Host device and method for accessing a virtual file in a storage device by bypassing a cache in the host device

• US 8,301,715 B2
• Filed: 06/29/2010
• Issued: 10/30/2012
• Est. Priority Date: 05/20/2010
• Status: Active Grant

• Current Assignee: Western Digital Israel Limited (Western Digital Corporation)
• Original Assignee: SanDisk IL Ltd. (Western Digital Corporation)
• Inventors: Ittah, Eyal, Hahn, Judah Gamliel, Drori, Yehuda, Meza, Joseph, Yoon, In-Soo, Cooper, Ofir
• Primary Examiner(s): JEAN GILLES, JUDE
• Application Number:
  US12/826,626
• Publication Number:
  US 20110289178A1
• Time in Patent Office: 854 Days
• Field of Search: 709/213, 709/220, 709/203, 709/206
• US Class Current: 709/213
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories

Abstract

A host device is provided comprising an interface configured to communicate with a storage device having a public memory area and a private memory area, wherein the public memory area stores a virtual file that is associated with content stored in the private memory area. The host device also comprises a cache, a host application, and a server. The server is configured to receive a request for the virtual file from the host application, send a request to the storage device for the virtual file, receive the content associated with the virtual file from the private memory area of the storage device, wherein the content is received by bypassing the cache, generate a response to the request from the host application, the response including the content, and send the response to the host application. In one embodiment, the server is a hypertext transfer protocol (HTTP) server. In another embodiment, the server can determine if a request is associated with a normal user permission or a super user permission, and send a response to the host application only if it is determined that the request is associated with the normal user permission.

Claims

1. A host device comprising:

an interface configured to communicate with a storage device having a public memory area and a private memory area, wherein the public memory area stores a virtual file that is associated with content stored in the private memory area;

a cache;

a host application in communication with the cache; and

a server in communication with the host application and the interface, wherein the server is configured to;

receive a request for the virtual file from the host application,

send a request to the storage device for the virtual file,

receive the content associated with the virtual file from the private memory area of the storage device, wherein the content is received by bypassing the cache,

generate a response to the request from the host application, the response including the content, and

send the response to the host application.

2. The host device of claim 1 further comprising an operating system, and wherein the server is further configured to send an instruction to the operating system to cause the operating system to bypass the cache when a response to the request for the virtual file is received from the storage device.

3. The host device of claim 2, wherein the instruction to bypass the cache comprises an O_DIRECT flag.

4. The host device of claim 1, wherein the server comprises a hypertext transfer protocol (HTTP) server.

5. The host device of claim 4, wherein the request received by the HTTP server comprises an HTTP Get request.

6. The host device of claim 4, wherein the HTTP server is further configured to:

receive a universal resource locator (URL) of the virtual file from the host application; and

translate the URL received from the host application to an address of the virtual file in the public memory area of the storage device.

7. The host device of claim 1, wherein the server is further configured to determine if the host application has permission to access the content.

8. The host device of claim 7, wherein the server is further configured to determine if the host application has permission based on an identifier received from the host application.

9. The host device of claim 1, wherein the server is further configured to log-in to an access control record on the storage device in order to open the virtual file.

10. The host device of claim 9, wherein the access control record contains a permissions control record, and wherein the server receives the content associated with the virtual file from the private area of the storage device only if the permissions control record indicates that the host device has permission to receive the content.

11. The host device of claim 1, wherein the server is further configured to create a secured session with the storage device, create a stream to the private memory area, use read stream operations to extract encrypted content from the private memory area of the storage device, and decrypting the encrypted content.

12. The host device of claim 1, wherein the server is further configured to:

determine if the request from the host application is associated with a normal user permission or a super user permission; and

send the response to the host application only if it is determined that the request is associated with the normal user permission.

13. The host device of claim 12, wherein the server is further configured to determine if the request from the host application is associated with the normal user or the super user permission by analyzing a “

ro.secure”

system property.

14. The host device of claim 12, wherein the server is further configured to determine if the request from the host application is associated with the normal user or the super user permission by analyzing a user identifier.

15. A method for accessing a virtual file in a storage device by bypassing a cache in a host device, the method comprising:

performing the following in a server in host device, wherein the host device is in communication with a storage device having a public memory area and a private memory area, and wherein the public memory area stores a virtual file that is associated with content stored in the private memory area;

receiving a request for the virtual file from a host application in the host device;

sending a request to the storage device for the virtual file;

receiving the content associated with the virtual file from the private memory area of the storage device, wherein the content is received by bypassing a cache in the host device;

generating a response to the request from the host application, the response including the content, and

sending the response to the host application.

16. The method of claim 15, wherein the host device further comprises an operating system, and wherein the method further comprises sending an instruction to the operating system to cause the operating system to bypass the cache when a response to the request for the virtual file is received from the storage device.

17. The method of claim 16, wherein the instruction to bypass the cache comprises an O_DIRECT flag.

18. The method of claim 15, wherein the server comprises a hypertext transfer protocol (HTTP) server.

19. The method of claim 18, wherein the request received by the HTTP server comprises an HTTP Get request.

20. The method of claim 18 further comprising:

receiving a universal resource locator (URL) of the virtual file from the host application; and

translating the URL received from the host application to an address of the virtual file in the public memory area of the storage device.

21. The method of claim 15 further comprising:

determining if the host application has permission to access the content.

22. The method of claim 21, wherein the server determines if the host application has permission based on an identifier received from the host application.

23. The method of claim 15 further comprising:

logging-in to an access control record on the storage device in order to open the virtual file.

24. The method of claim 23, wherein the access control record contains a permissions control record, and wherein the server receives the content associated with the virtual file from the private area of the storage device only if the permissions control record indicates that the host device has permission to receive the content.

25. The method of claim 15 further comprising:

creating a secured session with the storage device;

creating a stream to the private memory area;

using read stream operations to extract encrypted content from the private memory area of the storage device; and

decrypting the encrypted content.

26. The method of claim 15 further comprising:

determining if the request from the host application is associated with a normal user permission or a super user permission; and

sending the response to the host application only if it is determined that the request is associated with the normal user permission.

27. The method of claim 26, wherein the server is further configured to determine if the request from the host application is associated with the normal user or the super user permission by analyzing a “

ro.secure”

system property.

28. The method of claim 26, wherein the server is further configured to determine if the request from the host application is associated with the normal user or the super user permission by analyzing a user identifier.