+ /* It's tempting to `optimize' this code by opening a new file descriptor
+ * here so as to elide the additional call to fstat(2) above. But this
+ * doesn't work: if we successfully acquire the lock, we then have two file
+ * descriptors open on the lock file, so we have to close one -- but, under
+ * the daft fcntl(2) rules, even closing `nfd' will release the lock
+ * immediately.
+ */