CN100454302C - A file management system and management method - Google Patents

Abstract

The invention discloses a file management system and a management method, which are used for safely managing version files in an embedded system. The file management system includes: a first parameter storage unit, configured to store parameter information of the version file; a second parameter storage unit, configured to be mutually active and backup with the first parameter storage unit, and to store the version file information Parameter information; a file storage unit, used to store the version file according to the parameter information of the version file recorded by the first or second parameter storage unit, wherein each file has A version and B version, according to the position parameter stored separately. The method of the present invention manages the version files in the embedded system based on the above system. The invention can improve the reliability of the embedded system and reduce the maintenance cost of the product, thereby enhancing the market competitiveness of the product.

Description

A file management system and management method

technical field

The invention relates to the technical field of file management, in particular to a file management system and a management method.

Background technique

At present, more and more embedded devices appear in people's lives. These devices are often computer systems with embedded processors, and communication systems are representative of this aspect. The current communication system is becoming more and more complex. A system is often composed of a large number of nodes with processing capabilities, and these nodes are often an embedded computer system. The communication system is a system that requires high reliability, and it also puts forward high requirements for the management of version files of each processing node in the communication system.

Due to the complexity of the communication system itself, the communication system has software version upgrade requirements for the purpose of correcting software defects; the function expansion of the communication system, such as supporting new business functions through software upgrades, also requires version upgrades objectively. Version maintenance is an important part of communication system operation and maintenance. The complexity of the software itself (possible misuse), and the occurrence of some abnormal conditions (such as power failure) may lead to the destruction of the version. Once the version is damaged, the system cannot start normally. On the one hand, it will greatly increase the maintenance cost. On the other hand, as a provider of commercial products, it will also have a negative impact on the provider's reputation and subsequent market opportunities.

Therefore, in the face of complex embedded systems represented by communication systems, on the one hand, it is necessary to provide a version file management system to realize the convenient management of many software versions, and at the same time, it is necessary to provide a necessary means to ensure the operation of version files. safety.

Contents of the invention

The technical problem to be solved by the present invention is to provide a file management system and management method, which specially designs the version file management system in the embedded system, provides a security mechanism for file operation, and ensures the safety and high reliability of the version file operation Sex; at the same time shield the complexity of the implementation of the security mechanism to facilitate the use of upper-layer applications.

The present invention provides a file management system for safely managing version files in an embedded system, the system comprising:

The first parameter storage unit is used to store the parameter information of the version file, including the parameter storage unit effective sign and serial number, and the name of each file, A version master and backup signs, A version position, B version master and backup signs, B version location, etc.;

The second parameter storage unit is used to be mutually active and standby with the first parameter storage unit, and store the parameter information of the version file, including the effective flag and serial number of the parameter storage unit, as well as the name of each file, version A master Standby logo, A version location, B version master/standby logo, B version location, etc.;

The file storage unit is configured to store the version files according to the file parameters recorded by the first or second parameter storage unit, wherein each file has a version A and a version B, which are stored respectively according to position parameters.

The first and second parameter storage units further include a valid flag for version A and a valid flag for version B.

The document management system further includes:

The main and standby parameter judging unit is used to judge the main parameter storage unit and the standby parameter storage unit in the first and second parameter storage units according to the unit effective flag and serial number information recorded in the first and second parameter storage units. Parameter storage unit.

The document management system further includes:

The master-standby parameter switching unit is used to read the data image of the current master parameter storage unit into the internal memory according to the master and spare parameter storage unit judged by the master-standby parameter judging unit, and compare it with the file provided by the upper layer application In the file parameter information corresponding to the file name, the active and standby flags of the A version and the active and standby flags of the B version are switched, and the effective flag of the unit recorded in the main parameter storage unit is set to valid, the serial number is incremented, and the modified current master Write the current backup parameter storage unit with the image data of the parameter storage unit to replace the original data.

The document management system further includes:

The read operation unit is used to search the active and standby states of version A and version B of the file in the active parameter storage unit judged by the active and standby parameter judging unit according to the file name provided by the upper layer application, and determine the current active version and its location, and read out the file data of the master version accordingly.

