Method and device for realizing x86 cloud application file isolation

Abstract

The invention provides a method and device for achieving x86 cloud application file isolation, and the method comprises the steps that when a cloud application accesses a target file, a file system filtering drive program registered in a file system drive stack isolates the access of the cloud application to the target file into a virtual file directory tree corresponding to the cloud application, according to the method, the virtual file directory trees corresponding to the same cloud application are mutually isolated, and / or the virtual file directory trees corresponding to different cloud applications are mutually isolated, so that independent file storage and access spaces can be provided for the cloud applications of different users on the same x86 server, the security, isolation and high efficiency of file operation are ensured, and the user experience is improved. And meanwhile, the overall performance of the cloud application is not influenced.

Description

Technical Field

[0001] The present invention relates to the field of cloud applications, and in particular to a method and device for implementing x86 cloud application file isolation. Background Art

[0002] With the rise of x86 cloud applications (i.e., cloud applications running on x86 servers), multiple users may run different cloud applications or multiple instances of the same cloud application on the same x86 server at the same time. In this shared environment, file management becomes particularly important: if multiple users' application files are mixed and stored in the same file system, users may accidentally access or modify other users' files, resulting in data leakage or application file damage. In addition, the dynamic and complex nature of x86 cloud applications also requires an efficient, flexible and low-overhead file isolation method.

[0003] In view of this, how to provide a method to implement x86 cloud application file isolation to provide independent file storage and access space for cloud applications of different users on the same x86 server, ensure the security, isolation and efficiency of file operations, and at the same time not affect the overall performance of cloud applications, has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the embodiments of the present application provide a method and device for implementing x86 cloud application file isolation.

[0005] In a first aspect, an embodiment of the present application provides a method for implementing x86 cloud application file isolation, which is applied to an x86 server, including: When a cloud application accesses a target file, the file system filter driver registered in the file system driver stack isolates the cloud application's access to the target file into a virtual file directory tree corresponding to the cloud application. The virtual file directory trees corresponding to the same cloud application are isolated from each other, and / or the virtual file directory trees corresponding to different cloud applications are isolated from each other.

[0006] In a second aspect, an embodiment of the present application further provides a device for implementing x86 cloud application file isolation, which is applied to an x86 server and includes: The isolation unit is used to isolate the cloud application's access to the target file to the virtual file directory tree corresponding to the cloud application by the file system filter driver registered in the file system driver stack when the cloud application accesses the target file, so that the virtual file directory trees corresponding to the same cloud application are isolated from each other, and / or the virtual file directory trees corresponding to different cloud applications are isolated from each other.

[0007] In a third aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for implementing x86 cloud application file isolation as described in the first aspect are executed.

[0008] In a fourth aspect, an embodiment of the present application further provides an electronic device, comprising: a processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the storage medium through the bus, and the processor executes the machine-readable instructions to perform the steps of the method for implementing x86 cloud application file isolation as described in the first aspect.

[0009] In summary, the method and device, electronic device and storage medium for implementing x86 cloud application file isolation provided by the embodiments of the present application, when a cloud application accesses a target file, the cloud application's access to the target file is isolated in a virtual file directory tree corresponding to the cloud application through the file system filter driver registered in the file system driver stack, and the file spaces of different users are completely isolated, as if each user has his or her own independent file system, and the scheme only processes the cloud application's access to the target file, and does not process the system's access to the target file, thereby being able to provide independent file storage and access space for different users' cloud applications on the same x86 server, thereby ensuring the security, isolation and efficiency of file operations without affecting the overall performance of the cloud application. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A flowchart of an embodiment of a method for implementing x86 cloud application file isolation provided in an embodiment of the present application; Figure 2 A schematic diagram of a structure of an embodiment of a device for implementing x86 cloud application file isolation provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0011] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0012] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0013] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0014] Reference Figure 1 As shown, an embodiment of the present application provides a flow chart of a method for implementing x86 cloud application file isolation, which is applied to an x86 server (the server is a cloud server running a cloud application), including: S10. When a cloud application accesses a target file, the file system filter driver registered in the file system driver stack isolates the cloud application's access to the target file into a virtual file directory tree corresponding to the cloud application. The virtual file directory trees corresponding to the same cloud application are isolated from each other, and / or the virtual file directory trees corresponding to different cloud applications are isolated from each other.

