mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-09-21 10:19:03 +03:00
b9dca3300e
Instead of just having a giant KBuffer that is not resizeable easily, we use multiple AnonymousVMObjects in one Vector to store them. The idea is to not have to do giant memcpy or memset each time we need to allocate or de-allocate memory for TmpFS inodes, but instead, we can allocate only the desired block range when trying to write to it. Therefore, it is also possible to have data holes in the inode content in case of skipping an entire set of one data block or more when writing to the inode content, thus, making memory usage much more efficient. To ensure we don't run out of virtual memory range, don't allocate a Region in advance to each TmpFSInode, but instead try to allocate a Region on IO operation, and then use that Region to map the VMObjects in IO loop.
118 lines
4.2 KiB
C++
118 lines
4.2 KiB
C++
/*
|
|
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
|
|
* Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <Kernel/FileSystem/FileSystem.h>
|
|
#include <Kernel/FileSystem/Inode.h>
|
|
#include <Kernel/KBuffer.h>
|
|
#include <Kernel/Locking/MutexProtected.h>
|
|
#include <Kernel/Memory/AnonymousVMObject.h>
|
|
|
|
namespace Kernel {
|
|
|
|
class TmpFSInode;
|
|
|
|
class TmpFS final : public FileSystem {
|
|
friend class TmpFSInode;
|
|
|
|
public:
|
|
virtual ~TmpFS() override;
|
|
static ErrorOr<NonnullLockRefPtr<FileSystem>> try_create();
|
|
virtual ErrorOr<void> initialize() override;
|
|
|
|
virtual StringView class_name() const override { return "TmpFS"sv; }
|
|
|
|
virtual bool supports_watchers() const override { return true; }
|
|
|
|
virtual Inode& root_inode() override;
|
|
|
|
private:
|
|
TmpFS();
|
|
|
|
LockRefPtr<TmpFSInode> m_root_inode;
|
|
|
|
unsigned m_next_inode_index { 1 };
|
|
unsigned next_inode_index();
|
|
};
|
|
|
|
class TmpFSInode final : public Inode {
|
|
friend class TmpFS;
|
|
|
|
public:
|
|
virtual ~TmpFSInode() override;
|
|
|
|
TmpFS& fs() { return static_cast<TmpFS&>(Inode::fs()); }
|
|
TmpFS const& fs() const { return static_cast<TmpFS 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<NonnullLockRefPtr<Inode>> lookup(StringView name) override;
|
|
virtual ErrorOr<void> flush_metadata() 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> truncate(u64) override;
|
|
virtual ErrorOr<void> update_timestamps(Optional<time_t> atime, Optional<time_t> ctime, Optional<time_t> mtime) override;
|
|
|
|
private:
|
|
TmpFSInode(TmpFS& fs, InodeMetadata const& metadata, LockWeakPtr<TmpFSInode> parent);
|
|
static ErrorOr<NonnullLockRefPtr<TmpFSInode>> try_create(TmpFS&, InodeMetadata const& metadata, LockWeakPtr<TmpFSInode> parent);
|
|
static ErrorOr<NonnullLockRefPtr<TmpFSInode>> try_create_root(TmpFS&);
|
|
|
|
// ^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;
|
|
NonnullLockRefPtr<TmpFSInode> inode;
|
|
IntrusiveListNode<Child> list_node {};
|
|
using List = IntrusiveList<&Child::list_node>;
|
|
};
|
|
|
|
Child* find_child_by_name(StringView);
|
|
|
|
InodeMetadata m_metadata;
|
|
LockWeakPtr<TmpFSInode> 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;
|
|
};
|
|
|
|
DataBlock::List m_blocks;
|
|
Child::List m_children;
|
|
};
|
|
|
|
}
|