The document management system further includes:

Write operation unit, for according to the file name that is provided by upper-level application, in the master parameter storage unit judged by described master-standby parameter judging unit, look up the main-standby status of version A and version B of this file, determine current standby version and its position, and write new file data in this position to replace the original data, and then use the master-standby parameter switching unit to switch the master-standby state.

The main and standby parameter judging unit includes:

A unit effective flag judging unit is used to compare the unit effective flags recorded in the first and second parameter storage units. If only one is valid, the effective parameter storage unit is the main one, and the other one is the backup;

The serial number judging unit is used to further compare the size of the serial number when the unit valid flags recorded in the first and second parameter storage units are both valid, and the larger one is used as the main one, and the smaller one is reserved.

The present invention further provides a method for using the file management system to manage version files in the embedded system, for reading the files, which is characterized in that it includes the following steps:

selecting the primary parameter storage unit from the first and second parameter storage units;

Find the parameter information of the corresponding file in the main parameter storage unit according to the file name provided by the upper layer application;

According to the active and standby states of version A and version B of the parameter information of the corresponding file, determine the main version and its storage location;

According to the storage location of the main version, read the file data to the user buffer.

The step of selecting the main parameter storage unit includes the following steps:

reading unit effective flag information recorded in the first and second parameter storage units;

Judging the validity of the effective flag information of the unit;

If only one is valid, the valid parameter storage unit is the master;

If they are all valid, further read and compare the serial number information recorded in the first and second parameter storage units, and the one with the larger value is the main one.

The present invention further provides a method for using the file management system to manage version files in an embedded system for writing files, which is characterized in that it includes the following steps:

selecting the primary parameter storage unit from the first and second parameter storage units;

Find the parameter information of the corresponding file in the main parameter storage unit according to the file name provided by the upper layer application;

According to the primary and secondary states of version A and version B recorded in the information of the corresponding file, determine the backup version and its storage location;

Write new version file data in the standby version storage area to replace the original data;

Read the data image of the current main parameter storage unit to the memory;

Switching the active and standby flags of version A and the active and standby flags of version B in the file parameter information corresponding to the file name provided by the upper layer application;

Set the unit valid flag recorded in the main parameter storage unit as valid, and increment the serial number;

Write the modified image data of the current main parameter storage unit into the current standby parameter storage unit to replace the original data.

The step of selecting the main parameter storage unit includes the following steps:

reading unit effective flag information recorded in the first and second parameter storage units;

Judging the validity of the effective flag information of the unit;

If only one is valid, the valid parameter storage unit is the master;

If they are all valid, further read and compare the serial number information recorded in the first and second parameter storage units, and the one with the larger value is the main one.

The present invention further provides a method for using the file management system to manage version files in the embedded system, for switching the active and standby attributes of the specified file A and B versions, characterized in that it includes the following steps:

selecting the primary parameter storage unit from the first and second parameter storage units;

Read the data image of the current main parameter storage unit to the memory;

Switching the active and standby flags of version A and the active and standby flags of version B in the file parameter information corresponding to the file name provided by the upper layer application;

Set the unit valid flag recorded in the main parameter storage unit as valid, and increment the serial number;

Write the modified image data of the current main parameter storage unit into the current standby parameter storage unit to replace the original data.

The step of selecting the main parameter storage unit includes the following steps:

reading unit effective flag information recorded in the first and second parameter storage units;

Judging the validity of the effective flag information of the unit;

If only one is valid, the valid parameter storage unit is the master;

If they are all valid, further read and compare the serial number information recorded in the first and second parameter storage units, and the one with the larger value is the main one.

The present invention specially designs the file management system in the embedded system, adopts a dual-version storage and switching mechanism for version files, and implements transactional operations for updating files and their status on the premise of facilitating the use of upper-layer applications, which can Effectively realize the reliability operation of version file update, greatly enhance the reliability of the system, and prevent version damage that may occur during version file maintenance; at the same time, it is convenient for file users by shielding the complexity of the internal implementation of the file system. Utilizing the file management system and the management method of the invention can significantly improve the reliability of the embedded system and reduce the maintenance cost of the product, thereby improving the market competitiveness of the product.

