Kernel: Split the FATFileSystem.{cpp,h} files into smaller components

This commit is contained in:
Liav A 2022-10-24 08:25:16 +03:00 committed by Andrew Kaster
parent 5e6101dd3e
commit e882b2ed05
Notes: sideshowbarker 2024-07-17 04:41:06 +09:00
9 changed files with 334 additions and 287 deletions

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@ -111,7 +111,8 @@ set(KERNEL_SOURCES
FileSystem/Custody.cpp
FileSystem/DevPtsFS.cpp
FileSystem/Ext2FileSystem.cpp
FileSystem/FATFileSystem.cpp
FileSystem/FATFS/FileSystem.cpp
FileSystem/FATFS/Inode.cpp
FileSystem/FIFO.cpp
FileSystem/File.cpp
FileSystem/FileBackedFileSystem.cpp

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@ -0,0 +1,106 @@
/*
* Copyright (c) 2022, Undefine <undefine@undefine.pl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/EnumBits.h>
#include <AK/Types.h>
namespace Kernel {
struct [[gnu::packed]] FAT32BootRecord {
u8 boot_jump[3];
char oem_identifier[8];
u16 bytes_per_sector;
u8 sectors_per_cluster;
u16 reserved_sector_count;
u8 fat_count;
u16 root_directory_entry_count;
u16 unused1;
u8 media_descriptor_type;
u16 unused2;
u16 sectors_per_track;
u16 head_count;
u32 hidden_sector_count;
u32 sector_count;
u32 sectors_per_fat;
u16 flags;
u16 fat_version;
u32 root_directory_cluster;
u16 fs_info_sector;
u16 backup_boot_sector;
u8 unused3[12];
u8 drive_number;
u8 unused4;
u8 signature;
u32 volume_id;
char volume_label_string[11];
char system_identifier_string[8];
};
static_assert(sizeof(FAT32BootRecord) == 90);
enum class FATAttributes : u8 {
ReadOnly = 0x01,
Hidden = 0x02,
System = 0x04,
VolumeID = 0x08,
Directory = 0x10,
Archive = 0x20,
LongFileName = 0x0F
};
AK_ENUM_BITWISE_OPERATORS(FATAttributes);
union FATPackedTime {
u16 value;
struct {
u16 second : 5;
u16 minute : 6;
u16 hour : 5;
};
};
static_assert(sizeof(FATPackedTime) == 2);
union FATPackedDate {
u16 value;
struct {
u16 day : 5;
u16 month : 4;
u16 year : 7;
};
};
static_assert(sizeof(FATPackedDate) == 2);
struct [[gnu::packed]] FATEntry {
char filename[8];
char extension[3];
FATAttributes attributes;
u8 unused1;
u8 creation_time_seconds;
FATPackedTime creation_time;
FATPackedDate creation_date;
FATPackedDate last_accessed_date;
u16 first_cluster_high;
FATPackedTime modification_time;
FATPackedDate modification_date;
u16 first_cluster_low;
u32 file_size;
};
static_assert(sizeof(FATEntry) == 32);
struct [[gnu::packed]] FATLongFileNameEntry {
u8 entry_index;
u16 characters1[5];
FATAttributes attributes;
u8 entry_type;
u8 checksum;
u16 characters2[6];
u16 zero;
u16 characters3[2];
};
static_assert(sizeof(FATLongFileNameEntry) == 32);
}

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@ -0,0 +1,94 @@
/*
* Copyright (c) 2022, Undefine <undefine@undefine.pl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/FATFS/FileSystem.h>
#include <Kernel/FileSystem/FATFS/Inode.h>
namespace Kernel {
ErrorOr<NonnullLockRefPtr<FileSystem>> FATFS::try_create(OpenFileDescription& file_description)
{
return TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) FATFS(file_description)));
}
FATFS::FATFS(OpenFileDescription& file_description)
: BlockBasedFileSystem(file_description)
{
}
bool FATFS::is_initialized_while_locked()
{
VERIFY(m_lock.is_locked());
return !m_root_inode.is_null();
}
ErrorOr<void> FATFS::initialize_while_locked()
{
VERIFY(m_lock.is_locked());
VERIFY(!is_initialized_while_locked());
m_boot_record = TRY(KBuffer::try_create_with_size("FATFS: Boot Record"sv, m_logical_block_size));
auto boot_record_buffer = UserOrKernelBuffer::for_kernel_buffer(m_boot_record->data());
