lxccontainer: add reboot2() API extension

src/lxc/commands.c

@@ -909,8 +909,8 @@ int lxc_cmd_add_state_client(const char *name, const char *lxcpath,
 	if (state < 0) {
 		TRACE("%s - Failed to retrieve state of container", strerror(errno));
 		return -1;
-	} else if (states[state]) {
-		TRACE("Container is %s state", lxc_state2str(state));
+	} else if (states[state] == 1) {
+		TRACE("Container is in %s state", lxc_state2str(state));
 		return state;
 	}
 
@@ -1125,7 +1125,7 @@ static void lxc_cmd_fd_cleanup(int fd, struct lxc_handler *handler,
 			       struct lxc_epoll_descr *descr,
 			       const lxc_cmd_t cmd)
 {
-	struct state_client *client;
+	struct lxc_state_client *client;
 	struct lxc_list *cur, *next;
 
 	lxc_console_free(handler->conf, fd);
@@ -1136,7 +1136,7 @@ static void lxc_cmd_fd_cleanup(int fd, struct lxc_handler *handler,
 	}
 
 	process_lock();
-	lxc_list_for_each_safe(cur, &handler->state_clients, next) {
+	lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) {
 		client = cur->elem;
 		if (client->clientfd != fd)
 			continue;

src/lxc/commands_utils.c

@@ -193,7 +193,7 @@ int lxc_cmd_connect(const char *name, const char *lxcpath,
 int lxc_add_state_client(int state_client_fd, struct lxc_handler *handler,
 			 lxc_state_t states[MAX_STATE])
 {
-	struct state_client *newclient;
+	struct lxc_state_client *newclient;
 	struct lxc_list *tmplist;
 
 	newclient = malloc(sizeof(*newclient));
@@ -212,7 +212,7 @@ int lxc_add_state_client(int state_client_fd, struct lxc_handler *handler,
 
 	process_lock();
 	lxc_list_add_elem(tmplist, newclient);
-	lxc_list_add_tail(&handler->state_clients, tmplist);
+	lxc_list_add_tail(&handler->conf->state_clients, tmplist);
 	process_unlock();
 
 	TRACE("added state client %d to state client list", state_client_fd);

src/lxc/conf.c

@@ -2419,6 +2419,7 @@ struct lxc_conf *lxc_conf_init(void)
 	for (i = 0; i < NUM_LXC_HOOKS; i++)
 		lxc_list_init(&new->hooks[i]);
 	lxc_list_init(&new->groups);
+	lxc_list_init(&new->state_clients);
 	new->lsm_aa_profile = NULL;
 	new->lsm_se_context = NULL;
 	new->tmp_umount_proc = 0;

src/lxc/conf.h

@@ -248,6 +248,11 @@ enum lxchooks {
 
 extern char *lxchook_names[NUM_LXC_HOOKS];
 
+struct lxc_state_client {
+	int clientfd;
+	lxc_state_t states[MAX_STATE];
+};
+
 struct lxc_conf {
 	int is_execute;
 	char *fstab;
@@ -363,6 +368,8 @@ struct lxc_conf {
 	/* init working directory */
        char* init_cwd;
 
+	/* A list of clients registered to be informed about a container state. */
+	struct lxc_list state_clients;
 };
 
 int write_id_mapping(enum idtype idtype, pid_t pid, const char *buf,

src/lxc/lxccontainer.c

@@ -1793,6 +1793,73 @@ static bool do_lxcapi_reboot(struct lxc_container *c)
 
 WRAP_API(bool, lxcapi_reboot)
 
