block/nbd: move connection code from block/nbd to block/nbd-client

Keep all connection code in one file, to be able to implement reconnect
in further patches.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190201130138.94525-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: format tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>

1 files changed, 36 insertions, 2 deletions

diff --git a/block/nbd-client.c b/block/nbd-client.c
index fd58cda2f1..80dc8cff47 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -991,8 +991,29 @@ void nbd_client_close(BlockDriverState *bs)
     nbd_teardown_connection(bs);
 }
 
+static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr,
+                                                  Error **errp)
+{
+    QIOChannelSocket *sioc;
+    Error *local_err = NULL;
+
+    sioc = qio_channel_socket_new();
+    qio_channel_set_name(QIO_CHANNEL(sioc), "nbd-client");
+
+    qio_channel_socket_connect_sync(sioc, saddr, &local_err);
+    if (local_err) {
+        object_unref(OBJECT(sioc));
+        error_propagate(errp, local_err);
+        return NULL;
+    }
+
+    qio_channel_set_delay(QIO_CHANNEL(sioc), false);
+
+    return sioc;
+}
+
 int nbd_client_init(BlockDriverState *bs,
-                    QIOChannelSocket *sioc,
+                    SocketAddress *saddr,
                     const char *export,
                     QCryptoTLSCreds *tlscreds,
                     const char *hostname,
@@ -1002,6 +1023,16 @@ int nbd_client_init(BlockDriverState *bs,
     NBDClientSession *client = nbd_get_client_session(bs);
     int ret;
 
+    /*
+     * establish TCP connection, return error if it fails
+     * TODO: Configurable retry-until-timeout behaviour.
+     */
+    QIOChannelSocket *sioc = nbd_establish_connection(saddr, errp);
+
+    if (!sioc) {
+        return -ECONNREFUSED;
+    }
+
     /* NBD handshake */
     logout("session init %s\n", export);
     qio_channel_set_blocking(QIO_CHANNEL(sioc), true, NULL);
@@ -1017,6 +1048,7 @@ int nbd_client_init(BlockDriverState *bs,
     g_free(client->info.name);
     if (ret < 0) {
         logout("Failed to negotiate with the NBD server\n");
+        object_unref(OBJECT(sioc));
         return ret;
     }
     if (x_dirty_bitmap && !client->info.base_allocation) {
@@ -1042,7 +1074,6 @@ int nbd_client_init(BlockDriverState *bs,
     qemu_co_mutex_init(&client->send_mutex);
     qemu_co_queue_init(&client->free_sema);
     client->sioc = sioc;
-    object_ref(OBJECT(client->sioc));
 
     if (!client->ioc) {
         client->ioc = QIO_CHANNEL(sioc);
@@ -1068,6 +1099,9 @@ int nbd_client_init(BlockDriverState *bs,
         NBDRequest request = { .type = NBD_CMD_DISC };
 
         nbd_send_request(client->ioc ?: QIO_CHANNEL(sioc), &request);
+
+        object_unref(OBJECT(sioc));
+
         return ret;
     }
 }