Struct SuperBlockHeaderV32

pub struct SuperBlockHeaderV32 {
    pub generation: u64,
    pub root_parent_store_object_id: u64,
    pub root_parent_graveyard_directory_object_id: u64,
    pub root_store_object_id: u64,
    pub allocator_object_id: u64,
    pub journal_object_id: u64,
    pub journal_checkpoint: JournalCheckpointV32,
    pub super_block_journal_file_offset: u64,
    pub journal_file_offsets: FxHashMap<u64, u64>,
    pub borrowed_metadata_space: u64,
    pub earliest_version: Version,
    /* private fields */
}

Fields

generation: u64

There are two super-blocks which are used in an A/B configuration. The super-block with the greatest generation number is what is used when mounting an Fxfs image; the other is discarded.

root_parent_store_object_id: u64

The root parent store is an in-memory only store and serves as the backing store for the root store and the journal. The records for this store are serialized into the super-block and mutations are also recorded in the journal.

root_parent_graveyard_directory_object_id: u64

The root parent needs a graveyard and there’s nowhere else to store it other than in the super-block.

root_store_object_id: u64

The root object store contains all other metadata objects (including the allocator, the journal and the super-blocks) and is the parent for all other object stores.

allocator_object_id: u64

This is in the root object store.

journal_object_id: u64

This is in the root parent object store.

journal_checkpoint: JournalCheckpointV32

Start checkpoint for the journal file.

super_block_journal_file_offset: u64

Offset of the journal file when the super-block was written. If no entry is present in journal_file_offsets for a particular object, then an object might have dependencies on the journal from super_block_journal_file_offset onwards, but not earlier.

journal_file_offsets: FxHashMap<u64, u64>

object id -> journal file offset. Indicates where each object has been flushed to.

borrowed_metadata_space: u64

Records the amount of borrowed metadata space as applicable at super_block_journal_file_offset.

earliest_version: Version

The earliest version of Fxfs used to create any still-existing struct in the filesystem.

Note: structs in the filesystem may had been made with various different versions of Fxfs.

Implementations

impl SuperBlockHeaderV32

pub fn new( root_parent_store_object_id: u64, root_parent_graveyard_directory_object_id: u64, root_store_object_id: u64, allocator_object_id: u64, journal_object_id: u64, journal_checkpoint: JournalCheckpoint, earliest_version: Version, ) -> Self

Creates a new instance with random GUID.

Trait Implementations

impl Clone for SuperBlockHeaderV32

fn clone(&self) -> SuperBlockHeaderV32

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SuperBlockHeaderV32

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

Formats the value using the given formatter.

impl Default for SuperBlockHeaderV32

fn default() -> SuperBlockHeaderV32

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for SuperBlockHeaderV32

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for SuperBlockHeaderV32

fn eq(&self, other: &SuperBlockHeaderV32) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for SuperBlockHeaderV32

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl TypeFingerprint for SuperBlockHeaderV32

fn fingerprint() -> String

impl Versioned for SuperBlockHeaderV32

fn max_serialized_size() -> u64

fn deserialize_from<R>(reader: &mut R, _version: Version) -> Result<Self>

where R: Read + ?Sized, for<'de> Self: Deserialize<'de>,

fn serialize_into<W>(&self, writer: &mut W) -> Result<()>

where W: Write, Self: Serialize,

impl Eq for SuperBlockHeaderV32

impl StructuralPartialEq for SuperBlockHeaderV32