Linseed oil takes a very long time to harden. It gives a look like oil based finishes and darkens over time. You may be happier with a water-based poly-urethane if you like light colored floors. I would let it dry for a week or so then buff with #2 steel wool, shellac and coat with a water-based poly.
Test an out of the way area to see if you can get good adhesion.
If you want a lighter floor you will need to sand to bare wood.