You are not protected against the race condition I mentioned earlier. An unlink in Unix does not release the data from the file until the last file descriptor is closed. The second process will be able to read whatever information is in there (and write to it if it desires). Of course other processes wont know this since the file's name space entry is gone. The second process will continue under the assumption that it was accessing the locked file in a valid state (hey it was there when I opened it!).

In some cases, perhaps the current one, this is ok in others it is not -- it depends on the assumptions being made after this section of code. In general if you are going to do this, it is a good idea to put a comment in your code that says you know about the possible race condition and it is ok.