletion date.

[Description of Configuration of Second Embodiment]
The file management apparatus according to the present embodiment is realized by using the area securing unit 13a having the sort memory 131 as shown in FIG. 14 instead of the area securing unit 13 in the file management apparatus 1 of FIG. Is done.

  The area securing unit 13a has a configuration in which when the block 41 to be allocated to the file is secured from the block during the protection period, the memory 131 is used to secure in order from the block to which the deleted file having the oldest deletion date / time is allocated. This is different from the area securing means 13 shown in FIG. The area securing means 13a can also be realized by a program like the area securing means 13.

[Description of Operation of Second Embodiment]
Next, the operation of the present embodiment will be described. Since only the operation of the area securing unit 13a is different from the first embodiment, only the operation of the area securing unit 13a will be described here.

  FIG. 15 is a flowchart illustrating a processing example of the area securing unit 13a. When an area securing request including the file size of the file to be created is sent from the file creating unit 11, the area securing unit 13 a receives the block management stored in the data area management unit 30 as shown in the flowchart of FIG. 15. Of the information 31, attention is paid to the leading block management information 31 (step S151). Thereafter, the area securing unit 13a checks whether or not the block management information 31 being noticed corresponds to the block in use (step S153).

  When the block corresponds to the block in use, that is, when the identifier 32 is “reserved” (step S153: NO), attention is paid to the next block management information 31. On the other hand, when the block does not correspond to the block in use (YES in step S153), it is checked whether the block corresponds to an unused block (step S154).

  If it corresponds to an unused block (YES in step S154), the identifier 32 of the block management information 31 of interest is changed to “reserved” (step S156). On the other hand, if it does not correspond to an unused block (NO in step S154), it is checked whether or not it corresponds to a protection period elapsed block (step S155).

  If it corresponds to the protection period elapsed block (YES in step S155), the identifier of the block management information 31 of interest is changed to “reserved” (step S156). On the other hand, when it does not correspond to the protection period elapsed block (NO in step S155), it is checked whether or not it corresponds to the block during the protection period (step S159).

  When it does not correspond to a block during the protection period (step S159 is NO), attention is paid to the next block management information. On the other hand, if the block corresponds to the block during the protection period (YES in step S159), the block management information 31 currently focused on and the block number of the corresponding block are paired in the memory 131. Store (step S160). At this time, the pairs of the block management information 31 and the block numbers stored in the memory 131 are sorted so that the deletion date and time indicated by the date and time information 33 is in the order of oldest. When the process of step S160 is completed, the area securing unit 13a pays attention to the next block management information 31.

  When the identifier 32 in the corresponding block management information 31 is changed to “reserved” in step S156, the area securing unit 13a determines whether a block larger than the requested file size has been secured (step S157). . If a block larger than the file size can be secured (YES in step S157), the block number of all the secured blocks is notified to the file creation means 11 (step S158), and the process ends. On the other hand, when a block larger than the file size cannot be secured (NO in step S157), attention is paid to the next block management information 31.

  If the block management information 31 that has not been noticed disappears and a block larger than the file size cannot be secured (NO in step S152), the area releasing unit 13a deletes the first block number (deletion) stored in the memory 131. Attention is paid to the block number assigned to the file with the oldest date and time (step S161), and the identifier 32 in the block management information 31 specified by the block number is changed to “reserved” (step S163). Thereafter, it is checked whether or not a block larger than the file size has been secured (step S164). If the block has been secured, the process of step S158 described above is performed. On the other hand, when it cannot be secured (NO in step S164), attention is paid to the next block number stored in the memory 131 (step S161). If a block larger than the file size cannot be secured even though there are no unfocused block numbers (NO in step S162), the file creation unit 11 is notified of the failure to secure the area (step S165). , The process ends.

  Although not described in the above-described embodiment, as another related technique, when restoring a file system (consisting of the file management device 1 and the storage device 2), the identifier 22 of the file management information 21 is set. Can be used. The file system is repaired when it is necessary to verify the integrity of the file system, such as when the system is down. In the file system repair process, if the same block is referenced from a plurality of file management information 21, it is determined that the files are inconsistent, and the target file is cleared or referred to from one file management information 21. Repair is done. In the present invention, it is assumed that the file management information 21 of the deleted file and the file management information 21 of the file in use indicate the same block. In order to solve such a problem, in the file system repair process, the file management information 21 whose identification 32 child is “deleted” can be excluded from the consistency check target.

[Effects of Second Embodiment]
According to the present embodiment, it is possible to restore a file that is more likely to be requested to be restored by the user with a higher probability than in the first embodiment. The reason is that, when securing a block to be allocated to a file from among the blocks during the protection period, there is provided an area securing means 13a for securing a block to be allocated to a file in order from a block that has been allocated to a file whose deletion date / time is old. Because.

  INDUSTRIAL APPLICABILITY The present invention can be used for a business system having a characteristic in which transaction concentration jumps, a relatively small system that requires safety with limited resources, a trash can application used on a personal computer, and the like. .

