Kernel: Split the SysFS core files into smaller components

Kernel/FileSystem/SysFS/Component.cpp

@@ -4,8 +4,10 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <Kernel/FileSystem/SysFS.h>
 #include <Kernel/FileSystem/SysFS/Component.h>
+#include <Kernel/FileSystem/SysFS/DirectoryInode.h>
+#include <Kernel/FileSystem/SysFS/Inode.h>
+#include <Kernel/FileSystem/SysFS/LinkInode.h>
 #include <Kernel/FileSystem/SysFS/Registry.h>
 #include <Kernel/KLexicalPath.h>
 

Kernel/FileSystem/SysFS/DirectoryInode.cpp

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/StringView.h>
+#include <Kernel/FileSystem/SysFS/DirectoryInode.h>
+#include <Kernel/Sections.h>
+#include <Kernel/Time/TimeManagement.h>
+
+namespace Kernel {
+
+ErrorOr<NonnullLockRefPtr<SysFSDirectoryInode>> SysFSDirectoryInode::try_create(SysFS const& sysfs, SysFSComponent const& component)
+{
+    return adopt_nonnull_lock_ref_or_enomem(new (nothrow) SysFSDirectoryInode(sysfs, component));
+}
+
+SysFSDirectoryInode::SysFSDirectoryInode(SysFS const& fs, SysFSComponent const& component)
+    : SysFSInode(fs, component)
+{
+}
+
+SysFSDirectoryInode::~SysFSDirectoryInode() = default;
+
+InodeMetadata SysFSDirectoryInode::metadata() const
+{
+    // NOTE: No locking required as m_associated_component or its component index will never change during our lifetime.
+    InodeMetadata metadata;
+    metadata.inode = { fsid(), m_associated_component->component_index() };
+    metadata.mode = S_IFDIR | S_IRUSR | S_IRGRP | S_IROTH | S_IXOTH;
+    metadata.uid = 0;
+    metadata.gid = 0;
+    metadata.size = 0;
+    metadata.mtime = TimeManagement::boot_time();
+    return metadata;
+}
+
+ErrorOr<void> SysFSDirectoryInode::traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)> callback) const
+{
+    MutexLocker locker(fs().m_lock);
+    return m_associated_component->traverse_as_directory(fs().fsid(), move(callback));
+}
+
+ErrorOr<NonnullLockRefPtr<Inode>> SysFSDirectoryInode::lookup(StringView name)
+{
+    MutexLocker locker(fs().m_lock);
+    auto component = m_associated_component->lookup(name);
+    if (!component)
+        return ENOENT;
+    return TRY(component->to_inode(fs()));
+}
+
+}

Kernel/FileSystem/SysFS/DirectoryInode.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/FileSystem/SysFS/Inode.h>
+
+namespace Kernel {
+
+class SysFSDirectoryInode : public SysFSInode {
+    friend class SysFS;
+
+public:
+    static ErrorOr<NonnullLockRefPtr<SysFSDirectoryInode>> try_create(SysFS const&, SysFSComponent const&);
+    virtual ~SysFSDirectoryInode() override;
+
+    SysFS& fs() { return static_cast<SysFS&>(Inode::fs()); }
+    SysFS const& fs() const { return static_cast<SysFS const&>(Inode::fs()); }
+
+protected:
+    SysFSDirectoryInode(SysFS const&, SysFSComponent const&);
+    // ^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;
+};
+
+}

Kernel/FileSystem/SysFS/FileSystem.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/StringView.h>
+#include <Kernel/FileSystem/SysFS/FileSystem.h>
+#include <Kernel/FileSystem/SysFS/Inode.h>
+#include <Kernel/FileSystem/SysFS/Registry.h>
+
+namespace Kernel {
+
+ErrorOr<NonnullLockRefPtr<FileSystem>> SysFS::try_create()
+{
+    return TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) SysFS));
+}
+
+SysFS::SysFS() = default;
+SysFS::~SysFS() = default;
+
+ErrorOr<void> SysFS::initialize()
+{
+    m_root_inode = TRY(SysFSComponentRegistry::the().root_directory().to_inode(*this));
+    return {};
+}
+
+Inode& SysFS::root_inode()
+{
+    return *m_root_inode;
+}
+
+}

