virtio-rng: Fix crash with non-default backend

[qemu.git] / blockdev-nbd.c

diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 274fba6e46c0d3eae2728e02d4252e0ce76789ec..95f10c81e3faae3cf16c4f405e44e763e2e4df52 100644 (file)
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -9,15 +9,15 @@
  * later.  See the COPYING file in the top-level directory.
  */
 
-#include "blockdev.h"
-#include "hw/block-common.h"
-#include "monitor.h"
-#include "qerror.h"
-#include "sysemu.h"
+#include "sysemu/blockdev.h"
+#include "hw/block/block.h"
+#include "monitor/monitor.h"
+#include "qapi/qmp/qerror.h"
+#include "sysemu/sysemu.h"
 #include "qmp-commands.h"
 #include "trace.h"
-#include "nbd.h"
-#include "qemu_socket.h"
+#include "block/nbd.h"
+#include "qemu/sockets.h"
 
 static int server_fd = -1;
 
@@ -82,6 +82,11 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
     NBDExport *exp;
     NBDCloseNotifier *n;
 
+    if (server_fd == -1) {
+        error_setg(errp, "NBD server not running");
+        return;
+    }
+
     if (nbd_export_find(device)) {
         error_setg(errp, "NBD server already exporting device '%s'", device);
         return;
@@ -93,6 +98,13 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
         return;
     }
 
+    if (!has_writable) {
+        writable = false;
+    }
+    if (bdrv_is_read_only(bs)) {
+        writable = false;
+    }
+
     exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY,
                          nbd_server_put_ref);