TRY(raw_read(0, boot_record_buffer));
if constexpr (FAT_DEBUG) {
dbgln("FATFS: oem_identifier: {}", boot_record()->oem_identifier);
dbgln("FATFS: bytes_per_sector: {}", boot_record()->bytes_per_sector);
dbgln("FATFS: sectors_per_cluster: {}", boot_record()->sectors_per_cluster);
dbgln("FATFS: reserved_sector_count: {}", boot_record()->reserved_sector_count);
dbgln("FATFS: fat_count: {}", boot_record()->fat_count);
dbgln("FATFS: root_directory_entry_count: {}", boot_record()->root_directory_entry_count);
dbgln("FATFS: media_descriptor_type: {}", boot_record()->media_descriptor_type);
dbgln("FATFS: sectors_per_track: {}", boot_record()->sectors_per_track);
dbgln("FATFS: head_count: {}", boot_record()->head_count);
dbgln("FATFS: hidden_sector_count: {}", boot_record()->hidden_sector_count);
dbgln("FATFS: sector_count: {}", boot_record()->sector_count);
dbgln("FATFS: sectors_per_fat: {}", boot_record()->sectors_per_fat);
dbgln("FATFS: flags: {}", boot_record()->flags);
dbgln("FATFS: fat_version: {}", boot_record()->fat_version);
dbgln("FATFS: root_directory_cluster: {}", boot_record()->root_directory_cluster);
dbgln("FATFS: fs_info_sector: {}", boot_record()->fs_info_sector);
dbgln("FATFS: backup_boot_sector: {}", boot_record()->backup_boot_sector);
dbgln("FATFS: drive_number: {}", boot_record()->drive_number);
dbgln("FATFS: volume_id: {}", boot_record()->volume_id);
}
if (boot_record()->signature != signature_1 && boot_record()->signature != signature_2) {
dbgln("FATFS: Invalid signature");
return EINVAL;
}
m_logical_block_size = boot_record()->bytes_per_sector;
set_block_size(m_logical_block_size);
u32 root_directory_sectors = ((boot_record()->root_directory_entry_count * sizeof(FATEntry)) + (m_logical_block_size - 1)) / m_logical_block_size;
m_first_data_sector = boot_record()->reserved_sector_count + (boot_record()->fat_count * boot_record()->sectors_per_fat) + root_directory_sectors;
TRY(BlockBasedFileSystem::initialize_while_locked());
FATEntry root_entry {};
root_entry.first_cluster_low = boot_record()->root_directory_cluster & 0xFFFF;
root_entry.first_cluster_high = boot_record()->root_directory_cluster >> 16;
root_entry.attributes = FATAttributes::Directory;
m_root_inode = TRY(FATInode::create(*this, root_entry));
return {};
}
Inode& FATFS::root_inode()
{
return *m_root_inode;
}
BlockBasedFileSystem::BlockIndex FATFS::first_block_of_cluster(u32 cluster) const
{
return ((cluster - first_data_cluster) * boot_record()->sectors_per_cluster) + m_first_data_sector;
}
}

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@ -0,0 +1,53 @@
/*
* Copyright (c) 2022, Undefine <undefine@undefine.pl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/OwnPtr.h>
#include <AK/RefPtr.h>
#include <AK/Types.h>
#include <Kernel/FileSystem/BlockBasedFileSystem.h>
#include <Kernel/FileSystem/FATFS/Definitions.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/Forward.h>
#include <Kernel/KBuffer.h>
namespace Kernel {
class FATFS final : public BlockBasedFileSystem {
friend FATInode;
public:
static ErrorOr<NonnullLockRefPtr<FileSystem>> try_create(OpenFileDescription&);
virtual ~FATFS() override = default;
virtual StringView class_name() const override { return "FATFS"sv; }
virtual Inode& root_inode() override;
private:
virtual ErrorOr<void> initialize_while_locked() override;
virtual bool is_initialized_while_locked() override;
// FIXME: This is not a proper way to clear last mount of a FAT filesystem,
// but for now we simply have no other way to properly do it.
