You could argue that most book titles fall under this as well, at least conceptually. And the Dewey decimal system.

In fact, before the growth of the internet, Identifying and Requesting Data in Network Using Identifiers Which Are Based On Contents of Data would sound almost exactly like a long winded academic description of finding a book through the public library inter-lending network.

Wait. This isn't true. Most filesystems don't have an algorithmic identifier for the data being stored. They do often have checksums, but that's different.

No, the patent claims the identifier is derived from the data, and only the data, which a file name is not. It also have several other constraints and steps. (i.e. a patent describes a a system as a whole - the fact that individual parts of a patent is in wide use elsewhere doesn't necessarily mean those systems infringe or invalidate this patent)

One file system that comes to mind using the approach described in the patent is Venti though: http://www.stanford.edu/class/cs240/readings/venti-fast.pdf