diff --git a/nbd/server.c b/nbd/server.c
index 27a0aab..8e363d3 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -396,21 +396,19 @@
         error_prepend(errp, "read failed: ");
         return -EIO;
     }
-    trace_nbd_negotiate_options_flags();
     be32_to_cpus(&flags);
+    trace_nbd_negotiate_options_flags(flags);
     if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {
-        trace_nbd_negotiate_options_newstyle();
         fixedNewstyle = true;
         flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE;
     }
     if (flags & NBD_FLAG_C_NO_ZEROES) {
-        trace_nbd_negotiate_options_no_zeroes();
         client->no_zeroes = true;
         flags &= ~NBD_FLAG_C_NO_ZEROES;
     }
     if (flags != 0) {
         error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags);
-        return -EIO;
+        return -EINVAL;
     }
 
     while (1) {