[PATCH] Only verify_io_u on reads

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/verify.c b/verify.c
index 794244a..243b663 100644
--- a/verify.c
+++ b/verify.c
@@ -83,7 +83,7 @@
 	struct verify_header *hdr = (struct verify_header *) io_u->buf;
 	int ret;
 
-	if (td->o.verify == VERIFY_NULL)
+	if (td->o.verify == VERIFY_NULL || io_u->ddir != DDIR_READ)
 		return 0;
 
 	if (hdr->fio_magic != FIO_HDR_MAGIC) {