+static bool do_lxcapi_reboot2(struct lxc_container *c, int timeout)
+{
+	int killret, ret;
+	pid_t pid;
+	int rebootsignal = SIGINT, state_client_fd = -1;
+	lxc_state_t states[MAX_STATE] = {0};
+
+	if (!c)
+		return false;
+
+	if (!do_lxcapi_is_running(c))
+		return true;
+
+	pid = do_lxcapi_init_pid(c);
+	if (pid <= 0)
+		return true;
+
+	if (c->lxc_conf && c->lxc_conf->rebootsignal)
+		rebootsignal = c->lxc_conf->rebootsignal;
+
+	/* Add a new state client before sending the shutdown signal so that we
+	 * don't miss a state.
+	 */
+	if (timeout != 0) {
+		states[RUNNING] = 2;
+		ret = lxc_cmd_add_state_client(c->name, c->config_path, states,
+					       &state_client_fd);
+		if (ret < 0)
+			return false;
+
+		if (state_client_fd < 0)
+			return false;
+
+		if (ret == RUNNING)
+			return true;
+
+		if (ret < MAX_STATE)
+			return false;
+	}
+
+	/* Send reboot signal to container. */
+	killret = kill(pid, rebootsignal);
+	if (killret < 0) {
+		WARN("Could not send signal %d to pid %d", rebootsignal, pid);
+		if (state_client_fd >= 0)
+			close(state_client_fd);
+		return false;
+	}
+	TRACE("Sent signal %d to pid %d", rebootsignal, pid);
+
+	if (timeout == 0)
+		return true;
+
+	ret = lxc_cmd_sock_rcv_state(state_client_fd, timeout);
+	close(state_client_fd);
+	if (ret < 0)
+		return false;
+
+	TRACE("Received state \"%s\"", lxc_state2str(ret));
+	if (ret != RUNNING)
+		return false;
+
+	return true;
+}
+
+WRAP_API_1(bool, lxcapi_reboot2, int)
+
 static bool do_lxcapi_shutdown(struct lxc_container *c, int timeout)
 {
 	int ret, state_client_fd = -1;
@@ -4595,6 +4662,7 @@ struct lxc_container *lxc_container_new(const char *name, const char *configpath
 	c->createl = lxcapi_createl;
 	c->shutdown = lxcapi_shutdown;
 	c->reboot = lxcapi_reboot;
+	c->reboot2 = lxcapi_reboot2;
 	c->clear_config = lxcapi_clear_config;
 	c->clear_config_item = lxcapi_clear_config_item;
 	c->get_config_item = lxcapi_get_config_item;

src/lxc/lxccontainer.h

@@ -846,6 +846,17 @@ struct lxc_container {
 	 * \return \c 0 on success, nonzero on failure.
 	 */
 	int (*console_log)(struct lxc_container *c, struct lxc_console_log *log);
+
+	/*!
+	 * \brief Request the container reboot by sending it \c SIGINT.
+	 *
+	 * \param c Container.
+	 * \param timeout Seconds to wait before returning false.
+	 *  (-1 to wait forever, 0 to avoid waiting).
+	 *
+	 * \return \c true if the container was rebooted successfully, else \c false.
+	 */
+	bool (*reboot2)(struct lxc_container *c, int timeout);
 };
 
 /*!

src/lxc/start.c

@@ -200,6 +200,9 @@ restart:
 	fddir = dirfd(dir);
 
 	while ((direntp = readdir(dir))) {
+		struct lxc_list *cur;
+		bool matched = false;
+
 		if (!direntp)
 			break;
 
@@ -222,6 +225,20 @@ restart:
 		    (i < len_fds && fd == fds_to_ignore[i]))
 			continue;
 
+		/* Keep state clients that wait on reboots. */
+		lxc_list_for_each(cur, &conf->state_clients) {
+			struct lxc_state_client *client = cur->elem;
+
+			if (client->clientfd != fd)
+				continue;
+
+			matched = true;
+			break;
+		}
+
+		if (matched)
+			continue;
+
 		if (current_config && fd == current_config->logfd)
 			continue;
 
