Merge remote-tracking branch 'bonzini/nbd-next' into staging

# By Stefan Hajnoczi
# Via Paolo Bonzini
* bonzini/nbd-next:
  nbd: set TCP_NODELAY
  nbd: use TCP_CORK in nbd_co_send_request()
  nbd: unlock mutex in nbd_co_send_request() error path

Message-id: 1366381830-11267-1-git-send-email-pbonzini@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

block/nbd.c

@@ -334,13 +334,23 @@ static int nbd_co_send_request(BDRVNBDState *s, struct nbd_request *request,
     s->send_coroutine = qemu_coroutine_self();
     qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, nbd_restart_write,
                             nbd_have_request, s);
+    if (qiov) {
+        if (!s->is_unix) {
+            socket_set_cork(s->sock, 1);
+        }
         rc = nbd_send_request(s->sock, request);
-    if (rc >= 0 && qiov) {
+        if (rc >= 0) {
             ret = qemu_co_sendv(s->sock, qiov->iov, qiov->niov,
                                 offset, request->len);
             if (ret != request->len) {
-            return -EIO;
+                rc = -EIO;
+            }
+        }
+        if (!s->is_unix) {
+            socket_set_cork(s->sock, 0);
         }
+    } else {
+        rc = nbd_send_request(s->sock, request);
     }
     qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, NULL,
                             nbd_have_request, s);
@@ -396,6 +406,9 @@ static int nbd_establish_connection(BlockDriverState *bs)
         sock = unix_socket_outgoing(qemu_opt_get(s->socket_opts, "path"));
     } else {
         sock = tcp_socket_outgoing_opts(s->socket_opts);
+        if (sock >= 0) {
+            socket_set_nodelay(sock);
+        }
     }
 
     /* Failed to establish connection */