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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Bitmap.h>
#include <AK/HashMap.h>
#include <Kernel/FileSystem/BlockBasedFileSystem.h>
#include <Kernel/FileSystem/Ext2FS/Definitions.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/KBuffer.h>
#include <Kernel/UnixTypes.h>
namespace Kernel {
class Ext2FSInode;
class Ext2FS final : public BlockBasedFileSystem {
friend class Ext2FSInode;
public:
enum class FeaturesReadOnly : u32 {
None = 0,
FileSize64bits = 1 << 1,
};
static ErrorOr<NonnullRefPtr<FileSystem>> try_create(OpenFileDescription&);
virtual ~Ext2FS() override;
virtual unsigned total_block_count() const override;
virtual unsigned free_block_count() const override;
virtual unsigned total_inode_count() const override;
virtual unsigned free_inode_count() const override;
virtual bool supports_watchers() const override { return true; }
virtual u8 internal_file_type_to_directory_entry_type(DirectoryEntryView const& entry) const override;
FeaturesReadOnly get_features_readonly() const;
virtual StringView class_name() const override { return "Ext2FS"sv; }
virtual Inode& root_inode() override;
private:
AK_TYPEDEF_DISTINCT_ORDERED_ID(unsigned, GroupIndex);
explicit Ext2FS(OpenFileDescription&);
ext2_super_block const& super_block() const { return m_super_block; }
ext2_group_desc const& group_descriptor(GroupIndex) const;
ext2_group_desc* block_group_descriptors() { return (ext2_group_desc*)m_cached_group_descriptor_table->data(); }
ext2_group_desc const* block_group_descriptors() const { return (ext2_group_desc const*)m_cached_group_descriptor_table->data(); }
void flush_block_group_descriptor_table();
u64 inodes_per_block() const;
u64 inodes_per_group() const;
u64 blocks_per_group() const;
u64 inode_size() const;
ErrorOr<NonnullRefPtr<Ext2FSInode>> build_root_inode() const;
ErrorOr<void> write_ext2_inode(InodeIndex, ext2_inode const&);
bool find_block_containing_inode(InodeIndex, BlockIndex& block_index, unsigned& offset) const;
ErrorOr<void> flush_super_block();
virtual ErrorOr<void> initialize_while_locked() override;
virtual bool is_initialized_while_locked() override;
virtual ErrorOr<void> prepare_to_clear_last_mount() override;
ErrorOr<NonnullRefPtr<Inode>> get_inode(InodeIdentifier) const;
ErrorOr<NonnullRefPtr<Inode>> create_inode(Ext2FSInode& parent_inode, StringView name, mode_t, dev_t, UserID, GroupID);
ErrorOr<NonnullRefPtr<Inode>> create_directory(Ext2FSInode& parent_inode, StringView name, mode_t, UserID, GroupID);
virtual void flush_writes() override;
BlockIndex first_block_index() const;
ErrorOr<InodeIndex> allocate_inode(GroupIndex preferred_group = 0);
ErrorOr<Vector<BlockIndex>> allocate_blocks(GroupIndex preferred_group_index, size_t count);
GroupIndex group_index_from_inode(InodeIndex) const;
GroupIndex group_index_from_block_index(BlockIndex) const;
ErrorOr<bool> get_inode_allocation_state(InodeIndex) const;
ErrorOr<void> set_inode_allocation_state(InodeIndex, bool);
ErrorOr<void> set_block_allocation_state(BlockIndex, bool);
void uncache_inode(InodeIndex);
ErrorOr<void> free_inode(Ext2FSInode&);
struct BlockListShape {
unsigned direct_blocks { 0 };
unsigned indirect_blocks { 0 };
unsigned doubly_indirect_blocks { 0 };
unsigned triply_indirect_blocks { 0 };
unsigned meta_blocks { 0 };
};
BlockListShape compute_block_list_shape(unsigned blocks) const;
u64 m_block_group_count { 0 };
mutable ext2_super_block m_super_block {};
mutable OwnPtr<KBuffer> m_cached_group_descriptor_table;
mutable HashMap<InodeIndex, RefPtr<Ext2FSInode>> m_inode_cache;
bool m_super_block_dirty { false };
bool m_block_group_descriptors_dirty { false };
struct CachedBitmap {
CachedBitmap(BlockIndex bi, NonnullOwnPtr<KBuffer> buf)
: bitmap_block_index(bi)
, buffer(move(buf))
{
}
BlockIndex bitmap_block_index { 0 };
bool dirty { false };
NonnullOwnPtr<KBuffer> buffer;
Bitmap bitmap(u32 blocks_per_group) { return Bitmap { buffer->data(), blocks_per_group }; }
};
ErrorOr<CachedBitmap*> get_bitmap_block(BlockIndex);
ErrorOr<void> update_bitmap_block(BlockIndex bitmap_block, size_t bit_index, bool new_state, u32& super_block_counter, u16& group_descriptor_counter);
Vector<OwnPtr<CachedBitmap>> m_cached_bitmaps;
RefPtr<Ext2FSInode> m_root_inode;
};
}
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