Kernel: Make VirtualFileSystem::Mount a top-level class

And move it to its own compilation unit.

Kernel/CMakeLists.txt

@@ -109,6 +109,7 @@ set(KERNEL_SOURCES
     FileSystem/Inode.cpp
     FileSystem/InodeFile.cpp
     FileSystem/InodeWatcher.cpp
+    FileSystem/Mount.cpp
     FileSystem/Plan9FileSystem.cpp
     FileSystem/ProcFS.cpp
     FileSystem/SysFS.cpp

Kernel/FileSystem/Forward.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+namespace Kernel {
+
+class FileSystem;
+class Inode;
+class Mount;
+class VirtualFileSystem;
+struct InodeMetadata;
+
+}

Kernel/FileSystem/Mount.cpp

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/FileSystem/Custody.h>
+#include <Kernel/FileSystem/FileSystem.h>
+#include <Kernel/FileSystem/Inode.h>
+#include <Kernel/FileSystem/Mount.h>
+
+namespace Kernel {
+
+Mount::Mount(FileSystem& guest_fs, Custody* host_custody, int flags)
+    : m_guest(guest_fs.root_inode())
+    , m_guest_fs(guest_fs)
+    , m_host_custody(host_custody)
+    , m_flags(flags)
+{
+}
+
+Mount::Mount(Inode& source, Custody& host_custody, int flags)
+    : m_guest(source)
+    , m_guest_fs(source.fs())
+    , m_host_custody(host_custody)
+    , m_flags(flags)
+{
+}
+
+String Mount::absolute_path() const
+{
+    if (!m_host_custody)
+        return "/";
+    return m_host_custody->absolute_path();
+}
+
+Inode* Mount::host()
+{
+    if (!m_host_custody)
+        return nullptr;
+    return &m_host_custody->inode();
+}
+
+Inode const* Mount::host() const
+{
+    if (!m_host_custody)
+        return nullptr;
+    return &m_host_custody->inode();
+}
+
+}

Kernel/FileSystem/Mount.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/NonnullRefPtr.h>
+#include <Kernel/FileSystem/Forward.h>
+
+namespace Kernel {
+
+class Mount {
+public:
+    Mount(FileSystem&, Custody* host_custody, int flags);
+    Mount(Inode& source, Custody& host_custody, int flags);
+
+    Inode const* host() const;
+    Inode* host();
+
+    Inode const& guest() const { return *m_guest; }
+    Inode& guest() { return *m_guest; }
+
+    FileSystem const& guest_fs() const { return *m_guest_fs; }
+
+    String absolute_path() const;
+
+    int flags() const { return m_flags; }
+    void set_flags(int flags) { m_flags = flags; }
+
+private:
+    NonnullRefPtr<Inode> m_guest;
+    NonnullRefPtr<FileSystem> m_guest_fs;
+    RefPtr<Custody> m_host_custody;
+    int m_flags;
+};
+
+}

Kernel/FileSystem/VirtualFileSystem.cpp

@@ -780,43 +780,6 @@ KResult VirtualFileSystem::rmdir(StringView path, Custody& base)
     return parent_inode.remove_child(KLexicalPath::basename(path));
 }
 
-VirtualFileSystem::Mount::Mount(FileSystem& guest_fs, Custody* host_custody, int flags)
-    : m_guest(guest_fs.root_inode())
-    , m_guest_fs(guest_fs)
-    , m_host_custody(host_custody)
-    , m_flags(flags)
-{
-}
-
-VirtualFileSystem::Mount::Mount(Inode& source, Custody& host_custody, int flags)
-    : m_guest(source)
-    , m_guest_fs(source.fs())
-    , m_host_custody(host_custody)
-    , m_flags(flags)
-{
-}
-
-String VirtualFileSystem::Mount::absolute_path() const
-{
-    if (!m_host_custody)
-        return "/";
-    return m_host_custody->absolute_path();
-}
-
-Inode* VirtualFileSystem::Mount::host()
-{
-    if (!m_host_custody)
-        return nullptr;
-    return &m_host_custody->inode();
-}
-
-const Inode* VirtualFileSystem::Mount::host() const
-{
-    if (!m_host_custody)
-        return nullptr;
-    return &m_host_custody->inode();
-}
-
 void VirtualFileSystem::for_each_mount(Function<void(const Mount&)> callback) const
 {
     for (auto& mount : m_mounts) {

Kernel/FileSystem/VirtualFileSystem.h

@@ -16,6 +16,7 @@
 #include <Kernel/FileSystem/FileSystem.h>
 #include <Kernel/FileSystem/InodeIdentifier.h>
 #include <Kernel/FileSystem/InodeMetadata.h>
+#include <Kernel/FileSystem/Mount.h>
 #include <Kernel/KResult.h>
 #include <Kernel/UnveilNode.h>
 
@@ -33,31 +34,6 @@ struct UidAndGid {
 class VirtualFileSystem {
     AK_MAKE_ETERNAL
 public:
-    class Mount {
-    public:
-        Mount(FileSystem&, Custody* host_custody, int flags);
-        Mount(Inode& source, Custody& host_custody, int flags);
-
-        const Inode* host() const;
-        Inode* host();
-
-        const Inode& guest() const { return *m_guest; }
-        Inode& guest() { return *m_guest; }
-
-        FileSystem const& guest_fs() const { return *m_guest_fs; }
-
-        String absolute_path() const;
-
-        int flags() const { return m_flags; }
-        void set_flags(int flags) { m_flags = flags; }
-
-    private:
-        NonnullRefPtr<Inode> m_guest;
-        NonnullRefPtr<FileSystem> m_guest_fs;
-        RefPtr<Custody> m_host_custody;
-        int m_flags;
-    };
-
     static void initialize();
     static VirtualFileSystem& the();