Trait kernel::block::mq::Operations

pub trait Operations: Sized {
    type QueueData: ForeignOwnable;

    const USE_VTABLE_ATTR: ();
    const HAS_QUEUE_RQ: bool = false;
    const HAS_COMMIT_RQS: bool = false;
    const HAS_COMPLETE: bool = false;
    const HAS_POLL: bool = false;

    // Required methods
    fn queue_rq(
        queue_data: <Self::QueueData as ForeignOwnable>::Borrowed<'_>,
        rq: ARef<Request<Self>>,
        is_last: bool
    ) -> Result;
    fn commit_rqs(queue_data: <Self::QueueData as ForeignOwnable>::Borrowed<'_>);
    fn complete(rq: ARef<Request<Self>>);

    // Provided method
    fn poll() -> bool { ... }
}

Implement this trait to interface blk-mq as block devices.

To implement a block device driver, implement this trait as described in the module level documentation. The kernel will use the implementation of the functions defined in this trait to interface a block device driver. Note: There is no need for an exit_request() implementation, because the drop implementation of the Request type will be invoked by automatically by the C/Rust glue logic.

Required Associated Types

type QueueData: ForeignOwnable

Data associated with the struct request_queue that is allocated for the GenDisk associated with this Operations implementation.

Required Associated Constants

const USE_VTABLE_ATTR: ()

A marker to prevent implementors from forgetting to use #[vtable] attribute when implementing this trait.

Provided Associated Constants

const HAS_QUEUE_RQ: bool = false

Indicates if the queue_rq method is overridden by the implementor.

const HAS_COMMIT_RQS: bool = false

Indicates if the commit_rqs method is overridden by the implementor.

const HAS_COMPLETE: bool = false

Indicates if the complete method is overridden by the implementor.

const HAS_POLL: bool = false

Indicates if the poll method is overridden by the implementor.

Required Methods

fn queue_rq( queue_data: <Self::QueueData as ForeignOwnable>::Borrowed<'_>, rq: ARef<Request<Self>>, is_last: bool ) -> Result

Called by the kernel to queue a request with the driver. If is_last is false, the driver is allowed to defer committing the request.

fn commit_rqs(queue_data: <Self::QueueData as ForeignOwnable>::Borrowed<'_>)

Called by the kernel to indicate that queued requests should be submitted.

fn complete(rq: ARef<Request<Self>>)

Called by the kernel when the request is completed.

Provided Methods

fn poll() -> bool

Called by the kernel to poll the device for completed requests. Only used for poll queues.

Object Safety

This trait is not object safe.

Implementors