Struct JournalSb 

#[repr(C, packed(1))]
pub struct JournalSb {
    pub magic: [u8; 8],
    pub commited: u64,
    pub tx_id: u64,
    _pad: [u8; 4072],
}

Represents the on-disk metadata for the journal superblock.

Fields

magic: [u8; 8]

Journal magic: “KeOSJOUR”.

commited: u64

Indicate journal has been commited.

tx_id: u64

Transaction id.

_pad: [u8; 4072]

Padding to fill a full block (4096 bytes).

Implementations

impl JournalSb

pub fn from_disk( disk: &Disk, lba: LogicalBlockAddress, ) -> Result<Box<Self>, KernelError>

Loads the journal superblock from disk.

Arguments

• disk: The underlying disk interface.
• lba: The logical block address where the journal superblock is located.

Returns

• Ok(Box<Self>): A parsed journal superblock.
• Err(KernelError): If the block could not be read or parsed.

pub fn writeback( &self, io: &JournalIO<'_>, ffs: &FastFileSystemInner, ) -> Result<(), KernelError>

Writes the current journal superblock to disk.

This updates the on-disk metadata for the journal ring buffer.

Arguments

• io: The I/O interface to the journal.
• ffs: Reference to the file system’s metadata layout.

Returns

• Ok(()): If the write succeeds.
• Err(KernelError): If the write fails.

Trait Implementations

impl Default for JournalSb

fn default() -> Self

Returns the “default value” for a type.