[lxc-devel] [PATCH] c/r: force users to provide a fresh directory for criu images

[Tycho Andersen]

CRIU can get confused if more than one c/r is done in the same directory, so we
should require lxcapi so that it refuses to dump to a directory with criu
images already in it.

This won't help if the user copies a checkpoint over another, but at least the
common case will be caught.

Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
---
 src/lxc/lxccontainer.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index dbcee99..4a290f1 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -3687,8 +3687,13 @@ static bool do_lxcapi_checkpoint(struct lxc_container *c, char *directory, bool
 	if (!criu_ok(c))
 		return false;
 
-	if (mkdir(directory, 0700) < 0 && errno != EEXIST)
+	if (mkdir(directory, 0700) < 0) {
+		if (errno == EEXIST)
+			ERROR("please use a new directory for criu state");
+		else
+			SYSERROR("mkdir failed");
 		return false;
+	}
 
 	if (!dump_net_info(c, directory))
 		return false;
-- 
2.1.4