[Qemu-block] [PATCH COLO-Block v5 10/15] NBD client: connect to nbd server later

[Wen Congyang]

The secondary qemu starts later than the primary qemu, so we
cannot connect to nbd server in bdrv_open(). Introduce a new
open flags to control it.

Signed-off-by: Wen Congyang <address@hidden>
Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
 block/nbd.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index bc9477a..4964cf8 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -298,11 +298,13 @@ static int nbd_open(BlockDriverState *bs, QDict *options, 
int flags,
         return -EINVAL;
     }
 
-    nbd_connect_server(bs, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        g_free(s->export);
-        return -EINVAL;
+    if (!(flags & BDRV_O_NO_CONNECT)) {
+        nbd_connect_server(bs, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            g_free(s->export);
+            return -EINVAL;
+        }
     }
 
     return 0;
-- 
2.1.0