Kernel/FileSystem/SysFS/FileSystem.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2021, 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/FileSystem/SysFS/Component.h>
+#include <Kernel/Forward.h>
+#include <Kernel/Locking/MutexProtected.h>
+
+namespace Kernel {
+
+class SysFS final : public FileSystem {
+    friend class SysFSInode;
+    friend class SysFSDirectoryInode;
+
+public:
+    virtual ~SysFS() override;
+    static ErrorOr<NonnullLockRefPtr<FileSystem>> try_create();
+
+    virtual ErrorOr<void> initialize() override;
+    virtual StringView class_name() const override { return "SysFS"sv; }
+
+    virtual Inode& root_inode() override;
+
+private:
+    SysFS();
+
+    LockRefPtr<SysFSInode> m_root_inode;
+};
+
+}

Kernel/FileSystem/SysFS/Inode.cpp

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/StringView.h>
+#include <Kernel/FileSystem/SysFS/Inode.h>
+#include <Kernel/Time/TimeManagement.h>
+
+namespace Kernel {
+
+ErrorOr<NonnullLockRefPtr<SysFSInode>> SysFSInode::try_create(SysFS const& fs, SysFSComponent const& component)
+{
+    return adopt_nonnull_lock_ref_or_enomem(new (nothrow) SysFSInode(fs, component));
+}
+
+SysFSInode::SysFSInode(SysFS const& fs, SysFSComponent const& component)
+    : Inode(const_cast<SysFS&>(fs), component.component_index())
+    , m_associated_component(component)
+{
+}
+
+void SysFSInode::did_seek(OpenFileDescription& description, off_t new_offset)
+{
+    if (new_offset != 0)
+        return;
+    auto result = m_associated_component->refresh_data(description);
+    if (result.is_error()) {
+        // Subsequent calls to read will return EIO!
+        dbgln("SysFS: Could not refresh contents: {}", result.error());
+    }
+}
+
+ErrorOr<void> SysFSInode::attach(OpenFileDescription& description)
+{
+    return m_associated_component->refresh_data(description);
+}
+
+ErrorOr<size_t> SysFSInode::read_bytes_locked(off_t offset, size_t count, UserOrKernelBuffer& buffer, OpenFileDescription* fd) const
+{
+    return m_associated_component->read_bytes(offset, count, buffer, fd);
+}
+
+ErrorOr<void> SysFSInode::traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const
+{
+    VERIFY_NOT_REACHED();
+}
+
+ErrorOr<NonnullLockRefPtr<Inode>> SysFSInode::lookup(StringView)
+{
+    VERIFY_NOT_REACHED();
+}
+
+InodeMetadata SysFSInode::metadata() const
+{
+    // NOTE: No locking required as m_associated_component or its component index will never change during our lifetime.
+    InodeMetadata metadata;
+    metadata.inode = { fsid(), m_associated_component->component_index() };
+    metadata.mode = S_IFREG | m_associated_component->permissions();
+    metadata.uid = 0;
+    metadata.gid = 0;
+    metadata.size = m_associated_component->size();
+    metadata.mtime = TimeManagement::boot_time();
+    return metadata;
+}
+
+ErrorOr<void> SysFSInode::flush_metadata()
+{
+    return {};
+}
+
+ErrorOr<size_t> SysFSInode::write_bytes_locked(off_t offset, size_t count, UserOrKernelBuffer const& buffer, OpenFileDescription* fd)
+{
+    return m_associated_component->write_bytes(offset, count, buffer, fd);
+}
+
+ErrorOr<NonnullLockRefPtr<Inode>> SysFSInode::create_child(StringView, mode_t, dev_t, UserID, GroupID)
+{
+    return EROFS;
+}
+
+ErrorOr<void> SysFSInode::add_child(Inode&, StringView, mode_t)
+{
+    return EROFS;
+}
+
+ErrorOr<void> SysFSInode::remove_child(StringView)
+{
+    return EROFS;
+}
+
+ErrorOr<void> SysFSInode::chmod(mode_t)
+{
+    return EPERM;
+}
+
+ErrorOr<void> SysFSInode::chown(UserID, GroupID)
+{
+    return EPERM;
+}
+
+ErrorOr<void> SysFSInode::truncate(u64 size)
+{
+    return m_associated_component->truncate(size);
+}
+
+ErrorOr<void> SysFSInode::update_timestamps(Optional<time_t>, Optional<time_t>, Optional<time_t>)
+{
+    return {};
+}
+
+}

