diff --git a/block/fops.c b/block/fops.c
index f3ff4e62413b..07f4d7336a76 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -714,6 +714,10 @@ blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
 
 static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from)
 {
+	/* Buffered fallback waits for writeback, which NOWAIT cannot allow. */
+	if (iocb->ki_flags & IOCB_NOWAIT)
+		return -EAGAIN;
+
 	return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops, NULL,
 			NULL);
 }