1 files changed, 9 insertions, 7 deletions
diff --git a/block/nbd.c b/block/nbd.c
index bcd6641e90..b3cbbeb4b0 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -250,13 +250,15 @@ static void nbd_client_attach_aio_context_bh(void *opaque)
     BlockDriverState *bs = opaque;
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
 
-    /*
-     * The node is still drained, so we know the coroutine has yielded in
-     * nbd_read_eof(), the only place where bs->in_flight can reach 0, or it is
-     * entered for the first time. Both places are safe for entering the
-     * coroutine.
-     */
-    qemu_aio_coroutine_enter(bs->aio_context, s->connection_co);
+    if (s->connection_co) {
+        /*
+         * The node is still drained, so we know the coroutine has yielded in
+         * nbd_read_eof(), the only place where bs->in_flight can reach 0, or
+         * it is entered for the first time. Both places are safe for entering
+         * the coroutine.
+         */
+        qemu_aio_coroutine_enter(bs->aio_context, s->connection_co);
+    }
     bdrv_dec_in_flight(bs);
 }