Kernel: Remove the big inode lock

This moves locking to the inodes themselves which allows reducing lock
times significantly. Main inodes (ext2 and tmpfs) still do contain a
single big mutex that gets locked during operations but now we have the
architecture to optimize these.

kernel/include/kernel/FS/Ext2/Inode.h

@@ -4,6 +4,7 @@
 #include <BAN/StringView.h>
 #include <kernel/FS/Ext2/Definitions.h>
 #include <kernel/FS/Inode.h>
+#include <kernel/Lock/Mutex.h>
 
 namespace Kernel
 {
@@ -110,6 +111,9 @@ namespace Kernel
 		Ext2::Inode m_inode;
 		const uint32_t m_ino;
 
+		// TODO: try to reduce locking or replace this with rwlock(?)
+		Mutex m_lock;
+
 		friend class Ext2FS;
 		friend class BAN::RefPtr<Ext2Inode>;
 	};