@@ -338,14 +355,14 @@ static int lxc_serve_state_clients(const char *name,
 {
 	ssize_t ret;
 	struct lxc_list *cur, *next;
-	struct state_client *client;
+	struct lxc_state_client *client;
 	struct lxc_msg msg = {.type = lxc_msg_state, .value = state};
 
 	handler->state = state;
 	TRACE("Set container state to %s", lxc_state2str(state));
 
 	process_lock();
-	if (lxc_list_empty(&handler->state_clients)) {
+	if (lxc_list_empty(&handler->conf->state_clients)) {
 		TRACE("No state clients registered");
 		process_unlock();
 		lxc_monitor_send_state(name, state, handler->lxcpath);
@@ -355,10 +372,10 @@ static int lxc_serve_state_clients(const char *name,
 	strncpy(msg.name, name, sizeof(msg.name));
 	msg.name[sizeof(msg.name) - 1] = 0;
 
-	lxc_list_for_each_safe(cur, &handler->state_clients, next) {
+	lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) {
 		client = cur->elem;
 
-		if (!client->states[state]) {
+		if (client->states[state] == 0) {
 			TRACE("State %s not registered for state client %d",
 			      lxc_state2str(state), client->clientfd);
 			continue;
@@ -527,7 +544,8 @@ struct lxc_handler *lxc_init_handler(const char *name, struct lxc_conf *conf,
 	handler->lxcpath = lxcpath;
 	handler->pinfd = -1;
 	handler->state_socket_pair[0] = handler->state_socket_pair[1] = -1;
-	lxc_list_init(&handler->state_clients);
+	if (handler->conf->reboot == 0)
+		lxc_list_init(&handler->conf->state_clients);
 
 	for (i = 0; i < LXC_NS_MAX; i++)
 		handler->nsfd[i] = -1;
@@ -550,10 +568,12 @@ struct lxc_handler *lxc_init_handler(const char *name, struct lxc_conf *conf,
 		      handler->state_socket_pair[1]);
 	}
 
-	handler->conf->maincmd_fd = lxc_cmd_init(name, lxcpath, "command");
-	if (handler->conf->maincmd_fd < 0) {
-		ERROR("Failed to set up command socket");
-		goto on_error;
+	if (handler->conf->reboot == 0) {
+		handler->conf->maincmd_fd = lxc_cmd_init(name, lxcpath, "command");
+		if (handler->conf->maincmd_fd < 0) {
+			ERROR("Failed to set up command socket");
+			goto on_error;
+		}
 	}
 	TRACE("Unix domain socket %d for command server is ready",
 	      handler->conf->maincmd_fd);
@@ -711,9 +731,11 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
 
 	lxc_set_state(name, handler, STOPPED);
 
-	/* close command socket */
-	close(handler->conf->maincmd_fd);
-	handler->conf->maincmd_fd = -1;
+	if (handler->conf->reboot == 0) {
+		/* close command socket */
+		close(handler->conf->maincmd_fd);
+		handler->conf->maincmd_fd = -1;
+	}
 
 	if (run_lxc_hooks(name, "post-stop", handler->conf, handler->lxcpath, NULL)) {
 		ERROR("Failed to run lxc.hook.post-stop for container \"%s\".", name);
@@ -735,8 +757,13 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
 	/* The command socket is now closed, no more state clients can register
 	 * themselves from now on. So free the list of state clients.
 	 */
-	lxc_list_for_each_safe(cur, &handler->state_clients, next) {
-		struct state_client *client = cur->elem;
+	lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) {
+		struct lxc_state_client *client = cur->elem;
+
+		/* Keep state clients that want to be notified about reboots. */
+		if ((handler->conf->reboot > 0) && (client->states[RUNNING] == 2))
+			continue;
+
 		/* close state client socket */
 		close(client->clientfd);
 		lxc_list_del(cur);
@@ -797,9 +824,8 @@ static int do_start(void *data)
 	lxc_sync_fini_parent(handler);
 
