Virtual file system with vnode reconstruction capability

• US 10,168,947 B2
• Filed: 05/07/2015
• Issued: 01/01/2019
• Est. Priority Date: 05/07/2015
• Status: Active Grant

• Current Assignee: Vmware LLC (Broadcom, Inc.)
• Original Assignee: VMware, Inc. (Broadcom, Inc.)
• Inventors: Wang, Wenguang, Lu, Yunshan
• Primary Examiner(s): Truong, Loan L. T.
• Application Number:
  US14/706,879
• Publication Number:
  US 20160328299A1
• Time in Patent Office: 1,335 Days
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0649 Lifecycle management
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A virtual file system and method for performing virtual file system operations uses a vnode descriptor to access a vnode for a vnode operation. If the vnode is not found in a vnode cache using the vnode descriptor, the vnode is reconstructed using information regarding the vnode found outside of the vnode cache using the vnode descriptor.

Claims

1. A method of performing virtual file system operations comprising:

receiving a file system request from an application process;

processing a vnode operation in response to the file system request, the vnode operation including a vnode descriptor to access a vnode for the vnode operation, the vnode being a representation of a file system object and corresponding to a particular inode, wherein the vnode has a one-to-one relationship with the particular inode;

searching for the vnode in a vnode cache using the vnode descriptor, the vnode including an address of the particular inode and metadata of the file system object; and

reconstructing the vnode using the vnode descriptor if the vnode is not found in the vnode cache, including searching another cache using the vnode descriptor to find information regarding the vnode to reconstruct the vnode if the another cache exists, and then searching for the information regarding the vnode from a physical storage system if the information regarding the vnode is not found in the another cache.

2. The method of claim 1, wherein the processing of the vnode operation includes processing the vnode operation in which the vnode operation does not include a vnode cache pointer.

3. The method of claim 2, wherein the vnode descriptor includes an inode address of the particular inode that corresponds to the vnode.

4. The method of claim 3, wherein the vnode descriptor includes a mount point of the particular inode.

5. The method of claim 1, wherein the vnode does not include any complex reference count as part of life cycle management information for the vnode.

6. The method of claim 1, wherein the vnode descriptor includes a volume number and the address of the particular inode.

7. A computer-readable storage medium containing program instructions for a method of performing virtual file system operations, wherein execution of the program instructions by one or more processors of a computer system causes the one or more processors to perform steps comprising:

receiving a file system request from an application process;

processing a vnode operation in response to the file system request, the vnode operation including a vnode descriptor to access a vnode for the vnode operation, the vnode being a representation of a file system object and corresponding to a particular inode, wherein the vnode has a one-to-one relationship with the particular inode;

searching for the vnode in a vnode cache using the vnode descriptor, the vnode including an address of the particular inode and metadata of the file system object; and

reconstructing the vnode using the vnode descriptor if the vnode is not found in the vnode cache, including searching another cache using the vnode descriptor to find information regarding the vnode to reconstruct the vnode if the another cache exists, and then searching for the information regarding the vnode from a physical storage system if the information regarding the vnode is not found in the another cache.

8. The computer-readable storage medium of claim 7, wherein the processing of the vnode operation includes processing the vnode operation in which the vnode operation does not include a vnode cache pointer.

9. The computer-readable storage medium of claim 8, wherein the vnode descriptor includes an inode address of the particular inode that corresponds to the vnode.

10. The computer-readable storage medium of claim 9, wherein the vnode descriptor includes a mount point of the particular inode.

11. The computer-readable storage medium of claim 7, wherein the vnode does not include any complex reference count as part of life cycle management information for the vnode.

12. The computer-readable storage medium of claim 7, wherein the vnode descriptor includes a volume number and the address of the particular inode.

13. A virtual file system comprising:

memory; and

a processor configured to;

receive a file system request from an application process;

process a vnode operation in response to the file system request, the vnode operation including a vnode descriptor to access a vnode for the vnode operation, the vnode being a representation of a file system object and corresponding to a particular inode, wherein the vnode has a one-to-one relationship with the particular inode;

search for the vnode in a vnode cache using the vnode descriptor, the vnode including an address of the particular inode and metadata of the file system object; and

reconstruct the vnode using the vnode descriptor if the vnode is not found in the vnode cache, including searching another cache using the vnode descriptor to find information regarding the vnode to reconstruct the vnode if the another cache exists, and then searching for the information regarding the vnode from a physical storage system if the information regarding the vnode is not found in the another cache.

14. The virtual file system of claim 13, wherein the processor is configured to process the vnode operation in which the vnode operation does not include a vnode cache pointer.

15. The virtual file system of claim 14, wherein the vnode descriptor includes an inode address of the particular inode that corresponds to the vnode.

16. The virtual file system of claim 15, wherein the vnode descriptor includes a mount point of the particular inode.

17. The virtual file system of claim 13, wherein the vnode descriptor includes a volume number and the address of the particular inode.