FILE ACCESS METHOD AND RELATED DEVICE

• US 20160378680A1
• Filed: 09/07/2016
• Published: 12/29/2016
• Est. Priority Date: 03/07/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Sha, Xingmian, Zhuge, Qingfeng, Zhu, Guanyu
• Granted Patent: US 10,452,562 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 16/11 File system administration, e.g. details of archiving or snapshots file system backup G06F11/14
• CPC Class Codes: G06F 16/1727 Details of free space management performed by the file system saving storage space on storage systems G06F3/0608; management of blocks in storage devices G06F3/064
• CPC Class Codes: G06F 2212/1008 Correctness of operation, e.g. memory ordering
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/657 Virtual address space management
• CPC Class Codes: G06F 3/0643 Management of files

Abstract

Embodiments of the application provide a file access method. A computing node receives a file open request that carries a file identifier. The computing node obtains an index node of a file that is identified by the file identifier. The computing node further obtains, based on the index node, a physical address space of a memory area in a file storage area, in which the file is stored. The computing node allocates a virtual address space to the file, and recodes a virtual-physical address mapping relationship by using a memory page table. The virtual-physical address mapping relationship includes a mapping relationship between the virtual address space and the physical address space.

Claims

13. A computing node, comprising:

a processor and a storage device, wherein the storage device is configured to store program code for executing by the processor, and, by executing the program code, the processor is configured to;

receive a file open request that carries a file identifier;

obtain an index node of a file identified by the file identifier, and based on the index node, obtain a physical address space, wherein the file is stored in the physical address space in a file storage area of the storage device of the computing node;

allocate a virtual address space to the file; and

record a virtual-physical address mapping relationship in a memory page table that is stored in a work process area of the storage device, wherein the virtual-physical address mapping relationship is a mapping relationship between the virtual address space and the physical address space.

1. A file access method performed by a processor of a computing node, wherein the computing node is controlled by an operating system and one or more processes are running in the computing node, the method comprising:

receiving a file open request that carries a file identifier;

obtaining an index node of a file identified by the file identifier, and, based on the index node, obtaining a physical address space, wherein the file is stored in the physical address space in a file storage area of a memory of the computing node;

allocating a virtual address space to the file; and

recording a virtual-physical address mapping relationship in a memory page table that is stored in a work process area of the memory, wherein the virtual-physical address mapping relationship is a mapping relationship between the virtual address space and the physical address space.

2. The method according to claim 1, wherein obtaining the physical address space of the file comprises:

obtaining, based on a file page table, the physical address space in the file storage area of the memory, wherein the file page table or a pointer pointing to the file page table is recorded in the index node.

3. The method according to claim 2, wherein recording the virtual-physical address mapping relationship in the memory page table comprises:

adding an entry in the memory page table for recording the virtual-physical address mapping relationship, wherein the virtual-physical address mapping relationship comprises the virtual address space and the file page table or the pointer pointing to the file page table.

4. The method according to claim 3, wherein a total quantity of levels of the memory page table is Y, a total quantity of levels of the file page table is X, X is a positive integer, and Y is a positive integer greater than X, and wherein

if the entry comprises the file page table, the entry is an entry in a (Y−

X+1)^th level of the memory page table;

or

if the entry comprises the pointer pointing to the file page table, the entry is an entry in a (Y−

X)^th level of the memory page table.

5. The method according to claim 1, further comprising:

recording the virtual address space or a start address of the virtual address space in the index node.

6. The method according to claim 1, further comprising:

recording the virtual address space or a start address of the virtual address space in a file object corresponding to the file.

7. The method according to claim 1, wherein the virtual address space is a kernel virtual address space or a user process virtual address space.

8. The method according to claim 1, further comprising:

receiving a file read request for reading a file content of the file, wherein the file read request carries a read-in memory address space and a data volume of the file content, wherein the read-in memory address space is an address space of a memory area in the work process area of the memory;

obtaining, according to the data volume of the file content, the virtual address space of the file and the virtual-physical address mapping relationship recorded in the memory page table, a read physical address space of the file content in the file storage area;

reading, according to the read physical address space, the file content from the file storage area; and

writing the file content to the memory area.

9. The method according to claim 1, further comprising:

receiving a file write request for writing a file content to the file, wherein the file write request carries a read-out memory address space and a data volume of the file content, wherein the read-out memory address space is an address space of a memory area in the work process area of the memory;

obtaining, according to the data volume of the file content, the virtual address space of the file and the virtual-physical address mapping relationship recorded in the memory page table, a write physical address space of the file content in the file storage area, wherein the write physical address space is a physical address space of a memory area in the file storage area of the memory; and

writing the file content stored in the memory area in the work process area of the memory to the memory area in the file storage area of the memory.

