cgroups/freezer: fix and improve cgroup2 freezer implementation

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/commands.c

@@ -1255,6 +1255,72 @@ static int lxc_cmd_unfreeze_callback(int fd, struct lxc_cmd_req *req,
 	return lxc_cmd_rsp_send(fd, &rsp);
 }
 
+int lxc_cmd_freeze(const char *name, const char *lxcpath, int timeout)
+{
+	int ret, stopped;
+	struct lxc_cmd_rr cmd = {
+		.req = {
+			.cmd = LXC_CMD_FREEZE,
+			.data = INT_TO_PTR(timeout),
+		},
+	};
+
+	ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
+	if (ret <= 0 || cmd.rsp.ret < 0)
+		return error_log_errno(errno, "Failed to freeze container");
+
+	return cmd.rsp.ret;
+}
+
+static int lxc_cmd_freeze_callback(int fd, struct lxc_cmd_req *req,
+				   struct lxc_handler *handler,
+				   struct lxc_epoll_descr *descr)
+{
+	int timeout = PTR_TO_INT(req->data);
+	struct lxc_cmd_rsp rsp = {
+	    .ret = -ENOENT,
+	};
+	struct cgroup_ops *ops = handler->cgroup_ops;
+
+	if (ops->cgroup_layout == CGROUP_LAYOUT_UNIFIED)
+		rsp.ret = ops->freeze(ops, timeout);
+
+	return lxc_cmd_rsp_send(fd, &rsp);
+}
+
+int lxc_cmd_unfreeze(const char *name, const char *lxcpath, int timeout)
+{
+	int ret, stopped;
+	struct lxc_cmd_rr cmd = {
+		.req = {
+			.cmd = LXC_CMD_UNFREEZE,
+			.data = INT_TO_PTR(timeout),
+		},
+	};
+
+	ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
+	if (ret <= 0 || cmd.rsp.ret < 0)
+		return error_log_errno(errno, "Failed to unfreeze container");
+
+	return cmd.rsp.ret;
+}
+
+static int lxc_cmd_unfreeze_callback(int fd, struct lxc_cmd_req *req,
+				   struct lxc_handler *handler,
+				   struct lxc_epoll_descr *descr)
+{
+	int timeout = PTR_TO_INT(req->data);
+	struct lxc_cmd_rsp rsp = {
+	    .ret = -ENOENT,
+	};
+	struct cgroup_ops *ops = handler->cgroup_ops;
+
+	if (ops->cgroup_layout == CGROUP_LAYOUT_UNIFIED)
+		rsp.ret = ops->unfreeze(ops, timeout);
+
+	return lxc_cmd_rsp_send(fd, &rsp);
+}
+
 static int lxc_cmd_process(int fd, struct lxc_cmd_req *req,
 			   struct lxc_handler *handler,
 			   struct lxc_epoll_descr *descr)