Kernel: Split the ProcFS core file into smaller components

Author: https://github.com/supercomputer7
Commit: 3906dd3aa3
Pull-request: https://github.com/SerenityOS/serenity/pull/15771
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/bgianfo

Kernel/FileSystem/ProcFS/GlobalInode.cpp

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Spencer Dixon <spencercdixon@gmail.com>
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/FileSystem/ProcFS/GlobalInode.h>
+
+namespace Kernel {
+
+ErrorOr<NonnullLockRefPtr<ProcFSGlobalInode>> ProcFSGlobalInode::try_create(ProcFS const& fs, ProcFSExposedComponent const& component)
+{
+    return adopt_nonnull_lock_ref_or_enomem(new (nothrow) ProcFSGlobalInode(fs, component));
+}
+
+ProcFSGlobalInode::ProcFSGlobalInode(ProcFS const& fs, ProcFSExposedComponent const& component)
+    : ProcFSInode(fs, component.component_index())
+    , m_associated_component(component)
+{
+}
+
+void ProcFSGlobalInode::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("ProcFS: Could not refresh contents: {}", result.error());
+    }
+}
+
+ErrorOr<void> ProcFSGlobalInode::attach(OpenFileDescription& description)
+{
+    return m_associated_component->refresh_data(description);
+}
+
+ErrorOr<size_t> ProcFSGlobalInode::read_bytes_locked(off_t offset, size_t count, UserOrKernelBuffer& buffer, OpenFileDescription* fd) const
+{
+    return m_associated_component->read_bytes(offset, count, buffer, fd);
+}
+
+StringView ProcFSGlobalInode::name() const
+{
+    return m_associated_component->name();
+}
+
+ErrorOr<void> ProcFSGlobalInode::traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const
+{
+    VERIFY_NOT_REACHED();
+}
+
+ErrorOr<NonnullLockRefPtr<Inode>> ProcFSGlobalInode::lookup(StringView)
+{
+    VERIFY_NOT_REACHED();
+}
+
+ErrorOr<void> ProcFSGlobalInode::truncate(u64 size)
+{
+    return m_associated_component->truncate(size);
+}
+
+ErrorOr<void> ProcFSGlobalInode::update_timestamps(Optional<time_t>, Optional<time_t>, Optional<time_t>)
+{
+    return {};
+}
+
+InodeMetadata ProcFSGlobalInode::metadata() const
+{
+    MutexLocker locker(m_inode_lock);
+    InodeMetadata metadata;
+    metadata.inode = { fsid(), m_associated_component->component_index() };
+    metadata.mode = S_IFREG | m_associated_component->required_mode();
+    metadata.uid = m_associated_component->owner_user();
+    metadata.gid = m_associated_component->owner_group();
+    metadata.size = 0;
+    metadata.mtime = m_associated_component->modified_time();
+    return metadata;
+}
+
+ErrorOr<size_t> ProcFSGlobalInode::write_bytes_locked(off_t offset, size_t count, UserOrKernelBuffer const& buffer, OpenFileDescription* fd)
+{
+    return m_associated_component->write_bytes(offset, count, buffer, fd);
+}
+
+}