rnull currently only supports direct completion. Add option for completing
requests across CPU nodes via soft IRQ or IPI.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
drivers/block/rnull/configfs.rs | 59 +++++++++++++++++++++++++++++++++++++++--
drivers/block/rnull/rnull.rs | 32 ++++++++++++++--------
2 files changed, 78 insertions(+), 13 deletions(-)
diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs
index 46710a1e1af4..8498e9bae6fd 100644
--- a/drivers/block/rnull/configfs.rs
+++ b/drivers/block/rnull/configfs.rs
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
use super::{NullBlkDevice, THIS_MODULE};
-use core::fmt::Write;
+use core::fmt::{Display, Write};
use kernel::{
block::mq::gen_disk::{GenDisk, GenDiskBuilder},
c_str,
@@ -36,7 +36,7 @@ impl AttributeOperations<0> for Config {
fn show(_this: &Config, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
let mut writer = kernel::str::Formatter::new(page);
- writer.write_str("blocksize,size,rotational\n")?;
+ writer.write_str("blocksize,size,rotational,irqmode\n")?;
Ok(writer.bytes_written())
}
}
@@ -58,6 +58,7 @@ fn make_group(
blocksize: 1,
rotational: 2,
size: 3,
+ irqmode: 4,
],
};
@@ -72,6 +73,7 @@ fn make_group(
rotational: false,
disk: None,
capacity_mib: 4096,
+ irq_mode: IRQMode::None,
name: name.try_into()?,
}),
}),
@@ -79,6 +81,34 @@ fn make_group(
}
}
+#[derive(Debug, Clone, Copy)]
+pub(crate) enum IRQMode {
+ None,
+ Soft,
+}
+
+impl TryFrom<u8> for IRQMode {
+ type Error = kernel::error::Error;
+
+ fn try_from(value: u8) -> Result<Self> {
+ match value {
+ 0 => Ok(Self::None),
+ 1 => Ok(Self::Soft),
+ _ => Err(EINVAL),
+ }
+ }
+}
+
+impl Display for IRQMode {
+ fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+ match self {
+ Self::None => f.write_str("0")?,
+ Self::Soft => f.write_str("1")?,
+ }
+ Ok(())
+ }
+}
+
#[pin_data]
pub(crate) struct DeviceConfig {
#[pin]
@@ -92,6 +122,7 @@ struct DeviceConfigInner {
block_size: u32,
rotational: bool,
capacity_mib: u64,
+ irq_mode: IRQMode,
disk: Option<GenDisk<NullBlkDevice>>,
}
@@ -121,6 +152,7 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
guard.block_size,
guard.rotational,
guard.capacity_mib,
+ guard.irq_mode,
)?);
guard.powered = true;
} else if guard.powered && !power_op {
@@ -205,3 +237,26 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
Ok(())
}
}
+
+#[vtable]
+impl configfs::AttributeOperations<4> for DeviceConfig {
+ type Data = DeviceConfig;
+
+ fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
+ let mut writer = kernel::str::Formatter::new(page);
+ writer.write_fmt(fmt!("{}\n", this.data.lock().irq_mode))?;
+ Ok(writer.bytes_written())
+ }
+
+ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
+ if this.data.lock().powered {
+ return Err(EBUSY);
+ }
+
+ let text = core::str::from_utf8(page)?.trim();
+ let value = text.parse::<u8>().map_err(|_| EINVAL)?;
+
+ this.data.lock().irq_mode = IRQMode::try_from(value)?;
+ Ok(())
+ }
+}
diff --git a/drivers/block/rnull/rnull.rs b/drivers/block/rnull/rnull.rs
index a19c55717c4f..1ec694d7f1a6 100644
--- a/drivers/block/rnull/rnull.rs
+++ b/drivers/block/rnull/rnull.rs
@@ -4,6 +4,7 @@
mod configfs;
+use configfs::IRQMode;
use kernel::{
block::{
self,
@@ -53,35 +54,44 @@ fn new(
block_size: u32,
rotational: bool,
capacity_mib: u64,
+ irq_mode: IRQMode,
) -> Result<GenDisk<Self>> {
let tagset = Arc::pin_init(TagSet::new(1, 256, 1), GFP_KERNEL)?;
+ let queue_data = Box::new(QueueData { irq_mode }, GFP_KERNEL)?;
+
gen_disk::GenDiskBuilder::new()
.capacity_sectors(capacity_mib << (20 - block::SECTOR_SHIFT))
.logical_block_size(block_size)?
.physical_block_size(block_size)?