Description of drawings

FIG. 1 is a schematic diagram of the storage physical space of the file system in the embodiment of the present invention;

Fig. 2 is a schematic structural diagram of the file system parameter area of the file system in the embodiment of the present invention;

Fig. 3 is a schematic diagram of the header information structure of the parameter area of the file system in the embodiment of the present invention;

Fig. 4 is a schematic diagram of the composition format of the file records of the file system in the embodiment of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

This file management system mainly ensures the reliable operation of the version and prevents version damage that may occur during version file maintenance by implementing transactional operations of file changes, including read operations, write operations, and master-standby parameter switching. This file management system generally exists on the FLASH (electrically erasable non-volatile storage device) memory in the system, but is not limited to the FLASH storage device.

Fig. 1 shows a schematic diagram of the memory physical space of the file management system of the present invention, wherein the first parameter storage unit is the file system parameter area A, the second parameter storage unit is the file system parameter area B, and the The file storage unit is the file data area. As shown in Figure 1, the physical storage is divided into three basic parts in this system, and the first two parts are used as the file system parameter area to store the information of the file system itself (file-related information). Two parameter areas, one master and one backup. The third area is used to store the actual version file data, and its use division is stipulated in the main system parameter area (recorded by file information).

Logically, this file management system has the following characteristics:

First, the file system is logically divided into two parts, one part is the file system parameter area (similar to the file allocation table), which is used to store various information states of the file (file storage location, validity, master and backup status, etc.), Hereinafter referred to as "parameter area"; the other part is the file data area, which is used to store actual file data. The structure of the file system is invisible to upper-layer applications (users of files), which is used to shield the complexity of the internal implementation of the file system and facilitate use.

Second, when implementing inside the file system, two storage areas are set up for a single file. When writing operations, the standby storage area is first written, and then the active and standby storage areas are switched; for reading operations, the main storage area is valid, and data is read from the main storage area; these The details of the operation are invisible to the upper-layer application (the user of the file), which is used to shield the complexity of the internal implementation of the file system and facilitate use.

Third, for upper-layer applications (users of files), the file system shields the implementation details of the internal security mechanism. For the upper-layer application, a file corresponds to a storage version, and the reading and writing of the file is performed through the file name. The upper-layer application does not know the dual-version storage and switching mechanism implemented inside the file system.

Fourth, two storage areas are also set up for the file system parameter area. When updating the version file, it is necessary to change the file-related information in the file system parameter area, and perform active-standby switchover for the parameter area to support file and file status modification. transactional operations. By switching the operation mode of the file system parameter area, not only the security of the operation of a single file is guaranteed, but also a security protection mechanism is provided for the security of the entire file system. If the switching mechanism is not adopted, once the parameter area is damaged, the entire file system will be destroyed.

Fifth, the file system provides transactional operations for file rewriting, and the basic unit of protection is the entire file, not a part of the file.

Physically, this file system has the following characteristics:

First, this file system divides the storage area into three areas, the first two areas are the file system parameter area A and B, which store relevant information of all files in the system, such as storage location, master and backup status, and validity information; Only the main parameter area is valid.

Second, when changing the status information of the file, first read the image of the main parameter area into the internal memory, then modify the file information, and then write the updated image of the main parameter area into the standby parameter area. The backup switch is used to realize the safe update of file data and status information.

Third, a file uses a file name flag. For the upper-layer application that uses the file, a file name uniquely corresponds to a file version, and the internal storage of the file is allocated two storage areas, which are divided into master and backup. Valid, the user will always read the main version,

Fig. 2 shows the structure of the file system parameter area of the present file system. It mainly includes the header of a file system parameter area and a series of file information records. Each file information record corresponds to a file, and through the file name mark and index, the file name in the system is unique, and the directory function is not provided.

