Struct Superblock 

#[repr(C)]
pub struct Superblock {

    pub magic: U32,
    pub checksum: U32,
    pub feature_compat: U32,
    pub blkszbits: u8,
    pub extslots: u8,
    pub root_nid: U16,
    pub inos: U64,
    pub build_time: U64,
    pub build_time_nsec: U32,
    pub blocks: U32,
    pub meta_blkaddr: U32,
    pub xattr_blkaddr: U32,
    pub uuid: [u8; 16],
    pub volume_name: [u8; 16],
    pub feature_incompat: U32,
    pub available_compr_algs: U16,
    pub extra_devices: U16,
    pub devt_slotoff: U16,
    pub dirblkbits: u8,
    pub xattr_prefix_count: u8,
    pub xattr_prefix_start: U32,
    pub packed_nid: U64,
    pub xattr_filter_reserved: u8,
    pub reserved2: [u8; 23],
}

EROFS filesystem superblock structure

Fields

magic: U32

EROFS magic number

checksum: U32

Filesystem checksum

feature_compat: U32

Compatible feature flags

blkszbits: u8

Block size in bits (log2 of block size)

extslots: u8

Number of extended attribute slots

root_nid: U16

Root inode number

inos: U64

Total number of inodes

build_time: U64

Build time in seconds since epoch

build_time_nsec: U32

Build time nanoseconds component

blocks: U32

Total number of blocks

meta_blkaddr: U32

Starting block address of metadata

xattr_blkaddr: U32

Starting block address of extended attributes

uuid: [u8; 16]

Filesystem UUID

volume_name: [u8; 16]

Volume name

feature_incompat: U32

Incompatible feature flags

available_compr_algs: U16

Available compression algorithms bitmap

extra_devices: U16

Number of extra devices

devt_slotoff: U16

Device slot offset

dirblkbits: u8

Directory block size in bits

xattr_prefix_count: u8

Number of xattr prefixes

xattr_prefix_start: U32

Starting position of xattr prefix table

packed_nid: U64

Packed inode number

xattr_filter_reserved: u8

Reserved for xattr filtering

reserved2: [u8; 23]

Reserved for future use

Trait Implementations

impl Debug for Superblock

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

Formats the value using the given formatter.

impl Default for Superblock

fn default() -> Superblock

Returns the “default value” for a type.

impl FromBytes for Superblock

where U32: FromBytes, u8: FromBytes, U16: FromBytes, U64: FromBytes, [u8; 16]: FromBytes, [u8; 23]: FromBytes,

fn ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout + Immutable,

Interprets the given source as a &Self.

fn ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout + Immutable,

Interprets the prefix of the given source as a &Self without copying.

fn ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: Immutable + KnownLayout,

Interprets the suffix of the given bytes as a &Self.

fn mut_from_bytes( source: &mut [u8], ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout,

Interprets the given source as a &mut Self.

fn mut_from_prefix( source: &mut [u8], ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout,

Interprets the prefix of the given source as a &mut Self without copying.

fn mut_from_suffix( source: &mut [u8], ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout,

Interprets the suffix of the given source as a &mut Self without copying.

fn ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the given source as a &Self with a DST length equal to count.

fn ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the prefix of the given source as a DST &Self with length equal to count.

fn ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the suffix of the given source as a DST &Self with length equal to count.

fn mut_from_bytes_with_elems( source: &mut [u8], count: usize, ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the given source as a &mut Self with a DST length equal to count.

fn mut_from_prefix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize>,

Interprets the prefix of the given source as a &mut Self with DST length equal to count.

fn mut_from_suffix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, Infallible>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize>,

Interprets the suffix of the given source as a &mut Self with DST length equal to count.

fn read_from_bytes(source: &[u8]) -> Result<Self, SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the given source.

fn read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the prefix of the given source.

fn read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the suffix of the given source.

fn read_from_io<R>(src: R) -> Result<Self, Error>

where Self: Sized, R: Read,

Reads a copy of self from an io::Read.

