Kernel: Add forward declaration header

Kernel/FileSystem/DiskBackedFileSystem.cpp

@@ -25,6 +25,7 @@
  */
 
 #include <Kernel/Arch/i386/CPU.h>
+#include <Kernel/Devices/BlockDevice.h>
 #include <Kernel/FileSystem/DiskBackedFileSystem.h>
 #include <Kernel/FileSystem/FileDescription.h>
 #include <Kernel/KBuffer.h>

Kernel/FileSystem/DiskBackedFileSystem.h

@@ -26,13 +26,11 @@
 
 #pragma once
 
-#include "FileSystem.h"
-#include <AK/ByteBuffer.h>
+#include <Kernel/FileSystem/FileSystem.h>
+#include <Kernel/Forward.h>
 
 namespace Kernel {
 
-class DiskCache;
-
 class DiskBackedFS : public FS {
 public:
     virtual ~DiskBackedFS() override;

Kernel/FileSystem/Ext2FileSystem.cpp

@@ -26,7 +26,9 @@
 
 #include <AK/Bitmap.h>
 #include <AK/BufferStream.h>
+#include <AK/HashMap.h>
 #include <AK/StdLibExtras.h>
+#include <Kernel/Devices/BlockDevice.h>
 #include <Kernel/FileSystem/Ext2FileSystem.h>
 #include <Kernel/FileSystem/FileDescription.h>
 #include <Kernel/FileSystem/ext2_fs.h>

Kernel/FileSystem/File.h

@@ -30,16 +30,13 @@
 #include <AK/RefCounted.h>
 #include <AK/String.h>
 #include <AK/Types.h>
+#include <Kernel/Forward.h>
 #include <Kernel/KResult.h>
 #include <Kernel/UnixTypes.h>
 #include <LibBareMetal/Memory/VirtualAddress.h>
 
 namespace Kernel {
 
-class FileDescription;
-class Process;
-class Region;
-
 // File is the base class for anything that can be referenced by a FileDescription.
 //
 // The most important functions in File are:

Kernel/FileSystem/FileSystem.h

@@ -26,17 +26,10 @@
 
 #pragma once
 
-#include <AK/ByteBuffer.h>
-#include <AK/Function.h>
-#include <AK/HashMap.h>
-#include <AK/OwnPtr.h>
 #include <AK/RefCounted.h>
 #include <AK/RefPtr.h>
 #include <AK/String.h>
-#include <AK/WeakPtr.h>
-#include <Kernel/Devices/BlockDevice.h>
 #include <Kernel/FileSystem/InodeIdentifier.h>
-#include <Kernel/FileSystem/InodeMetadata.h>
 #include <Kernel/KResult.h>
 #include <Kernel/Lock.h>
 #include <Kernel/UnixTypes.h>

Kernel/FileSystem/Inode.h

@@ -34,17 +34,12 @@
 #include <Kernel/FileSystem/FileSystem.h>
 #include <Kernel/FileSystem/InodeIdentifier.h>
 #include <Kernel/FileSystem/InodeMetadata.h>
+#include <Kernel/Forward.h>
 #include <Kernel/KResult.h>
 #include <Kernel/Lock.h>
 
 namespace Kernel {
 
-class FileDescription;
-class InodeVMObject;
-class InodeWatcher;
-class LocalSocket;
-class Custody;
-
 class Inode : public RefCounted<Inode>
     , public Weakable<Inode>
     , public InlineLinkedListNode<Inode> {

Kernel/FileSystem/ProcFS.cpp

@@ -33,6 +33,7 @@
 #include <AK/JsonObjectSerializer.h>
 #include <AK/JsonValue.h>
 #include <Kernel/Arch/i386/CPU.h>
+#include <Kernel/Devices/BlockDevice.h>
 #include <Kernel/FileSystem/Custody.h>
 #include <Kernel/FileSystem/DiskBackedFileSystem.h>
 #include <Kernel/FileSystem/FileDescription.h>

Kernel/FileSystem/ProcFS.h

@@ -26,6 +26,7 @@
 
 #pragma once
 
+#include <AK/HashMap.h>
 #include <AK/Types.h>
 #include <Kernel/FileSystem/FileSystem.h>
 #include <Kernel/FileSystem/Inode.h>

Kernel/FileSystem/TmpFS.h

@@ -26,6 +26,7 @@
 
 #pragma once
 
+#include <AK/HashMap.h>
 #include <AK/Optional.h>
 #include <Kernel/FileSystem/FileSystem.h>
 #include <Kernel/FileSystem/Inode.h>

Kernel/FileSystem/VirtualFileSystem.cpp

@@ -26,7 +26,7 @@
 
 #include <AK/FileSystemPath.h>
 #include <AK/StringBuilder.h>
-#include <Kernel/Devices/CharacterDevice.h>
+#include <Kernel/Devices/BlockDevice.h>
 #include <Kernel/FileSystem/Custody.h>
 #include <Kernel/FileSystem/DiskBackedFileSystem.h>
 #include <Kernel/FileSystem/FileDescription.h>