[0015] In this embodiment, it should be noted that the file system filter driver is a kernel module that needs to be loaded into the kernel. It is responsible for intercepting the access operation request of the cloud application to the file and mapping the request to the virtual file directory tree corresponding to the cloud application. For example, the access operation request of the cloud application XXX of user A to the file is mapped to the directory O:\gs1\, and the access operation request of the cloud application YYY of user B to the file is mapped to the directory O:\gs2\, thereby achieving deep interception and control of file operations, ensuring that the operations of the cloud applications of different users on the file do not affect each other, and achieving stable multi-user simultaneous use. In addition, the callback notification created by the process can be captured by the process callback notification module registered to the system, and the cloud application process and the virtual file directory tree can be bound.

[0016] The method for implementing x86 cloud application file isolation provided in the embodiment of the present application, when a cloud application accesses a target file, isolates the cloud application's access to the target file to a virtual file directory tree corresponding to the cloud application through a file system filter driver registered in the file system driver stack, and completely isolates the file spaces of different users, as if each user has his or her own independent file system. Moreover, the scheme only processes the cloud application's access to the target file, and does not process the system's access to the target file. Therefore, it is possible to provide independent file storage and access space for cloud applications of different users on the same x86 server, thereby ensuring the security, isolation, and efficiency of file operations without affecting the overall performance of the cloud application.

[0017] Based on the aforementioned method embodiment, the file system filter driver registered in the file system driver stack isolates the cloud application's access to the target file into the virtual file directory tree corresponding to the cloud application, which may include: When the cloud application requests to open the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the handle of the target file under the mapping directory is returned; otherwise, the handle of the target file requested to be opened by the cloud application is returned; and / or When the cloud application requests to create a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application, and if not, creates the target file under the mapping directory; and / or When the cloud application requests to write a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is written; otherwise, the target file requested to be written by the cloud application is copied to the mapping directory, and the target file under the mapping directory is written; and / or When the cloud application requests to delete the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application, and if so, deletes the target file under the mapping directory; and / or When a cloud application requests to rename a target file, the file system filter driver determines whether the target file exists under a mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is renamed; otherwise, the target file requested to be renamed by the cloud application is copied to the mapping directory, and the target file under the mapping directory is renamed.

[0018] In this embodiment, it should be noted that the directory of the target file corresponds one-to-one to the mapping directory of the target file in the virtual file directory tree corresponding to the cloud application.

[0019] When a cloud application requests to open a target file, the file system filter driver will preferentially return the handle of the target file under the mapped directory in the virtual file directory tree corresponding to the cloud application. Only when the target file does not exist under the mapped directory in the virtual file directory tree corresponding to the cloud application, will the handle of the target file in the real directory be returned. For example, the original directory of the virtual file directory tree is O:\gs1\, and the path of the target file requested to be opened by the cloud application is C:\A\a.txt, then if a.txt exists under the directory O:\gs1\C\A\, the handle of O:\gs1\C\A\a.txt is returned; or if a.txt does not exist under the directory O:\gs1\C\A\, the handle of C:\A\a.txt is returned, wherein the directory O:\gs1\C\A\ is the mapped directory of the target file C:\A\a.txt requested to be opened by the cloud application in the virtual file directory tree corresponding to the cloud application.

[0020] When the cloud application requests to create a target file, the file system filter driver will redirect the target file path to the corresponding virtual file directory tree to create the target file in the virtual file directory tree. For example, the original directory of the virtual file directory tree is O:\gs1\, and the path of the target file requested to be created by the cloud application is C:\A\a.txt. Then, the a.txt file can be created under the directory O:\gs1\C\A\. The directory O:\gs1\C\A\ is the mapping directory of the target file C:\A\a.txt requested to be created by the cloud application in the virtual file directory tree corresponding to the cloud application. It can be understood that when creating, it is necessary to determine whether there is an a.txt file under the directory O:\gs1\C\A\. If not, then the a.txt file is directly created under the directory O:\gs1\C\A\. Otherwise, then the a.txt file is created under the directory O:\gs1\C\A\ and overwrites the a.txt file originally existing under the directory O:\gs1\C\A\.