impl FromZeros for Superblock

where U32: FromZeros, u8: FromZeros, U16: FromZeros, U64: FromZeros, [u8; 16]: FromZeros, [u8; 23]: FromZeros,

fn zero(&mut self)

Overwrites self with zeros.

fn new_zeroed() -> Self

where Self: Sized,

Creates an instance of Self from zeroed bytes.

fn new_box_zeroed() -> Result<Box<Self>, AllocError>

where Self: Sized,

Creates a Box<Self> from zeroed bytes.

fn new_box_zeroed_with_elems(count: usize) -> Result<Box<Self>, AllocError>

where Self: KnownLayout<PointerMetadata = usize>,

Creates a Box<[Self]> (a boxed slice) from zeroed bytes.

fn new_vec_zeroed(len: usize) -> Result<Vec<Self>, AllocError>

where Self: Sized,

Creates a Vec<Self> from zeroed bytes.

fn extend_vec_zeroed( v: &mut Vec<Self>, additional: usize, ) -> Result<(), AllocError>

where Self: Sized,

Extends a Vec<Self> by pushing additional new items onto the end of the vector. The new items are initialized with zeros.

fn insert_vec_zeroed( v: &mut Vec<Self>, position: usize, additional: usize, ) -> Result<(), AllocError>

where Self: Sized,

Inserts additional new items into Vec<Self> at position. The new items are initialized with zeros.

impl IntoBytes for Superblock

where U32: IntoBytes, u8: IntoBytes, U16: IntoBytes, U64: IntoBytes, [u8; 16]: IntoBytes, [u8; 23]: IntoBytes, (): PaddingFree<Self, { _ }>,

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

where Self: Immutable,

Gets the bytes of this value.

fn as_mut_bytes(&mut self) -> &mut [u8]

where Self: FromBytes,

Gets the bytes of this value mutably.

fn write_to(&self, dst: &mut [u8]) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to dst.

fn write_to_prefix( &self, dst: &mut [u8], ) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to the prefix of dst.

fn write_to_suffix( &self, dst: &mut [u8], ) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to the suffix of dst.

fn write_to_io<W>(&self, dst: W) -> Result<(), Error>

where Self: Immutable, W: Write,

Writes a copy of self to an io::Write.

impl KnownLayout for Superblock

where [u8; 23]: KnownLayout,

type PointerMetadata = <[u8; 23] as KnownLayout>::PointerMetadata

The type of metadata stored in a pointer to Self.

fn size_for_metadata(meta: Self::PointerMetadata) -> Option<usize>

Computes the size of an object of type Self with the given pointer metadata.

impl TryFromBytes for Superblock

where U32: TryFromBytes, u8: TryFromBytes, U16: TryFromBytes, U64: TryFromBytes, [u8; 16]: TryFromBytes, [u8; 23]: TryFromBytes,

fn try_ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the given source as a &Self.

fn try_ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the prefix of the given source as a &Self.

fn try_ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the suffix of the given source as a &Self.

fn try_mut_from_bytes( bytes: &mut [u8], ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the given source as a &mut Self without copying.

fn try_mut_from_prefix( source: &mut [u8], ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the prefix of the given source as a &mut Self.

fn try_mut_from_suffix( source: &mut [u8], ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the suffix of the given source as a &mut Self.

fn try_ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the given source as a &Self with a DST length equal to count.

fn try_ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the prefix of the given source as a &Self with a DST length equal to count.

fn try_ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the suffix of the given source as a &Self with a DST length equal to count.

fn try_mut_from_bytes_with_elems( source: &mut [u8], count: usize, ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the given source as a &mut Self with a DST length equal to count.

fn try_mut_from_prefix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the prefix of the given source as a &mut Self with a DST length equal to count.

fn try_mut_from_suffix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the suffix of the given source as a &mut Self with a DST length equal to count.

fn try_read_from_bytes( source: &[u8], ) -> Result<Self, ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read the given source as a Self.

fn try_read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the prefix of the given source.

fn try_read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the suffix of the given source.

impl Immutable for Superblock

where U32: Immutable, u8: Immutable, U16: Immutable, U64: Immutable, [u8; 16]: Immutable, [u8; 23]: Immutable,