Wherein, the header of the file system parameter area is shown in FIG. 3 , which includes several fields, as shown in Table 1, for judging the master and backup status of the file system parameter area. The method of judging the master and backup of the parameter area will be explained in Table 1 in the follow-up content

area length describe valid flag 4 It is used to mark the validity of the parameter area, the constant 0x5555AAAA is valid, and other values are invalid. serial number 4 Each time the parameter area is switched, the sequence number is increased by 1 to prevent valid area identification when both parameter areas are valid. reserve 8 Reserved, not used.

Wherein, the format of the file information record is shown in FIG. 4 , which includes several information fields, and the meaning of each field is shown in Table 2, which indicates file-related information.

Form 2

area length (bytes) describe file name 16 A string used to identify the version file A version address 4 A version storage location A version length 4 Area A stores the actual length of the version A version maximum length 4 A version length limit to prevent the written file from being too large and damaging other files Valid flag of version A 2 Valid flag of version A A version master and backup flag 2 Active and standby status of version A B version address 4 B version storage location B version length 4 The actual length of the version stored in area B B version maximum length 4 The B version length limit prevents the written file from being too large and damaging other files B version effective flag 2 B version effective flag B version master and backup flags 2 Active and standby status of version B

Based on the above-mentioned file management system, the processing mechanism of this file system ensures the absolute security of the main version. When the user reads the file, the file system will pass the read content of the main version to the user, and the read operation needs to be realized by the read operation unit; when the user writes the file, the file system will target the backup storage After the write operation is successful, switch between the main and backup versions of the two version storage areas, and the write operation is implemented by the write operation unit; in this case, all operations on the version file are atomic transactions operate. That is to say, if the operation on the file is unsuccessful, the state of the file system will remain in the original state before the operation.

In addition, because in the file system, under normal circumstances, each file has two main and backup versions. In order to meet some other testing and security requirements, the main and standby switching interface of the file is also provided to realize the main and standby switching of the main and standby versions of the file. The switching is realized by the active-standby parameter switching unit.

Since all the operations on the file involve the master/standby judgment of the parameter area, the master/standby judgment method of the parameter area is described below, and the master/standby judgment is realized by the master/standby parameter judgment unit.

The method of judging the master and backup status of the parameter area is as follows:

Step 1: Read the headers of the two parameter areas.

Step 2: Judge the validity of the header valid flag, if only one is valid, then the valid one is the master and the other one is the backup, return to end.

Step 3: If both are valid, then we compare the serial numbers at the head of the parameter area to determine the master and backup of the parameter area. The one with the larger serial number is the primary, and the one with the smaller serial number is the backup. (The effective flag is set as a constant 0x5555AAAA, and the serial number is initialized to 0 when the file system is initialized for the first time, and will be increased by 1 each time an active-standby switchover occurs thereafter).

The implementation steps of the read operation, the write operation, and the active/standby parameter switching operation are described in detail below.

The first embodiment of the present invention is the read operation of the file, which is realized by the read operation unit.

The following describes the read operation. The read operation is relatively simple and does not change the file system at the same time, and will not cause damage to the file or file system. It includes the following steps:

Step 101: Select the main parameter area.

Step 102: Index to related file records in the file information records in the main parameter area according to the file name provided by the file user.

Step 103: From the file record found in step 102, find information such as the storage location and length of the main version.

Step 104: Read file data to user buffer.

The second embodiment of the present invention is the write operation to the file, which is realized by the write operation unit.

The write operation is described below. The write operation is relatively complicated. The transactional operation of file writing is realized by switching the primary and secondary storage areas of the file, and the switching of the primary and secondary storage areas of the file is through the primary and secondary switching of the file system parameter area. To achieve, including the following steps:

Step 201: Obtain the active and standby states of the two parameter areas.

Step 202: Index to relevant file information records in the main parameter area according to the file name.

Step 203: find the backup version storage location from the file information record found in step 202.

Step 204: If the memory is a FLASH device, erase the spare version storage area.

Step 205: Write user version file data in the standby version storage area.