[0021] When a cloud application requests to write a target file, the file system filter driver will redirect the target file path to the corresponding virtual file directory tree. Specifically: the file system filter driver will determine whether the target file requested to be written by the cloud application exists under the mapping directory in the virtual file directory tree. If so, the write operation will be performed on the existing target file; or if not, the target file requested to be written by the cloud application will be copied to the mapping directory in the virtual file directory tree, and the write operation will be performed on the target file copied to the mapping directory. For example, the original directory of the virtual file directory tree is O:\gs1\, and the path of the target file requested to be written by the cloud application is C:\A\a.txt. If the a.txt file exists in the directory O:\gs1\C\A\, the write operation is performed directly on O:\gs1\C\A\a.txt. Otherwise, C:\A\a.txt is first copied to the directory O:\gs1\C\A\, and then the write operation is performed on O:\gs1\C\A\a.txt. The directory O:\gs1\C\A\ is the mapping directory of the target file C:\A\a.txt requested to be written by the cloud application in the virtual file directory tree corresponding to the cloud application.

[0022] When a cloud application requests to delete a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is deleted. Otherwise, a message of successful deletion can be directly returned to the cloud application, or the target file under the real directory can be copied to the mapping directory of the target file in the virtual file directory tree corresponding to the cloud application, and then the target file under the mapping directory is deleted. For example, the original directory of the virtual file directory tree is O:\gs1\, and the path of the target file requested to be deleted by the cloud application is C:\A\a.txt. If a.txt exists in the directory O:\gs1\C\A\, then O:\gs1\C\A\a.txt is directly deleted. Otherwise, a message indicating that C:\A\a.txt has been successfully deleted can be directly returned to the cloud application, or C:\A\a.txt can be copied to the directory O:\gs1\C\A\ first, and then O:\gs1\C\A\a.txt can be deleted. Among them, the directory O:\gs1\C\A\ is the mapping directory of the target file C:\A\a.txt requested to be deleted by the cloud application in the virtual file directory tree corresponding to the cloud application.

[0023] When a cloud application requests to rename a target file, the file system filter driver program will redirect the target file path to the corresponding virtual file directory tree to rename the target file in the virtual file directory tree. Specifically: if the target file exists in a mapping directory in the virtual file directory tree corresponding to the cloud application, the target file in the mapping directory will be renamed directly; otherwise, the target file in the real directory will need to be copied to the mapping directory first, and then the target file in the mapping directory will be renamed. For example, the original directory of the virtual file directory tree is O:\gs1\, and the path of the target file that the cloud application requests to be renamed is C:\A\a.txt. If an a.txt file exists in the directory O:\gs1\C\A\, then O:\gs1\C\A\a.txt is directly renamed. Otherwise, C:\A\a.txt is first copied to the directory O:\gs1\C\A\, and then O:\gs1\C\A\a.txt is renamed. The directory O:\gs1\C\A\ is the mapping directory of the target file C:\A\a.txt that the cloud application requests to be renamed in the virtual file directory tree corresponding to the cloud application.

[0024] In addition, it should be noted that each time a cloud application accesses a target file, relevant access information can be recorded, such as the full path, suffix, size, access time, access operation (such as creation, writing, deletion, renaming, etc.) of the accessed file.

[0025] Based on the aforementioned method embodiment, the file system filter driver registered in the file system driver stack isolates the cloud application's access to the target file into the virtual file directory tree corresponding to the cloud application, and may also include: When the cloud application requests to query the target file directory, the file system filter driver merges the target file directory and the mapping directory of the target file directory in the virtual file directory tree corresponding to the cloud application, and returns the merged result.

[0026] In the present embodiment, it should be noted that, for the cloud application, its access to the target file is mapped to the virtual file directory tree. Therefore, when the cloud application requests to query the target file directory, it is necessary to merge the target file directory and the mapping directory in the virtual file directory tree to return the accurate directory content. For example, there are files a.txt and b.txt under the directory C:\A\, and there is file c.txt under the mapped directory O:\gs1\C\A\, and file b.txt is marked for deletion. The cloud application requests to query the directory C:\A\. After the directory C:\A\ and the mapped directory O:\gs1\C\A\ are merged, there are files a.txt and c.txt under the directory C:\A\, and what is returned to the cloud application is a list of files a.txt and c.txt.

