Defines structures and enums for the Extended 2 (ext2) filesystem format and relevant Filesystem, Directory and File classes. More...

#include <cstdint>
#include <common/spinlock.h>
#include <common/macros.h>
#include <drivers/disk/disk.h>
#include <drivers/clock/clock.h>
#include <filesystem/filesystem.h>
#include <memory/memoryIO.h>

Classes
struct	MaxOS::filesystem::format::ext2::SuperBlock
	The metadata of the ext2 filesystem. Found at an offset of 1024 bytes from the start of the partition. More...

struct	MaxOS::filesystem::format::ext2::BlockGroupDescriptor
	The metadata for a block group in ext2. More...

struct	MaxOS::filesystem::format::ext2::Inode
	The metadata for a file or directory in ext2. More...

struct	MaxOS::filesystem::format::ext2::InodeOS2Linux
	The OS specific data for Linux created ext2 inodes. More...

struct	MaxOS::filesystem::format::ext2::DirectoryEntry
	An entry in a directory that points to a file or subdirectory (the name follows this struct) More...

class	MaxOS::filesystem::format::ext2::Ext2Volume
	Common operations for an ext2 volume that are used by both files & directories (like block & inode allocation) More...

class	MaxOS::filesystem::format::ext2::InodeHandler
	Simplfies the management of an inode & its blocks. More...

class	MaxOS::filesystem::format::ext2::Ext2File
	Handles the file operations on the ext2 filesystem. More...

class	MaxOS::filesystem::format::ext2::Ext2Directory
	Handles the directory operations on the ext2 filesystem. More...

class	MaxOS::filesystem::format::ext2::Ext2FileSystem
	Handles the ext2 filesystem operations. More...

Typedefs
typedef struct PACKED MaxOS::filesystem::format::ext2::SuperBlock	MaxOS::filesystem::format::ext2::superblock_t
	Alias for SuperBlock struct.

typedef struct PACKED MaxOS::filesystem::format::ext2::BlockGroupDescriptor	MaxOS::filesystem::format::ext2::block_group_descriptor_t
	Alias for BlockGroupDescriptor struct.

typedef struct PACKED MaxOS::filesystem::format::ext2::Inode	MaxOS::filesystem::format::ext2::inode_t
	Alias for Inode struct.

typedef struct PACKED MaxOS::filesystem::format::ext2::InodeOS2Linux	MaxOS::filesystem::format::ext2::linux_os_2_t
	Alias for InodeOS2Linux struct.

typedef struct PACKED MaxOS::filesystem::format::ext2::DirectoryEntry	MaxOS::filesystem::format::ext2::directory_entry_t
	Alias for DirectoryEntry struct.

Enumerations
enum class	MaxOS::filesystem::format::ext2::FileSystemState { CLEAN = 1 , ERROR = 2 }
	The state of the filesystem. More...

enum class	MaxOS::filesystem::format::ext2::ErrorOperation { IGNORE = 1 , REMOUNT = 2 , PANIC = 3 }
	What to do when an error occurs. More...

enum class	MaxOS::filesystem::format::ext2::CreatorOS { LINUX , GNU_HURD , MASIX , FREE_BSD , OTHER_LITES }
	The OS which created the filesystem. More...

enum class	MaxOS::filesystem::format::ext2::OptionalFeatures { PREALLOCATE_DIRECTORY = 0x1 , AFS_SERVER_INODES = 0x2 , JOURNAL_ENABLED = 0x4 , ATTRIBUTES_EXTENDED = 0x8 , RESIZEABLE = 0x10 , HASH_INDEXING = 0x20 }
	What features that are optional are supported by this filesystem. More...

enum class	MaxOS::filesystem::format::ext2::RequiredFeatures { COMPRESSION = 0x1 , DIRECTORY_HAS_TYPE = 0x2 , MUST_REPLAY_JOURNAL = 0x4 , JOURNAL_DEVICE = 0x8 }
	What features that are required are supported by this filesystem. More...

