Electronic device for controlling file system and operating method thereof

• US 10,430,345 B2
• Filed: 08/04/2016
• Issued: 10/01/2019
• Est. Priority Date: 08/12/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Woo-Joong, Lee, Sang-Woo, Yeom, Jun-Beom, Kim, Min-Jung
• Primary Examiner(s): Thai, Hanh B
• Application Number:
  US15/228,567
• Publication Number:
  US 20170046358A1
• Time in Patent Office: 1,153 Days
• Field of Search: 707822
• CPC Class Codes: G06F 12/1009 using page tables, e.g. page table structures
• CPC Class Codes: G06F 12/109 for multiple virtual address spaces, e.g. segmentation G06F12/1036 takes precedence
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: G06F 2212/163 Server or database system
• CPC Class Codes: G06F 2212/651 Multi-level translation tables
• CPC Class Codes: G06F 2212/656 Address space sharing
• CPC Class Codes: G06F 2212/657 Virtual address space management

Abstract

A method of operating an electronic device and the electronic device are provided. The method includes mounting at least one lower file system, which is configured to generate a file object managing a page cache, and mounting a highest file system, to which a virtual file system directly accesses, at a higher layer of a layer corresponding to the lower file system; in response to a file mapping request of a software program, generating a virtual memory area including a virtual address for a file corresponding to the file mapping request; and generating a first virtual address link between a file object of at least one lower file system having a page cache of a file corresponding to the file mapping request and the virtual memory area.

Claims

1. An electronic device comprising:

a memory; and

at least one processor electrically connected to the memory,

wherein the memory stores instructions which, when executed by the at least one processor, cause the at least one processor to;

provide at least one first file system and a second file system stacked above the at least one first file system in the memory,

provide a virtual memory area including a virtual address for a file corresponding to a file mapping request in the memory, and

provide a first virtual address link between the virtual memory area and a file object of the at least one first file system including a page cache of the file corresponding to the file mapping request,

wherein the second file system is directly accessed by a virtual file system, in response to the file mapping request of a software program, and does not include the page cache.

2. The electronic device of claim 1, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to provide a second virtual address link between a file object of the second file system corresponding to the file mapping request and the virtual memory area.

3. The electronic device of claim 2, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to identify file mapping of a process corresponding to the software program on the basis of the second virtual address link.

4. The electronic device of claim 1, wherein the software program includes at least one of an application program, a process loader, and a library loader program, or a combination thereof.

5. The electronic device of claim 1, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to provide another file system, which does not provide a file object managing the page cache, at a higher layer of or a lower layer of a layer corresponding to the at least one first file system.

6. The electronic device of claim 1, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to provide a mapping information link of a file between a file system having the page cache of the file and the virtual memory area.

7. The electronic device of claim 6, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to identify the virtual memory area on the basis of the mapping information link of the file, when page migration or page reclamation of a page cache included in the file system having the page cache of the file is performed.

8. The electronic device of claim 1, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to set a non-mappable flag for a file flag of the at least one file system when at least one file system among a plurality of file systems including at least one of the second file system or the at least one first file system does not maintain a page cache corresponding to the file.

9. The electronic device of claim 8, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to set, when a virtual memory area for the memory mapping is generated with respect to a file system, in which the non-mappable flag is not configured, among the plurality of file systems, the first virtual address link for the virtual memory area and a file system having the page cache of the file, and the second virtual address link between the virtual memory area and the file object of the second file system of the file.

10. The electronic device of claim 9, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to move, when a file system corresponding to a current layer among the plurality of file systems corresponds to a file system in which the non-mappable flag is configured, to a file of the first file system of the file system corresponding to the current layer.

11. The electronic device of claim 10, wherein the memory stores an instruction which, when executed by the at least one processor, causes the processor to:

set, when the moved first file system corresponds to the file system in which the non-mappable flag is not configured, and when a virtual memory area for the memory mapping is generated, the first virtual address link for the virtual memory area and the file system having the page cache of the file, and

set the second virtual address link for the virtual memory area and the second file system of the file.

12. The electronic device of claim 8, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to set at least one link of an up-link corresponding to a file system mounted at an upper side of each file system of the plurality of file systems, and a down-link corresponding to a file system mounted at lower side of the each file system.

13. The electronic device of claim 12, wherein the memory stores an instruction which, when executed by the at least one processor, causes the at least one processor to set the non-mappable flag for a file system that does not maintain the page cache corresponding to the file among the plurality of file systems on the basis of at least one of the generated up-link and down-link.

14. A method of operating an electronic device, the method comprising:

providing at least one first file system and a second file system stacked above the at least one first file system in a memory of the electronic device;

providing a virtual memory area including a virtual address for a file corresponding to a file mapping request, in response to the file mapping request by a software program; and

providing a first virtual address link between the virtual memory area and a file object of the at least one first file system including a page cache of the file corresponding to the file mapping request,

wherein the second file system is directly accessed by a virtual file system, in response to the file mapping request of the software program, and does not include the page cache.

15. The method of claim 14, further comprising:

providing a second virtual address link between a file object of the second file system corresponding to the file mapping request and the virtual memory area.

16. The method of claim 14, wherein

the method further comprises identifying file mapping of a process corresponding to the software program on the basis of the second virtual address link.

17. The method of claim 16, further comprising:

providing a mapping information link of a file between a file system having the page cache of the file and the virtual memory area.

18. The method of claim 17, wherein identifying the file mapping of the process corresponding to the software program on the basis of the second virtual address link comprises identifying the virtual memory area on the basis of the mapping information link of the file when page migration or page reclamation of a page cache included in the file system having the page cache of the file is performed.