Step 206: If the memory is a FLASH device, erase the spare file system parameter area.

Step 207: Read the image of the primary file system parameter area to the memory, set the primary and backup information of the original primary area of the corresponding file as the backup, and set the primary and secondary information of the original backup area (current file operation area) as the primary And set the valid flag to be valid, and add 1 to the serial number of the head of the parameter area in the image.

Step 208: Master-standby switching of the file system parameter area (write the changed master parameter area image into the backup file system parameter area in step 207), at this time the switching of the file master and backup versions has been realized.

During this operation, we operate on the file in the file backup storage area. If any problems occur during the period (such as abnormal power failure), then the file system parameter area will not realize the master-standby switch, so for the entire file The system parameter area and the original content of the file being operated (existing in the main storage area) are not affected; if the main and standby parameter areas of the file system are successfully switched, then the update process of the entire version file must be completely executed ( successful). This enables transactional operations on versioned file changes.

The third embodiment of the present invention is the master/backup switching of files, which is realized by the master/backup parameter switching unit.

The following describes the master-slave switchover operation of the file. The master-slave switchover operation is similar to the write operation, except that it does not operate on the file content, but only modifies the master-slave attribute of the file in the main parameter area of the file system, so it only involves the file system. The active/standby switchover in the parameter area includes the following steps:

Step 301: Obtain the active and standby states of the two parameter areas.

Step 302: Read the image of the current main parameter area into the memory.

Step 303: Index to the file information record in the main parameter area image in the internal memory according to the file name.

Step 304: Switch the main and standby flags of the two storage areas in the file information record indexed in the main parameter area map in step 303.

Step 305: Increase the serial number of the head of the memory image in the main parameter area by 1, and set the effective flag of the parameter area to be valid.

Step 306: If the memory is a FLASH device, erase the current spare parameter area.

Step 307: Write the image of the active parameter area modified in step 305 into the standby parameter area.

After this process, the master/standby switchover is performed in the parameter area, and the master/standby information of the corresponding file in the master parameter area has been modified after the switchover, thus realizing the master/standby switchover of the file content. Similarly, this process is also transactional operation.

The present invention uses a new method to specially design the version file management system in the embedded system. Under the premise of being convenient for upper-layer applications, it can realize the transactional operation of file modification, which can ensure the high reliability of file operation and prevent version Possible version corruption during file maintenance. The reliability of the embedded system can be significantly improved and the maintenance cost of the product can be reduced, thereby improving the market competitiveness of the product.

Claims (13)

