jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <AK/AtomicRefCounted.h>
10#include <AK/Error.h>
11#include <AK/Function.h>
12#include <AK/StringView.h>
13#include <AK/Types.h>
14#include <Kernel/FileSystem/File.h>
15#include <Kernel/FileSystem/FileSystem.h>
16#include <Kernel/FileSystem/OpenFileDescription.h>
17#include <Kernel/Forward.h>
18#include <Kernel/Library/LockRefPtr.h>
19
20namespace Kernel {
21
22struct SysFSInodeData : public OpenFileDescriptionData {
23 OwnPtr<KBuffer> buffer;
24};
25
26class SysFSDirectory;
27class SysFSComponent : public AtomicRefCounted<SysFSComponent> {
28 friend class SysFSDirectory;
29
30public:
31 virtual StringView name() const = 0;
32 virtual ErrorOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer&, OpenFileDescription*) const { return Error::from_errno(ENOTIMPL); }
33 virtual ErrorOr<void> traverse_as_directory(FileSystemID, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const { VERIFY_NOT_REACHED(); }
34 virtual LockRefPtr<SysFSComponent> lookup(StringView) { VERIFY_NOT_REACHED(); };
35 virtual mode_t permissions() const;
36 virtual ErrorOr<void> truncate(u64) { return EPERM; }
37 virtual size_t size() const { return 0; }
38 virtual ErrorOr<size_t> write_bytes(off_t, size_t, UserOrKernelBuffer const&, OpenFileDescription*) { return EROFS; }
39 virtual ErrorOr<void> refresh_data(OpenFileDescription&) const { return {}; }
40
41 virtual ErrorOr<NonnullRefPtr<SysFSInode>> to_inode(SysFS const&) const;
42
43 InodeIndex component_index() const { return m_component_index; };
44
45 virtual ~SysFSComponent() = default;
46
47 ErrorOr<NonnullOwnPtr<KString>> relative_path(NonnullOwnPtr<KString>, size_t current_hop = 0) const;
48 ErrorOr<size_t> relative_path_hops_count_from_mountpoint(size_t current_hop = 0) const;
49
50protected:
51 explicit SysFSComponent(SysFSDirectory const& parent_directory);
52 SysFSComponent();
53
54 LockRefPtr<SysFSDirectory> m_parent_directory;
55
56 IntrusiveListNode<SysFSComponent, NonnullLockRefPtr<SysFSComponent>> m_list_node;
57
58private:
59 InodeIndex m_component_index {};
60};
61
62class SysFSSymbolicLink : public SysFSComponent {
63public:
64 virtual ErrorOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer&, OpenFileDescription*) const override final;
65 virtual ErrorOr<NonnullRefPtr<SysFSInode>> to_inode(SysFS const& sysfs_instance) const override final;
66
67protected:
68 ErrorOr<NonnullOwnPtr<KString>> try_generate_return_path_to_mount_point() const;
69 ErrorOr<NonnullOwnPtr<KBuffer>> try_to_generate_buffer() const;
70
71 explicit SysFSSymbolicLink(SysFSDirectory const& parent_directory, SysFSComponent const& pointed_component);
72
73 LockRefPtr<SysFSComponent> m_pointed_component;
74};
75
76class SysFSDirectory : public SysFSComponent {
77public:
78 virtual ErrorOr<void> traverse_as_directory(FileSystemID, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const override final;
79 virtual LockRefPtr<SysFSComponent> lookup(StringView name) override final;
80
81 virtual ErrorOr<NonnullRefPtr<SysFSInode>> to_inode(SysFS const& sysfs_instance) const override final;
82
83 using ChildList = SpinlockProtected<IntrusiveList<&SysFSComponent::m_list_node>, LockRank::None>;
84
85protected:
86 virtual bool is_root_directory() const { return false; }
87
88 SysFSDirectory() {};
89 explicit SysFSDirectory(SysFSDirectory const& parent_directory);
90 ChildList m_child_components {};
91};
92
93}