Merge pull request #906 from tych0/fix-console-none-migration

src/lxc/criu.c

@@ -259,9 +259,10 @@ static void exec_criu(struct criu_opts *opts)
 		DECLARE_ARG("--freeze-cgroup");
 		DECLARE_ARG(log);
 
+		if (opts->tty_id[0]) {
 			DECLARE_ARG("--ext-mount-map");
 			DECLARE_ARG("/dev/console:console");
-		if (opts->tty_id[0]) {
+
 			DECLARE_ARG("--external");
 			DECLARE_ARG(opts->tty_id);
 		}
@@ -289,6 +290,11 @@ static void exec_criu(struct criu_opts *opts)
 		DECLARE_ARG(opts->cgroup_path);
 
 		if (tty_info[0]) {
+			if (opts->console_fd < 0) {
+				ERROR("lxc.console configured on source host but not target");
+				goto err;
+			}
+
 			ret = snprintf(buf, sizeof(buf), "fd[%d]:%s", opts->console_fd, tty_info);
 			if (ret < 0 || ret >= sizeof(buf))
 				goto err;
@@ -623,12 +629,13 @@ void do_restore(struct lxc_container *c, int status_pipe, char *directory, bool
 		os.cgroup_path = cgroup_canonical_path(handler);
 		os.console_fd = c->lxc_conf->console.slave;
 
+		if (os.console_fd >= 0) {
 			/* Twiddle the FD_CLOEXEC bit. We want to pass this FD to criu
 			 * via --inherit-fd, so we don't want it to close.
 			 */
 			flags = fcntl(os.console_fd, F_GETFD);
 			if (flags < 0) {
-			SYSERROR("F_GETFD failed");
+				SYSERROR("F_GETFD failed: %d", os.console_fd);
 				goto out_fini_handler;
 			}
 
@@ -638,6 +645,7 @@ void do_restore(struct lxc_container *c, int status_pipe, char *directory, bool
 				SYSERROR("F_SETFD failed");
 				goto out_fini_handler;
 			}
+		}
 		os.console_name = c->lxc_conf->console.name;
 
 		/* exec_criu() returning is an error */