From e3fdf5cc9c60eb97f8520f059ad1a09d3f73509d Mon Sep 17 00:00:00 2001
From: Serge Hallyn <serge.hallyn@ubuntu.com>
Date: Fri, 16 Aug 2013 15:50:25 -0500
Subject: [PATCH] lxc-clone: default to overlaysf for -s clone of dir

If you go to the trouble to request a -s (snapshot) clone of
a container which is dir backingstore, then you deserve an
overlayfs clone.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
---
 src/lxc/bdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/lxc/bdev.c b/src/lxc/bdev.c
index c96ccfe50..60d929033 100644
--- a/src/lxc/bdev.c
+++ b/src/lxc/bdev.c
@@ -1922,6 +1922,12 @@ struct bdev *bdev_copy(const char *src, const char *oldname, const char *cname,
 		}
 	}
 
+	/*
+	 * If newtype is NULL and snapshot is set, then use overlayfs
+	 */
+	if (!bdevtype && snap && strcmp(orig->type , "dir") == 0)
+		bdevtype = "overlayfs";
+
 	new = bdev_get(bdevtype ? bdevtype : orig->type);
 	if (!new) {
 		ERROR("no such block device type: %s", bdevtype ? bdevtype : orig->type);