WO2012100726A1

WO2012100726A1 - Method, device, and system for erasing invalid data

Info

Publication number: WO2012100726A1
Application number: PCT/CN2012/070638
Authority: WO
Inventors: 高志宏; 李科; 杨琴琴
Original assignee: 成都市华为赛门铁克科技有限公司
Priority date: 2011-01-30
Filing date: 2012-01-20
Publication date: 2012-08-02
Also published as: CN102622310A

Abstract

Provided in embodiments of the present invention are a method, device, and system for erasing invalid data. In embodiments of the present invention, information of a command to erase the invalid data is received, and a dirty data recycling process is launched immediately to erase all invalid data. This allows for all invalid data to be thoroughly erased from a storage medium, effectively protecting secured information of the user.

Description

Invalid data erasing method, device and system The present application claims priority to Chinese patent application filed on January 30, 2011 by the Chinese Patent Office, application number 201110035556.0, and the invention name is "invalid data erasing method, device and system" The entire contents of which are incorporated herein by reference.

Technical field

The present invention relates to the field of storage technologies, and in particular, to an invalid data erasing method, apparatus and system. Background technique

Solid State Drive, also known as an electronic hard drive or solid state electronic drive, is a hard drive consisting of a control unit and a solid state storage unit (usually a NAND FLASH chip). Unlike the traditional disk write process, the SSD can perform a read operation multiple times after writing data, but erase the location before writing the data before writing new data. In order to avoid the impact of frequently performing the erasing operation on the life of the SSD, and the moving of the valid data each time the data is erased, the SSD in the prior art is usually stored in a new physical address when performing a write operation. The unit writes new data without writing the new data in the original address after erasing the original address data, thereby effectively avoiding frequent erasure of the storage medium. However, the inventor has found that in the prior art, when a user needs to write new data at a specified address to overwrite the original data, or needs to delete the data of the specified location, only the mapping relationship between the logical address and the physical address of the data is cleared, and the display is performed. The information to the user indicates that the original data has been overwritten or deleted, but in essence, the original data still exists, and the professional technician can read the data, so the prior art cannot guarantee that the deleted data information is not leaked.

Summary of the invention

The embodiment of the invention provides an invalid data erasing method, device and system, which prevent user information leakage and effectively improve the security of user information. An embodiment of the present invention provides an invalid data erasing method, including:

Receiving invalid data erasure instruction information;

Start the dirty data reclamation process immediately to erase all invalid data.

The embodiment of the invention further provides an invalid data erasing device, comprising:

An instruction receiving unit, configured to receive invalid data erasure instruction information; The invalid data erasing unit is configured to immediately start the dirty data recycling process to erase all invalid data when the instruction receiving unit receives the invalid data erasing instruction information.

The embodiment of the invention further provides a storage system, comprising the foregoing invalid data erasing device. In the prior art, the system only provides the user with an instruction selection involving data deletion. When the user deletes the data, only the mapping relationship between the logical address and the physical address of the specified data storage is deleted, and the designation is still substantially stored in the storage medium. The data, but usually after the storage system's free space is lower than the preset value, or after the storage system runs for a certain period of time, etc., initiates a dirty data recovery process; in the embodiment of the present invention, the user is provided whether to perform invalid data erasure. Select, after receiving the invalid data erase command information, immediately start the dirty data recovery process, so that all invalid data can be completely erased from the storage medium, effectively protecting the user's security information.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor. 1 is a flowchart of an invalid data erasing method according to an embodiment of the present invention; FIG. 2 is a flowchart of dirty data recovery according to an embodiment of the present invention; FIG. 3 is an invalid data according to an embodiment of the present invention; FIG. 4 is a structural diagram of another invalid data erasing apparatus according to an embodiment of the present invention.

detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Referring to FIG. 1, an embodiment of the present invention provides an invalid data erasing method, including: Step 10: Receive invalid data erasure instruction information; wherein the "invalid data erasure" in this embodiment indicates that the user needs to store from The invalid data is completely erased on the medium. It should be noted that the "delete" mentioned in the embodiment of the present invention is for the user-level operation, and the erasure according to the embodiment of the present invention is an operation at the storage medium level, and the user thinks The deleted data may actually exist on the storage medium (no erasure is performed); usually, the operating system will directly delete the data that needs to be deleted or erased when receiving the data deletion or erasing command of the SSD. Marked as dirty data, and clear the mapping between the logical address of the data and the physical address. For example, the window 7 operating system, after receiving the SSD, will receive the Trim command once it receives the instruction to delete the data on the SSD. The data to be deleted is marked as dirty data, and the mapping relationship between the logical address and the physical address of the data is cleared. In the embodiment of the present invention, when the user selects the data "invalid data erasure" instruction, the system sends the invalid data erasure instruction information to the storage system, which may be a non-volatile storage system, such as an SSD; Step 12: Immediately start dirty data recovery Process to erase all invalid data;

