@@ -354,6 +354,15 @@ config VIRTIO_BLK
This is the virtual block driver for virtio. It can be used with
QEMU based VMMs (like KVM or Xen). Say Y or M.
+config BLK_DEV_RUST_NULL
+ tristate "Rust null block driver (Experimental)"
+ depends on RUST
+ help
+ This is the Rust implementation of the null block driver. For now it
+ is only a minimal stub.
+
+ If unsure, say N.
+
config BLK_DEV_RBD
tristate "Rados block device (RBD)"
depends on INET && BLOCK
@@ -9,6 +9,9 @@
# needed for trace events
ccflags-y += -I$(src)
+obj-$(CONFIG_BLK_DEV_RUST_NULL) += rnull_mod.o
+rnull_mod-y := rnull.o
+
obj-$(CONFIG_MAC_FLOPPY) += swim3.o
obj-$(CONFIG_BLK_DEV_SWIM) += swim_mod.o
obj-$(CONFIG_BLK_DEV_FD) += floppy.o
new file mode 100644
@@ -0,0 +1,82 @@
+// 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::{
+ 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, gen_disk::Added>>>>,
+}
+
+fn add_disk(tagset: Arc<TagSet<NullBlkDevice>>) -> Result<GenDisk<NullBlkDevice, gen_disk::Added>> {
+ let block_size: u16 = 4096;
+ if block_size % 512 != 0 || !(512..=4096).contains(&block_size) {
+ return Err(kernel::error::code::EINVAL);
+ }
+
+ let mut disk = gen_disk::try_new(tagset)?;
+ disk.set_name(format_args!("rnullb{}", 0))?;
+ disk.set_capacity_sectors(4096 << 11);
+ disk.set_queue_logical_block_size(block_size.into());
+ disk.set_queue_physical_block_size(block_size.into());
+ disk.set_rotational(false);
+ disk.add()
+}
+
+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::try_new(1, 256, 1))?;
+ let disk = Box::pin_init(new_mutex!(add_disk(tagset)?, "nullb:disk"))?;
+
+ 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)
+ .expect("Failed to complete request");
+
+ Ok(())
+ }
+
+ fn commit_rqs() {}
+
+ fn complete(rq: ARef<mq::Request<Self>>) {
+ mq::Request::end_ok(rq)
+ .map_err(|_e| kernel::error::code::EIO)
+ .expect("Failed to complete request")
+ }
+}
@@ -263,7 +263,7 @@ $(obj)/%.lst: $(src)/%.c FORCE
# Compile Rust sources (.rs)
# ---------------------------------------------------------------------------
-rust_allowed_features := new_uninit,offset_of
+rust_allowed_features := new_uninit,offset_of,allocator_api
# `--out-dir` is required to avoid temporaries being created by `rustc` in the
# current working directory, which may be not accessible in the out-of-tree