console: adapt lxc_console_mainloop_add()

src/lxc/console.c

@@ -269,31 +269,25 @@ static int lxc_console_mainloop_add_peer(struct lxc_console *console)
 	return 0;
 }
 
-extern int lxc_console_mainloop_add(struct lxc_epoll_descr *descr,
-				    struct lxc_conf *conf)
+int lxc_console_mainloop_add(struct lxc_epoll_descr *descr,
+			     struct lxc_console *console)
 {
 	int ret;
-	struct lxc_console *console = &conf->console;
-
-	if (!conf->rootfs.path) {
-		INFO("no rootfs, no console.");
-		return 0;
-	}
 
 	if (console->master < 0) {
 		INFO("no console");
 		return 0;
 	}
 
-	if (lxc_mainloop_add_handler(descr, console->master,
-				     lxc_console_cb_con, console)) {
-		ERROR("failed to add to mainloop console handler for '%d'",
-		      console->master);
+	ret = lxc_mainloop_add_handler(descr, console->master,
+				       lxc_console_cb_con, console);
+	if (ret < 0) {
+		ERROR("Failed to add handler for %d to mainloop", console->master);
 		return -1;
 	}
 
-	/* we cache the descr so that we can add an fd to it when someone
-	 * does attach to it in lxc_console_allocate()
+	/* We cache the descr so that we can add an fd to it when someone
+	 * does attach to it in lxc_console_allocate().
 	 */
 	console->descr = descr;
 	ret = lxc_console_mainloop_add_peer(console);

src/lxc/console.h

@@ -114,7 +114,7 @@ extern void lxc_console_free(struct lxc_conf *conf, int fd);
 /*
  * Register pty event handlers in an open mainloop
  */
-extern int  lxc_console_mainloop_add(struct lxc_epoll_descr *, struct lxc_conf *);
+extern int  lxc_console_mainloop_add(struct lxc_epoll_descr *, struct lxc_console *);
 
 /*
  * Handle SIGWINCH events on the allocated ptys.

src/lxc/start.c

@@ -459,6 +459,7 @@ int lxc_set_state(const char *name, struct lxc_handler *handler,
 int lxc_poll(const char *name, struct lxc_handler *handler)
 {
 	int ret;
+	bool has_console = (handler->conf->rootfs.path != NULL);
 	struct lxc_epoll_descr descr, descr_console;
 
 	ret = lxc_mainloop_open(&descr);
@@ -467,11 +468,13 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
 		goto out_sigfd;
 	}
 
+	if (has_console) {
 		ret = lxc_mainloop_open(&descr_console);
 		if (ret < 0) {
 			ERROR("Failed to create console mainloop");
 			goto out_mainloop;
 		}
+	}
 
 	ret = lxc_mainloop_add_handler(&descr, handler->sigfd, signal_handler, handler);
 	if (ret < 0) {
@@ -479,12 +482,6 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
 		goto out_mainloop_console;
 	}
 
-	ret = lxc_console_mainloop_add(&descr, handler->conf);
-	if (ret < 0) {
-		ERROR("Failed to add console handlers to mainloop");
-		goto out_mainloop_console;
-	}
-
 	if (handler->conf->need_utmp_watch) {
 		#if HAVE_LIBCAP
 		if (lxc_utmp_mainloop_add(&descr, handler)) {
@@ -495,13 +492,22 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
 			DEBUG("Not starting utmp handler as CAP_SYS_BOOT cannot be dropped without capabilities support.");
 		#endif
 	}
-	TRACE("lxc mainloop is ready");
 
-	ret = lxc_console_mainloop_add(&descr_console, handler->conf);
+	if (has_console) {
+		struct lxc_console *console = &handler->conf->console;
+
+		ret = lxc_console_mainloop_add(&descr, console);
+		if (ret < 0) {
+			ERROR("Failed to add console handlers to mainloop");
+			goto out_mainloop_console;
+		}
+
+		ret = lxc_console_mainloop_add(&descr_console, console);
 		if (ret < 0) {
 			ERROR("Failed to add console handlers to console mainloop");
 			goto out_mainloop_console;
 		}
+	}
 
 	ret = lxc_cmd_mainloop_add(name, &descr, handler);
 	if (ret < 0) {
@@ -517,15 +523,19 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
 	if (ret < 0 || !handler->init_died)
 		goto out_mainloop;
 
+	if (has_console)
 		ret = lxc_mainloop(&descr_console, 0);
 
+
 out_mainloop:
 	lxc_mainloop_close(&descr);
 	TRACE("Closed mainloop");
 
 out_mainloop_console:
+	if (has_console) {
 		lxc_mainloop_close(&descr_console);
 		TRACE("Closed console mainloop");
+	}
 
 out_sigfd:
 	close(handler->sigfd);

src/lxc/tools/lxc_attach.c

@@ -356,7 +356,7 @@ static int get_pty_on_host(struct lxc_container *c, struct wrapargs *wrap, int *
 		goto err2;
 	}
 
-	if (lxc_console_mainloop_add(&descr, conf) < 0) {
+	if (lxc_console_mainloop_add(&descr, &conf->console) < 0) {
 		fprintf(stderr, "Failed to add handlers to lxc mainloop.\n");
 		goto err3;
 	}