Struct btrfs_diskformat::Chunk

#[repr(C, packed)]
pub struct Chunk {
    pub length: U64<LE>,
    pub owner: U64<LE>,
    pub stripe_len: U64<LE>,
    pub type: U64<LE>,
    pub io_align: U32<LE>,
    pub io_width: U32<LE>,
    pub sector_size: U32<LE>,
    pub num_stripes: U16<LE>,
    pub sub_stripes: U16<LE>,
    pub stripe: Stripe,
}

This structure contains the mapping from a virtualized usable byte range within the backing storage to a set of one or more stripes on individual backing devices. In addition to the mapping, hints on optimal I/O parameters for this chunk. It is associated with CHUNK_ITEM.

Although the structure definition only contains one stripe member, CHUNK_ITEM contain as many struct Stripe structures as specified in the num_stripes and sub_stripes fields.

Fields

length: U64<LE>

The size of this chunk, in bytes.

owner: U64<LE>

The object ID of the root referencing this chunk. This is always the ID of an extent root.

stripe_len: U64<LE>

The replication stripe length.

type: U64<LE>

Flags indicating allocation type and replication policy.

io_align: U32<LE>

The optimal I/O alignment for this chunk.

io_width: U32<LE>

The optimal I/O width for this chunk.

sector_size: U32<LE>

The minimal I/O size for this chunk.

num_stripes: U16<LE>

The number of replication stripes.

sub_stripes: U16<LE>

The number of sub-stripes. This is only used for RAID-10.

stripe: Stripe

The first of one or more stripes that map to device extents.

Trait Implementations

impl AsBytes for Chunk

fn as_bytes(&self) -> &[u8]

Get the bytes of this value.

fn as_bytes_mut(&mut self) -> &mut [u8]where
    Self: FromBytes,

Get the bytes of this value mutably.

impl Clone for Chunk

fn clone(&self) -> Chunk

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Chunk

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

Formats the value using the given formatter.

impl Copy for Chunk

impl FromBytes for Chunk

impl Unaligned for Chunk