File system management

• US 9,411,812 B2
• Filed: 03/10/2015
• Issued: 08/09/2016
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Giampaolo, Dominic B., Cisler, Pavel, Weiss, Eric A., McIntyre, Kristen A.
• Primary Examiner(s): HO, BINH VAN
• Application Number:
  US14/644,070
• Publication Number:
  US 20150186396A1
• Time in Patent Office: 518 Days
• Field of Search: 707/821
• US Class Current: 1/1
• CPC Class Codes: G06F 16/16 File or folder operations, e.g. details of user interfaces specifically adapted to file systems
• CPC Class Codes: G06F 16/1794 Details of file format conversion
• CPC Class Codes: H04L 9/3213 using tickets or tokens, e.g. Kerberos network architectures or network communication protocols for entities authentication using tickets in a packet data network H04L63/0807

Abstract

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for file system management. In one aspect, a method includes receiving a request at a kernel to perform a file operation on a particular file; identifying a flag bit associated with the file; invoking user space file handler to perform particular action when the flag bit is set; determining whether notification that action has been performed by file handler is received; and allowing the file operation on the file when notification is received.

Claims

1. A method comprising:

by a kernel of a computing device;

receiving a request to perform an operation on a file;

reading a file attribute when a flag bit associated with the file indicates that special file handling should be performed;

determining, based on the special file handling, that a file content needs to be downloaded before the operation can be performed;

invoking by the kernel a user space file handler to perform a particular action, wherein the particular action comprises;

i) downloading the file content and ii) modifying the file based on the file content to produce a modified file;

holding the operation and setting a time for the file handler to perform the particular action without setting any resource locks;

determining that the particular action has been performed by the file handler; and

allowing the operation to be performed on the modified file.

2. The method of claim 1, wherein expiration of the set time without a request for further time results in the kernel performing the operation.

3. The method of claim 2, wherein the kernel executes in a kernel space of a memory of a computer system.

4. The method of claim 3, wherein the kernel space is reserved for execution of the kernel, kernel extensions, and device drivers.

5. The method of claim 3, wherein particular operations can be performed in a user space that cannot be performed in the kernel space and vice versa.

6. The method of claim 1, wherein the operation is a read file operation.

7. The method of claim 1, wherein the operation is a modify file operation and the file handler copies the file prior to the modify file operation being performed.

8. The method of claim 1, further comprising:

identifying i-node information for the file, wherein the i-node information includes one or more flag bits.

9. The method of claim 8, further comprising:

loading the file attribute into a memory when the file operation request is received; and

when the flag bit is set;

accessing the file attribute from the memory to identify the particular action to be performed by the file handler.

10. The method of claim 9, wherein the file attribute identifies a particular user space handler to be invoked, the particular user space handler being designated to perform particular operations.

11. The method of claim 1, wherein the file attribute indicates that the file is to be backed up before the operation is performed.

12. The method of claim 2, wherein a user space comprises a memory area in which user mode applications execute and the kernel does not execute.

13. A system comprising:

one or more computing devices operable to perform operations comprising;

receiving a request at a kernel to perform an operation on a file;

reading a file attribute when a flag bit associated with the file indicates that special file handling should be performed;

determining, based on the file attribute, that a file content needs to be downloaded before the operation can be performed;

invoking by the kernel a user space file handler to perform a particular action, wherein the particular action comprises;

i) downloading the file content and ii) modifying the file based on the file content to produce a modified file;

holding the operation and setting a time for the file handler to perform the particular action without setting any resource locks;

determining at the kernel that the particular action has been performed by the file handler; and

allowing, at the kernel, the operation to be performed on the modified file.

14. The system of claim 13, wherein expiration of the set time without a request for further time results in the kernel performing the operation.

15. The system of claim 13, wherein the operation is a read file operation.

16. The system of claim 13, wherein the operation is a modify file operation and the file handler copies the file prior to the modify file operation being performed.

17. The system of claim 13, further operable to perform operations comprising:

identifying i-node information for the file, wherein the i-node information includes one or more flag bits.

18. The system of claim 17, further comprising:

when the flag bit is set;

loading the file attribute into a memory when the file operation request is received; and

accessing the file attribute from the memory to identify the particular action to be performed by the file handler.

19. The system of claim 13, wherein the file attribute indicates that the file is to be backed up before the operation is performed.

20. The system of claim 13, wherein the file attribute identifies a particular user space handler to be invoked, the particular user space handler being designated to perform particular operations.

21. A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising:

receiving a request at a kernel to perform an operation on a file;

reading a file attribute when a flag bit associated with the file indicates that special file handling should be performed;

determining, based on the special file handling, that a file content needs to be downloaded before the operation can be performed;

invoking by the kernel a user space file handler to perform a particular action, wherein the particular action comprises;

i) downloading the file content and ii) modifying the file based on the file content to produce a modified file;

holding the operation and setting a time for the file handler to perform the particular action without setting any resource locks;

determining that the particular action has been performed by the file handler; and

allowing the operation to be performed on the modified file.

22. The non-transitory computer storage medium of claim 21 , wherein expiration of the set time without a request for further time results in the kernel performing the operation.

23. The non-transitory computer storage medium of claim 21, wherein the operation is a read file operation.

24. The non-transitory computer storage medium of claim 21 wherein the operation is a modify file operation and the file handler copies the file prior to the modify file operation being performed.

25. The non-transitory computer storage medium of claim 21, further operable to cause the data processing apparatus to perform operations comprising:

identifying i-node information for the file, wherein the i-node information includes one or more flag bits.

26. The non-transitory computer storage medium of claim 21, further operable to cause the data processing apparatus to perform operations comprising:

loading the file attribute into a memory when the file operation request is received; and

when the flag bit is set;

accessing the file attribute from the memory to identify the particular action to be performed by the file handler.

27. The non-transitory computer storage medium of claim 21, wherein the file attribute indicates that the file is to be backed up before the operation is performed.

28. The non-transitory computer storage medium of claim 21, wherein the file attribute identifies a particular user space handler to be invoked, the particular user space handler being designated to perform particular operations.

29. A method comprising:

by a kernel of a computing device;

receiving a request to perform an operation on a file;

reading metadata associated with the file, the metadata indicating whether a prior operation has been performed on the file within a time period;

invoking a user space file handler to perform an action in user space when no prior operation has been performed within the time period;

holding the operation and setting a time for the file handler to perform the particular action without setting any resource locks;

determining that the action has been performed by the file handler in user space; and

allowing the operation to be performed on the file.

30. The method of claim 29, wherein the request is a file modification and the particular action is to perform a copy of the file.

31. The method of claim 29, wherein the time period is a first time window of a sequence of time windows, and wherein the action is performed on the file once during each time window of the sequence of time windows.

32. The method of claim 29, wherein the first time window is an hour block of time.