In the prior art, the system only provides the user with an instruction selection involving data deletion. When the user deletes the data, only the mapping relationship between the logical address and the physical address of the specified data storage is deleted, and the designation is still substantially stored in the storage medium. Data, but usually after the storage system's free space is lower than the preset value, or after the storage system runs for a certain period of time, etc., start the dirty data recovery process. In the embodiment of the present invention, the user is provided with the option of performing invalid data erasure. After receiving the invalid data erasure instruction information, the dirty data recovery process is started immediately, so that all invalid data can be completely erased from the storage medium, and the protection is effectively protected. User's safety information. Referring to FIG. 2, the dirty data collection process is performed by erasing all the invalid data, and the data in all the storage units is erased by traversing the dirty data storage unit linked list, and may include the following process: Step 201: Traversing the dirty data storage unit linked list to obtain a physical storage unit corresponding to the storage unit number in the dirty data storage unit linked list; wherein, the dirty data storage unit linked list is used to manage dirty data, and store the number of the storage unit storing the dirty data, for example The storage block number (block number) is stored in the dirty data storage unit linked list, wherein the storage unit in the embodiment of the present invention represents a data erasing unit or a reading unit in the storage medium, and the size thereof can be defined according to the actual situation, the embodiment of the present invention Generally, when the data is erased, the storage unit may be defined as a block-level unit, and when the data is read, the storage unit may be defined as a page-level unit; Step 202: determining whether the storage unit contains valid data, and if so, Go to step 203, If no, proceed to step 204; taking the storage unit as a block, if the dirty data exceeds a certain ratio in the block, the block number is put into the dirty data link table, or, as long as there is dirty data in the block, The block number is placed in the dirty data link table. Therefore, in the storage medium corresponding to the block number in the dirty data storage unit linked list, there may also be valid data, and the valid data needs to be migrated before the block is erased; Step 203: Move valid data in the storage unit to Other storage units; in the embodiment of the present invention, the migration of data to other storage units generally refers to copying data to other storage units; Step 204: erasing data in the acquired storage units; The stored storage unit is stored in the idle storage unit group. In the specific implementation, the idle storage unit linked list may be maintained, and the free storage unit number is placed in the linked list. Step 205: Determine whether the current linked list item is a dirty data storage unit linked list. The last linked list item, if not, returns to step 201, and if so, ends the process. In the dirty data collection process provided in the above embodiment, each time the dirty data collection process is started, the data in all the storage units in the dirty data storage unit linked list is erased to ensure that the data information that the user needs to delete is not When it is leaked, it improves information security. Referring to FIG. 3, an embodiment of the present invention provides an invalid data erasing apparatus, including: an instruction receiving unit 31, configured to receive invalid data erasure instruction information; and an invalid data erasing unit 32, configured to receive at the instruction receiving unit 31. When the invalid data erase instruction information is invalid, the dirty data collection process is immediately started to erase all invalid data; wherein the "invalid data erasure" in this embodiment indicates that the user needs to completely erase the invalid data from the storage medium. It should be noted that the “delete” mentioned in the embodiment of the present invention is directed to the operation at the user level, and the erasure according to the embodiment of the present invention is an operation at the storage medium level, and the data that the user thinks has been deleted actually has It may still exist on the storage medium (no erasure is performed), and the data is completely deleted only after the erase is actually performed; usually, the operating system receives the data delete or erase command of the SSD directly. Mark the data to be deleted or erased as dirty data, and clear the mapping relationship between the logical address and the physical address of the data. For example, the window 7 operating system, after receiving the SSD, receives an instruction to delete the data on the SSD. When the Trim command is issued, the data to be deleted is marked as dirty data, and the mapping relationship between the logical address and the physical address of the data is cleared. In the embodiment of the present invention, when the user selects the data "invalid data erasure" instruction, the system sends the invalid data erasure instruction information to the storage system, which may be a non-volatile storage system, such as an SSD. In the prior art, the system only provides The user selects an instruction related to data deletion. When the user deletes the data, only the mapping relationship between the logical address and the physical address of the specified data storage is deleted, and the specified data is still substantially stored in the storage medium, and is usually in the storage system. The dirty data recovery process is started after the free space is lower than the preset value or after the storage system runs for a certain period of time. In the embodiment of the present invention, the user is provided with the option of performing invalid data erasure. After receiving the invalid data erasure instruction information, the dirty data recovery process is started immediately, so that all invalid data can be completely erased from the storage medium, and the protection is effectively protected. User's safety information. Referring to FIG. 4, an embodiment of the present invention further provides an invalid data erasing apparatus, including: an instruction receiving unit 41, configured to receive invalid data erasure instruction information; and an invalid data erasing unit 42 for receiving at the instruction receiving unit 31. When the invalid data erase instruction information is reached, the dirty data storage unit linked list is traversed, and all the data in all the storage units are erased;

