Improve comments after review

[lttng-tools.git] / src / bin / lttng-sessiond / main.c

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index d22e2a63d7d5d96526a7e93b2c2761a0c0894924..195174a4edf259d24e2e0d523f0dd243805e4f01 100644 (file)
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -90,7 +90,6 @@ static struct consumer_data kconsumer_data = {
        .cmd_unix_sock_path = DEFAULT_KCONSUMERD_CMD_SOCK_PATH,
        .err_sock = -1,
        .cmd_sock = -1,
-       .metadata_sock.fd = -1,
        .pid_mutex = PTHREAD_MUTEX_INITIALIZER,
        .lock = PTHREAD_MUTEX_INITIALIZER,
        .cond = PTHREAD_COND_INITIALIZER,
@@ -102,7 +101,6 @@ static struct consumer_data ustconsumer64_data = {
        .cmd_unix_sock_path = DEFAULT_USTCONSUMERD64_CMD_SOCK_PATH,
        .err_sock = -1,
        .cmd_sock = -1,
-       .metadata_sock.fd = -1,
        .pid_mutex = PTHREAD_MUTEX_INITIALIZER,
        .lock = PTHREAD_MUTEX_INITIALIZER,
        .cond = PTHREAD_COND_INITIALIZER,
@@ -114,7 +112,6 @@ static struct consumer_data ustconsumer32_data = {
        .cmd_unix_sock_path = DEFAULT_USTCONSUMERD32_CMD_SOCK_PATH,
        .err_sock = -1,
        .cmd_sock = -1,
-       .metadata_sock.fd = -1,
        .pid_mutex = PTHREAD_MUTEX_INITIALIZER,
        .lock = PTHREAD_MUTEX_INITIALIZER,
        .cond = PTHREAD_COND_INITIALIZER,
@@ -693,9 +690,6 @@ static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
                                        rcu_read_lock();
                                        cds_lfht_for_each_entry(ksess->consumer->socks->ht,
                                                        &iter.iter, socket, node.node) {
-                                               /* Code flow error */
-                                               assert(socket->fd >= 0);
-
                                                pthread_mutex_lock(socket->lock);
                                                ret = kernel_consumer_send_channel_stream(socket,
                                                                channel, ksess,
@@ -730,6 +724,12 @@ static void update_ust_app(int app_sock)
 {
        struct ltt_session *sess, *stmp;
 
+       /* Consumer is in an ERROR state. Stop any application update. */
+       if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
+               /* Stop the update process since the consumer is dead. */
+               return;
+       }
+
        /* For all tracing session(s) */
        cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
                session_lock(sess);
@@ -1019,15 +1019,16 @@ restart:
                /* Connect both socket, command and metadata. */
                consumer_data->cmd_sock =
                        lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
-               consumer_data->metadata_sock.fd =
+               consumer_data->metadata_fd =
                        lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
-               if (consumer_data->cmd_sock < 0 ||
-                               consumer_data->metadata_sock.fd < 0) {
+               if (consumer_data->cmd_sock < 0
+                               || consumer_data->metadata_fd < 0) {
                        PERROR("consumer connect cmd socket");
                        /* On error, signal condition and quit. */
                        signal_consumer_condition(consumer_data, -1);
                        goto error;
                }
+               consumer_data->metadata_sock.fd_ptr = &consumer_data->metadata_fd;
                /* Create metadata socket lock. */
                consumer_data->metadata_sock.lock = zmalloc(sizeof(pthread_mutex_t));
                if (consumer_data->metadata_sock.lock == NULL) {
@@ -1040,7 +1041,7 @@ restart:
                signal_consumer_condition(consumer_data, 1);
                DBG("Consumer command socket ready (fd: %d", consumer_data->cmd_sock);
                DBG("Consumer metadata socket ready (fd: %d)",
-                               consumer_data->metadata_sock.fd);
+                               consumer_data->metadata_fd);
        } else {
                ERR("consumer error when waiting for SOCK_READY : %s",
                                lttcomm_get_readable_code(-code));
@@ -1060,7 +1061,7 @@ restart:
        }
 
