JP5483933B2 - Storage device, control method therefor, and program - Google Patents

Description

  The present invention relates to a storage device that stores and manages files in a file system, and in particular, a file from a secondary storage device by storing an arbitrarily designated file only in a volatile storage device that is a main storage device. The present invention relates to a storage device that does not require complete erasure of data.

  In recent years, in a storage device using a file system including a secondary storage device, it is common to use a nonvolatile device such as an HDD as the secondary storage device. In such a storage device, the storage destination of file data is usually a secondary storage device.

  As a feature of non-volatile devices such as HDDs, which are generally used as secondary storage devices, even if the data once written is erased, the residual magnetism on the HDD is analyzed by special means. The erased data can be restored.

  For this reason, when sensitive data is written to a storage device using a file system equipped with a secondary storage device, the following processing is required in addition to the normal erasure processing when erasing the written data. It becomes. That is, a process called complete erasure is required in which a random number or zero is written a plurality of times in the area on the secondary storage device where data has been written.

  In order to avoid such a complicated complete erasure process, a method is known in which specific data is not written to a secondary storage device, but is processed and stored only by a volatile storage device.

  For example, the following technique is proposed in Patent Document 1 below.

  That is, Patent Document 1 proposes a technique that uses a combination of two file systems: a file system configured on a main storage device and a file system different from the file system configured on a secondary storage device. Has been. Thus, an arbitrary file is processed only on the main storage device.

  Further, in Patent Document 2 below, when an image forming apparatus including a unit using a job management method such as a printer driver determines that data included in a transmission job is confidential, it stores volatile data. The job is processed only by the device to form an image.

  Further, in Patent Document 3 below, in an image forming apparatus capable of handling print data accompanied by confidentiality identification data indicating the presence or absence of confidentiality, when it is determined that confidentiality is determined based on confidentiality identification data The print data is processed only by a volatile storage device.

JP 2008-90378 A JP 2004-318624 A JP 2007-249951 A

  However, in the technique described in Patent Document 1, it is natural that the operating system needs to have two file system functions, which leads to enlargement of the operating system. In addition, the file system where the file is placed necessarily restricts the path on the directory tree where the file is placed.

  Furthermore, in the technologies described in Patent Document 2 and Patent Document 3, since the presence / absence of confidentiality depends on the data, the data confidentiality or the data is processed only by a volatile storage device in an apparatus that handles the data. There was a problem that it was not possible to freely decide whether or not to do so.

  Further, the techniques described in Patent Document 2 and Patent Document 3 have a problem that the sensitivity cannot be determined unless a special application is used.

  In the technologies described in Patent Document 2 and Patent Document 3, when data is processed only on a volatile storage device, the file cannot be in the form of a file on the file system, so that the data is handled from a plurality of processes. There was a problem that could not.

  An object of the present invention is to provide a storage device that can eliminate the need for complete erasure of file data from a secondary storage device without using a special application and using a single file system. .

In order to achieve the above object, a storage device according to claim 1 is a storage device including a volatile main storage device and a non-volatile secondary storage device. Specifying means for specifying whether or not to store only in the device, and whether to store the file data stored in the kernel space of the main storage device in the secondary storage device based on the specification of the specifying means Control means for controlling whether or not.

  According to the storage device of the present invention, it is possible to eliminate the need for complete erasure of file data from the secondary storage device without using a special application and using a single file system.

1 is a system configuration diagram of a storage device according to an embodiment of the present invention. FIG. 2 is a block diagram showing a state in which a file is processed and stored only in a RAM (main storage device) that is a volatile device without transferring a file to an HDD (secondary storage device) in the storage device of FIG. 1. It is a flowchart which shows the procedure of 1st Embodiment of the file data storage location designation | designated process performed by the file data storage location designation | designated part in FIG. It is a flowchart which shows the procedure of 1st Embodiment of the secondary storage device transcription | transfer process performed by the secondary storage device transcription | transfer part in FIG. 3 is a flowchart showing a procedure of main storage device data erasure processing executed by a main storage device data erasure unit in FIG. 2. It is a figure which shows the specific example which described the propriety of the transcription | transfer to a secondary storage device about each file with the secondary storage device transcription | transfer flag in FIG. It is a flowchart which shows the procedure of 2nd Embodiment of the file data storage location designation | designated process performed by the file data storage location designation | designated part in FIG. It is a flowchart which shows the procedure of 2nd Embodiment of the secondary storage device transcription | transfer process performed by the secondary storage device transcription | transfer part in FIG. FIG. 4 is a diagram showing a specific example in which a specific area on the main storage device in which file data that cannot be transferred to the secondary storage device is placed is specified by the specific area specifying section on the main storage device in FIG. 2.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a system configuration diagram of a storage device according to an embodiment of the present invention.

  In the storage device 100, processing of a plurality of processes and interruption processing are usually executed. The storage device 100 includes a CPU 110, a RAM 120, a ROM 130, an HDD 140, and a network interface 150.

  The CPU 110 executes various programs and controls various parts of the apparatus. The CPU 110 does not perform processing of multiple processes and interrupt processing at the same time, but concentrates on only one process and switches the processing target in a short span, as if performing multiple processes at the same time. Showing.

