diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index d85cb372f2927e908ec992f706b05808a9ad2af8..c073d6c1576dd3b2119fb2e808a428c966e7d08f 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -391,8 +391,16 @@ static u32 req_to_nbd_cmd_type(struct request *req)
 
 static struct nbd_config *nbd_get_config_unlocked(struct nbd_device *nbd)
 {
-	if (refcount_inc_not_zero(&nbd->config_refs))
+	if (refcount_inc_not_zero(&nbd->config_refs)) {
+		/*
+		 * Add smp_mb__after_atomic to ensure that reading nbd->config_refs
+		 * and reading nbd->config is ordered. The pair is the barrier in
+		 * nbd_alloc_and_init_config(), avoid nbd->config_refs is set
+		 * before nbd->config.
+		 */
+		smp_mb__after_atomic();
 		return nbd->config;
+	}
 
 	return NULL;
 }
@@ -1563,7 +1571,15 @@ static int nbd_alloc_and_init_config(struct nbd_device *nbd)
 	init_waitqueue_head(&config->conn_wait);
 	config->blksize = NBD_DEF_BLKSIZE;
 	atomic_set(&config->live_connections, 0);
+
 	nbd->config = config;
+	/*
+	 * Order refcount_set(&nbd->config_refs, 1) and nbd->config assignment,
+	 * its pair is the barrier in nbd_get_config_unlocked().
+	 * So nbd_get_config_unlocked() won't see nbd->config as null after
+	 * refcount_inc_not_zero() succeed.
+	 */
+	smp_mb__before_atomic();
 	refcount_set(&nbd->config_refs, 1);
 
 	return 0;