        /* Add metadata socket that is successfully connected. */
-       ret = lttng_poll_add(&events, consumer_data->metadata_sock.fd,
+       ret = lttng_poll_add(&events, consumer_data->metadata_fd,
                        LPOLLIN | LPOLLRDHUP);
        if (ret < 0) {
                goto error;
@@ -1119,7 +1120,7 @@ restart_poll:
                                                lttcomm_get_readable_code(-code));
 
                                goto exit;
-                       } else if (pollfd == consumer_data->metadata_sock.fd) {
+                       } else if (pollfd == consumer_data->metadata_fd) {
                                /* UST metadata requests */
                                ret = ust_consumer_metadata_request(
                                                &consumer_data->metadata_sock);
@@ -1138,6 +1139,13 @@ restart_poll:
 
 exit:
 error:
+       /*
+        * We lock here because we are about to close the sockets and some other
+        * thread might be using them so get exclusive access which will abort all
+        * other consumer command by other threads.
+        */
+       pthread_mutex_lock(&consumer_data->lock);
+
        /* Immediately set the consumerd state to stopped */
        if (consumer_data->type == LTTNG_CONSUMER_KERNEL) {
                uatomic_set(&kernel_consumerd_state, CONSUMER_ERROR);
@@ -1163,15 +1171,12 @@ error:
                }
                consumer_data->cmd_sock = -1;
        }
-       if (consumer_data->metadata_sock.fd >= 0) {
-               ret = close(consumer_data->metadata_sock.fd);
+       if (*consumer_data->metadata_sock.fd_ptr >= 0) {
+               ret = close(*consumer_data->metadata_sock.fd_ptr);
                if (ret) {
                        PERROR("close");
                }
        }
-       /* Cleanup metadata socket mutex. */
-       pthread_mutex_destroy(consumer_data->metadata_sock.lock);
-       free(consumer_data->metadata_sock.lock);
 
        if (sock >= 0) {
                ret = close(sock);
@@ -1183,6 +1188,11 @@ error:
        unlink(consumer_data->err_unix_sock_path);
        unlink(consumer_data->cmd_unix_sock_path);
        consumer_data->pid = 0;
+       pthread_mutex_unlock(&consumer_data->lock);
+
+       /* Cleanup metadata socket mutex. */
+       pthread_mutex_destroy(consumer_data->metadata_sock.lock);
+       free(consumer_data->metadata_sock.lock);
 
        lttng_poll_clean(&events);
 error_poll:
@@ -2710,6 +2720,10 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
                break;
        case LTTNG_DOMAIN_UST:
        {
+               if (!ust_app_supported()) {
+                       ret = LTTNG_ERR_NO_UST;
+                       goto error;
+               }
                /* Consumer is in an ERROR state. Report back to client */
                if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
                        ret = LTTNG_ERR_NO_USTCONSUMERD;
@@ -4075,12 +4089,12 @@ static int set_permissions(char *rundir)
        ret = allowed_group();
        if (ret < 0) {
                WARN("No tracing group detected");
-               ret = 0;
-               goto end;
+               /* Setting gid to 0 if no tracing group is found */
+               gid = 0;
+       } else {
+               gid = ret;
        }
 
-       gid = ret;
-
        /* Set lttng run dir */
        ret = chown(rundir, 0, gid);
        if (ret < 0) {
@@ -4088,7 +4102,7 @@ static int set_permissions(char *rundir)
                PERROR("chown");
        }
 
-       /* Ensure tracing group can search the run dir */
+       /* Ensure all applications and tracing group can search the run dir */
        ret = chmod(rundir, S_IRWXU | S_IXGRP | S_IXOTH);
        if (ret < 0) {
                ERR("Unable to set permissions on %s", rundir);
@@ -4125,7 +4139,6 @@ static int set_permissions(char *rundir)
 
        DBG("All permissions are set");
 
-end:
        return ret;
 }