conf: port state_clients to new list type

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

src/lxc/commands.c

@@ -1905,22 +1905,14 @@ static void lxc_cmd_fd_cleanup(int fd, struct lxc_handler *handler,
 			       const lxc_cmd_t cmd)
 {
 	if (cmd == LXC_CMD_ADD_STATE_CLIENT) {
-		struct lxc_list *cur, *next;
+		struct lxc_state_client *client, *nclient;
-
-		lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) {
-			struct lxc_state_client *client = cur->elem;
 
+		list_for_each_entry_safe(client, nclient, &handler->conf->state_clients, head) {
 			if (client->clientfd != fd)
 				continue;
 
-			/*
+			list_del(&client->head);
-			 * Only kick client from list so it can't be found
+			free(client);
-			 * anymore. The actual close happens, as for all other
-			 * file descriptors, below.
-			 */
-			lxc_list_del(cur);
-			free(cur->elem);
-			free(cur);
 
 			/*
 			 * No need to walk the whole list. If we found the state

src/lxc/commands_utils.c

@@ -168,7 +168,6 @@ int lxc_add_state_client(int state_client_fd, struct lxc_handler *handler,
 			 lxc_state_t states[MAX_STATE])
 {
 	__do_free struct lxc_state_client *newclient = NULL;
-	__do_free struct lxc_list *tmplist = NULL;
 	int state;
 
 	newclient = zalloc(sizeof(*newclient));
@@ -179,14 +178,10 @@ int lxc_add_state_client(int state_client_fd, struct lxc_handler *handler,
 	memcpy(newclient->states, states, sizeof(newclient->states));
 	newclient->clientfd = state_client_fd;
 
-	tmplist = zalloc(sizeof(*tmplist));
-	if (!tmplist)
-		return -ENOMEM;
-
 	state = handler->state;
 	if (states[state] != 1) {
-		lxc_list_add_elem(tmplist, move_ptr(newclient));
+		list_add_tail(&newclient->head, &handler->conf->state_clients);
-		lxc_list_add_tail(&handler->conf->state_clients, move_ptr(tmplist));
+		move_ptr(newclient);
 	} else {
 		TRACE("Container already in requested state");
 		return state;

src/lxc/conf.c

@@ -3395,7 +3395,7 @@ 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);
+	INIT_LIST_HEAD(&new->state_clients);
 	new->lsm_aa_profile = NULL;
 	lxc_list_init(&new->lsm_aa_raw);
 	new->lsm_se_context = NULL;

src/lxc/conf.h

@@ -299,6 +299,7 @@ __hidden extern char *lxchook_names[NUM_LXC_HOOKS];
 struct lxc_state_client {
 	int clientfd;
 	lxc_state_t states[MAX_STATE];
+	struct list_head head;
 };
 
 typedef enum lxc_bpf_devices_rule_t {
@@ -486,7 +487,7 @@ struct lxc_conf {
 	char *init_cwd;
 
 	/* A list of clients registered to be informed about a container state. */
-	struct lxc_list state_clients;
+	struct list_head state_clients;
 
 	/* sysctls */
 	struct lxc_list sysctls;

src/lxc/start.c

@@ -245,6 +245,7 @@ int lxc_check_inherited(struct lxc_conf *conf, bool closeall,
 	DIR *dir;
 	struct dirent *direntp;
 	unsigned int listen_fds_max;
+	struct lxc_state_client *client, *nclient;
 
 	if (conf && conf->close_all_fds)
 		closeall = true;
@@ -267,7 +268,6 @@ restart:
 
 	while ((direntp = readdir(dir))) {
 		int ret;
-		struct lxc_list *cur;
 		bool matched = false;
 
 		if (strequal(direntp->d_name, "."))
@@ -292,9 +292,7 @@ restart:
 