virtual ErrorOr<void> prepare_to_clear_last_mount() override { return {}; }
FATFS(OpenFileDescription&);
static constexpr u8 signature_1 = 0x28;
static constexpr u8 signature_2 = 0x29;
static constexpr u32 first_data_cluster = 2;
FAT32BootRecord const* boot_record() const { return reinterpret_cast<FAT32BootRecord const*>(m_boot_record->data()); };
BlockBasedFileSystem::BlockIndex first_block_of_cluster(u32 cluster) const;
OwnPtr<KBuffer> m_boot_record;
LockRefPtr<FATInode> m_root_inode;
u32 m_first_data_sector;
};
}

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@ -6,93 +6,11 @@
#include <AK/Time.h>
#include <Kernel/Debug.h>
#include <Kernel/Devices/BlockDevice.h>
#include <Kernel/FileSystem/FATFileSystem.h>
#include <Kernel/Memory/Region.h>
#include <Kernel/FileSystem/FATFS/Inode.h>
#include <Kernel/KBufferBuilder.h>
namespace Kernel {
ErrorOr<NonnullLockRefPtr<FileSystem>> FATFS::try_create(OpenFileDescription& file_description)
{
return TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) FATFS(file_description)));
}
FATFS::FATFS(OpenFileDescription& file_description)
: BlockBasedFileSystem(file_description)
{
}
bool FATFS::is_initialized_while_locked()
{
VERIFY(m_lock.is_locked());
return !m_root_inode.is_null();
}
ErrorOr<void> FATFS::initialize_while_locked()
{
VERIFY(m_lock.is_locked());
VERIFY(!is_initialized_while_locked());
m_boot_record = TRY(KBuffer::try_create_with_size("FATFS: Boot Record"sv, m_logical_block_size));
auto boot_record_buffer = UserOrKernelBuffer::for_kernel_buffer(m_boot_record->data());
TRY(raw_read(0, boot_record_buffer));
if constexpr (FAT_DEBUG) {
dbgln("FATFS: oem_identifier: {}", boot_record()->oem_identifier);
dbgln("FATFS: bytes_per_sector: {}", boot_record()->bytes_per_sector);
dbgln("FATFS: sectors_per_cluster: {}", boot_record()->sectors_per_cluster);
dbgln("FATFS: reserved_sector_count: {}", boot_record()->reserved_sector_count);
dbgln("FATFS: fat_count: {}", boot_record()->fat_count);
dbgln("FATFS: root_directory_entry_count: {}", boot_record()->root_directory_entry_count);
dbgln("FATFS: media_descriptor_type: {}", boot_record()->media_descriptor_type);
dbgln("FATFS: sectors_per_track: {}", boot_record()->sectors_per_track);
dbgln("FATFS: head_count: {}", boot_record()->head_count);
dbgln("FATFS: hidden_sector_count: {}", boot_record()->hidden_sector_count);
dbgln("FATFS: sector_count: {}", boot_record()->sector_count);
dbgln("FATFS: sectors_per_fat: {}", boot_record()->sectors_per_fat);
dbgln("FATFS: flags: {}", boot_record()->flags);
dbgln("FATFS: fat_version: {}", boot_record()->fat_version);
dbgln("FATFS: root_directory_cluster: {}", boot_record()->root_directory_cluster);
dbgln("FATFS: fs_info_sector: {}", boot_record()->fs_info_sector);
dbgln("FATFS: backup_boot_sector: {}", boot_record()->backup_boot_sector);
dbgln("FATFS: drive_number: {}", boot_record()->drive_number);
dbgln("FATFS: volume_id: {}", boot_record()->volume_id);
}
if (boot_record()->signature != signature_1 && boot_record()->signature != signature_2) {
dbgln("FATFS: Invalid signature");
return EINVAL;
}
m_logical_block_size = boot_record()->bytes_per_sector;
set_block_size(m_logical_block_size);
