| Message ID | 20240521140323.2960069-3-nmi@metaspace.dk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Rust block device driver API and null block driver | expand |
On 21.05.24 16:03, Andreas Hindborg wrote: > From: Andreas Hindborg <a.hindborg@samsung.com> > > This patch adds an initial version of the Rust null block driver. > > Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com> > --- > drivers/block/Kconfig | 9 +++++ > drivers/block/Makefile | 3 ++ > drivers/block/rnull.rs | 86 +++++++++++++++++++++++++++++++++++++++++ > rust/kernel/block/mq.rs | 4 +- > 4 files changed, 101 insertions(+), 1 deletion(-) > create mode 100644 drivers/block/rnull.rs > > diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig > index 5b9d4aaebb81..ed209f4f2798 100644 > --- a/drivers/block/Kconfig > +++ b/drivers/block/Kconfig > @@ -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 > diff --git a/drivers/block/Makefile b/drivers/block/Makefile > index 101612cba303..1105a2d4fdcb 100644 > --- a/drivers/block/Makefile > +++ b/drivers/block/Makefile > @@ -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 > diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs > new file mode 100644 > index 000000000000..1d6ab6f0f26f > --- /dev/null > +++ b/drivers/block/rnull.rs > @@ -0,0 +1,86 @@ > +// 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, gen_disk::Added>>>>, > +} > + > +fn add_disk(tagset: Arc<TagSet<NullBlkDevice>>) -> Result<GenDisk<NullBlkDevice, gen_disk::Added>> { Any reason that this is its own function and not in the `NullBlkModule::init` function? > + 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), flags::GFP_KERNEL)?; > + let disk = Box::pin_init( > + new_mutex!(add_disk(tagset)?, "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) > + .expect("Failed to complete request"); This error would only happen if `rq` is not the only ARef to that request, right? > + > + Ok(()) > + } > + > + fn commit_rqs() {} > + > + fn complete(rq: ARef<mq::Request<Self>>) { Am I correct in thinking that this function is never actually called, since all requests that are queued are immediately ended? > + mq::Request::end_ok(rq) > + .map_err(|_e| kernel::error::code::EIO) > + .expect("Failed to complete request") > + } > +} > diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs > index efbd2588791b..54e032bbdffd 100644 > --- a/rust/kernel/block/mq.rs > +++ b/rust/kernel/block/mq.rs > @@ -51,6 +51,7 @@ > //! > //! ```rust > //! use kernel::{ > +//! alloc::flags, > //! block::mq::*, > //! new_mutex, > //! prelude::*, > @@ -77,7 +78,8 @@ > //! } > //! } > //! > -//! let tagset: Arc<TagSet<MyBlkDevice>> = Arc::pin_init(TagSet::try_new(1, 256, 1))?; > +//! let tagset: Arc<TagSet<MyBlkDevice>> = > +//! Arc::pin_init(TagSet::try_new(1, 256, 1), flags::GFP_KERNEL)?; This change should probably be in the patch before (seems like an artifact from rebasing). --- Cheers, Benno > //! let mut disk = gen_disk::try_new(tagset)?; > //! disk.set_name(format_args!("myblk"))?; > //! disk.set_capacity_sectors(4096); > -- > 2.44.0 > >
Benno Lossin <benno.lossin@proton.me> writes: > On 21.05.24 16:03, Andreas Hindborg wrote: >> From: Andreas Hindborg <a.hindborg@samsung.com> >> >> This patch adds an initial version of the Rust null block driver. >> >> Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com> >> --- >> drivers/block/Kconfig | 9 +++++ >> drivers/block/Makefile | 3 ++ >> drivers/block/rnull.rs | 86 +++++++++++++++++++++++++++++++++++++++++ >> rust/kernel/block/mq.rs | 4 +- >> 4 files changed, 101 insertions(+), 1 deletion(-) >> create mode 100644 drivers/block/rnull.rs >> >> diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig >> index 5b9d4aaebb81..ed209f4f2798 100644 >> --- a/drivers/block/Kconfig >> +++ b/drivers/block/Kconfig >> @@ -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 >> diff --git a/drivers/block/Makefile b/drivers/block/Makefile >> index 101612cba303..1105a2d4fdcb 100644 >> --- a/drivers/block/Makefile >> +++ b/drivers/block/Makefile >> @@ -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 >> diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs >> new file mode 100644 >> index 000000000000..1d6ab6f0f26f >> --- /dev/null >> +++ b/drivers/block/rnull.rs >> @@ -0,0 +1,86 @@ >> +// 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, gen_disk::Added>>>>, >> +} >> + >> +fn add_disk(tagset: Arc<TagSet<NullBlkDevice>>) -> Result<GenDisk<NullBlkDevice, gen_disk::Added>> { > > Any reason that this is its own function and not in the > `NullBlkModule::init` function? Would you embed it inside the `init` function? To what end? I don't think that would read well. > >> + 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), flags::GFP_KERNEL)?; >> + let disk = Box::pin_init( >> + new_mutex!