74 lines
1.8 KiB
Rust
74 lines
1.8 KiB
Rust
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
|
||
|
|
//! This is a Rust implementation of the C null block driver.
|
||
|
|
//!
|
||
|
|
//! Supported features:
|
||
|
|
//!
|
||
|
|
//! - blk-mq interface
|
||
|
|
//! - direct completion
|
||
|
|
//! - block size 4k
|
||
|
|
//!
|
||
|
|
//! The driver is not configurable.
|
||
|
|
|
||
|
|
use kernel::{
|
||
|
|
alloc::flags,
|
||
|
|
block::mq::{
|
||
|
|
self,
|
||
|
|
gen_disk::{self, GenDisk},
|
||
|
|
Operations, TagSet,
|
||
|
|
},
|
||
|
|
error::Result,
|
||
|
|
new_mutex, pr_info,
|
||
|
|
prelude::*,
|
||
|
|
sync::{Arc, Mutex},
|
||
|
|
types::ARef,
|
||
|
|
};
|
||
|
|
|
||
|
|
module! {
|
||
|
|
type: NullBlkModule,
|
||
|
|
name: "rnull_mod",
|
||
|
|
author: "Andreas Hindborg",
|
||
|
|
license: "GPL v2",
|
||
|
|
}
|
||
|
|
|
||
|
|
struct NullBlkModule {
|
||
|
|
_disk: Pin<Box<Mutex<GenDisk<NullBlkDevice>>>>,
|
||
|
|
}
|
||
|
|
|
||
|
|
impl kernel::Module for NullBlkModule {
|
||
|
|
fn init(_module: &'static ThisModule) -> Result<Self> {
|
||
|
|
pr_info!("Rust null_blk loaded\n");
|
||
|
|
let tagset = Arc::pin_init(TagSet::new(1, 256, 1), flags::GFP_KERNEL)?;
|
||
|
|
|
||
|
|
let disk = gen_disk::GenDiskBuilder::new()
|
||
|
|
.capacity_sectors(4096 << 11)
|
||
|
|
.logical_block_size(4096)?
|
||
|
|
.physical_block_size(4096)?
|
||
|
|
.rotational(false)
|
||
|
|
.build(format_args!("rnullb{}", 0), tagset)?;
|
||
|
|
|
||
|
|
let disk = Box::pin_init(new_mutex!(disk, "nullb:disk"), flags::GFP_KERNEL)?;
|
||
|
|
|
||
|
|
Ok(Self { _disk: disk })
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
struct NullBlkDevice;
|
||
|
|
|
||
|
|
#[vtable]
|
||
|
|
impl Operations for NullBlkDevice {
|
||
|
|
#[inline(always)]
|
||
|
|
fn queue_rq(rq: ARef<mq::Request<Self>>, _is_last: bool) -> Result {
|
||
|
|
mq::Request::end_ok(rq)
|
||
|
|
.map_err(|_e| kernel::error::code::EIO)
|
||
|
|
// We take no refcounts on the request, so we expect to be able to
|
||
|
|
// end the request. The request reference must be unique at this
|
||
|
|
// point, and so `end_ok` cannot fail.
|
||
|
|
.expect("Fatal error - expected to be able to end request");
|
||
|
|
|
||
|
|
Ok(())
|
||
|
|
}
|
||
|
|
|
||
|
|
fn commit_rqs() {}
|
||
|
|
}
|