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This patch adds an initial version of the Rust null block driver. Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240611114551.228679-3-nmi@metaspace.dk Signed-off-by: Jens Axboe <axboe@kernel.dk>
74 lines
1.8 KiB
Rust
74 lines
1.8 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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//! This is a Rust implementation of the C null block driver.
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//!
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//! Supported features:
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//!
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//! - blk-mq interface
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//! - direct completion
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//! - block size 4k
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//!
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//! The driver is not configurable.
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use kernel::{
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alloc::flags,
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block::mq::{
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self,
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gen_disk::{self, GenDisk},
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Operations, TagSet,
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},
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error::Result,
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new_mutex, pr_info,
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prelude::*,
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sync::{Arc, Mutex},
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types::ARef,
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};
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module! {
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type: NullBlkModule,
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name: "rnull_mod",
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author: "Andreas Hindborg",
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license: "GPL v2",
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}
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struct NullBlkModule {
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_disk: Pin<Box<Mutex<GenDisk<NullBlkDevice>>>>,
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}
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impl kernel::Module for NullBlkModule {
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fn init(_module: &'static ThisModule) -> Result<Self> {
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pr_info!("Rust null_blk loaded\n");
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let tagset = Arc::pin_init(TagSet::new(1, 256, 1), flags::GFP_KERNEL)?;
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let disk = gen_disk::GenDiskBuilder::new()
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.capacity_sectors(4096 << 11)
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.logical_block_size(4096)?
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.physical_block_size(4096)?
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.rotational(false)
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.build(format_args!("rnullb{}", 0), tagset)?;
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let disk = Box::pin_init(new_mutex!(disk, "nullb:disk"), flags::GFP_KERNEL)?;
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Ok(Self { _disk: disk })
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}
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}
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struct NullBlkDevice;
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#[vtable]
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impl Operations for NullBlkDevice {
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#[inline(always)]
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fn queue_rq(rq: ARef<mq::Request<Self>>, _is_last: bool) -> Result {
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mq::Request::end_ok(rq)
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.map_err(|_e| kernel::error::code::EIO)
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// We take no refcounts on the request, so we expect to be able to
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// end the request. The request reference must be unique at this
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// point, and so `end_ok` cannot fail.
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.expect("Fatal error - expected to be able to end request");
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Ok(())
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}
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fn commit_rqs() {}
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}
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