Add 'fsync_on_close' option

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/filesetup.c b/filesetup.c
index 4a5a665..2a7e7cf 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -465,6 +465,9 @@
 	if (--f->references)
 		return;
 
+	if (should_fsync(td) && td->fsync_on_close)
+		fsync(f->fd);
+
 	if (td->io_ops->close_file)
 		td->io_ops->close_file(td, f);
 	td->nr_open_files--;