enum class	MaxOS::filesystem::format::ext2::ReadOnlyFeatures { SPARSE_SUPER_BLOCKS = 0x1 , FILES_64_BIT = 0x2 , BINARY_TREE_DIRECTORIES = 0x4 }
	What features that are only required in read-only mode. More...

enum class	MaxOS::filesystem::format::ext2::InodeType { UNKNOWN , FIFO = 0x1000 , CHARACTER_DEVICE = 0x2000 , DIRECTORY = 0x4000 , BLOCK_DEVICE = 0x6000 , FILE = 0x8000 , SYMBOLIC_LINK = 0xA000 , SOCKET = 0xC000 }
	The type of an inode. More...

enum class	MaxOS::filesystem::format::ext2::InodePermissions { OTHER_EXECUTE = 0x1 , OTHER_WRITE = 0x2 , OTHER_READ = 0x4 , GROUP_EXECUTE = 0x8 , GROUP_WRITE = 0x10 , GROUP_READ = 0x20 , USER_EXECUTE = 0x40 , USER_WRITE = 0x80 , USER_READ = 0x100 , STICKY = 0x200 , GROUP_ID = 0x400 , USER_ID = 0x800 }
	The permissions that an inode can have. More...

enum class	MaxOS::filesystem::format::ext2::InodePermissionsDefaults { FILE = 0x1A4 , DIRECTORY = 0x1ED }
	The default permissions for files and directories. More...

enum class	MaxOS::filesystem::format::ext2::InodeFlags { SECURE_DELETE = 0x1 , KEEP_DATA = 0x2 , FILE_COMPRESSION = 0x4 , SYNC_UPDATES = 0x8 , FILE_IMMUTABLE = 0x10 , APPEND_ONLY = 0x20 , DONT_DUMP = 0x40 , NO_LAST_ACCESS = 0x80 , HASH_INDEXED = 0x10000 , AFS_DIRECTORY = 0x20000 , JOURNAL_FILE_DATA = 0x40000 }
	The flags that can be set on an inode. More...

enum class	MaxOS::filesystem::format::ext2::EntryType { UNKNOWN , FILE , DIRECTORY , CHARACTER_DEVICE , BLOCK_DEVICE , FIFO , SOCKET , SYMBOLIC_LINK }
	The type of a directory entry. More...

Detailed Description

Defines structures and enums for the Extended 2 (ext2) filesystem format and relevant Filesystem, Directory and File classes.

Date: 17th July 2025

Author: Max Tyson

Definition in file ext2.h.

Typedef Documentation

◆ block_group_descriptor_t

MaxOS::filesystem::format::ext2::block_group_descriptor_t

Alias for BlockGroupDescriptor struct.

Todo:: Support updating directory_count when creating/deleting directories

◆ linux_os_2_t

MaxOS::filesystem::format::ext2::linux_os_2_t

Alias for InodeOS2Linux struct.

Todo:: HURD, MASIX

Enumeration Type Documentation

◆ CreatorOS

enum class MaxOS::filesystem::format::ext2::CreatorOS

strong

The OS which created the filesystem.

Todo:: Add MaxOS

Definition at line 104 of file ext2.h.

                         {
        LINUX,
        GNU_HURD,
        MASIX,
        FREE_BSD,
        OTHER_LITES,
    };

◆ EntryType

enum class MaxOS::filesystem::format::ext2::EntryType

strong

The type of a directory entry.

Warning: MaxOS only supports FILE, DIRECTORY

Todo:: Support more

Definition at line 305 of file ext2.h.

                         {
        UNKNOWN,
        FILE,
        DIRECTORY,
        CHARACTER_DEVICE,
        BLOCK_DEVICE,
        FIFO,
        SOCKET,
        SYMBOLIC_LINK
    };

◆ ErrorOperation

enum class MaxOS::filesystem::format::ext2::ErrorOperation

strong

What to do when an error occurs.

Definition at line 92 of file ext2.h.

                              {
        IGNORE = 1,
        REMOUNT = 2,
        PANIC = 3,
    };

◆ FileSystemState

enum class MaxOS::filesystem::format::ext2::FileSystemState

strong

The state of the filesystem.

Definition at line 83 of file ext2.h.