It is a block diagram which shows the structural example of 1st Embodiment of the file management apparatus concerning this invention. 3 is a diagram illustrating an example of contents of a storage device 2. FIG. 4 is a diagram for explaining types of blocks 41 existing in a data area 40. FIG. 4 is a flowchart illustrating a processing example of a file creation unit 11. 5 is a flowchart illustrating an example of processing of an area securing unit 13. 5 is a flowchart illustrating an example of processing of an area securing unit 13. 5 is a flowchart showing a processing example of a file deletion unit 12. 5 is a flowchart showing a processing example of an area releasing unit 14. 4 is a flowchart showing a processing example of a recovery means 15. 4 is a flowchart showing a processing example of a deletion file reference unit 16. FIG. 10 is a block diagram illustrating an example of processing performed by a file name deletion unit 17. 4 is a flowchart showing a processing example of a guarantee period / protection period setting means 18; It is a figure which shows an example of a guarantee period / protection period setting screen. It is a block diagram which shows the structural example of the area securing means 13a used by 2nd Embodiment of the file management apparatus concerning this invention. It is a block diagram which shows the process example of the area securing means 13a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... File management apparatus 11 ... File creation means 12 ... File deletion means 13, 13a ... Area securing means 131 ... Memory 14 ... Area release means 15 ... Recovery means 16 ... Deleted file reference means 17 ... File name deletion means 18 ... Warranty period Protection period setting means 2 ... storage device 20 ... file management unit 21 ... file management information 22 ... identifier 23 ... date and time information 24 ... location information 25 ... number 26 ... file management information 30 of deleted file directory ... data area management unit 31 ... Block management information 32 ... identifier 33 ... date and time information 40 ... data area 41 ... block 42 ... file contents 43 ... file name 44 ... number 45 ... deleted file directory entry 50 ... guarantee period storage unit 51 ... guarantee period 60 ... protection period storage Unit 61 ... Protection period 3 ... Host device 4 ... Input unit 5 ... Display unit

Claims (10)

A data area where files are stored;
A warranty period storage unit for storing a warranty period for the deleted file;
A protection period storage unit that stores a protection period longer than the warranty period for the deleted file;
When creating a file, it is assigned to an unused area in the data area to which the file has not yet been assigned, and a deleted file for which the protection period stored in the protection period storage unit has elapsed since the deletion date and time. If the area allocated to the file is secured from the protection period elapsed area, and the unused area and the protection period elapsed area alone cannot secure the area necessary for creating the file, the deletion date and time The protection period stored in the warranty period storage unit has elapsed, but the protection period stored in the protection period storage unit has not yet elapsed. An area allocated for the file was secured, but an area necessary for creating the file could not be secured. If the file management apparatus characterized by comprising an area ensuring means to ensure fail. The file management apparatus according to claim 1, wherein
When the area securing means secures an area allocated to the file from the area during the protection period, the file management is configured to secure in order from the area allocated to the deleted file with the oldest deletion date and time. apparatus. A data area composed of a plurality of blocks and storing files;
A warranty period storage unit for storing a warranty period for the deleted file;
A protection period storage unit that stores a protection period longer than the warranty period for the deleted file;
When creating a file, it is assigned to an unused block in the data area to which the file has not yet been assigned and a deleted file for which the protection period stored in the protection period storage unit has elapsed since the deletion date and time. If a block to be allocated to the file is secured from the protection period elapsed block, and a block necessary for creating the file cannot be secured only by the unused block and the protection period elapsed block, from the deletion date and time From the block during the protection period assigned to the deleted file that has passed the warranty period stored in the warranty period storage unit but has not passed the protection period stored in the protection period storage unit To reserve a block to allocate to the file and still create the file If you can not ensure become essential blocks, the file management apparatus characterized by comprising an area ensuring means to ensure fail. The file management apparatus according to claim 3, wherein
When the area securing means secures blocks to be allocated to the file from the block during the protection period, the file management has a configuration of securing in order from the block allocated to the deleted file with the oldest deletion date and time. apparatus. The file management apparatus according to claim 4, wherein
Block management information for each block in the data area, including an identifier indicating whether or not the block is allocated to a file in use, and the date and time when the file allocated to the block is deleted A data area management unit storing block management information, and
The file management apparatus characterized in that the area securing means recognizes an unused block, a protection period elapsed block, and a protection period elapsed block based on block management information stored in the data area management unit . The file management apparatus according to claim 5, wherein
A file management apparatus comprising: a guarantee period / protection period setting means for storing an inputted guarantee period in the guarantee period storage unit and storing an inputted protection period in the protection period storage unit. A file management apparatus having a data area for storing a file, a guarantee period storage unit for storing a guarantee period for a deleted file, and a protection period storage unit for storing a protection period longer than the guarantee period for the deleted file In
When creating a file, it is assigned to an unused area in the data area to which the file has not yet been assigned, and a deleted file for which the protection period stored in the protection period storage unit has elapsed since the deletion date and time. If the area allocated to the file is secured from the protection period elapsed area, and the unused area and the protection period elapsed area alone cannot secure the area necessary for creating the file, the deletion date and time The protection period stored in the warranty period storage unit has elapsed, but the protection period stored in the protection period storage unit has not yet elapsed. An area allocated for the file was secured, but an area necessary for creating the file could not be secured. If the file management method is characterized in that to ensure failure. The file management method according to claim 7,
The file management method according to claim 1, wherein when securing an area to be assigned to the file from the protection period area, the area is secured in order from the area assigned to the deleted file with the oldest deletion date and time. A computer having a data area for storing a file, a guarantee period storage unit for storing a guarantee period for a deleted file, and a protection period storage unit for storing a protection period longer than the guarantee period for the deleted file;
When creating a file, it is assigned to an unused area in the data area to which the file has not yet been assigned, and a deleted file for which the protection period stored in the protection period storage unit has elapsed since the deletion date and time. If the area allocated to the file is secured from the protection period elapsed area, and the unused area and the protection period elapsed area alone cannot secure the area necessary for creating the file, the deletion date and time The protection period stored in the warranty period storage unit has elapsed, but the protection period stored in the protection period storage unit has not yet elapsed. An area allocated for the file was secured, but an area necessary for creating the file could not be secured. If the program to function as an area ensuring means to ensure fail. The program according to claim 9, wherein
When the area securing means secures an area allocated to the file from the area during the protection period, the program has a configuration of securing in order from an area allocated to a deleted file having an old deletion date and time.

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