Kernel: Rename Kernel/VM/ to Kernel/Memory/

This directory isn't just about virtual memory, it's about all kinds
of memory management.

Kernel/Memory/InodeVMObject.cpp

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/FileSystem/Inode.h>
+#include <Kernel/Memory/InodeVMObject.h>
+
+namespace Kernel {
+
+InodeVMObject::InodeVMObject(Inode& inode, size_t size)
+    : VMObject(size)
+    , m_inode(inode)
+    , m_dirty_pages(page_count(), false)
+{
+}
+
+InodeVMObject::InodeVMObject(InodeVMObject const& other)
+    : VMObject(other)
+    , m_inode(other.m_inode)
+    , m_dirty_pages(page_count(), false)
+{
+    for (size_t i = 0; i < page_count(); ++i)
+        m_dirty_pages.set(i, other.m_dirty_pages.get(i));
+}
+
+InodeVMObject::~InodeVMObject()
+{
+}
+
+size_t InodeVMObject::amount_clean() const
+{
+    size_t count = 0;
+    VERIFY(page_count() == m_dirty_pages.size());
+    for (size_t i = 0; i < page_count(); ++i) {
+        if (!m_dirty_pages.get(i) && m_physical_pages[i])
+            ++count;
+    }
+    return count * PAGE_SIZE;
+}
+
+size_t InodeVMObject::amount_dirty() const
+{
+    size_t count = 0;
+    for (size_t i = 0; i < m_dirty_pages.size(); ++i) {
+        if (m_dirty_pages.get(i))
+            ++count;
+    }
+    return count * PAGE_SIZE;
+}
+
+int InodeVMObject::release_all_clean_pages()
+{
+    ScopedSpinLock locker(m_lock);
+
+    int count = 0;
+    for (size_t i = 0; i < page_count(); ++i) {
+        if (!m_dirty_pages.get(i) && m_physical_pages[i]) {
+            m_physical_pages[i] = nullptr;
+            ++count;
+        }
+    }
+    if (count) {
+        for_each_region([](auto& region) {
+            region.remap();
+        });
+    }
+    return count;
+}
+
+u32 InodeVMObject::writable_mappings() const
+{
+    u32 count = 0;
+    const_cast<InodeVMObject&>(*this).for_each_region([&](auto& region) {
+        if (region.is_writable())
+            ++count;
+    });
+    return count;
+}
+
+u32 InodeVMObject::executable_mappings() const
+{
+    u32 count = 0;
+    const_cast<InodeVMObject&>(*this).for_each_region([&](auto& region) {
+        if (region.is_executable())
+            ++count;
+    });
+    return count;
+}
+
+}