ceph: clean up on forwarded aborted mds request

If an mds request is aborted (timeout, SIGKILL), it is left registered to
keep our state in sync with the mds.  If we get a forward notification,
though, we know the request didn't succeed and we can unregister it
safely.  We were trying to resend it, but then bailing out (and not
unregistering) in __do_request.

Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/mds_client.c

@@ -2014,16 +2014,21 @@ static void handle_forward(struct ceph_mds_client *mdsc,
 	mutex_lock(&mdsc->mutex);
 	req = __lookup_request(mdsc, tid);
 	if (!req) {
-		dout("forward %llu to mds%d - req dne\n", tid, next_mds);
+		dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
 		goto out;  /* dup reply? */
 	}
 
-	if (fwd_seq <= req->r_num_fwd) {
-		dout("forward %llu to mds%d - old seq %d <= %d\n",
+	if (req->r_aborted) {
+		dout("forward tid %llu aborted, unregistering\n", tid);
+		__unregister_request(mdsc, req);
+	} else if (fwd_seq <= req->r_num_fwd) {
+		dout("forward tid %llu to mds%d - old seq %d <= %d\n",
 		     tid, next_mds, req->r_num_fwd, fwd_seq);
 	} else {
 		/* resend. forward race not possible; mds would drop */
-		dout("forward %llu to mds%d (we resend)\n", tid, next_mds);
+		dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
+		BUG_ON(req->r_err);
+		BUG_ON(req->r_got_result);
 		req->r_num_fwd = fwd_seq;
 		req->r_resend_mds = next_mds;
 		put_request_session(req);