Struct Disk

pub struct Disk(/* private fields */);

An asynchronous block device.

This type is cheap to clone, for sharing the disk among multiple concurrent users.

Implementations

impl Disk

pub fn new(disk: impl 'static + DiskIo) -> Result<Self, InvalidDisk>

Returns a new disk wrapping the given backing object.

pub fn sector_count(&self) -> u64

Returns the current sector count.

For some backing stores, this may change at runtime. Use wait_resize to detect this change.

pub fn sector_size(&self) -> u32

Returns the logical sector size of the backing store.

pub fn sector_shift(&self) -> u32

Returns log2 of the logical sector size of the backing store.

pub 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.

pub fn physical_sector_size(&self) -> u32

Returns the physical sector size of the backing store.

pub fn is_fua_respected(&self) -> bool

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

pub fn is_read_only(&self) -> bool

Returns true if the disk is read only.

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

Unmap sectors from the disk.

pub fn unmap_behavior(&self) -> UnmapBehavior

Returns the behavior of the unmap operation.

pub fn optimal_unmap_sectors(&self) -> u32

Returns the optimal granularity for unmaps, in sectors.

pub fn pr(&self) -> Option<&dyn PersistentReservation>

Optionally returns a trait object to issue persistent reservation requests.

pub fn eject( &self, ) -> impl use<'_> + Future<Output = Result<(), DiskError>> + Send

Issues an asynchronous eject media operation to the disk.

pub fn read_vectored<'a>( &'a self, buffers: &'a RequestBuffers<'_>, sector: u64, ) -> impl use<'a> + 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.

pub fn write_vectored<'a>( &'a self, buffers: &'a RequestBuffers<'_>, sector: u64, fua: bool, ) -> impl use<'a> + 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.

Panics

The caller must pass a buffer with an integer number of sectors.

pub fn sync_cache( &self, ) -> impl use<'_> + Future<Output = Result<(), DiskError>> + Send

Issues an asynchronous flush operation to the disk.

pub fn wait_resize( &self, sector_count: u64, ) -> impl use<'_> + Future<Output = u64>

Waits for the disk sector size to be different than the specified value.

Trait Implementations

impl Clone for Disk

fn clone(&self) -> Disk

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Disk

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Inspect for Disk

fn inspect(&self, req: Request<'_>)

Inspects the object.