- VLOG_WARN("%s: failed to lock file: %s",
- lock_name, strerror(error));
+ if (pid) {
+ VLOG_WARN("%s: cannot lock file because it is already locked by "
+ "pid %ld", lock_name, (long int) pid);
+ } else {
+ VLOG_WARN("%s: failed to lock file: %s",
+ lock_name, strerror(error));
+ }