1, a kind of file management system, is used for carrying out security management to the version file in the embedded system, is characterized in that, comprises: The first parameter storage unit is used to store the parameter information of the version file, including unit valid flag and serial number, and the name of each file, A version master and backup flag, A version position, B version master and backup flag, B version Location; The second parameter storage unit is used to interact with the first parameter storage unit as master and backup, and store the parameter information of the version file, including unit valid flag and serial number, and the name of each file, A version master and backup flag , A version location, B version master/standby flag, B version location; The file storage unit is configured to store the version files according to the file parameters recorded by the first or second parameter storage unit, wherein each file has a version A and a version B, which are stored respectively according to position parameters. 2. The system according to claim 1, wherein said first and second parameter storage units further include a valid flag for version A and a valid flag for version B. 3. The system of claim 1, further comprising: The main and standby parameter judging unit is used to judge the main parameter storage unit and the standby parameter storage unit in the first and second parameter storage units according to the unit effective flag and serial number information recorded in the first and second parameter storage units. Parameter storage unit. 4. The system of claim 3, further comprising: The master-standby parameter switching unit is used to read the data image of the current master parameter storage unit into the internal memory according to the master and spare parameter storage unit judged by the master-standby parameter judging unit, and compare it with the file provided by the upper layer application In the file parameter information corresponding to the file name, the active and standby flags of the A version and the active and standby flags of the B version are switched, and the effective flag of the unit recorded in the main parameter storage unit is set to valid, the serial number is incremented, and the modified current master Write the current backup parameter storage unit with the image data of the parameter storage unit to replace the original data. 5. The system of claim 3, further comprising: The read operation unit is used to search the active and standby states of version A and version B of the file in the active parameter storage unit judged by the active and standby parameter judging unit according to the file name provided by the upper layer application, and determine the current active version and its location, and read out the file data of the master version accordingly. 6. The system of claim 4, further comprising: Write operation unit, for according to the file name that is provided by upper-level application, in the master parameter storage unit judged by described master-standby parameter judging unit, look up the main-standby status of version A and version B of this file, determine current standby version and its position, and write new file data in this position to replace the original data, and then use the master-standby parameter switching unit to switch the master-standby state. 7. The system according to claim 3, wherein the main and standby parameter judging unit comprises: A unit effective flag judging unit is used to compare the unit effective flags recorded in the first and second parameter storage units. If only one is valid, the effective parameter storage unit is the main one, and the other one is the backup; The serial number judging unit is used to further compare the size of the serial number when the unit valid flags recorded in the first and second parameter storage units are both valid, and the larger one is used as the main one, and the smaller one is reserved. 8. A method for managing version files in an embedded system using the system as claimed in claim 1, for performing a read operation on the files, comprising the steps of: selecting the primary parameter storage unit from the first and second parameter storage units; Find the parameter information of the corresponding file in the main parameter storage unit according to the file name provided by the upper layer application; According to the active and standby states of version A and version B of the parameter information of the corresponding file, determine the main version and its storage location; According to the storage location of the main version, read the file data to the user buffer. 9. The method according to claim 8, wherein the step of selecting the main parameter storage unit comprises the following steps: reading unit effective flag information recorded in the first and second parameter storage units; Judging the validity of the effective flag information of the unit; If only one is valid, the valid parameter storage unit is the master; If they are all valid, further read and compare the serial number information recorded in the first and second parameter storage units, and the one with the larger value is the main one. 10. A method for managing version files in an embedded system using the system according to claim 1, for writing files, comprising the steps of: selecting the primary parameter storage unit from the first and second parameter storage units; Find the parameter information of the corresponding file in the main parameter storage unit according to the file name provided by the upper layer application; According to the primary and secondary states of version A and version B of the parameter information of the corresponding file, determine the backup version and its storage location; Write new version file data in the standby version storage area to replace the original data; Read the data image of the current main parameter storage unit to the memory; Switching the active and standby flags of version A and the active and standby flags of version B in the file parameter information corresponding to the file name provided by the upper layer application; Set the unit valid flag recorded in the main parameter storage unit as valid, and increment the serial number; Write the modified image data of the current main parameter storage unit into the current standby parameter storage unit to replace the original data. 11. The method according to claim 10, wherein the step of selecting the main parameter storage unit comprises the following steps: reading unit effective flag information recorded in the first and second parameter storage units; Judging the validity of the effective flag information of the unit; If only one is valid, the valid parameter storage unit is the master; If they are all valid, further read and compare the serial number information recorded in the first and second parameter storage units, and the one with the larger value is the main one. 12. A method for managing version files in an embedded system using the system as claimed in claim 1, for switching the active and standby attributes of the specified file A and B versions, characterized in that it comprises the following steps: selecting the primary parameter storage unit from the first and second parameter storage units; Read the data image of the current main parameter storage unit to the memory; Switching the active and standby flags of version A and the active and standby flags of version B in the file parameter information corresponding to the file name provided by the upper layer application; Set the unit valid flag recorded in the main parameter storage unit as valid, and increment the serial number; Write the modified image data of the current main parameter storage unit into the current standby parameter storage unit to replace the original data. 13. The method according to claim 12, wherein the step of selecting the main parameter storage unit comprises the following steps: reading unit effective flag information recorded in the first and second parameter storage units; Judging the validity of the effective flag information of the unit; If only one is valid, the valid parameter storage unit is the master; If they are all valid, further read and compare the serial number information recorded in the first and second parameter storage units, and the one with the larger value is the main one.

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