(add_disk(tagset)?, "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) >> + .expect("Failed to complete request"); > > This error would only happen if `rq` is not the only ARef to that > request, right? Yes, it should never happen. If it happens, something is seriously broken and panic is adequate. Other drivers might want to retry later or something, but in this case it should just work. > >> + >> + Ok(()) >> + } >> + >> + fn commit_rqs() {} >> + >> + fn complete(rq: ARef<mq::Request<Self>>) { > > Am I correct in thinking that this function is never actually called, > since all requests that are queued are immediately ended? Yes, re my other email. It is a callback that cannot be triggered for now. I will move it to a later patch where it belongs. > >> + mq::Request::end_ok(rq) >> + .map_err(|_e| kernel::error::code::EIO) >> + .expect("Failed to complete request") >> + } >> +} >> diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs >> index efbd2588791b..54e032bbdffd 100644 >> --- a/rust/kernel/block/mq.rs >> +++ b/rust/kernel/block/mq.rs >> @@ -51,6 +51,7 @@ >> //! >> //! ```rust >> //! use kernel::{ >> +//! alloc::flags, >> //! block::mq::*, >> //! new_mutex, >> //! prelude::*, >> @@ -77,7 +78,8 @@ >> //! } >> //! } >> //! >> -//! let tagset: Arc<TagSet<MyBlkDevice>> = Arc::pin_init(TagSet::try_new(1, 256, 1))?; >> +//! let tagset: Arc<TagSet<MyBlkDevice>> = >> +//! Arc::pin_init(TagSet::try_new(1, 256, 1), flags::GFP_KERNEL)?; > > This change should probably be in the patch before (seems like an > artifact from rebasing). Yes, thank you for spotting that. I thought I checked that this was building, so this is strange to me. Maybe I failed to build the doctests between the two patches. It is weird that kernel robot did not pick this up. Maybe it is not building doctests? Best regards, Andreas
On 29.05.24 15:00, Andreas Hindborg wrote: > Benno Lossin <benno.lossin@proton.me> writes: > >> On 21.05.24 16:03, Andreas Hindborg wrote: >>> From: Andreas Hindborg <a.hindborg@samsung.com> >>> >>> This patch adds an initial version of the Rust null block driver. >>> >>> Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com> >>> --- >>> drivers/block/Kconfig | 9 +++++ >>> drivers/block/Makefile | 3 ++ >>> drivers/block/rnull.rs | 86 +++++++++++++++++++++++++++++++++++++++++ >>> rust/kernel/block/mq.rs | 4 +- >>> 4 files changed, 101 insertions(+), 1 deletion(-) >>> create mode 100644 drivers/block/rnull.rs >>> >>> diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig >>> index 5b9d4aaebb81..ed209f4f2798 100644 >>> --- a/drivers/block/Kconfig >>> +++ b/drivers/block/Kconfig >>> @@ -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 >>> diff --git a/drivers/block/Makefile b/drivers/block/Makefile >>> index 101612cba303..1105a2d4fdcb 100644 >>> --- a/drivers/block/Makefile >>> +++ b/drivers/block/Makefile >>> @@ -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 >>> diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs >>> new file mode 100644 >>> index 000000000000..1d6ab6f0f26f >>> --- /dev/null >>> +++ b/drivers/block/rnull.rs >>> @@ -0,0 +1,86 @@ >>> +// 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, gen_disk::Added>>>>, >>> +} >>> + >>> +fn add_disk(tagset: Arc<TagSet<NullBlkDevice>>) -> Result<GenDisk<NullBlkDevice, gen_disk::Added>> { >> >> Any reason that this is its own function and not in the >> `NullBlkModule::init` function? > > Would you embed it inside the `init` function? To what end? I don't > think that would read well. I just found it strange that you have this extracted into its own function, since I just expected it to be present in the init function. Does this look really that bad?: impl kernel::Module for NullBlkModule { fn init(_module: &'static ThisModule) -> Result<Self> { pr_info!("Rust null_blk loaded\n"); let block_size: u16 = 4096; if block_size % 512 != 0 || !(512..=4096).contains(&block_size) { return Err(kernel::error::code::EINVAL); } let disk = { let tagset = Arc::pin_init(TagSet::try_new(1, 256, 1), flags::GFP_KERNEL)?; 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() }; let disk = Box::pin_init( new_mutex!(disk, "nullb:disk"), flags::GFP_KERNEL, )?; Ok(Self { _disk: disk }) } } >>> + 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), flags::GFP_KERNEL)?; >>> + let disk = Box::pin_init( >>> + new_mutex!