diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 9f5152b42b0e..ced8687f3b7b 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -152,7 +152,8 @@ extern ssize_t zfcp_fsf_scnprint_fc_security(char *buf, size_t size,
 /* zfcp_qdio.c */
 extern int zfcp_qdio_setup(struct zfcp_adapter *);
 extern void zfcp_qdio_destroy(struct zfcp_qdio *);
-extern int zfcp_qdio_sbal_get(struct zfcp_qdio *);
+extern int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
+	__must_hold(qdio->req_q_lock);
 extern int zfcp_qdio_send(struct zfcp_qdio *, struct zfcp_qdio_req *);
 extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
 				   struct scatterlist *);
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index ce1af72d9b61..bac8385e069f 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -281,6 +281,7 @@ static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
  */
 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
+	__must_hold(qdio->req_q_lock)
 {
 	long ret;