Fix: destroy chunk registry on element creation failure

[lttng-tools.git] / src / bin / lttng-relayd / sessiond-trace-chunks.c

diff --git a/src/bin/lttng-relayd/sessiond-trace-chunks.c b/src/bin/lttng-relayd/sessiond-trace-chunks.c
index 31fbb31891dffc03c611bca7489fbb332bcbe281..e7a7d112d93e586ee3ee256bee91a0efb4c09d07 100644 (file)
--- a/src/bin/lttng-relayd/sessiond-trace-chunks.c
+++ b/src/bin/lttng-relayd/sessiond-trace-chunks.c
@@ -112,7 +112,6 @@ void trace_chunk_registry_ht_element_free(struct rcu_head *node)
        struct trace_chunk_registry_ht_element *element =
                        container_of(node, typeof(*element), rcu_node);
 
-       lttng_trace_chunk_registry_destroy(element->trace_chunk_registry);
        free(element);
 }
 
@@ -136,6 +135,7 @@ void trace_chunk_registry_ht_element_release(struct urcu_ref *ref)
                element->sessiond_trace_chunk_registry = NULL;
        }
 
+       lttng_trace_chunk_registry_destroy(element->trace_chunk_registry);
        /* Defered reclaim of the object */
        call_rcu(&element->rcu_node, trace_chunk_registry_ht_element_free);
 }
@@ -213,6 +213,7 @@ int trace_chunk_registry_ht_element_create(
        urcu_ref_init(&new_element->ref);
        cds_lfht_node_init(&new_element->ht_node);
        new_element->trace_chunk_registry = trace_chunk_registry;
+       trace_chunk_registry = NULL;
 
        /* Attempt to publish the new element. */
        rcu_read_lock();
@@ -261,6 +262,7 @@ end:
                ERR("Failed to create trace chunk registry for session daemon {%s}",
                                uuid_str);
        }
+       lttng_trace_chunk_registry_destroy(trace_chunk_registry);
        return ret;
 }
 
@@ -399,6 +401,19 @@ struct lttng_trace_chunk *sessiond_trace_chunk_registry_publish_chunk(
 
         published_chunk = lttng_trace_chunk_registry_publish_chunk(
                        element->trace_chunk_registry, session_id, new_chunk);
+       /*
+        * At this point, two references to the published chunks exist. One
+        * is taken by the registry while the other is being returned to the
+        * caller. In the use case of the relay daemon, the reference held
+        * by the registry itself is undesirable.
+        *
+        * We want the trace chunk to be removed from the registry as soon
+        * as it is not being used by the relay daemon (through a session
+        * or a stream). This differs from the behaviour of the consumer
+        * daemon which relies on an explicit command from the session
+        * daemon to release the registry's reference.
+        */
+       lttng_trace_chunk_put(published_chunk);
 end:
        trace_chunk_registry_ht_element_put(element);
        return published_chunk;