ceph: add feature bits to connection handshake (protocol change)

Define supported and required feature set.  Fail connection if the server
requires features we do not support (TAG_FEATURES), or if the server does
not support features we require.

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

1 files changed, 37 insertions, 10 deletions

diff --git a/fs/ceph/messenger.c b/fs/ceph/messenger.c
index 506b638a023b..68052f664280 100644
--- a/fs/ceph/messenger.c
+++ b/fs/ceph/messenger.c
@@ -631,6 +631,7 @@ static void prepare_write_connect(struct ceph_messenger *msgr,
         dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
              con->connect_seq, global_seq, proto);
 
+        con->out_connect.features = CEPH_FEATURE_SUPPORTED;
         con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
         con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
         con->out_connect.global_seq = cpu_to_le32(global_seq);
@@ -1080,15 +1081,37 @@ static int process_banner(struct ceph_connection *con)
         return 0;
 }
 
+static void fail_protocol(struct ceph_connection *con)
+{
+        reset_connection(con);
+        set_bit(CLOSED, &con->state);  /* in case there's queued work */
+
+        mutex_unlock(&con->mutex);
+        if (con->ops->bad_proto)
+                con->ops->bad_proto(con);
+        mutex_lock(&con->mutex);
+}
+
 static int process_connect(struct ceph_connection *con)
 {
+        u64 sup_feat = CEPH_FEATURE_SUPPORTED;
+        u64 req_feat = CEPH_FEATURE_REQUIRED;
+        u64 server_feat = le64_to_cpu(con->in_reply.features);
+
         dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
 
         switch (con->in_reply.tag) {
+        case CEPH_MSGR_TAG_FEATURES:
+                pr_err("%s%lld %s feature set mismatch,"
+                       " my %llx < server's %llx, missing %llx\n",
+                       ENTITY_NAME(con->peer_name),
+                       pr_addr(&con->peer_addr.in_addr),
+                       sup_feat, server_feat, server_feat & ~sup_feat);
+                con->error_msg = "missing required protocol features";
+                fail_protocol(con);
+                return -1;
+
         case CEPH_MSGR_TAG_BADPROTOVER:
-                dout("process_connect got BADPROTOVER my %d != their %d\n",
-                     le32_to_cpu(con->out_connect.protocol_version),
-                     le32_to_cpu(con->in_reply.protocol_version));
                 pr_err("%s%lld %s protocol version mismatch,"
                        " my %d != server's %d\n",
                        ENTITY_NAME(con->peer_name),
@@ -1096,13 +1119,7 @@ static int process_connect(struct ceph_connection *con)
                        le32_to_cpu(con->out_connect.protocol_version),
                        le32_to_cpu(con->in_reply.protocol_version));
                 con->error_msg = "protocol version mismatch";
-                reset_connection(con);
-                set_bit(CLOSED, &con->state);  /* in case there's queued work */
-
-                mutex_unlock(&con->mutex);
-                if (con->ops->bad_proto)
-                        con->ops->bad_proto(con);
-                mutex_lock(&con->mutex);
+                fail_protocol(con);
                 return -1;
 
         case CEPH_MSGR_TAG_BADAUTHORIZER:
@@ -1173,6 +1190,16 @@ static int process_connect(struct ceph_connection *con)
                 break;
 
         case CEPH_MSGR_TAG_READY:
+                if (req_feat & ~server_feat) {
+                        pr_err("%s%lld %s protocol feature mismatch,"
+                               " my required %llx > server's %llx, need %llx\n",
+                               ENTITY_NAME(con->peer_name),
+                               pr_addr(&con->peer_addr.in_addr),
+                               req_feat, server_feat, req_feat & ~server_feat);
+                        con->error_msg = "missing required protocol features";
+                        fail_protocol(con);
+                        return -1;
+                }
                 clear_bit(CONNECTING, &con->state);
                 con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
                 con->connect_seq++;