Struct SuperBlockHeaderV61 

pub struct SuperBlockHeaderV61 {
    pub guid: UuidWrapperV32,
    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 reserved_metadata_space: FxHashMap<u64, u64>,
    pub earliest_version: Version,
}

Fields

guid: UuidWrapperV32

The globally unique identifier for the filesystem.

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.

reserved_metadata_space: FxHashMap<u64, u64>

Key 0 maps to the total reserved metadata space (M_total), and each child store object id maps to the metadata space borrowed by that store (B_S) as of 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 SuperBlockHeaderV61

pub fn new( generation: u64, 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 SuperBlockHeaderV61

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SuperBlockHeaderV61

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

Formats the value using the given formatter.

impl Default for SuperBlockHeaderV61

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for SuperBlockHeaderV61

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for SuperBlockHeaderV61

impl From<SuperBlockHeaderV32> for SuperBlockHeaderV61

fn from(header: SuperBlockHeaderV32) -> Self

Converts to this type from the input type.

impl PartialEq for SuperBlockHeaderV61

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for SuperBlockHeaderV61

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for SuperBlockHeaderV61

impl TypeFingerprint for SuperBlockHeaderV61

fn fingerprint() -> String

impl Versioned for SuperBlockHeaderV61

fn max_serialized_size() -> Option<u64>

Maximum size of a serialized version of this type. Serialization and deserialization will fail if the limit is exceeded. If None, there is no limit. None is preferred over u64::MAX because serializing and deserializing with a limit has runtime overhead.

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 VersionedLatest for SuperBlockHeaderV61

fn deserialize_from_version<R>(reader: &mut R, version: Version) -> Result<Self>

where R: Read, Self: Sized,

Deserializes from a given version format and upgrades to the latest version.

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

where R: Read, Self: Sized,

Like deserialize_from_version but reads Version from reader first, then uses it to deserialize self.

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

where W: Write, Self: Sized,

Like serialize_into but serialized Version first, then self.