 	/* Don't leak the pinfd to the container. */
-	if (handler->pinfd >= 0) {
+	if (handler->pinfd >= 0)
 		close(handler->pinfd);
-	}
 
 	if (lxc_sync_wait_parent(handler, LXC_SYNC_STARTUP))
 		return -1;

src/lxc/start.h

@@ -85,9 +85,6 @@ struct lxc_handler {
 	/* The container's in-memory configuration. */
 	struct lxc_conf *conf;
 
-	/* A list of clients registered to be informed about a container state. */
-	struct lxc_list state_clients;
-
 	/* A set of operations to be performed at various stages of the
 	 * container's life.
 	 */
@@ -110,11 +107,6 @@ struct lxc_operations {
 	int (*post_start)(struct lxc_handler *, void *);
 };
 
-struct state_client {
-	int clientfd;
-	lxc_state_t states[MAX_STATE];
-};
-
 extern int lxc_poll(const char *name, struct lxc_handler *handler);
 extern int lxc_set_state(const char *name, struct lxc_handler *handler, lxc_state_t state);
 extern void lxc_abort(const char *name, struct lxc_handler *handler);

src/lxc/state.c

@@ -45,9 +45,9 @@
 
 lxc_log_define(lxc_state, lxc);
 
-static const char * const strstate[] = {
-	"STOPPED", "STARTING", "RUNNING", "STOPPING",
-	"ABORTING", "FREEZING", "FROZEN", "THAWED",
+static const char *const strstate[] = {
+    "STOPPED",  "STARTING", "RUNNING", "STOPPING",
+    "ABORTING", "FREEZING", "FROZEN",  "THAWED",
 };
 
 const char *lxc_state2str(lxc_state_t state)

src/lxc/tools/lxc_stop.c

@@ -94,62 +94,6 @@ Options :\n\
 	.timeout  = -2,
 };
 
-/* returns -1 on failure, 0 on success */
-static int do_reboot_and_check(struct lxc_arguments *a, struct lxc_container *c)
-{
-	int ret;
-	pid_t pid;
-	pid_t newpid;
-	int timeout = a->timeout;
-
-	pid = c->init_pid(c);
-	if (pid == -1)
-		return -1;
-	if (!c->reboot(c))
-		return -1;
-	if (a->nowait)
-		return 0;
-	if (timeout == 0)
-		goto out;
-
-	for (;;) {
-		/* can we use c-> wait for this, assuming it will
-		 * re-enter RUNNING?  For now just sleep */
-		int elapsed_time, curtime = 0;
-		struct timeval tv;
-
-		newpid = c->init_pid(c);
-		if (newpid != -1 && newpid != pid)
-			return 0;
-
-		if (timeout != -1) {
-			ret = gettimeofday(&tv, NULL);
-			if (ret)
-				break;
-			curtime = tv.tv_sec;
-		}
-
-		sleep(1);
-		if (timeout != -1) {
-			ret = gettimeofday(&tv, NULL);
-			if (ret)
-				break;
-			elapsed_time = tv.tv_sec - curtime;
-			if (timeout - elapsed_time <= 0)
-				break;
-			timeout -= elapsed_time;
-		}
-	}
-
-out:
-	newpid = c->init_pid(c);
-	if (newpid == -1 || newpid == pid) {
-		printf("Reboot did not complete before timeout\n");
-		return -1;
-	}
-	return 0;
-}
-
 int main(int argc, char *argv[])
 {
 	struct lxc_container *c;
@@ -259,7 +203,11 @@ int main(int argc, char *argv[])
 
 	/* reboot */
 	if (my_args.reboot) {
-		ret = do_reboot_and_check(&my_args, c) < 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+		ret = c->reboot2(c, my_args.timeout);
+		if (ret < 0)
+			ret = EXIT_FAILURE;
+		else
+			ret = EXIT_SUCCESS;
 		goto out;
 	}