Kernel/FileSystem/SysFS/Inode.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/FileSystem/Inode.h>
+#include <Kernel/FileSystem/SysFS/Component.h>
+#include <Kernel/FileSystem/SysFS/FileSystem.h>
+
+namespace Kernel {
+
+class SysFSInode : public Inode {
+    friend class SysFS;
+    friend class SysFSDirectoryInode;
+
+public:
+    static ErrorOr<NonnullLockRefPtr<SysFSInode>> try_create(SysFS const&, SysFSComponent const&);
+    StringView name() const { return m_associated_component->name(); }
+
+protected:
+    SysFSInode(SysFS const&, SysFSComponent const&);
+    virtual ErrorOr<size_t> read_bytes_locked(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) 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 InodeMetadata metadata() const override;
+    virtual ErrorOr<size_t> write_bytes_locked(off_t, size_t, UserOrKernelBuffer const&, OpenFileDescription*) 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;
+
+    virtual ErrorOr<void> attach(OpenFileDescription& description) override final;
+    virtual void did_seek(OpenFileDescription&, off_t) override final;
+
+    NonnullLockRefPtr<SysFSComponent> m_associated_component;
+};
+
+}

Kernel/FileSystem/SysFS/LinkInode.cpp

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/FileSystem/SysFS/LinkInode.h>
+#include <Kernel/Time/TimeManagement.h>
+
+namespace Kernel {
+
+ErrorOr<NonnullLockRefPtr<SysFSLinkInode>> SysFSLinkInode::try_create(SysFS const& sysfs, SysFSComponent const& component)
+{
+    return adopt_nonnull_lock_ref_or_enomem(new (nothrow) SysFSLinkInode(sysfs, component));
+}
+
+SysFSLinkInode::SysFSLinkInode(SysFS const& fs, SysFSComponent const& component)
+    : SysFSInode(fs, component)
+{
+}
+
+SysFSLinkInode::~SysFSLinkInode() = default;
+
+InodeMetadata SysFSLinkInode::metadata() const
+{
+    // NOTE: No locking required as m_associated_component or its component index will never change during our lifetime.
+    InodeMetadata metadata;
+    metadata.inode = { fsid(), m_associated_component->component_index() };
+    metadata.mode = S_IFLNK | S_IRUSR | S_IRGRP | S_IROTH | S_IXOTH;
+    metadata.uid = 0;
+    metadata.gid = 0;
+    metadata.size = 0;
+    metadata.mtime = TimeManagement::boot_time();
+    return metadata;
+}
+
+}

Kernel/FileSystem/SysFS/LinkInode.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/FileSystem/SysFS/Inode.h>
+
+namespace Kernel {
+
+class SysFSLinkInode : public SysFSInode {
+    friend class SysFS;
+
+public:
+    static ErrorOr<NonnullLockRefPtr<SysFSLinkInode>> try_create(SysFS const&, SysFSComponent const&);
+    virtual ~SysFSLinkInode() override;
+
+protected:
+    SysFSLinkInode(SysFS const&, SysFSComponent const&);
+    // ^Inode
+    virtual InodeMetadata metadata() const override;
+};
+
+}

Kernel/FileSystem/SysFS/Subsystems/Firmware/BIOS/Directory.h

@@ -8,7 +8,6 @@
 
 #include <AK/Types.h>
 #include <AK/Vector.h>
-#include <Kernel/FileSystem/SysFS.h>
 #include <Kernel/FileSystem/SysFS/Subsystems/Firmware/Directory.h>
 #include <Kernel/Library/LockRefPtr.h>
 #include <Kernel/PhysicalAddress.h>

Kernel/FileSystem/SysFS/Subsystems/Firmware/Directory.h

@@ -7,7 +7,7 @@
 #pragma once
 
 #include <AK/Types.h>
-#include <Kernel/FileSystem/SysFS.h>
+#include <Kernel/FileSystem/SysFS/Component.h>
 
 namespace Kernel {
 

Kernel/FileSystem/SysFS/Subsystems/Kernel/PowerStateSwitch.h

@@ -9,7 +9,6 @@
 
 #include <AK/Types.h>
 #include <AK/Vector.h>
-#include <Kernel/FileSystem/SysFS.h>
 #include <Kernel/FileSystem/SysFS/Subsystems/Kernel/Directory.h>
 #include <Kernel/KBuffer.h>
 #include <Kernel/Library/LockRefPtr.h>