libceph: unregister request in __map_request failed and nofail == false

commit 73d9f7ee upstream.

For nofail == false request, if __map_request failed, the caller does
cleanup work, like releasing the relative pages.  It doesn't make any sense
to retry this request.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Sage Weil <sage@inktank.com>
[bwh: Backported to 3.2: adjust indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/ceph/osd_client.c

@@ -1721,6 +1721,8 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc,
 				dout("osdc_start_request failed map, "
 				     " will retry %lld\n", req->r_tid);
 				rc = 0;
+			} else {
+				__unregister_request(osdc, req);
 			}
 			goto out_unlock;
 		}