drivers/block/rnull/configfs.rs

Source file repositories/reference/linux-study-clean/drivers/block/rnull/configfs.rs

File Facts

System
Linux kernel
Corpus path
drivers/block/rnull/configfs.rs
Extension
.rs
Size
6949 bytes
Lines
262
Domain
Driver Families
Bucket
drivers/block
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct DeviceConfigInner {
    powered: bool,
    name: CString,
    block_size: u32,
    rotational: bool,
    capacity_mib: u64,
    irq_mode: IRQMode,
    disk: Option<GenDisk<NullBlkDevice>>,
}

#[vtable]
impl configfs::AttributeOperations<0> for DeviceConfig {
    type Data = DeviceConfig;

    fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
        let mut writer = kernel::str::Formatter::new(page);

        if this.data.lock().powered {
            writer.write_str("1\n")?;
        } else {
            writer.write_str("0\n")?;
        }

        Ok(writer.bytes_written())
    }

    fn store(this: &DeviceConfig, page: &[u8]) -> Result {
        let power_op = kstrtobool_bytes(page)?;
        let mut guard = this.data.lock();

        if !guard.powered && power_op {
            guard.disk = Some(NullBlkDevice::new(
                &guard.name,
                guard.block_size,
                guard.rotational,
                guard.capacity_mib,
                guard.irq_mode,
            )?);
            guard.powered = true;
        } else if guard.powered && !power_op {
            drop(guard.disk.take());
            guard.powered = false;
        }

        Ok(())
    }
}

#[vtable]
impl configfs::AttributeOperations<1> 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().block_size))?;
        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::<u32>().map_err(|_| EINVAL)?;

        GenDiskBuilder::validate_block_size(value)?;
        this.data.lock().block_size = value;
        Ok(())
    }
}

#[vtable]
impl configfs::AttributeOperations<2> for DeviceConfig {
    type Data = DeviceConfig;

    fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result<usize> {
        let mut writer = kernel::str::Formatter::new(page);

        if this.data.lock().rotational {
            writer.write_str("1\n")?;
        } else {
            writer.write_str("0\n")?;
        }

        Ok(writer.bytes_written())
    }

    fn store(this: &DeviceConfig, page: &[u8]) -> Result {
        if this.data.lock().powered {

Annotation

Implementation Notes