u32 root_directory_sectors = ((boot_record()->root_directory_entry_count * sizeof(FATEntry)) + (m_logical_block_size - 1)) / m_logical_block_size;
m_first_data_sector = boot_record()->reserved_sector_count + (boot_record()->fat_count * boot_record()->sectors_per_fat) + root_directory_sectors;
TRY(BlockBasedFileSystem::initialize_while_locked());
FATEntry root_entry {};
root_entry.first_cluster_low = boot_record()->root_directory_cluster & 0xFFFF;
root_entry.first_cluster_high = boot_record()->root_directory_cluster >> 16;
root_entry.attributes = FATAttributes::Directory;
m_root_inode = TRY(FATInode::create(*this, root_entry));
return {};
}
Inode& FATFS::root_inode()
{
return *m_root_inode;
}
BlockBasedFileSystem::BlockIndex FATFS::first_block_of_cluster(u32 cluster) const
{
return ((cluster - first_data_cluster) * boot_record()->sectors_per_cluster) + m_first_data_sector;
}
ErrorOr<NonnullLockRefPtr<FATInode>> FATInode::create(FATFS& fs, FATEntry entry, Vector<FATLongFileNameEntry> const& lfn_entries)
{
auto filename = TRY(compute_filename(entry, lfn_entries));

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@ -0,0 +1,75 @@
/*
* Copyright (c) 2022, Undefine <undefine@undefine.pl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/OwnPtr.h>
#include <AK/RefPtr.h>
#include <Kernel/FileSystem/FATFS/Definitions.h>
#include <Kernel/FileSystem/FATFS/FileSystem.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/KBuffer.h>
#include <Kernel/KString.h>
namespace Kernel {
class FATInode final : public Inode {
friend FATFS;
public:
virtual ~FATInode() override = default;
static ErrorOr<NonnullLockRefPtr<FATInode>> create(FATFS&, FATEntry, Vector<FATLongFileNameEntry> const& = {});
FATFS& fs() { return static_cast<FATFS&>(Inode::fs()); }
FATFS const& fs() const { return static_cast<FATFS const&>(Inode::fs()); }
private:
FATInode(FATFS&, FATEntry, NonnullOwnPtr<KString> filename);
static constexpr u32 no_more_clusters = 0x0FFFFFF8;
static constexpr u32 cluster_number_mask = 0x0FFFFFFF;
static constexpr u8 end_entry_byte = 0x00;
static constexpr u8 unused_entry_byte = 0xE5;
static constexpr u8 lfn_entry_text_termination = 0xFF;
static constexpr u16 first_fat_year = 1980;
static constexpr u8 normal_filename_length = 8;
static constexpr u8 normal_extension_length = 3;
static ErrorOr<NonnullOwnPtr<KString>> compute_filename(FATEntry&, Vector<FATLongFileNameEntry> const& = {});
static StringView byte_terminated_string(StringView, u8);
static time_t fat_date_time(FATPackedDate date, FATPackedTime time);
ErrorOr<Vector<BlockBasedFileSystem::BlockIndex>> compute_block_list();
ErrorOr<NonnullOwnPtr<KBuffer>> read_block_list();
ErrorOr<LockRefPtr<FATInode>> traverse(Function<ErrorOr<bool>(LockRefPtr<FATInode>)> callback);
u32 first_cluster() const;
// ^Inode
virtual ErrorOr<size_t> write_bytes_locked(off_t, size_t, UserOrKernelBuffer const& data, OpenFileDescription*) override;
virtual ErrorOr<size_t> read_bytes_locked(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const override;
virtual InodeMetadata metadata() const override;
virtual ErrorOr<void> traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const override;
virtual ErrorOr<NonnullLockRefPtr<Inode>> lookup(StringView name) override;
