libceph: MOSDOpReply v7 encoding

Empty request_redirect_t (struct ceph_request_redirect in the kernel
client) is now encoded with a bool.  NEW_OSDOPREPLY_ENCODING feature
bit overlaps with already supported CRUSH_TUNABLES5.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index f8f2359..3534e12 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1770,6 +1770,7 @@
 	u32 osdmap_epoch;
 	int already_completed;
 	u32 bytes;
+	u8 decode_redir;
 	unsigned int i;
 
 	tid = le64_to_cpu(msg->hdr.tid);
@@ -1841,6 +1842,15 @@
 		p += 8 + 4; /* skip replay_version */
 		p += 8; /* skip user_version */
 
+		if (le16_to_cpu(msg->hdr.version) >= 7)
+			ceph_decode_8_safe(&p, end, decode_redir, bad_put);
+		else
+			decode_redir = 1;
+	} else {
+		decode_redir = 0;
+	}
+
+	if (decode_redir) {
 		err = ceph_redirect_decode(&p, end, &redir);
 		if (err)
 			goto bad_put;