vapfs_ufs/src/structs.rs

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use vapfs::{Index, Timestamp};
/// # Magic
/// Constant value that identifies the Superblock as a valid VapUFS filesystem
pub const MAGIC: u64 = 0x766170554653;
/// # Superblock
/// The primary struct of a VapUFS filesystem, contains metadata about the filesystem.
/// Located at byte offset 1024 of the block device.
/// All values are big-endian unless otherwise specified.
/// Directly after the Superblock are the free data blocks bitmap and the free inodes bitmap.
/// Free data blocks bitmap is data_block_count / 8 bytes long (rounded up).
/// Free inodes bitmap is inode_count / 8 bytes long (rounded up).
#[repr(C)]
pub struct Superblock {
/// magic number that identifies the Superblock as a valid VapUFS filesystem
pub magic: u64,
/// size of each block in bytes
pub block_size: u32,
/// location of first data block in blocks
pub first_data_block: Index,
/// location of first inode block in blocks
pub first_inode_block: Index,
/// location of first journal block in blocks
pub first_journal_block: Index,
/// total count of inodes, including unused inodes
pub inode_count: Index,
/// total count of data blocks, including unused blocks
pub data_block_count: Index,
/// total count of blocks dedicated to journal
pub journal_block_count: Index,
/// total count of inodes in use
pub allocated_inode_count: Index,
/// total count of data blocks in use
pub allocated_data_block_count: Index,
/// timestamp of creation
pub creation_time: Timestamp,
/// timestamp of last modification
pub last_modification_time: Timestamp,
/// reserved values for expansion
pub reserved: [u64; 8],
// 156 bytes used so far
// rest of the block is used by the free data blocks bitmap and the free inodes bitmap
}
/// # UNIXPermissions
/// UNIX permissions
#[repr(u16)]
pub enum UNIXMode {
/// Read, Other
Read = 1 << 0,
/// Write, Other
Write = 1 << 1,
/// Execute, Other
Execute = 1 << 2,
/// Read, Group
ReadGroup = 1 << 3,
/// Write, Group
WriteGroup = 1 << 4,
/// Execute, Group
ExecuteGroup = 1 << 5,
/// Read, Owner
ReadOwner = 1 << 6,
/// Write, Owner
WriteOwner = 1 << 7,
/// Execute, Owner
ExecuteOwner = 1 << 8,
/// Sticky bit
Sticky = 1 << 9,
/// Set GID
SetGID = 1 << 10,
/// Set UID
SetUID = 1 << 11,
}
/// # Filetype
/// Represents a file's type in the last 4 bits of the mode field of an inode.
#[repr(u16)]
pub enum Filetype {
/// Named FIFO pipe
FIFO = 0b0001 << 12,
/// Character device
CharDevice = 0b0010 << 12,
/// Directory
Directory = 0b0011 << 12,
/// Block device
BlockDevice = 0b0100 << 12,
/// Regular file
RegularFile = 0b0101 << 12,
/// Symbolic link
SymbolicLink = 0b0110 << 12,
/// Socket
Socket = 0b0111 << 12,
}
/// # Inode
/// Usually represents a file or directory, used to store metadata and locations of data blocks.
#[repr(C)]
pub struct Inode {
/// UNIX permissions / mode and filetype
pub mode: u16,
/// Number of links to this inode
pub link_count: u16,
/// User ID of owner
pub uid: u32,
/// Group ID of owner
pub gid: u32,
/// Size in bytes
pub size: Index,
/// Size in blocks
pub block_count: Index,
/// Timestamp of creation
pub creation_time: Timestamp,
/// Timestamp of last access
pub last_access_time: Timestamp,
/// Timestamp of last modification
pub last_modification_time: Timestamp,
/// Timestamp of last Inode modification
pub last_inode_modification_time: Timestamp,
/// Timestamp of deletion
pub deletion_time: Timestamp,
/// Flags field, see `InodeFlags`
pub flags: u32,
/// Direct-Block-Addresses, last three are indirect if `InodeFlags::INDIRECT` is set
/// Indirect blocks are Indexes to other blocks, their contents are a u64 count "N" followed by N u64 indexes
pub direct_block_addresses: [Index; 12],
/// CRC32 checksum of this inode
pub checksum: u32,
}
/// # InodeFlags
/// Flags field of an inode
#[repr(u32)]
pub enum InodeFlags {
/// File is corrupted
CORRUPT = 1 << 0,
/// File uses indirect blocks
INDIRECT = 1 << 1,
}