I have a flooring issue that needs some attention!

Can you peel the flooring back to get a look at it? I had to do a repair in my bathroom. I had to remove the sink and vanity cut the water lines. I was able to peel back the linoleum to do it. I ripped a 2x4 to make a box inside the other floor joists and attached with screws. Have a cup of coffee and look at it on how would be the easiest way.