Fix: don't start session if no channel

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

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 6a195e1bdd8352c752ab1b22de82bd08ac573faf..2a61eee064f5af2fa558e73db87f2057fd8eb120 100644 (file)
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -462,9 +462,6 @@ static int init_kernel_tracing(struct ltt_kernel_session *session)
        if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
                cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
                                socket, node.node) {
-                       /* Code flow error */
-                       assert(socket->fd >= 0);
-
                        pthread_mutex_lock(socket->lock);
                        ret = kernel_consumer_send_session(socket, session);
                        pthread_mutex_unlock(socket->lock);
@@ -674,9 +671,6 @@ int cmd_setup_relayd(struct ltt_session *session)
                /* For each consumer socket, send relayd sockets */
                cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
                                socket, node.node) {
-                       /* Code flow error */
-                       assert(socket->fd >= 0);
-
                        pthread_mutex_lock(socket->lock);
                        ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
                                        usess->consumer, socket);
@@ -693,9 +687,6 @@ int cmd_setup_relayd(struct ltt_session *session)
                        && ksess->consumer->enabled) {
                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 = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
                                        ksess->consumer, socket);
@@ -1592,6 +1583,7 @@ error:
 int cmd_start_trace(struct ltt_session *session)
 {
        int ret;
+       unsigned long nb_chan = 0;
        struct ltt_kernel_session *ksession;
        struct ltt_ust_session *usess;
 
@@ -1607,6 +1599,21 @@ int cmd_start_trace(struct ltt_session *session)
                goto error;
        }
 
+       /*
+        * Starting a session without channel is useless since after that it's not
+        * possible to enable channel thus inform the client.
+        */
+       if (usess && usess->domain_global.channels) {
+               nb_chan += lttng_ht_get_count(usess->domain_global.channels);
+       }
+       if (ksession) {
+               nb_chan += ksession->channel_count;
+       }
+       if (!nb_chan) {
+               ret = LTTNG_ERR_NO_CHANNEL;
+               goto error;
+       }
+
        session->enabled = 1;
 
        /* Kernel tracing */
@@ -1965,7 +1972,14 @@ int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
        {
                struct lttng_kernel_calibrate kcalibrate;
 
-               kcalibrate.type = calibrate->type;
+               switch (calibrate->type) {
+               case LTTNG_CALIBRATE_FUNCTION:
+               default:
+                       /* Default and only possible calibrate option. */
+                       kcalibrate.type = LTTNG_KERNEL_CALIBRATE_KRETPROBE;
+                       break;
+               }
+
                ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
                if (ret < 0) {
                        ret = LTTNG_ERR_KERN_ENABLE_FAIL;
@@ -1977,7 +1991,14 @@ int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
        {
                struct lttng_ust_calibrate ucalibrate;
 
-               ucalibrate.type = calibrate->type;
+               switch (calibrate->type) {
+               case LTTNG_CALIBRATE_FUNCTION:
+               default:
+                       /* Default and only possible calibrate option. */
+                       ucalibrate.type = LTTNG_UST_CALIBRATE_TRACEPOINT;
+                       break;
+               }
+
                ret = ust_app_calibrate_glb(&ucalibrate);
                if (ret < 0) {
                        ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
@@ -2027,13 +2048,15 @@ int cmd_register_consumer(struct ltt_session *session, int domain,
                        ret = LTTNG_ERR_CONNECT_FAIL;
                        goto error;
                }
+               cdata->cmd_sock = sock;
 
-               socket = consumer_allocate_socket(sock);
+               socket = consumer_allocate_socket(&cdata->cmd_sock);
                if (socket == NULL) {
                        ret = close(sock);
                        if (ret < 0) {
                                PERROR("close register consumer");
                        }
+                       cdata->cmd_sock = -1;
                        ret = LTTNG_ERR_FATAL;
                        goto error;
                }
@@ -2630,12 +2653,17 @@ static int record_ust_snapshot(struct ltt_ust_session *usess,
 
        ret = ust_app_snapshot_record(usess, output, wait, nb_streams);
        if (ret < 0) {
-               if (ret == -EINVAL) {
+               switch (-ret) {
+               case EINVAL:
                        ret = LTTNG_ERR_INVALID;
-                       goto error_snapshot;
+                       break;
+               case ENODATA:
+                       ret = LTTNG_ERR_SNAPSHOT_NODATA;
+                       break;
+               default:
+                       ret = LTTNG_ERR_SNAPSHOT_FAIL;
+                       break;
                }
-
-               ret = LTTNG_ERR_SNAPSHOT_FAIL;
                goto error_snapshot;
        }