[lxc-devel] [PATCH] overlayfs_mount: create delta dir if it doesn't exist

[Serge Hallyn]

(This *should* fix the lxc-test-snapshot testcase, but doesn't seem
to by itself.)

If it doesn't exist, we may as well start with an empty one.  This
is needed when creating an overlayfs snapshot.

Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
---
 src/lxc/bdev.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/lxc/bdev.c b/src/lxc/bdev.c
index 64e8832..b81827e 100644
--- a/src/lxc/bdev.c
+++ b/src/lxc/bdev.c
@@ -2224,6 +2224,10 @@ static int overlayfs_mount(struct bdev *bdev)
 	*upper = '\0';
 	upper++;
 
+	// if delta doesn't yet exist, create it
+	if (mkdir_p(upper, 0755) < 0 && errno != EEXIST)
+		return -22;
+
 	// overlayfs.v22 or higher needs workdir option
 	// if upper is /var/lib/lxc/c2/delta0,
 	// then workdir is /var/lib/lxc/c2/olwork
-- 
2.5.0