10. The method according to claim 9, wherein a storage capacity of the memory area in the file storage area of the memory is greater than or equal to the data volume of the file content.

11. The method according to claim 1, further comprising:

receiving a file close request for closing the file;

releasing the virtual address space allocated to the file; and

releasing the virtual-physical address mapping relationship recorded in the memory page table.

12. The method according to claim 1, further comprising:

creating the file in the file storage area when it is determined that the file identified by the file identifier is not stored in the file storage area; and

creating the index node of the file.

14. The computing node according to claim 13, wherein in obtaining the physical address space of the file, the processor is configured to:

obtain, based on a file page table, the physical address space in the file storage area of the storage device, wherein the file page table or a pointer pointing to the file page table is recorded in the index node.

15. The computing node according to claim 14, wherein in recording the virtual-physical address mapping relationship in the memory page table,

the processor is configured to add an entry in the memory page table for recording the virtual-physical address mapping relationship, wherein the virtual-physical address mapping relationship comprises the virtual address space and the file page table or the pointer pointing to the file page table.

16. The computing node according to claim 15, wherein a total quantity of levels of the memory page table is Y, a total quantity of levels of the first file page table is X, X is a positive integer, and Y is a positive integer greater than X, and wherein

if the entry comprises the file page table, the entry is an entry in a (Y−

X+1)^th level of the memory page table;

or

if the entry comprises the pointer pointing to the file page table, the entry is an entry in a (Y−

X)^th level of the memory page table.

17. The computing node according to claim 13, wherein the processor is further configured to record the virtual address space or a start address of the virtual address space in the index node.

18. The computing node according to claim 13, wherein the processor is further configured to record the virtual address space or a start address of the virtual address space in a file object corresponding to the file.

19. The computing node according to claim 13, wherein the virtual address space is a kernel virtual address space or a user process virtual address space.

20. The computing node according to claim 13, wherein the processor is further configured to:

receive a file write request for writing a file content to the file, wherein the file write request carries a read-out memory address space and a data volume of the file content, wherein the read-out memory address space is an address space of a memory area in the work process area of the storage device;

obtain, according to the data volume of the file content, the virtual address space of the file and the virtual-physical address mapping relationship recorded in the memory page table, a write physical address space of the file content in the file storage area, wherein the write physical address space is a physical address space of a memory area in the file storage area of the storage device; and

write the file content stored in the memory area in the work process area of the storage device to the memory area in the file storage area of the storage device.

21. The computing node according to claim 13, wherein the processor is further configured to:

receive a file close request for closing the file;

release the virtual address space allocated to the file; and

release the virtual-physical address mapping relationship recorded in the memory page table.

22. The computing node according to claim 13, wherein the processor is further configured to:

create the file in the file storage area when it is determined that the file identified by the file identifier is not stored in the file storage area, and

creating the index node of the file.

23. The computing node according to claim 13, wherein the computing node is controlled by an operating system software, and the operating system software is stored in the storage device.

19-1. The computing node according to claim 13, wherein the processor is further configured to:

receive a file read request used for reading a file content of the file, wherein the file read request carries a read-in memory address space and a data volume of the file content, wherein the read-in memory address space is an address space of a memory area in the work process area of the storage device;

obtain, according to the data volume of the file content, the virtual address space of the file and the virtual-physical address mapping relationship recorded in the memory page table, a read physical address space of the file content in the file storage area;

read, according to the read physical address space, the first file content from the file storage area; and

write the file content to the memory area.

24. A storage device of a computing node, comprising a non-transitory storage medium storing computer executable instructions, wherein the instructions, when being executed by a processor of the computing node, cause the processor to:

receive a file open request that carries a file identifier;

obtain an index node of a file identified by the file identifier, and, based on the index node, obtain a physical address space, wherein the file is stored in the physical address space in a file storage area of the storage device;

allocate a virtual address space to the file; and

record a virtual-physical address mapping relationship in a memory page table that is stored in a work process area of the storage device, wherein the virtual-physical address mapping relationship is a mapping relationship between the virtual address space and the physical address space.

25. The storage device according to claim 24, wherein the computer executable instructions comprise an operating system, and the computing node is controlled by the operating system.