From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

When we don't have a connection and blocking is false, we return NULL
but don't set errp. That's wrong.

We have two paths for calling nbd_co_establish_connection():

1. nbd_open() -> nbd_do_establish_connection() -> ...
  but that will never set blocking=false

2. nbd_reconnect_attempt() -> nbd_co_do_establish_connection() -> ...
  but that uses errp=NULL

So, we are safe with our wrong errp policy in
nbd_co_establish_connection(). Still let's fix it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210906190654.183421-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 nbd/client-connection.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/nbd/client-connection.c b/nbd/client-connection.c
index 7123b1e18900..695f85575414 100644
--- a/nbd/client-connection.c
+++ b/nbd/client-connection.c
@@ -318,6 +318,7 @@ nbd_co_establish_connection(NBDClientConnection *conn, NBDExportInfo *info,
         }

         if (!blocking) {
+            error_setg(errp, "No connection at the moment");
             return NULL;
         }

-- 
2.31.1