  The RAM 120 is a volatile main storage device. The RAM 120 is a temporary storage device that temporarily stores programs and operating systems that implement each unit of FIG. 2 to be described later, and data and instructions being processed by the CPU 110 such as processes and packets.

  Although a file system may be built on the ROM 130, the file system is usually built on the HDD 140, which is a non-volatile secondary storage device. The HDD 140 is an external storage device that stores a program corresponding to a processing procedure performed by the CPU 110 such as a program for realizing each unit of FIG.

  Another information processing apparatus is connected to the network interface 150. Through this, packets are exchanged.

  FIG. 2 is a block diagram showing how the storage device in FIG. 1 processes and stores a file only in a volatile device RAM (main storage device) without transferring the file to the HDD (secondary storage device). is there.

  When a request for creating a new file is issued to the storage device 100, first, the file data 202 is placed on the RAM 120 in the user space, and the file data 202 is immediately stored as the file data 204 on the RAM 120 in the kernel space. Copied.

  Similarly, at the time of a new file creation request, the file data storage location specifying unit 210 is used to specify that file data is stored only on the main storage device. Then, the file data storage location specifying unit 210 describes in the secondary storage device transfer flag 220 that the file data cannot be transferred to the secondary storage device.

  After that, the secondary storage device transcription unit 230 operates, and when the secondary storage device transcription unit 230 confirms the content of the secondary storage device transcription flag 220, it is described that transcription to the secondary storage device is impossible. The file data is kept only on the main storage device and is not transferred to the secondary storage device.

  When the file data storage location specifying unit 210 is not used to specify that file data is stored only on the main storage device when a new file creation request is made, the following processing is performed. That is, in this case, the file data storage location specifying unit 210 describes in the secondary storage device transfer flag 220 that the file data can be transferred to the secondary storage device.

  After that, the secondary storage device transcription unit 230 is operated, and when the secondary storage device transcription unit 230 confirms the content of the secondary storage device transcription flag 220, it is described that transcription to the secondary storage device is possible. Then, the file data on the main storage device is transferred to the HDD 140 as the secondary storage device, and the main storage device data erasure unit 240 is operated. The main storage device data erasure unit 240 erases the file data 204 on the RAM 120 after a predetermined time has elapsed.

(First embodiment)
The storage device control method of the present invention will be described below.

  FIG. 3 is a flowchart showing the procedure of the first embodiment of the file data storage location designation process executed by the file data storage location designation unit in FIG.

  The processes S (steps) 300, S310, S320, and S330 will be described below.

  In S300, the file data storage location specifying unit 210 is activated in response to a new file creation request.

  In S310, the file data storage location specifying unit 210 confirms whether the instruction to itself is to place file data only on the main storage device, and if the instruction is to place only on the main storage device, The process proceeds to S320, and if not, the process proceeds to S330.

  In S320, the file data storage location specifying unit 210 describes in the secondary storage device transfer flag 220 that the file data cannot be transferred to the secondary storage device.

  In S330, the file data storage location specifying unit 210 describes in the secondary storage device transfer flag 220 that the file data can be transferred to the secondary storage device.

  FIG. 4 is a flowchart showing the procedure of the first embodiment of the secondary storage device transcription process executed by the secondary storage device transcription unit in FIG.

  The processes S400, S410, S420, and S430 will be described below.

  In S400, the secondary storage device transcription unit 230 is activated.

  In S410, the secondary storage device transcription unit 230 checks the content of the secondary storage device transcription flag 220, and if there is a file that can be transcribed to the secondary storage device, the process proceeds to S420. If not, the process ends.

  In S420, the secondary storage device transcription unit 230 checks whether the file that can be transferred to the secondary storage device exists on the main storage device, and if the file exists on the main storage device. , The process proceeds to S430, and if not, the process ends.

  In S430, the secondary storage device transfer unit 230 transfers the file to the secondary storage device, and causes the main storage device data erasure unit 240 to operate on the file.

  FIG. 5 is a flowchart showing a procedure of main memory data erasure processing executed by the main memory data erasure unit in FIG.

  Hereinafter, the processes S500 and S510 will be described.

  In S500, the main storage device data erasure unit 240 is activated by the secondary storage device transcription unit 230.

  In S510, the main storage device data erasure unit 240 deletes the file data designated by the secondary storage device transfer unit 230 from the main storage device.

  FIG. 6 is a diagram showing a specific example in which whether or not each file can be transferred to the secondary storage device is described by the secondary storage device transfer flag in FIG.

  In this example, files A, B, and D can be transferred to the secondary storage device, and file C can be transferred to the secondary storage device.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. 1, 2, 5, 7, 8, and 9.

  In the second embodiment, instead of using the secondary storage device transfer flag in the first embodiment, the main storage device defined by the specific area instruction unit 250 on the main storage device shown in FIG. Write file data only to the specific area above. This indicates that the file cannot be transferred to the secondary storage device.

  That is, in FIG. 2, when a request for creating a new file is made to the storage device 100, first, file data 202 is placed on the RAM 120 in the user space, and the file data 202 is immediately stored in the kernel space. Copied to the RAM 120.

