memory copy of the file is dirty, is will be synced when the child exists.
But the parent may have done changes to the database in the meantime, resulting
in a db corruption.
Fix this by calling sync_file() just before the fork. The child will still have
a reference to the db, but won't try to write it on exit.
with both names. So log the "Unsolicited notification" with LOG_DEBUG
instead of LOG_ERR.
Don't return failure if we received a notification for which the host is
unknown, or we don't have outstanding requests. The remote host will retry
forever otherwise.
