this is my #controller

public function store(Request $request)
    {
        $this->validate($request, [
            'title' => 'required',
            'body' => 'required',
            'cover_image' => 'image|nullable|max:1999',
        ]);

        // Handle File upload
        if($request->hasFile('cover_image')){
            // get filename with the extention
            $fileNameWithExt = $request->file('cover_image')->getClientOrginalName();

            // get just filename 
            $fileName = pathinfo($fileNameWithExt, PATHINFO_FILENAME);

            // get just Ext
            $extention = $request->file('cover_image')->getClientOrginalExtention();

            // Filename to store
            $fileNameToStore = $filename.'_'.time().'.'.$extention;

            // upload image
            $path = $request->file('cover_image')->storeAs('public/cover_images',$fileNameToStore);
        }else{
            $fileNameStore='noimage.jpg';
        }        
        //create post
        $post=new Post;
        $post->title = $request->input('title');
        $post->body = $request->input('body');
        $post->user_id = auth()->user()->id;
        $post->cover_image = $fileNameToStore;
        $post->save();

        return redirect('/posts')->with('success','Post created');

    }

why this error occurd ?