[0027] Based on the foregoing method embodiment, the method may further include: When the cloud application exits, delete all directories except the original directory in the virtual file directory tree corresponding to the cloud application.

[0028] In this embodiment, assuming that the original directory of the virtual file directory tree is O:\gs1\, when the cloud application exits, the objects and files under the directory O:\gs1\ need to be deleted so that the next user can use the cloud application immediately.

[0029] Based on the foregoing method embodiment, the method may further include: Caches the access information of cloud applications to target files.

[0030] In this embodiment, a cache mechanism can be used to improve the file access speed. Specifically, the file system filter driver can cache the information of the most recently accessed files in the memory. When accessing the same file again, the relevant information can be directly obtained from the cache, thereby reducing the number of I / O operations on the actual file system, thereby improving performance. In addition, when caching file information, the summary of the file path can be used as an index, and the frequently accessed file information can be placed in front according to the file access frequency, so as to further improve the file operation speed.

[0031] Reference Figure 2As shown, it is a structural schematic diagram of a device for implementing x86 cloud application file isolation provided by an embodiment of the present application, and the device is applied to an x86 server, including: The isolation unit 20 is used to isolate the cloud application's access to the target file to the virtual file directory tree corresponding to the cloud application when the cloud application accesses the target file. The virtual file directory trees corresponding to the same cloud application are isolated from each other, and / or the virtual file directory trees corresponding to different cloud applications are isolated from each other.

[0032] The device for implementing x86 cloud application file isolation provided in the embodiment of the present application, when a cloud application accesses a target file, isolates the cloud application's access to the target file to a virtual file directory tree corresponding to the cloud application through a file system filter driver registered in the file system driver stack, and completely isolates the file spaces of different users, as if each user has his or her own independent file system. Moreover, the scheme only processes the cloud application's access to the target file, and does not process the system's access to the target file. Therefore, it is possible to provide independent file storage and access space for cloud applications of different users on the same x86 server, thereby ensuring the security, isolation, and efficiency of file operations without affecting the overall performance of the cloud application.

[0033] Based on the above device embodiment, the isolation unit can be used for: When the cloud application requests to open the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the handle of the target file under the mapping directory is returned; otherwise, the handle of the target file requested to be opened by the cloud application is returned; and / or When the cloud application requests to create a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application, and if not, creates the target file under the mapping directory; and / or When the cloud application requests to write a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is written; otherwise, the target file requested to be written by the cloud application is copied to the mapping directory, and the target file under the mapping directory is written; and / or When the cloud application requests to delete the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application, and if so, deletes the target file under the mapping directory; and / or When a cloud application requests to rename a target file, the file system filter driver determines whether the target file exists under a mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is renamed; otherwise, the target file requested to be renamed by the cloud application is copied to the mapping directory, and the target file under the mapping directory is renamed.

[0034] Based on the above device embodiment, the isolation unit may also be used for: When the cloud application requests to query the target file directory, the file system filter driver merges the target file directory and the mapping directory of the target file directory in the virtual file directory tree corresponding to the cloud application, and returns the merged result.

[0035] Based on the above device embodiment, the isolation unit may also be used for: When the cloud application exits, delete all directories except the original directory in the virtual file directory tree corresponding to the cloud application.

[0036] Based on the above device embodiment, the isolation unit may also be used for: Caches the access information of cloud applications to target files.

[0037] The device for implementing x86 cloud application file isolation provided in the embodiment of the present application has an implementation process that is consistent with the method for implementing x86 cloud application file isolation provided in the embodiment of the present application, and the effect that can be achieved is also the same as the method for implementing x86 cloud application file isolation provided in the embodiment of the present application, and will not be repeated here.

[0038] like Figure 3 As shown, an electronic device provided by an embodiment of the present application includes: a processor 30, a memory 31 and a bus 32, wherein the memory 31 stores machine-readable instructions executable by the processor 30, and when the electronic device is running, the processor 30 communicates with the memory 31 through the bus 32, and the processor 30 executes the machine-readable instructions to perform the steps of the method for implementing x86 cloud application file isolation as described above.