(add_disk(tagset)?, "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) >>> + .expect("Failed to complete request"); >> >> This error would only happen if `rq` is not the only ARef to that >> request, right? > > Yes, it should never happen. If it happens, something is seriously > broken and panic is adequate. > > Other drivers might want to retry later or something, but in this case > it should just work. In that case, I think the error message should reflect that and not just be a generic "failed to complete request" error. >>> + >>> + Ok(()) >>> + } >>> + >>> + fn commit_rqs() {} >>> + >>> + fn complete(rq: ARef<mq::Request<Self>>) { >> >> Am I correct in thinking that this function is never actually called, >> since all requests that are queued are immediately ended? > > Yes, re my other email. It is a callback that cannot be triggered for > now. I will move it to a later patch where it belongs. > >> >>> + mq::Request::end_ok(rq) >>> + .map_err(|_e| kernel::error::code::EIO) >>> + .expect("Failed to complete request") >>> + } >>> +} >>> diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs >>> index efbd2588791b..54e032bbdffd 100644 >>> --- a/rust/kernel/block/mq.rs >>> +++ b/rust/kernel/block/mq.rs >>> @@ -51,6 +51,7 @@ >>> //! >>> //! ```rust >>> //! use kernel::{ >>> +//! alloc::flags, >>> //! block::mq::*, >>> //! new_mutex, >>> //! prelude::*, >>> @@ -77,7 +78,8 @@ >>> //! } >>> //! } >>> //! >>> -//! let tagset: Arc<TagSet<MyBlkDevice>> = Arc::pin_init(TagSet::try_new(1, 256, 1))?; >>> +//! let tagset: Arc<TagSet<MyBlkDevice>> = >>> +//! Arc::pin_init(TagSet::try_new(1, 256, 1), flags::GFP_KERNEL)?; >> >> This change should probably be in the patch before (seems like an >> artifact from rebasing). > > Yes, thank you for spotting that. I thought I checked that this was > building, so this is strange to me. Maybe I failed to build the > doctests between the two patches. It is weird that kernel robot did not > pick this up. Maybe it is not building doctests? Hmm, that is strange... --- Cheers, Benno
Benno Lossin <benno.lossin@proton.me> writes: [...] >>>> + >>>> +fn add_disk(tagset: Arc<TagSet<NullBlkDevice>>) -> Result<GenDisk<NullBlkDevice, gen_disk::Added>> { >>> >>> Any reason that this is its own function and not in the >>> `NullBlkModule::init` function? >> >> Would you embed it inside the `init` function? To what end? I don't >> think that would read well. > > I just found it strange that you have this extracted into its own > function, since I just expected it to be present in the init function. > Does this look really that bad?: > > impl kernel::Module for NullBlkModule { > fn init(_module: &'static ThisModule) -> Result<Self> { > pr_info!("Rust null_blk loaded\n"); > let block_size: u16 = 4096; > if block_size % 512 != 0 || > !(512..=4096).contains(&block_size) { > return Err(kernel::error::code::EINVAL); > } > > let disk = { > let tagset = Arc::pin_init(TagSet::try_new(1, 256, 1), > flags::GFP_KERNEL)?; > 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() > }; > let disk = Box::pin_init( > new_mutex!(disk, "nullb:disk"), > flags::GFP_KERNEL, > )?; > > Ok(Self { _disk: disk }) > } > } I don't mind either way. I guess we could combine it. [...] >>>> +#[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"); >>> >>> This error would only happen if `rq` is not the only ARef to that >>> request, right? >> >> Yes, it should never happen. If it happens, something is seriously >> broken and panic is adequate. >> >> Other drivers might want to retry later or something, but in this case >> it should just work. > > In that case, I think the error message should reflect that and not just > be a generic "failed to complete request" error. Right, that is a good point. Best regards, Andreas
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 5b9d4aaebb81..ed209f4f2798 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -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 diff --git a/drivers/block/Makefile b/drivers/block/Makefile index 101612cba303..1105a2d4fdcb 100644 --- a/drivers/block/Makefile +++ b/drivers/block/Makefile @@ -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 diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs new file mode 100644 index 000000000000..1d6ab6f0f26f --- /dev/null +++ b/drivers/block/rnull.rs @@ -0,0 +1,86 @@ +// 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, 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), flags::GFP_KERNEL)?; + let disk = Box::pin_init( + new_mutex!(add_disk(tagset)?, "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) + .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") + } +} diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs index efbd2588791b..54e032bbdffd 100644 --- a/rust/kernel/block/mq.rs +++ b/rust/kernel/block/mq.rs @@ -51,6 +51,7 @@ //! //! ```rust //! use kernel::{ +//! alloc::flags, //! block::mq::*, //! new_mutex, //! prelude::*, @@ -77,7 +78,8 @@ //! } //! } //! -//! let tagset: Arc<TagSet<MyBlkDevice>> = Arc::pin_init(TagSet::try_new(1, 256, 1))?; +//! let tagset: Arc<TagSet<MyBlkDevice>> = +//! Arc::pin_init(TagSet::try_new(1, 256, 1), flags::GFP_KERNEL)?; //! let mut disk = gen_disk::try_new(tagset)?; //! disk.set_name(format_args!("myblk"))?; //! disk.set_capacity_sectors(4096);