in some environment the following race is possible:

• client sends GETATTR with say 1K reply buffer
• MDS replies back with 2K buffer (LOVEA has just changed)
• client resends GETATTR with an extended buffer
• MDS finds the original request on on export's list and reject the new one
• client has no reply, times out

if the client holds a lock for this request, then the client can get evicted and applications can may hit EIO problem.