Trait DiskIo

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pub trait DiskIo:
    'static
    + Send
    + Sync
    + Inspect {
Show 16 methods    // Required methods
    fn disk_type(&self) -> &str;
    fn sector_count(&self) -> u64;
    fn sector_size(&self) -> u32;
    fn disk_id(&self) -> Option<[u8; 16]>;
    fn physical_sector_size(&self) -> u32;
    fn is_fua_respected(&self) -> bool;
    fn is_read_only(&self) -> bool;
    fn unmap(
        &self,
        sector: u64,
        count: u64,
        block_level_only: bool,
    ) -> impl Future<Output = Result<(), DiskError>> + Send;
    fn unmap_behavior(&self) -> UnmapBehavior;
    fn read_vectored(
        &self,
        buffers: &RequestBuffers<'_>,
        sector: u64,
    ) -> impl Future<Output = Result<(), DiskError>> + Send;
    fn write_vectored(
        &self,
        buffers: &RequestBuffers<'_>,
        sector: u64,
        fua: bool,
    ) -> impl Future<Output = Result<(), DiskError>> + Send;
    fn sync_cache(&self) -> impl Future<Output = Result<(), DiskError>> + Send;

    // Provided methods
    fn optimal_unmap_sectors(&self) -> u32 { ... }
    fn pr(&self) -> Option<&dyn PersistentReservation> { ... }
    fn eject(&self) -> impl Future<Output = Result<(), DiskError>> + Send { ... }
    fn wait_resize(&self, sector_count: u64) -> impl Future<Output = u64> + Send { ... }
}

Expand description

Disk metadata and IO operations.

Required Methods§

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fn disk_type(&self) -> &str

Returns the disk type name as a string.

This is used for diagnostic purposes.

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fn sector_count(&self) -> u64

Returns the current sector count.

For some backing stores, this may change at runtime. If it does, then the backing store must also implement DiskIo::wait_resize.

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fn sector_size(&self) -> u32

Returns the logical sector size of the backing store.

This must not change at runtime.

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fn disk_id(&self) -> Option<[u8; 16]>

Optionally returns a 16-byte identifier for the disk, if there is a natural one for this backing store.

This may be exposed to the guest as a unique disk identifier. This must not change at runtime.

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fn physical_sector_size(&self) -> u32

Returns the physical sector size of the backing store.

This must not change at runtime.

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fn is_fua_respected(&self) -> bool

Returns true if the fua parameter to DiskIo::write_vectored is respected by the backing store by ensuring that the IO is immediately committed to disk.

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fn is_read_only(&self) -> bool

Returns true if the disk is read only.

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fn unmap( &self, sector: u64, count: u64, block_level_only: bool, ) -> impl Future<Output = Result<(), DiskError>> + Send

Unmap sectors from the layer.

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fn unmap_behavior(&self) -> UnmapBehavior

Returns the behavior of the unmap operation.

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fn read_vectored( &self, buffers: &RequestBuffers<'_>, sector: u64, ) -> impl Future<Output = Result<(), DiskError>> + Send

Issues an asynchronous read-scatter operation to the disk.

§Arguments

buffers - An object representing the data buffers into which the disk data will be transferred.
sector - The logical sector at which the read operation starts.

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fn write_vectored( &self, buffers: &RequestBuffers<'_>, sector: u64, fua: bool, ) -> impl Future<Output = Result<(), DiskError>> + Send

Issues an asynchronous write-gather operation to the disk.

§Arguments

buffers - An object representing the data buffers containing the data to transfer to the disk.
sector - The logical sector at which the write operation starts.
fua - A flag indicates if FUA (force unit access) is requested.

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