  At this time, the file data storage location designating unit 210, which also operates when a new file creation request is made, performs the following process when it is impossible to transfer the file data to the secondary storage device.

  In other words, in this case, the file data storage location specifying unit 210 copies the file data to a specific area on the kernel space determined by the specific area instruction unit 250 on the main storage device. When the file data can be transferred to the secondary storage device, the file data is copied outside the specific area on the kernel space defined by the specific area instruction unit 250 on the main storage device. To do.

  The file data storage location specifying unit 210 and the secondary storage device transcription unit 230 are different from the first embodiment in that the secondary storage device transcription flag 220 is not used. This will be described with reference to FIG.

  FIG. 7 is a flowchart showing the procedure of the second embodiment of the file data storage location designation process executed by the file data storage location designation unit in FIG.

  S300 and S310 are as described in the description of the first embodiment shown in FIG.

  In S720, the file data storage location designating unit 210 copies the file data to the specific area determined by the specific area instruction unit 250 on the main storage device when copying from the user space to the kernel space.

  In S730, the file data storage location specifying unit 210 copies the file data outside the specific area determined by the specific area instruction unit 250 on the main storage device when copying from the user space to the kernel space.

  FIG. 8 is a flowchart showing the procedure of the second embodiment of the secondary storage device transfer process executed by the secondary storage device transfer unit in FIG.

  S400 is as described in the description of the first embodiment shown in FIG.

  In S810, the secondary storage device transcription unit 230 confirms whether the position on the memory where the file data is placed is placed in a predetermined specific area, and the specific area instruction unit 250 on the main storage device. If it is placed in the specified specific area, the process proceeds to S820. Otherwise, the process ends.

  In S820, the secondary storage device transfer unit 230 transfers the file to the secondary storage device, and causes the main storage device data erasure unit 240 to operate on the file.

  FIG. 9 is a diagram showing a specific example in which a specific area on the main storage device in which file data that cannot be transferred to the secondary storage device is placed is indicated by the specific area specifying section on the main storage device in FIG. is there.

  In this example, the specific area on the main storage device is set to 0xe000,0000 to 0xe1ff, ffff.

  In this example, a specific area on the main storage device is indicated using an address, but it goes without saying that a description method other than this example may be used as long as the position on the main storage device can be uniquely specified. Yes.

  The object of the present invention can also be achieved by causing a computer (or CPU, MPU, etc.) of a system or apparatus to read out and execute software program codes for realizing the functions of the above-described embodiments from a storage medium. .

  Various storage media for supplying the program code can be used. Alternatively, the program code may be downloaded via a network.

  Further, the functions of the above-described embodiments are realized by performing part or all of actual processing by an OS (operating system) or the like running on the computer based on an instruction of the program code read by the computer. Cases are also included.

100 storage device 110 CPU
120 RAM
130 ROM
140 HDD
210 File data storage location designation unit 220 Secondary storage device transfer flag 230 Secondary storage device transcription unit 240 Main storage device data erasure unit 250 Main storage device specific area instruction unit

Claims (7)

In a storage device comprising a volatile main storage device and a non-volatile secondary storage device,
Designating means for designating whether to store file data only in the main storage device at the time of a new file creation request;
Control means for controlling whether or not the file data stored in the kernel space of the main storage device is stored in the secondary storage device based on the specification of the specifying means. Storage device. The control means includes
A transfer means for transferring the file data on the main storage device to the secondary storage device when the specification means specifies that the file data is stored in the secondary storage device;
Erasing means for erasing the file data on the main storage device after the transfer of the file data by the posting means;
The storage device according to claim 1, further comprising:   Each of the file data on the main storage device is provided with a transfer flag indicating whether or not transfer to the secondary storage device is possible, and the transfer means can transfer to the secondary storage device with the transfer flag. The storage device according to claim 2, wherein only the file data set as the target is to be transferred to the secondary storage device. Instructing means for instructing a specific area to the main storage device,
3. The transfer unit according to claim 2 , wherein the transfer unit does not set the file data stored in the specific area of the main storage device instructed by the instruction unit to be transferred to the secondary storage device. Storage device. In a method for controlling a storage device comprising a volatile main storage device and a non-volatile secondary storage device,
A designation step for designating whether to store file data only in the main storage device when a new file creation request is made;
And a control step for controlling whether or not the file data stored in the kernel space of the main storage device is stored in the secondary storage device based on the specification in the specifying step. Storage device control method. The control step includes
A transfer step for transferring the file data on the main storage device to the secondary storage device when the specification step specifies that the file data is stored in the secondary storage device;
An erasing step of erasing the file data on the main storage device after transcription of the file data by the transcription step;
The storage device control method according to claim 5, further comprising: In a program for causing a computer to execute a control method of a storage device including a volatile main storage device and a nonvolatile secondary storage device,
The control method of the storage device is:
A designation step for designating whether to store file data only in the main storage device when a new file creation request is made;
And a control step for controlling whether or not the file data stored in the kernel space of the main storage device is stored in the secondary storage device based on the specification in the specifying step. program.