Moving a tablespace

Suppose, hypothetically of course, someone lacked foresight, and put a tablespace somewhere with a dumb name, like
"/disk2",instead of using a symbolic link with a more descriptive name.   And then /disk2 needs to be renamed, say to
"/postgres_data",and this (hypothetical) DBA realizes he has made a dumb mistake. 

Is there a way to move a tablespace to a new location without a dump/restore?  I, er, this hypothetical guy, knows he
canmove it and put a symbolic link in for /disk2, but this is somewhat unsatisfactory since "/disk2" would have to
existforever. 

Thanks,
Craig