libceph: assume argonaut on the server side

No one is running pre-argonaut.  In addition one of the argonaut
features (NOSRCADDR) has been required since day one (and a half,
2.6.34 vs 2.6.35) of the kernel client.

Allow for the possibility of reusing these feature bits later.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

fs/ceph/mds_client.c

@@ -80,12 +80,8 @@ static int parse_reply_info_in(void **p, void *end,
 	info->symlink = *p;
 	*p += info->symlink_len;
 
-	if (features & CEPH_FEATURE_DIRLAYOUTHASH)
 	ceph_decode_copy_safe(p, end, &info->dir_layout,
 			      sizeof(info->dir_layout), bad);
-	else
-		memset(&info->dir_layout, 0, sizeof(info->dir_layout));
-
 	ceph_decode_32_safe(p, end, info->xattr_len, bad);
 	ceph_decode_need(p, end, info->xattr_len, bad);
 	info->xattr_data = *p;
@@ -3182,10 +3178,8 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
 	recon_state.pagelist = pagelist;
 	if (session->s_con.peer_features & CEPH_FEATURE_MDSENC)
 		recon_state.msg_version = 3;
-	else if (session->s_con.peer_features & CEPH_FEATURE_FLOCK)
-		recon_state.msg_version = 2;
 	else
-		recon_state.msg_version = 1;
+		recon_state.msg_version = 2;
 	err = iterate_session_caps(session, encode_caps_cb, &recon_state);
 	if (err < 0)
 		goto fail;

include/linux/ceph/ceph_features.h

@@ -213,12 +213,6 @@ DEFINE_CEPH_FEATURE_DEPRECATED(63, 1, RESERVED_BROKEN, LUMINOUS) // client-facin
 	 CEPH_FEATURE_NEW_OSDOPREPLY_ENCODING |	\
 	 CEPH_FEATURE_CEPHX_V2)
 
-#define CEPH_FEATURES_REQUIRED_DEFAULT   \
-	(CEPH_FEATURE_NOSRCADDR |	 \
-	 CEPH_FEATURE_SUBSCRIBE2 |	 \
-	 CEPH_FEATURE_RECONNECT_SEQ |	 \
-	 CEPH_FEATURE_PGID64 |		 \
-	 CEPH_FEATURE_PGPOOL3 |		 \
-	 CEPH_FEATURE_OSDENC)
+#define CEPH_FEATURES_REQUIRED_DEFAULT	0
 
 #endif