virtual ErrorOr<NonnullLockRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
virtual ErrorOr<void> add_child(Inode&, StringView name, mode_t) override;
virtual ErrorOr<void> remove_child(StringView name) override;
virtual ErrorOr<void> chmod(mode_t) override;
virtual ErrorOr<void> chown(UserID, GroupID) override;
virtual ErrorOr<void> flush_metadata() override;
Vector<BlockBasedFileSystem::BlockIndex> m_block_list;
FATEntry m_entry;
NonnullOwnPtr<KString> m_filename;
InodeMetadata m_metadata;
};
}

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@ -1,201 +0,0 @@
/*
* Copyright (c) 2022, Undefine <undefine@undefine.pl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/OwnPtr.h>
#include <AK/RefPtr.h>
#include <AK/Types.h>
#include <Kernel/FileSystem/BlockBasedFileSystem.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/KBuffer.h>
namespace Kernel {
struct [[gnu::packed]] FAT32BootRecord {
u8 boot_jump[3];
char oem_identifier[8];
u16 bytes_per_sector;
u8 sectors_per_cluster;
u16 reserved_sector_count;
u8 fat_count;
u16 root_directory_entry_count;
u16 unused1;
u8 media_descriptor_type;
u16 unused2;
u16 sectors_per_track;
u16 head_count;
u32 hidden_sector_count;
u32 sector_count;
u32 sectors_per_fat;
u16 flags;
u16 fat_version;
u32 root_directory_cluster;
u16 fs_info_sector;
u16 backup_boot_sector;
u8 unused3[12];
u8 drive_number;
u8 unused4;
u8 signature;
u32 volume_id;
char volume_label_string[11];
char system_identifier_string[8];
};
static_assert(sizeof(FAT32BootRecord) == 90);
enum class FATAttributes : u8 {
ReadOnly = 0x01,
Hidden = 0x02,
System = 0x04,
VolumeID = 0x08,
Directory = 0x10,
Archive = 0x20,
LongFileName = 0x0F
};
AK_ENUM_BITWISE_OPERATORS(FATAttributes);
union FATPackedTime {
u16 value;
struct {
u16 second : 5;
u16 minute : 6;
u16 hour : 5;
};
};
static_assert(sizeof(FATPackedTime) == 2);
union FATPackedDate {
u16 value;
struct {
u16 day : 5;
u16 month : 4;
u16 year : 7;
};
};
static_assert(sizeof(FATPackedDate) == 2);
struct [[gnu::packed]] FATEntry {
char filename[8];
char extension[3];
FATAttributes attributes;
u8 unused1;
u8 creation_time_seconds;
FATPackedTime creation_time;
FATPackedDate creation_date;
FATPackedDate last_accessed_date;
u16 first_cluster_high;
FATPackedTime modification_time;
FATPackedDate modification_date;
u16 first_cluster_low;
u32 file_size;
};
static_assert(sizeof(FATEntry) == 32);
struct [[gnu::packed]] FATLongFileNameEntry {
u8 entry_index;
u16 characters1[5];
FATAttributes attributes;
u8 entry_type;
u8 checksum;
u16 characters2[6];
u16 zero;
u16 characters3[2];
};
static_assert(sizeof(FATLongFileNameEntry) == 32);
class FATInode;
class FATFS final : public BlockBasedFileSystem {
friend FATInode;
public:
static ErrorOr<NonnullLockRefPtr<FileSystem>> try_create(OpenFileDescription&);
virtual ~FATFS() override = default;
virtual StringView class_name() const override { return "FATFS"sv; }
virtual Inode& root_inode() override;
private:
virtual ErrorOr<void> initialize_while_locked() override;
virtual bool is_initialized_while_locked() override;
// FIXME: This is not a proper way to clear last mount of a FAT filesystem,
// but for now we simply have no other way to properly do it.
