You can install ceramic tile over linoleum using a latex modified thinset mortar although I would recommend the installation of a ceramic tile backerboard over the linoleum similiar to 1/4" - 1/2" HardiBacker or cement backerboard. In any case, loose floor coverings will need to be removed as screwing it down is not enough. Assuming the linoleum does not contain asbestos, sanding and scrarifying the surface will greatly improve the mechanical adhesion of the thinset mortar.
Yes, the linoleum will act as a barrier. What does this mean? Probably nothing. In other words I don't see a difference between tiling over wood or linoleum as both systems are more likely to fail than a tile installed over a ceramic tile backerboard with proper subfloor requirements.