cpn lock is wrapped around all transfers, including those that don't need it
When calling "ifdh cp" like:
ifdh cp /some/bluearc/file dest \; /some/pnfs/file dest \; /lots/more/pnfs/files dest
ifdh takes out one lock that it holds while doing all the copies. This is inefficient since the lock is held while doing the pnfs copies. I suppose the way to fix it is to sort the list of transfers into those that need a cpn lock and those that don't, take out one cpn lock for the former set, release it, and then do the latter set. This seems fiddly (especially after looking at the ifdh_cp code), but this problem is making minerva genie jobs run with low efficiency, like 25%.