                               {
        CLEAN = 1,
        ERROR = 2,
    };

◆ InodeFlags

enum class MaxOS::filesystem::format::ext2::InodeFlags

strong

The flags that can be set on an inode.

Definition at line 251 of file ext2.h.

                          {
        SECURE_DELETE = 0x1,  // Zero out data on deletion
        KEEP_DATA = 0x2,
        FILE_COMPRESSION = 0x4,
        SYNC_UPDATES = 0x8,
        FILE_IMMUTABLE = 0x10,
        APPEND_ONLY = 0x20,
        DONT_DUMP = 0x40,
        NO_LAST_ACCESS = 0x80,
        HASH_INDEXED = 0x10000,
        AFS_DIRECTORY = 0x20000,
        JOURNAL_FILE_DATA = 0x40000,
    };

◆ InodePermissions

enum class MaxOS::filesystem::format::ext2::InodePermissions

strong

The permissions that an inode can have.

Definition at line 221 of file ext2.h.

                                {
        OTHER_EXECUTE = 0x1,
        OTHER_WRITE = 0x2,
        OTHER_READ = 0x4,
        GROUP_EXECUTE = 0x8,
        GROUP_WRITE = 0x10,
        GROUP_READ = 0x20,
        USER_EXECUTE = 0x40,
        USER_WRITE = 0x80,
        USER_READ = 0x100,
        STICKY = 0x200,
        GROUP_ID = 0x400,
        USER_ID = 0x800,
    };

◆ InodePermissionsDefaults

enum class MaxOS::filesystem::format::ext2::InodePermissionsDefaults

strong

The default permissions for files and directories.

Todo:: Document these values

Definition at line 242 of file ext2.h.

                                        {
        FILE = 0x1A4,
        DIRECTORY = 0x1ED,
    };

◆ InodeType

enum class MaxOS::filesystem::format::ext2::InodeType

strong

The type of an inode.

Definition at line 206 of file ext2.h.

                         {
        UNKNOWN,
        FIFO = 0x1000,
        CHARACTER_DEVICE = 0x2000,
        DIRECTORY = 0x4000,
        BLOCK_DEVICE = 0x6000,
        FILE = 0x8000,
        SYMBOLIC_LINK = 0xA000,
        SOCKET = 0xC000,
    };

◆ OptionalFeatures

enum class MaxOS::filesystem::format::ext2::OptionalFeatures

strong

What features that are optional are supported by this filesystem.

Definition at line 116 of file ext2.h.

                                {
        PREALLOCATE_DIRECTORY = 0x1,
        AFS_SERVER_INODES = 0x2,
        JOURNAL_ENABLED = 0x4,
        ATTRIBUTES_EXTENDED = 0x8,
        RESIZEABLE = 0x10,
        HASH_INDEXING = 0x20,
    };

◆ ReadOnlyFeatures

enum class MaxOS::filesystem::format::ext2::ReadOnlyFeatures

strong

What features that are only required in read-only mode.

Definition at line 140 of file ext2.h.

                                {
        SPARSE_SUPER_BLOCKS = 0x1,
        FILES_64_BIT = 0x2,
        BINARY_TREE_DIRECTORIES = 0x4,
    };

◆ RequiredFeatures

enum class MaxOS::filesystem::format::ext2::RequiredFeatures

strong

What features that are required are supported by this filesystem.

Definition at line 129 of file ext2.h.

                                {
        COMPRESSION = 0x1,
        DIRECTORY_HAS_TYPE = 0x2,
        MUST_REPLAY_JOURNAL = 0x4,
        JOURNAL_DEVICE = 0x8,
    };

Classes

Typedefs

Enumerations

Detailed Description

Typedef Documentation

◆ block_group_descriptor_t

◆ linux_os_2_t

Enumeration Type Documentation

◆ CreatorOS

◆ EntryType

◆ ErrorOperation

◆ FileSystemState

◆ InodeFlags

◆ InodePermissions

◆ InodePermissionsDefaults

◆ InodeType

◆ OptionalFeatures

◆ ReadOnlyFeatures

◆ RequiredFeatures