Possible database corruption - urgent

I have a situation where pg_xlog started growing until it filled up the disk drive.

I got alerted to the error and started investigating.

Checked the logs and I am seeing the following entry repeatedly:

2013-01-07 01:49:12 GMT ERROR:  could not open file "base/16748/181979366_fsm": No such file or directory

2013-01-07 01:49:12 GMT CONTEXT:  writing block 1 of relation base/16748/181979366_fsm

2013-01-07 01:49:12 GMT WARNING:  could not write block 1 of base/16748/181979366_fsm

I checked the actual file system, and that file is indeed missing.  181979366 exists.

Is there a way to get the system back up and running?

I stopped the postmaster and am moving the pg_xlog directory to a partition which has room left in it, but I need to resolve this missing file problem