US 8,997,120 B1Granted

Lightweight communication channel for control of device driver components

AssigneeEMC Corporation

InventorsAlan Lee Taylor, Paul T. McGrath, Miles A. de Forest, Dayanand Suldhal, Nagapraveen Veeravenkata Seela, Samuel Lee Mullis, II

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Abstract

In a data storage system, a fixture communication channel is created for communications between a fixture and another component, where the fixture is a component of a device driver that provides extended input/output functionality with respect to one or more storage devices. A handle identifies the fixture communication channel, and callbacks are registered with a driver handler and reference callback functions of the fixture. Fixture communication messages each include the handle and a message-specific operation code for an operation to be performed by the fixture, and each is conveyed by (1) issuing a fixture-control input/output control command to the handler that includes the handle and message-specific operation code, and (2) at the handler, using the handle and message-specific operation code to select a callback and invoke a corresponding callback function of the fixture.

Claims14

Dependent claims

A method of operating a processor of a storage system, comprising:

creating a fixture communication channel for communications between a fixture and another component of the storage system, the fixture being a component of a device driver providing extended input/output functionality with respect to a storage device accessed via the device driver, the fixture communication channel including a handle and a set of callbacks, the handle specifically identifying the fixture communication channel, the callbacks referencing respective callback functions of the fixture that provide the extended input/output functionality, and the callbacks being registered with a handler responsible for invoking the device driver in response to input/output control commands directed to the storage device, the input/output control commands being of a plurality of types including a fixture-control type;
and
using the fixture communication channel to convey contents of fixture communication messages between the another component and the fixture, each fixture communication message including the handle and a message-specific operation code for an operation to be performed by the fixture, each fixture communication message being conveyed by:
generating an input/output control command of the fixture-control type and issuing it to the handler, the fixture-control input/output control command including the message-specific operation code and the handle from the fixture communication message;
and
at the handler, using the handle and message-specific operation code from the fixture-control input/output control command to select a corresponding callback and invoke a corresponding callback function of the fixture.

3 more elements

A storage system, comprising:

a set of storage devices;
a processor coupled to the storage devices to perform data storage operations thereon;
and
interface circuitry coupling the storage system to external users of the storage system;
the processor being operative to execute computer program instructions to cause the processor to perform a method including:
creating a fixture communication channel for communications between a fixture and another component of the storage system, the fixture being a component of a device driver providing extended input/output functionality with respect to a storage device accessed via the device driver, the fixture communication channel including a handle and a set of callbacks, the handle specifically identifying the fixture communication channel, the callbacks referencing respective callback functions of the fixture that provide the extended input/output functionality, and the callbacks being registered with a handler responsible for invoking the device driver in response to input/output control commands directed to the storage device, the input/output control commands being of a plurality of types including a fixture-control type;
and
using the fixture communication channel to convey contents of fixture communication messages between the another component and the fixture, each fixture communication message including the handle and a message-specific operation code for an operation to be performed by the fixture, each fixture communication message being conveyed by:
generating an input/output control command of the fixture-control type and issuing it to the handler, the fixture-control input/output control command including the message-specific operation code and the handle from the fixture communication message;
and
at the handler, using the handle and message-specific operation code from the fixture-control input/output control command to select a corresponding callback and invoke a corresponding callback function of the fixture.

8 more elements

Dependencies are inferred from the claim text.