Systems and methods for error simulation and code testing

1. A method for error simulation in a data storage subsystem providing abstractions of one or more storage devices, the method comprising:

dividing the data storage subsystem into two or more hierarchically organized subsystems, wherein the subsystems interact using IO Request Packets (IORPs), such that relatively higher level subsystems create and populate IORPs and pass them to relatively lower level subsystems for corresponding processing; and

defining an IORP modifier configured to attach to a matching IORP based on one or more attributes of the IORP modifier and to modify at least one of the processing and one or more attributes of the IORP in order to simulate errors in the data storage subsystem;

maintaining the defined IORP modifier in a searchable red-black tree data structure maintaining a plurality of IORP modifiers, wherein a key for each node in the tree is a data block address range over which an IORP modifier is operative.

2. The method of claim 1 , wherein the defined IORP modifier is configured to modify the IORP such that it returns an immediate failure.

3. The method of claim 1 , wherein the defined IORP modifier is configured to modify the IORP such that it returns a failure after delay.

4. The method of claim 1 , wherein the defined IORP modifier is configured to modify the IORP such that it is delayed prior to forwarding to a relatively lower level subsystem.

5. The method of claim 4 , wherein the defined IORP modifier is further configured to modify the IORP such that it returns a failure.

6. The method of claim 1 , wherein the defined IORP modifier comprises an attribute specifying a region of interest for which it applies, the region of interest defining an address range of data blocks.

7. The method of claim 6 , wherein the defined IORP modifier further comprises an attribute specifying a top level subsystem, wherein the defined IORP modifier only attaches to an IORP sourcing from the specified top level subsystem.

8. The method of claim 6 , wherein the defined IORP modifier further comprises an attribute specifying an IORP request type that triggers action by the defined IORP modifier.

9. The method of claim 8 , wherein the defined IORP modifier further comprises an attribute specifying a length in time relating to how long the defined IORP modifier delays the IORP.

10. The method of claim 8 , wherein the defined IORP modifier further comprises one or more attributes specifying a recurrence pattern and rate defining how often the triggered action may recur.

11. An information handling system comprising:

a data storage subsystem providing abstractions of one or more storage devices, the data storage subsystem divided into two or more hierarchically organized subsystems, wherein the subsystems interact using IO Request Packets (IORPs);

a plurality of IORP modifiers, each configured to attach to a matching IORP passed between the subsystems and modify at least one of the processing and one or more attributes of the IORP in order to simulate errors in the data storage subsystem; and

a searchable red-black tree data structure for maintaining the plurality of IORP modifiers, wherein a key for each node in the tree is a data block address range over which an IORP modifier is operative.

12. The information handling system of claim 11 , further comprising an IORP modifier interface providing access to at least one of create, modify, and delete an IORP modifier.

13. The information handling system of claim 12 , wherein at least one of the plurality of IORP modifiers comprises an attribute specifying a region of interest for which it applies, the region of interest defining an address range of data blocks.

14. The information handling system of claim 11 , wherein at least one of the plurality of IORP modifiers comprises an attribute specifying an IORP request type that triggers action by the IORP modifier.

15. The information handling system of claim 14 , wherein at least one of the plurality of IORP modifiers further comprises an attribute specifying an IORP request type that disables action by the IORP modifier regardless of other matching criteria.

16. A method for error simulation in a data storage subsystem providing abstractions of one or more storage devices, the method comprising:

providing a data storage subsystem divided into two or more hierarchically organized subsystems, wherein the subsystems interact using IO Request Packets (IORPs);

matching an IORP modifier with an IORP based on one or more attributes defined for the IORP modifier, the IORP modifier maintained in a searchable red-black tree data structure maintaining a plurality of IORP modifiers, wherein a key for each node in the tree is a data block address range over which an IORP modifier is operative; and

modifying at least one of the IORP and the manner in which the IORP is processed in order to simulate errors in the data storage subsystem.

17. The method of claim 16 , wherein each of plurality of IORP modifiers comprises:

a region of interest attribute specifying a region of interest for which it applies, the region of interest defining a data block address range; and

a request type attribute specifying an IORP request type that triggers action by the IORP modifier.

18. The method of claim 17 , wherein matching an IORP modifier with an IORP comprises determining a match when a block address range of the IORP overlaps the region of interest of a particular IORP modifier maintained in the red-black tree data structure for at least one data block and the request type of the IORP matches that of the request type attribute of the particular IORP modifier.