ladybird/Kernel/FileSystem/BlockBasedFileSystem.h
Brian Gianforcaro a6db2f985a Kernel: Handle OOM in DiskCache when mounting Ext2 filesystems
Create the disk cache up front, so we can verify it succeeds.
Make the KBuffer allocation fail-able, so we can properly handle
failure when the user asks up to mount a Ext2 filesystem under
OOM conditions.
2021-08-03 18:54:23 +02:00

59 lines
1.8 KiB
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/FileSystem/FileBackedFileSystem.h>
namespace Kernel {
class BlockBasedFileSystem : public FileBackedFileSystem {
public:
TYPEDEF_DISTINCT_ORDERED_ID(u64, BlockIndex);
virtual ~BlockBasedFileSystem() override;
virtual bool initialize() override;
u64 logical_block_size() const { return m_logical_block_size; };
virtual void flush_writes() override;
void flush_writes_impl();
protected:
explicit BlockBasedFileSystem(FileDescription&);
KResult read_block(BlockIndex, UserOrKernelBuffer*, size_t count, size_t offset = 0, bool allow_cache = true) const;
KResult read_blocks(BlockIndex, unsigned count, UserOrKernelBuffer&, bool allow_cache = true) const;
bool raw_read(BlockIndex, UserOrKernelBuffer&);
bool raw_write(BlockIndex, const UserOrKernelBuffer&);
bool raw_read_blocks(BlockIndex index, size_t count, UserOrKernelBuffer&);
bool raw_write_blocks(BlockIndex index, size_t count, const UserOrKernelBuffer&);
KResult write_block(BlockIndex, const UserOrKernelBuffer&, size_t count, size_t offset = 0, bool allow_cache = true);
KResult write_blocks(BlockIndex, unsigned count, const UserOrKernelBuffer&, bool allow_cache = true);
u64 m_logical_block_size { 512 };
private:
DiskCache& cache() const;
void flush_specific_block_if_needed(BlockIndex index);
mutable Mutex m_cache_lock;
mutable OwnPtr<DiskCache> m_cache;
};
}
template<>
struct AK::Formatter<Kernel::BlockBasedFileSystem::BlockIndex> : AK::Formatter<FormatString> {
void format(FormatBuilder& builder, Kernel::BlockBasedFileSystem::BlockIndex value)
{
return AK::Formatter<FormatString>::format(builder, "{}", value.value());
}
};