virtual ErrorOr<void> prepare_to_clear_last_mount() override { return {}; }
FATFS(OpenFileDescription&);
static constexpr u8 signature_1 = 0x28;
static constexpr u8 signature_2 = 0x29;
static constexpr u32 first_data_cluster = 2;
FAT32BootRecord const* boot_record() const { return reinterpret_cast<FAT32BootRecord const*>(m_boot_record->data()); };
BlockBasedFileSystem::BlockIndex first_block_of_cluster(u32 cluster) const;
OwnPtr<KBuffer> m_boot_record;
LockRefPtr<FATInode> m_root_inode;
u32 m_first_data_sector;
};
class FATInode final : public Inode {
friend FATFS;
public:
virtual ~FATInode() override = default;
static ErrorOr<NonnullLockRefPtr<FATInode>> create(FATFS&, FATEntry, Vector<FATLongFileNameEntry> const& = {});
FATFS& fs() { return static_cast<FATFS&>(Inode::fs()); }
FATFS const& fs() const { return static_cast<FATFS const&>(Inode::fs()); }
private:
FATInode(FATFS&, FATEntry, NonnullOwnPtr<KString> filename);
static constexpr u32 no_more_clusters = 0x0FFFFFF8;
static constexpr u32 cluster_number_mask = 0x0FFFFFFF;
static constexpr u8 end_entry_byte = 0x00;
static constexpr u8 unused_entry_byte = 0xE5;
static constexpr u8 lfn_entry_text_termination = 0xFF;
static constexpr u16 first_fat_year = 1980;
static constexpr u8 normal_filename_length = 8;
static constexpr u8 normal_extension_length = 3;
static ErrorOr<NonnullOwnPtr<KString>> compute_filename(FATEntry&, Vector<FATLongFileNameEntry> const& = {});
static StringView byte_terminated_string(StringView, u8);
static time_t fat_date_time(FATPackedDate date, FATPackedTime time);
ErrorOr<Vector<BlockBasedFileSystem::BlockIndex>> compute_block_list();
ErrorOr<NonnullOwnPtr<KBuffer>> read_block_list();
ErrorOr<LockRefPtr<FATInode>> traverse(Function<ErrorOr<bool>(LockRefPtr<FATInode>)> callback);
u32 first_cluster() const;
// ^Inode
virtual ErrorOr<size_t> write_bytes_locked(off_t, size_t, UserOrKernelBuffer const& data, OpenFileDescription*) override;
virtual ErrorOr<size_t> read_bytes_locked(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const override;
virtual InodeMetadata metadata() const override;
virtual ErrorOr<void> traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const override;
virtual ErrorOr<NonnullLockRefPtr<Inode>> lookup(StringView name) override;
virtual ErrorOr<NonnullLockRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) override;
virtual ErrorOr<void> add_child(Inode&, StringView name, mode_t) override;
virtual ErrorOr<void> remove_child(StringView name) override;
virtual ErrorOr<void> chmod(mode_t) override;
virtual ErrorOr<void> chown(UserID, GroupID) override;
virtual ErrorOr<void> flush_metadata() override;
Vector<BlockBasedFileSystem::BlockIndex> m_block_list;
FATEntry m_entry;
NonnullOwnPtr<KString> m_filename;
InodeMetadata m_metadata;
};
}

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@ -20,6 +20,7 @@ class Device;
class DiskCache;
class DoubleBuffer;
class File;
class FATInode;
class OpenFileDescription;
class DisplayConnector;
class FileSystem;

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@ -7,7 +7,7 @@
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/FileSystem/DevPtsFS.h>
#include <Kernel/FileSystem/Ext2FileSystem.h>
#include <Kernel/FileSystem/FATFileSystem.h>
#include <Kernel/FileSystem/FATFS/FileSystem.h>
#include <Kernel/FileSystem/ISO9660FileSystem.h>
#include <Kernel/FileSystem/Plan9FileSystem.h>
#include <Kernel/FileSystem/ProcFS.h>