Struct ChunkMap 

pub struct ChunkMap { /* private fields */ }

The chunk-tree logical→physical map: the union of every CHUNK_ITEM’s span and its physical placement. Covers single-device profiles (SINGLE/DUP); for DUP the first stripe (first mirror) is returned.

Implementations

impl ChunkMap

pub fn new() -> Self

An empty map.

pub fn add_from_node(&mut self, node: &Node)

Add every CHUNK_ITEM found in a chunk-tree leaf node to the map.

pub fn logical_to_physical(&self, logical: u64) -> Option<(u64, u64)>

Translate a logical address to (devid, physical_byte) on the first stripe’s device, for single-device single/DUP chunks. Returns None if no chunk covers logical, or the covering chunk has no stripe.

pub fn walk(image: &[u8], sb: &Superblock) -> Result<Self, BtrfsError>

Build the full chunk map by bootstrapping from the superblock’s sys_chunk_array and walking the chunk tree from sb.chunk_root.

The sys_chunk_array covers the chunk_root’s own logical range (that is its whole purpose), so chunk_root is reachable; each subsequently read node’s blockptrs are translated through the map built so far (the chunk tree is self-describing). On the oracle the chunk tree is a single leaf, but interior nodes are followed recursively (bounded).

Errors

• BtrfsError::Truncated if sb.chunk_root cannot be translated to a readable node within image (a failed bootstrap is loud, never an empty map — see the Paranoid Gatekeeper standard).

Trait Implementations

impl Clone for ChunkMap

fn clone(&self) -> ChunkMap

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ChunkMap

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

Formats the value using the given formatter.

impl Default for ChunkMap

fn default() -> ChunkMap

Returns the “default value” for a type.

impl Eq for ChunkMap

impl PartialEq for ChunkMap

fn eq(&self, other: &ChunkMap) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ChunkMap