System and method for out of user space block mode I/O directly between an application instance and an I/O adapter

• US 20060265561A1
• Filed: 05/23/2005
• Published: 11/23/2006
• Est. Priority Date: 05/23/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Recio, Renato John, Vega, Madeline, Boyd, William Todd, Mena, Agustin III, Hufferd, John Lewis
• Granted Patent: US 7,502,872 B2
• Time in Patent Office: Days
• US Class Current: 711/163
• CPC Class Codes: G06F 12/1458 by checking the subject access rights
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0623 in relation to content
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

The present invention provides a system, method, and computer program product that enables application instances to pass block mode storage requests directly to a physical I/O adapter without run-time involvement from the local operating system or hypervisor. Specifically, a mechanism for providing and using a linear block address (LBA) translation protection table (TPT) to control out of user space I/O operations is provided. In one aspect of the present invention, the LBATPT includes an adapter protection table that has entries for each portion of a storage device. Entries include access control values which identify whether the entry is valid and what access type operations may be performed on a corresponding portion of a storage device. I/O requests may be checked against these access control values to determine if an application instance that submitted the I/O requests may access the LBAs identified in the I/O requests in the manner requested.

Claims

1. A method, in an input/output (I/O) adapter coupled to a host system running an application instance, comprising:

retrieving, in the I/O adapter, a work queue entry from a work queue associated with the application instance and the I/O adapter;

identifying, in the I/O adapter, a permitted type of access of a portion of a storage device targeted by the work queue entry;

performing, in the I/O adapter, validation checks on the work queue entry based on the permitted type of access of the portion of the storage device targeted by the work queue entry; and

processing, in the I/O adapter, the work queue entry only if the validation checks on the work queue entry are completed successfully.

2. The method of claim 1, wherein the work queue entry corresponds to an I/O request submitted by the application instance and includes a key value, and wherein identifying a permitted type of access of a portion of a storage device targeted by the work queue entry includes retrieving an adapter protection table entry corresponding to the work queue entry based on the key value.

3. The method of claim 2, wherein the adapter protection table entry stores one or more access control values that identify a type of access permitted on a portion of the storage device associated with the adapter protection table entry.

4. The method of claim 3, wherein performing validation checks on the work queue entry based on the permitted type of access of the portion of the storage device targeted by the work queue entry includes performing validation checks on the work queue entry based on the one or more access control values stored in the adapter protection table entry.

5. The method of claim 3, wherein the one or more access control values include a valid identification access control value and a permitted operation access control value.

6. The method of claim 5, wherein if the valid identification access control value has a first value, the adapter protection table entry is valid, and wherein if the permitted operation access control value has the first value, read and write operations are permitted on an associated portion of the storage device.

7. The method of claim 5, wherein performing validation checks on the work queue entry includes:

determining if a value of the valid identification access control value of the adapter protection table entry indicates that the adapter protection table entry is valid.

8. The method of claim 7, wherein if the valid identification access control value of the adapter protection table entry indicates that the adapter protection table entry is valid, and an access type being requested by the work queue entry is a read operation, then the validation checks on the work queue entry are completed successfully.

9. The method of claim 7, wherein if the valid identification access control value of the adapter protection table entry indicates that the adapter protection table entry is valid, the permitted operation access control value indicates that write operations are permitted, and the access type being requested by the work queue entry is a write operation, then the validation checks on the work queue entry are completed successfully.

10. The method of claim 2, wherein performing validation checks on the work queue entry further comprises:

determining if the portion of the storage device targeted by the work queue entry is within a range of portions of the storage device associated with the adapter protection table entry; and

denying access to the portion of the storage device targeted by the work queue entry if the portion of the storage device targeted by the work queue entry is outside the range of portions of the storage device associated with the adapter protection table entry.

11. A computer program product comprising a computer useable medium having a computer readable program, wherein the computer readable program, when executed on an input/output (I/O) adapter coupled to a host system running an application instance, causes the I/O adapter to:

retrieve a work queue entry from a work queue associated with the application instance and the I/O adapter;

identify a permitted type of access of a portion of a storage device targeted by the work queue entry;

perform validation checks on the work queue entry based on the permitted type of access of the portion of the storage device targeted by the work queue entry; and

process the work queue entry only if the validation checks on the work queue entry are completed successfully.

12. The computer program product of claim 11, wherein the work queue entry corresponds to an I/O request submitted by the application instance and includes a key value, and wherein the computer readable program causes the I/O adapter to identify a permitted type of access of a portion of a storage device targeted by the work queue entry by retrieving an adapter protection table entry corresponding to the work queue entry based on the key value.

13. The computer program product of claim 12, wherein the adapter protection table entry stores one or more access control values that identify a type of access permitted on a portion of the storage device associated with the adapter protection table entry.

14. The computer program product of claim 13, wherein the computer readable program causes the I/O adapter to perform validation checks on the work queue entry based on the permitted type of access of the portion of the storage device targeted by the work queue entry by performing validation checks on the work queue entry based on the one or more access control values stored in the adapter protection table entry.

15. The computer program product of claim 13, wherein the one or more access control values include a valid identification access control value and a permitted operation access control value.

16. The computer program product of claim 15, wherein the computer readable program causes the I/O adapter to perform validation checks on the work queue entry by:

determining if a value of the valid identification access control value of the adapter protection table entry indicates that the adapter protection table entry is valid.

17. The computer program product of claim 16, wherein if the valid identification access control value of the adapter protection table entry indicates that the adapter protection table entry is valid, and an access type being requested by the work queue entry is a read operation, then the validation checks on the work queue entry are completed successfully.

18. The computer program product of claim 16, wherein if the valid identification access control value of the adapter protection table entry indicates that the adapter protection table entry is valid, the permitted operation access control value indicates that write operations are permitted, and the access type being requested by the work queue entry is a write operation, then the validation checks on the work queue entry are completed successfully.

19. The computer program product of claim 12, wherein the computer readable program further causes the I/O adapter to:

determine if the portion of the storage device targeted by the work queue entry is within a range of portions of the storage device associated with the adapter protection table entry; and

deny access to the portion of the storage device targeted by the work queue entry if the portion of the storage device targeted by the work queue entry is outside the range of portions of the storage device associated with the adapter protection table entry.

20. A data processing system, comprising:

a host system; and

an input/output (I/O) adapter coupled to the host system, wherein the host system runs an application instance, and wherein the I/O adapter;

retrieves a work queue entry from a work queue associated with the application instance and the I/O adapter;

identifies a permitted type of access of a portion of a storage device targeted by the work queue entry;

performs validation checks on the work queue entry based on the permitted type of access of the portion of the storage device targeted by the work queue entry; and

processes the work queue entry only if the validation checks on the work queue entry are completed successfully.