.rotational(rotational)
- .build(fmt!("{}", name.to_str()?), tagset, ())
+ .build(fmt!("{}", name.to_str()?), tagset, queue_data)
}
}
+struct QueueData {
+ irq_mode: IRQMode,
+}
+
#[vtable]
impl Operations for NullBlkDevice {
- type QueueData = ();
+ type QueueData = KBox<QueueData>;
#[inline(always)]
- fn queue_rq(_queue_data: (), 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");
-
+ fn queue_rq(queue_data: &QueueData, rq: ARef<mq::Request<Self>>, _is_last: bool) -> Result {
+ match queue_data.irq_mode {
+ IRQMode::None => 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"),
+ IRQMode::Soft => mq::Request::complete(rq),
+ }
Ok(())
}
- fn commit_rqs(_queue_data: ()) {}
+ fn commit_rqs(_queue_data: &QueueData) {}
fn complete(rq: ARef<mq::Request<Self>>) {
mq::Request::end_ok(rq)
--
2.47.2
> On 22 Aug 2025, at 09:14, Andreas Hindborg <a.hindborg@kernel.org> wrote: > > rnull currently only supports direct completion. Add option for completing > requests across CPU nodes via soft IRQ or IPI. > > Reviewed-by: Alice Ryhl <aliceryhl@google.com> > Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> > --- > drivers/block/rnull/configfs.rs | 59 +++++++++++++++++++++++++++++++++++++++-- > drivers/block/rnull/rnull.rs | 32 ++++++++++++++-------- > 2 files changed, 78 insertions(+), 13 deletions(-) > > diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs > index 46710a1e1af4..8498e9bae6fd 100644 > --- a/drivers/block/rnull/configfs.rs > +++ b/drivers/block/rnull/configfs.rs > @@ -1,7 +1,7 @@ > // SPDX-License-Identifier: GPL-2.0 > > use super::{NullBlkDevice, THIS_MODULE}; > -use core::fmt::Write; > +use core::fmt::{Display, Write}; > use kernel::{ > block::mq::gen_disk::{GenDisk, GenDiskBuilder}, > c_str, > @@ -36,7 +36,7 @@ impl AttributeOperations<0> for Config { > > fn show(_this: &Config, page: &mut [u8; PAGE_SIZE]) -> Result<usize> { > let mut writer = kernel::str::Formatter::new(page); > - writer.write_str("blocksize,size,rotational\n")?; > + writer.write_str("blocksize,size,rotational,irqmode\n")?; > Ok(writer.bytes_written()) > } > } > @@ -58,6 +58,7 @@ fn make_group( > blocksize: 1, > rotational: 2, > size: 3, > + irqmode: 4, > ], > }; > > @@ -72,6 +73,7 @@ fn make_group( > rotational: false, > disk: None, > capacity_mib: 4096, > + irq_mode: IRQMode::None, > name: name.try_into()?, > }), > }), > @@ -79,6 +81,34 @@ fn make_group( > } > } > > +#[derive(Debug, Clone, Copy)] > +pub(crate) enum IRQMode { > + None, > + Soft, > +} > + > +impl TryFrom<u8> for IRQMode { > + type Error = kernel::error::Error; > + > + fn try_from(value: u8) -> Result<Self> { > + match value { > + 0 => Ok(Self::None), > + 1 => Ok(Self::Soft), > + _ => Err(EINVAL), > + } > + } > +} > + > +impl Display for IRQMode { > + fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result { > + match self { > + Self::None => f.write_str("0")?, > + Self::Soft => f.write_str("1")?, > + } > + Ok(()) > + } > +} > + > #[pin_data] > pub(crate) struct DeviceConfig { > #[pin] > @@ -92,6 +122,7 @@ struct DeviceConfigInner { > block_size: u32, > rotational: bool, > capacity_mib: u64, > + irq_mode: IRQMode, > disk: Option<GenDisk<NullBlkDevice>>, > } > > @@ -121,6 +152,7 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result { > guard.block_size, > guard.rotational, > guard.capacity_mib, > + guard.irq_mode, > )?); > guard.powered = true; > } else if guard.powered && !power_op { > @@ -205,3 +237,26 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result { > Ok(()) > } > } > + > +#[vtable] > +impl configfs::AttributeOperations<4> for DeviceConfig { > + type Data = DeviceConfig; > + > + fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> { > + let mut writer = kernel::str::Formatter::new(page); > + writer.write_fmt(fmt!("{}\n", this.data.lock().irq_mode))?; > + Ok(writer.bytes_written()) > + } > + > + fn store(this: &DeviceConfig, page: &[u8]) -> Result { > + if this.data.lock().powered { > + return Err(EBUSY); > + } > + > + let text = core::str::from_utf8(page)?.trim(); > + let value = text.parse::<u8>().map_err(|_| EINVAL)?; > + > + this.data.lock().irq_mode = IRQMode::try_from(value)?; > + Ok(()) > + } > +} > diff --git a/drivers/block/rnull/rnull.rs b/drivers/block/rnull/rnull.rs > index a19c55717c4f..1ec694d7f1a6 100644 > --- a/drivers/block/rnull/rnull.rs > +++ b/drivers/block/rnull/rnull.rs > @@ -4,6 +4,7 @@ > > mod configfs; > > +use configfs::IRQMode; > use kernel::{ > block::{ > self, > @@ -53,35 +54,44 @@ fn new( > block_size: u32, > rotational: bool, > capacity_mib: u64, > + irq_mode: IRQMode, > ) -> Result<GenDisk<Self>> { > let tagset = Arc::pin_init(TagSet::new(1, 256, 1), GFP_KERNEL)?; > > + let queue_data = Box::new(QueueData { irq_mode }, GFP_KERNEL)?; > + > gen_disk::GenDiskBuilder::new() > .capacity_sectors(capacity_mib << (20 - block::SECTOR_SHIFT)) > .logical_block_size(block_size)? > .physical_block_size(block_size)? > .rotational(rotational) > - .build(fmt!("{}", name.to_str()?), tagset, ()) > + .build(fmt!("{}", name.to_str()?), tagset, queue_data) > } > } > > +struct QueueData { > + irq_mode: IRQMode, > +} > + > #[vtable] > impl Operations for NullBlkDevice { > - type QueueData = (); > + type QueueData = KBox<QueueData>; > > #[inline(always)] > - fn queue_rq(_queue_data: (), 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"); Same comment here as on the last patch. Otherwise LGTM. > - > + fn queue_rq(queue_data: &QueueData, rq: ARef<mq::Request<Self>>, _is_last: bool) -> Result { > + match queue_data.irq_mode { > + IRQMode::None => 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"), > + IRQMode::Soft => mq::Request::complete(rq), > + } > Ok(()) > } > > - fn commit_rqs(_queue_data: ()) {} > + fn commit_rqs(_queue_data: &QueueData) {} > > fn complete(rq: ARef<mq::Request<Self>>) { > mq::Request::end_ok(rq) > > -- > 2.47.2 > > >
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