Add snapshot command to lttng UI

[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 528665a141680d70d94bb979f5c76583bf454790..bcf349f9290476de0268dce0e9a535e331d6dedc 100644 (file)
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -606,10 +606,11 @@ close_sock:
 error:
        if (ret != LTTNG_OK) {
                /*
-                * On error, nullify the consumer sequence index so streams are not
-                * associated with it once sent to the consumer.
+                * The consumer output for this session should not be used anymore
+                * since the relayd connection failed thus making any tracing or/and
+                * streaming not usable.
                 */
-               uatomic_set(&consumer->net_seq_index, -1);
+               consumer->enabled = 0;
        }
        return ret;
 }
@@ -754,7 +755,7 @@ static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
 
        /* Setup kernel consumer socket and send fds to it */
        ret = init_kernel_tracing(ksess);
-       if (ret < 0) {
+       if (ret != 0) {
                ret = LTTNG_ERR_KERN_START_FAIL;
                goto error;
        }
@@ -856,6 +857,15 @@ int cmd_enable_channel(struct ltt_session *session,
 
        DBG("Enabling channel %s for session %s", attr->name, session->name);
 
+       /*
+        * Don't try to enable a channel if the session has been started at
+        * some point in time before. The tracer does not allow it.
+        */
+       if (session->started) {
+               ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
+               goto error;
+       }
+
        rcu_read_lock();
 
        switch (domain->type) {
@@ -876,18 +886,6 @@ int cmd_enable_channel(struct ltt_session *session,
                }
 
                kernel_wait_quiescent(kernel_tracer_fd);
-
-               /*
-                * If the session was previously started, start as well this newly
-                * created kernel session so the events/channels enabled *after* the
-                * start actually work.
-                */
-               if (session->started && !session->kernel_session->started) {
-                       ret = start_kernel_session(session->kernel_session, wpipe);
-                       if (ret != LTTNG_OK) {
-                               goto error;
-                       }
-               }
                break;
        }
        case LTTNG_DOMAIN_UST:
@@ -902,17 +900,6 @@ int cmd_enable_channel(struct ltt_session *session,
                } else {
                        ret = channel_ust_enable(usess, uchan);
                }
-
-               /* Start the UST session if the session was already started. */
-               if (session->started && !usess->start_trace) {
-                       ret = ust_app_start_trace_all(usess);
-                       if (ret < 0) {
-                               ret = LTTNG_ERR_UST_START_FAIL;
-                               goto error;
-                       }
-                       ret = LTTNG_OK;
-                       usess->start_trace = 1;
-               }
                break;
        }
        default:
@@ -1076,7 +1063,7 @@ error:
 int cmd_add_context(struct ltt_session *session, int domain,
                char *channel_name, struct lttng_event_context *ctx, int kwpipe)
 {
-       int ret;
+       int ret, chan_kern_created = 0, chan_ust_created = 0;
 
        switch (domain) {
        case LTTNG_DOMAIN_KERNEL:
@@ -1088,6 +1075,7 @@ int cmd_add_context(struct ltt_session *session, int domain,
                        if (ret != LTTNG_OK) {
                                goto error;
                        }
+                       chan_kern_created = 1;
                }
 
                /* Add kernel context to kernel tracer */
@@ -1118,6 +1106,7 @@ int cmd_add_context(struct ltt_session *session, int domain,
                                goto error;
                        }
                        free(attr);
+                       chan_ust_created = 1;
                }
 
                ret = context_ust_add(usess, domain, ctx, channel_name);
@@ -1136,9 +1125,30 @@ int cmd_add_context(struct ltt_session *session, int domain,
                goto error;
        }
 
-       ret = LTTNG_OK;
+       return LTTNG_OK;
 
 error:
+       if (chan_kern_created) {
+               struct ltt_kernel_channel *kchan =
+                       trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
+                                       session->kernel_session);
+               /* Created previously, this should NOT fail. */
+               assert(kchan);
+               kernel_destroy_channel(kchan);
+       }
+
+       if (chan_ust_created) {
+               struct ltt_ust_channel *uchan =
+                       trace_ust_find_channel_by_name(
+                                       session->ust_session->domain_global.channels,
+                                       DEFAULT_CHANNEL_NAME);
+               /* Created previously, this should NOT fail. */
+               assert(uchan);
+               /* Remove from the channel list of the session. */
+               trace_ust_delete_channel(session->ust_session->domain_global.channels,
+                               uchan);
+               trace_ust_destroy_channel(uchan);
+       }
        return ret;
 }
 
@@ -1553,7 +1563,7 @@ int cmd_stop_trace(struct ltt_session *session)
        session->enabled = 0;
 
        /* Kernel tracer */
-       if (ksession) {
+       if (ksession && ksession->started) {
                DBG("Stop kernel tracing");
 
                /* Flush metadata if exist */
@@ -1583,7 +1593,7 @@ int cmd_stop_trace(struct ltt_session *session)
                ksession->started = 0;
        }
 
-       if (usess) {
+       if (usess && usess->start_trace) {
                usess->start_trace = 0;
 
                ret = ust_app_stop_trace_all(usess);
@@ -1593,8 +1603,6 @@ int cmd_stop_trace(struct ltt_session *session)
                }
        }
 
-       session->started = 0;
-
        ret = LTTNG_OK;
 
 error:
@@ -1831,7 +1839,7 @@ int cmd_register_consumer(struct ltt_session *session, int domain,
                const char *sock_path, struct consumer_data *cdata)
 {
        int ret, sock;
-       struct consumer_socket *socket;
+       struct consumer_socket *socket = NULL;
 
        assert(session);
        assert(cdata);
@@ -1891,9 +1899,12 @@ int cmd_register_consumer(struct ltt_session *session, int domain,
                goto error;
        }
 
-       ret = LTTNG_OK;
+       return LTTNG_OK;
 
 error:
+       if (socket) {
+               consumer_destroy_socket(socket);
+       }
        return ret;
 }