Commit 53328a36 authored by Benoît du Garreau's avatar Benoît du Garreau Committed by Jens Axboe
Browse files

block: rnull: Initialize the module in place 



Using `InPlaceModule` avoids an allocation and an indirection.

Signed-off-by: default avatarBenoît du Garreau <benoit@dugarreau.fr>
Acked-by: default avatarAndreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241204-rnull_in_place-v1-1-efe3eafac9fb@dugarreau.fr


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ccb9868a

drivers/block/rnull.rs

+18 −12
Original line number Diff line number Diff line
@@ -32,25 +32,31 @@ 
    license: "GPL v2",

}



#[pin_data]

struct NullBlkModule {

    _disk: Pin<KBox<Mutex<GenDisk<NullBlkDevice>>>>,

    #[pin]

    _disk: Mutex<GenDisk<NullBlkDevice>>,

}



impl kernel::Module for NullBlkModule {

    fn init(_module: &'static ThisModule) -> Result<Self> {

impl kernel::InPlaceModule for NullBlkModule {

    fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {

        pr_info!("Rust null_blk loaded\n");



        // Use a immediately-called closure as a stable `try` block

        let disk = /* try */ (|| {

            let tagset = Arc::pin_init(TagSet::new(1, 256, 1), flags::GFP_KERNEL)?;



        let disk = gen_disk::GenDiskBuilder::new()

            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 = KBox::pin_init(new_mutex!(disk, "nullb:disk"), flags::GFP_KERNEL)?;

                .build(format_args!("rnullb{}", 0), tagset)

        })();



        Ok(Self { _disk: disk })

        try_pin_init!(Self {

            _disk <- new_mutex!(disk?, "nullb:disk"),

        })

    }

}