METHOD AND SYSTEM FOR IMPLEMENTING A MULTILEVEL FILE SYSTEM IN A VIRTUALIZED ENVIRONMENT

• US 20140046986A1
• Filed: 08/09/2012
• Published: 02/13/2014
• Est. Priority Date: 08/09/2012
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Faden, Glenn T., Aleshire, Richard E.
• Granted Patent: US 9,547,656 B2
• Time in Patent Office: Days
• US Class Current: 707/822
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database

Abstract

A global zone executing on a host OS that includes a multilevel filesystem (MLFS) associated with a label range, where the MLFS includes files and directories, where each of the files is associated with its own label and where each of the directories is associated with its own label. The global zone further includes a first non-global zone, where the MLFS is mounted in the first non-global zone as a first loopback file system. The host OS is configured to receive, from a process executing on the host OS, a request to access a first file in the MLFS, make a first determination that a process label dominates a first file label, based on the first determination, make a second determination that the first file label is equal to the process label, and in response to the second determination, provide read and write access to the first file.

Claims

1. A system, comprising:

a processor;

a host operating system (OS) configured to execute on the processor, wherein the host OS comprises;

a global zone comprising a multilevel filesystem (MLFS) mounted in the global zone, wherein the MLFS is associated with a label range, wherein the MLFS comprises a first plurality of files and a first plurality of directories, wherein each of the first plurality of files is associated with its own label and wherein each of the first plurality of directories is associated with its own label; and

a first non-global zone, wherein the MLFS is mounted in the first non-global zone as a first loopback file system,

wherein the host OS is configured to;

receive, from a process executing on the host OS, a request to access a first file of the plurality of files in the MLFS,

obtain a process label associated with the process,

obtain a first file label associated with the first file,

make a first determination that the process label dominates the first file label,

based on the first determination, make a second determination that the first file label is equal to the process label, and

in response to the second determination, provide read and write access to the first file.

2. The system of claim 1, further comprising:

a second non-global zone, wherein the MLFS is mounted in the second non-global zone as a second loopback file system.

3. The system of claim 1, wherein the host OS is further configured to:

receive, from the process executing on the host OS, a request to access a second file of the plurality of files in the MLFS,

obtain a second file label associated with the second file,

make a third determination that the process label dominates the second file label,

based on the third determination, make a fourth determination that the second file label does not equal the process label, and

in response to the fourth determination provide read only access to the second file.

4. The system of claim 1, wherein the host OS is further configured to:

receive, from a second process executing on the host, a request to access the first file of the plurality of files in the MLFS,

obtain a second process label associated with the second process,

making a third determination that the second process label dominates the first file label,

based on the third determination, making a fourth determination that the first file label does not equal the second process label, and

in response to the fourth determination providing read only access to the first file.

5. The system of claim 4, wherein the first process is in the first non-global zone and the second process is in a second non-global zone on the host OS.

6. The system of claim 5, wherein the first non-global zone is associated with a first zone label and the second non-global zone is associated with a second zone label, wherein the first zone label is different than the second zone label.

7. The system of claim 6, wherein the process label is equal to the first zone label.

8. The system of claim 5, wherein the first non-global zone is associated with a first zone label and the second non-global zone is associated with a second zone label, wherein the first zone label dominates the second zone label.

9. The system of claim 1, wherein the host OS is further configured to:

after the process has modified the first file to generate a first updated file;

receive, from a second process executing on the host, a request to access the first updated file of the plurality of files in the MLFS, wherein the first updated file is associated with the first file label,

obtain a second process label associated with the second process,

making a third determination that the second process label dominates the first file label,

based on the third determination, making a fourth determination that the first file label does not equal the process label, and

in response to the fourth determination providing read only access to the updated first file.

10. The system of claim 1, wherein the MLFS is mounted in the first non-global zone with read and write permissions.

11. The system of claim 1, wherein the first non-global zone comprises a non-MLFS, wherein the first non-global zone is associated with a first label, wherein the non-MLFS is associated with a second label, wherein the first label and the second label are equal, and wherein the non-MLFS comprises a second plurality of files and a second plurality of directories, wherein each of the second plurality of files is implicitly associated with the second label and wherein each of the second plurality of directories is implicitly associated with the second label.

12. The system of claim 1, wherein the host OS is further configured to:

receive, from the process executing on the host OS, a request to access a directory of the plurality of directories in the MLFS,

obtain a directory label associated with the directory,

make a third determination that the process label dominates the directory label, and

in response to the third determination provide a listing of contents of the directory.

13. The system of claim 12, wherein all content in the directory is associated with its own label, and wherein labels associated with the content are monotonic non-decreasing relative to the directory label.

14. The system of claim 12, wherein the directory comprises a file with a second file label and wherein the second file label strictly dominates the directory label.

15. The system of claim 14, wherein the second file label strictly dominates the process label.

16. The system of claim 1, wherein the host OS is further configured to:

receive, from the process executing on the host OS, a request to access a directory of the plurality of directories in the MLFS,

obtain a directory label associated with the directory,

make a third determination that the process label dominates the directory label, and

in response to the third determination provide a listing of contents of the directory,

wherein the listing only includes files and sub-directories whose label is dominated by the process label.

17. The system of claim 1, wherein the host OS is further configured to:

receive, from the process executing on the host OS, a request to create a second file in a directory in the MLFS,

making a third determination that the process label is in the label range;

obtain a directory label associated with the directory,

make a fourth determination that the process label dominates the directory label, and

in response to the fourth determination create the second file, wherein the second file is associated with the process label.

18. The system of claim 17, wherein the process label strictly dominates the directory label.

19. A system, comprising:

a first computer comprising;

a processor;

a host operating system (OS) configured to execute on the processor, wherein the host OS comprises;

a global zone comprising a multilevel filesystem (MLFS) mounted in the global zone, wherein the MLFS is associated with a label range, wherein the MLFS comprises a first plurality of files and a first plurality of directories, wherein each of the first plurality of files is associated with its own label and wherein each of the first plurality of directories is associated with its own label; and

a second computer separate from the first computer, wherein the second computer includes an interface to the MLFS;

wherein the host OS is configured to;

receive, from a process executing on second computer, a request to access a first file of the plurality of files in the MLFS,

obtain a process label associated with the process,

obtain a first file label associated with the first file,

make a first determination that the process label dominates the first file label,

based on the first determination, make a second determination that the first file label is equal to the process label, and

in response to the second determination, provide read and write access to the first file.

20. The system of claim 19, wherein the interface is implemented using at least one selected from a group consisting of Network File System (NFS) protocol and Common Internet File System (CIFS) protocol.