ceph: fix request time stamp encoding

commit 1f041a89 upstream.

struct timespec uses 'long' to present second and nanosecond. 'long'
is 64 bits on 64bits machine. ceph MDS expects time stamp to be
encoded as struct ceph_timespec, which uses 'u32' to present second
and nanosecond.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
BugLink: http://tracker.ceph.com/issues/15302
BugLink: http://bugs.launchpad.net/bugs/1564950
[ kamal: backport to 3.16-stable: no time stamp in __prepare_send_request() ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

fs/ceph/mds_client.c

@@ -1841,7 +1841,11 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
 	head->num_releases = cpu_to_le16(releases);
 
 	/* time stamp */
-	ceph_encode_copy(&p, &req->r_stamp, sizeof(req->r_stamp));
+	{
+		struct ceph_timespec ts;
+		ceph_encode_timespec(&ts, &req->r_stamp);
+		ceph_encode_copy(&p, &ts, sizeof(ts));
+	}
 
 	BUG_ON(p > end);
 	msg->front.iov_len = p - msg->front.iov_base;