[0039] Specifically, the above-mentioned memory 31 and processor 30 can be general-purpose memory and processor, which are not specifically limited here. When the processor 30 runs the computer program stored in the memory 31, it can execute the above-mentioned method for implementing x86 cloud application file isolation.

[0040] Corresponding to the above-mentioned method for implementing x86 cloud application file isolation, an embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for implementing x86 cloud application file isolation are executed.

[0041] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for implementing x86 cloud application file isolation, characterized in that: Applicable to x86 servers, including: When a cloud application accesses a target file, the file system filter driver registered in the file system driver stack isolates the cloud application's access to the target file into a virtual file directory tree corresponding to the cloud application. The virtual file directory trees corresponding to the same cloud application are isolated from each other, and / or the virtual file directory trees corresponding to different cloud applications are isolated from each other.

2. The method according to claim 1, characterized in that The file system filter driver registered in the file system driver stack isolates the cloud application's access to the target file into a virtual file directory tree corresponding to the cloud application, including: When the cloud application requests to open the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the handle of the target file under the mapping directory is returned; otherwise, the handle of the target file requested to be opened by the cloud application is returned; and / or When the cloud application requests to create a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application, and if not, creates the target file under the mapping directory; and / or When the cloud application requests to write a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is written; otherwise, the target file requested to be written by the cloud application is copied to the mapping directory, and the target file under the mapping directory is written; and / or When the cloud application requests to delete the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application, and if so, deletes the target file under the mapping directory; and / or When a cloud application requests to rename a target file, the file system filter driver determines whether the target file exists under a mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is renamed; otherwise, the target file requested to be renamed by the cloud application is copied to the mapping directory, and the target file under the mapping directory is renamed.

3. The method according to claim 1 or 2, characterized in that The file system filter driver registered in the file system driver stack isolates the cloud application's access to the target file into the virtual file directory tree corresponding to the cloud application, and further includes: When the cloud application requests to query the target file directory, the file system filter driver merges the target file directory and the mapping directory of the target file directory in the virtual file directory tree corresponding to the cloud application, and returns the merged result.

4. The method according to claim 1, characterized in that Also includes: When the cloud application exits, delete all directories except the original directory in the virtual file directory tree corresponding to the cloud application.

5. The method according to claim 1, characterized in that Also includes: Caches the access information of cloud applications to target files.

6. A device for implementing x86 cloud application file isolation, characterized in that: Applicable to x86 servers, including: The isolation unit is used to isolate the cloud application's access to the target file to the virtual file directory tree corresponding to the cloud application by the file system filter driver registered in the file system driver stack when the cloud application accesses the target file, so that the virtual file directory trees corresponding to the same cloud application are isolated from each other, and / or the virtual file directory trees corresponding to different cloud applications are isolated from each other.

7. The device according to claim 6, characterized in that The isolation unit is used for: When the cloud application requests to open the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, it returns the handle of the target file under the mapping directory. Otherwise, it returns the handle of the target file requested to be opened by the cloud application. and / or When the cloud application requests to create a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If not, the target file is created under the mapping directory. and / or When a cloud application requests to write a target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is written; otherwise, the target file requested to be written by the cloud application is copied to the mapping directory, and the target file under the mapping directory is written; and / or When the cloud application requests to delete the target file, the file system filter driver determines whether the target file exists under the mapping directory in the virtual file directory tree corresponding to the cloud application, and if so, deletes the target file under the mapping directory; and / or When a cloud application requests to rename a target file, the file system filter driver determines whether the target file exists under a mapping directory in the virtual file directory tree corresponding to the cloud application. If so, the target file under the mapping directory is renamed; otherwise, the target file requested to be renamed by the cloud application is copied to the mapping directory, and the target file under the mapping directory is renamed.

8. The device according to claim 6 or 7, characterized in that The isolation unit is further used for: When the cloud application requests to query the target file directory, the file system filter driver merges the target file directory and the mapping directory of the target file directory in the virtual file directory tree corresponding to the cloud application, and returns the merged result.

9. The device according to claim 6, characterized in that The isolation unit is further used for: When the cloud application exits, delete all directories except the original directory in the virtual file directory tree corresponding to the cloud application.

10. The device according to claim 6, characterized in that The isolation unit is further used for: Caches the access information of cloud applications to target files.

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