Method and apparatus for decomposing I/O tasks in a RAID system

An apparatus, comprising:

• a network adapter configured to receive a data access request;
• a processor configured to represent a logical combination of one or more physical storage components of a storage operating system as a hierarchical set of objects;
• the processor further configured to generate a parent I/O task from a first object in the hierarchical set of objects in response to the data access request;
• the processor further configured to generate a child I/O task from a second object in the hierarchical set of objects to implement at least a portion of the parent I/O task;
• the processor further configured to suspend the parent I/O task until the child I/O task is completed;
• the processor further configured to execute the child I/O task in response to a first event indicating a resource required by the child I/O task is available, such that scheduling of the child I/O task is not conditional on execution of the parent I/O task;
• and
• the processor further configured to resume the parent I/O task in response to a second event indicating to the parent I/O task the completion of the child I/O task.

A computer-readable storage media, comprising:

• the computer-readable storage media comprising instructions for execution by a processor of a storage system for a method of decomposing a data access request from a storage operating system of the storage system into a plurality of lower-level I/O tasks, the computer-readable storage media further comprising instructions for,
• representing a logical combination and configuration of one or more physical storage components of the storage operating system as a hierarchical set of objects;
• generating a parent I/O task from a first object in the hierarchical set of objects in response to the data access request from the storage operating system;
• generating a child I/O task from a second object in the hierarchical set of objects to implement at least a portion of the parent I/O task;
• suspending the parent I/O task until the child I/O task is completed;
• executing the child I/O task in response to a first event indicating a resource of the storage system required by the child I/O task is available, such that scheduling of the child I/O task is not conditional on execution of the parent I/O task;
• and resuming the parent I/O task in response to a second event indicating to the parent I/O task the completion of the child I/O task.