ladybird/Kernel/FileSystem/RAMFS/Inode.h
Liav A b63a1dda63 Kernel/FileSystem: Enforce locking of m_inode_lock when truncating Inode
Such operation is almost equivalent to writing on an Inode, so lock the
Inode m_inode_lock exclusively.
All FileSystem Inode implementations then override a new method called
truncate_locked which should implement the actual truncating.
2024-02-24 16:45:26 -07:00

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3.7 KiB
C++

/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
* Copyright (c) 2022-2023, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/FileSystem/RAMFS/FileSystem.h>
#include <Kernel/Forward.h>
#include <Kernel/Memory/AnonymousVMObject.h>
namespace Kernel {
class RAMFSInode final : public Inode {
friend class RAMFS;
public:
virtual ~RAMFSInode() override;
RAMFS& fs() { return static_cast<RAMFS&>(Inode::fs()); }
RAMFS const& fs() const { return static_cast<RAMFS const&>(Inode::fs()); }
// ^Inode
virtual InodeMetadata metadata() const override;
virtual ErrorOr<void> traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const override;
virtual ErrorOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
virtual ErrorOr<void> flush_metadata() override;
virtual ErrorOr<NonnullRefPtr<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> replace_child(StringView name, Inode& child) override;
virtual ErrorOr<void> chmod(mode_t) override;
virtual ErrorOr<void> chown(UserID, GroupID) override;
virtual ErrorOr<void> truncate_locked(u64) override;
virtual ErrorOr<void> update_timestamps(Optional<UnixDateTime> atime, Optional<UnixDateTime> ctime, Optional<UnixDateTime> mtime) override;
private:
RAMFSInode(RAMFS& fs, InodeMetadata const& metadata, LockWeakPtr<RAMFSInode> parent);
explicit RAMFSInode(RAMFS& fs);
static ErrorOr<NonnullRefPtr<RAMFSInode>> try_create(RAMFS&, InodeMetadata const& metadata, LockWeakPtr<RAMFSInode> parent);
static ErrorOr<NonnullRefPtr<RAMFSInode>> try_create_root(RAMFS&);
// ^Inode
virtual ErrorOr<size_t> read_bytes_locked(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const override;
virtual ErrorOr<size_t> write_bytes_locked(off_t, size_t, UserOrKernelBuffer const& buffer, OpenFileDescription*) override;
ErrorOr<size_t> do_io_on_content_space(Memory::Region& mapping_region, size_t offset, size_t io_size, UserOrKernelBuffer& buffer, bool write);
struct Child {
NonnullOwnPtr<KString> name;
NonnullRefPtr<RAMFSInode> inode;
IntrusiveListNode<Child> list_node {};
using List = IntrusiveList<&Child::list_node>;
};
Child* find_child_by_name(StringView);
InodeMetadata m_metadata;
LockWeakPtr<RAMFSInode> m_parent;
ErrorOr<void> ensure_allocated_blocks(size_t offset, size_t io_size);
ErrorOr<void> truncate_to_block_index(size_t block_index);
ErrorOr<size_t> read_bytes_from_content_space(size_t offset, size_t io_size, UserOrKernelBuffer& buffer) const;
ErrorOr<size_t> write_bytes_to_content_space(size_t offset, size_t io_size, UserOrKernelBuffer const& buffer);
struct DataBlock {
public:
using List = Vector<OwnPtr<DataBlock>>;
static ErrorOr<NonnullOwnPtr<DataBlock>> create();
constexpr static size_t block_size = 128 * KiB;
Memory::AnonymousVMObject& vmobject() { return *m_content_buffer_vmobject; }
Memory::AnonymousVMObject const& vmobject() const { return *m_content_buffer_vmobject; }
private:
explicit DataBlock(NonnullLockRefPtr<Memory::AnonymousVMObject> content_buffer_vmobject)
: m_content_buffer_vmobject(move(content_buffer_vmobject))
{
}
NonnullLockRefPtr<Memory::AnonymousVMObject> m_content_buffer_vmobject;
};
bool const m_root_directory_inode { false };
DataBlock::List m_blocks;
Child::List m_children;
};
}