 		/* Keep state clients that wait on reboots. */
 		if (conf) {
-			lxc_list_for_each(cur, &conf->state_clients) {
+			list_for_each_entry_safe(client, nclient, &conf->state_clients, head) {
-				struct lxc_state_client *client = cur->elem;
-
 				if (client->clientfd != fd)
 					continue;
 
@@ -472,10 +470,13 @@ static int signal_handler(int fd, uint32_t events, void *data,
 int lxc_serve_state_clients(const char *name, struct lxc_handler *handler,
 			    lxc_state_t state)
 {
+	struct lxc_msg msg = {
+		.type	= lxc_msg_state,
+		.value	= state,
+	};
 	size_t retlen;
 	ssize_t ret;
-	struct lxc_list *cur, *next;
+	struct lxc_state_client *client, *nclient;
-	struct lxc_msg msg = {.type = lxc_msg_state, .value = state};
 
 	if (state == THAWED)
 		handler->state = RUNNING;
@@ -484,16 +485,14 @@ int lxc_serve_state_clients(const char *name, struct lxc_handler *handler,
 
 	TRACE("Set container state to %s", lxc_state2str(state));
 
-	if (lxc_list_empty(&handler->conf->state_clients))
+	if (list_empty(&handler->conf->state_clients))
 		return log_trace(0, "No state clients registered");
 
 	retlen = strlcpy(msg.name, name, sizeof(msg.name));
 	if (retlen >= sizeof(msg.name))
 		return -E2BIG;
 
-	lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) {
+	list_for_each_entry_safe(client, nclient, &handler->conf->state_clients, head) {
-		struct lxc_state_client *client = cur->elem;
-
 		if (client->states[state] == 0) {
 			TRACE("State %s not registered for state client %d",
 			      lxc_state2str(state), client->clientfd);
@@ -508,10 +507,9 @@ int lxc_serve_state_clients(const char *name, struct lxc_handler *handler,
 			SYSERROR("Failed to send message to client");
 
 		/* kick client from list */
-		lxc_list_del(cur);
+		list_del(&client->head);
 		close(client->clientfd);
-		free(cur->elem);
+		free(client);
-		free(cur);
 	}
 
 	return 0;
@@ -706,7 +704,7 @@ struct lxc_handler *lxc_init_handler(struct lxc_handler *old,
 	handler->state_socket_pair[0] = -EBADF;
 	handler->state_socket_pair[1] = -EBADF;
 	if (handler->conf->reboot == REBOOT_NONE)
-		lxc_list_init(&handler->conf->state_clients);
+		INIT_LIST_HEAD(&handler->conf->state_clients);
 
 	for (lxc_namespace_t idx = 0; idx < LXC_NS_MAX; idx++) {
 		handler->nsfd[idx] = -EBADF;
@@ -915,9 +913,9 @@ void lxc_expose_namespace_environment(const struct lxc_handler *handler)
 void lxc_end(struct lxc_handler *handler)
 {
 	int ret;
-	struct lxc_list *cur, *next;
 	const char *name = handler->name;
 	struct cgroup_ops *cgroup_ops = handler->cgroup_ops;
+	struct lxc_state_client *client, *nclient;
 
 	/* The STOPPING state is there for future cleanup code which can take
 	 * awhile.
@@ -1009,19 +1007,16 @@ void lxc_end(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->conf->state_clients, next) {
+	list_for_each_entry_safe(client, nclient, &handler->conf->state_clients, head) {
-		struct lxc_state_client *client = cur->elem;
-
 		/* Keep state clients that want to be notified about reboots. */
 		if ((handler->conf->reboot > REBOOT_NONE) &&
 		    (client->states[RUNNING] == 2))
 			continue;
 
 		/* close state client socket */
-		lxc_list_del(cur);
+		list_del(&client->head);
 		close(client->clientfd);
-		free(cur->elem);
+		free(client);
-		free(cur);
 	}
 
 	if (handler->conf->ephemeral == 1 && handler->conf->reboot != REBOOT_REQ)