The invalid data erasing unit 42 includes: a searching unit 421, configured to traverse the dirty data storage unit linked list, and obtain a physical storage unit corresponding to the storage unit number in the dirty data storage unit linked list;

The first determining unit 422 is configured to determine whether the acquired storage unit includes valid data, and if yes, transfer the valid data in the storage unit to another storage unit, and then issue an invalid data erasure command; if not, The invalid data erasing instruction is directly issued; the processing unit 423 is configured to receive the invalid data erasing instruction sent by the determining unit, and erase the data in the obtained storage unit according to the instruction;

The second determining unit 424 is configured to determine whether the current linked list item is the dirty data storage unit chain The last linked list entry in the entry, if not, the instruction lookup unit 421 continues to traverse the dirty data storage unit linked list entry to obtain the next physical storage unit to be erased until the data in the corresponding physical storage unit in the dirty data storage unit linked list entry Erase all. The invalid data erasing apparatus provided by the embodiment of the present invention, after receiving the invalid data erasing instruction, erases data in all the storage units in the dirty data storage unit linked list to ensure the data information that needs to be deleted by the user. Not leaked, improve information security. The embodiment of the present invention further provides a storage system, including the invalid data erasing device described in the embodiment corresponding to FIG. 3 or FIG. 4; wherein the storage system may be a non-volatile storage system, such as an SSD. The storage system provided by the embodiment of the present invention, after receiving the invalid data erasing instruction, erases data in all the storage units in the dirty data storage unit linked list to ensure that the data information that needs to be deleted by the user is not leaked. , improve information security. It will be understood by those skilled in the art that all or part of the steps of implementing the above embodiments may be completed by a program instructing related hardware, and the program may be stored in a computer readable storage medium, the storage medium being a ROM. /RAM, disk, CD, etc.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

Rights request

1. An invalid data erasing method, comprising:

Receiving invalid data erasure instruction information;

Start the dirty data reclamation process immediately to erase all invalid data.

The invalid data erasing method according to claim 1, wherein the dirty data recovery process comprises: traversing the dirty data storage unit linked list, and erasing all the data in all the storage units.

The invalid data erasing method according to claim 2, wherein the traversing the dirty data storage unit linked list and erasing all the data in all the storage units comprises:

Traversing the dirty data storage unit linked list, and obtaining a physical storage unit corresponding to the storage unit number in the linked list entry;

Determining whether the acquired storage unit contains valid data, and if yes, after migrating the valid data in the storage unit to another storage unit, erasing the data in the acquired storage unit, and if not, The data in the acquired storage unit is erased;

Determining whether the current linked list entry is the last linked list entry in the dirty data storage unit linked list, and if not, returning the step of traversing the dirty data storage unit linked list to obtain a physical storage unit corresponding to the storage unit number in the linked list entry.

4. An invalid data erasing device, comprising:

An instruction receiving unit, configured to receive invalid data erasure instruction information;

The invalid data erasing unit is configured to immediately start the dirty data recycling process to erase all invalid data when the instruction receiving unit receives the invalid data erasing instruction information.

The invalid data erasing apparatus according to claim 4, wherein the invalid data erasing unit is specifically configured to traverse the dirty data storage unit linked list when the instruction receiving unit receives the invalid data erasing instruction information. , erase all the data in all the storage units.

The invalid data erasing apparatus according to claim 4 or 5, wherein the invalid data erasing unit comprises:

a searching unit, configured to traverse the dirty data storage unit linked list, and obtain a physical storage unit corresponding to the storage unit number in the linked list of the dirty data storage unit;

a first determining unit, configured to determine whether the obtained storage unit contains valid data, if In addition to the instruction; if not, the invalid data erase command is directly issued;

a processing unit, configured to receive an invalid data erase instruction sent by the determining unit, and erase data in the acquired storage unit according to the instruction;

a second determining unit, configured to determine whether the current linked list entry is the last linked list entry in the dirty data storage unit linked list entry, and if not, instructing the searching unit to continue to traverse the dirty data storage unit linked list entry, obtaining the next need to be erased The physical storage unit is erased until the data in the corresponding physical storage unit in the dirty data storage unit linked list entry.

A memory system, comprising any of the invalid data erasing devices described in claims 4 to 5.

The storage system according to claim 7, wherein the storage system is a solid state hard disk.