Fix: relayd: rotation failure for multi-domain session

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

diff --git a/src/bin/lttng-relayd/sessiond-trace-chunks.cpp b/src/bin/lttng-relayd/sessiond-trace-chunks.cpp
index e0c46e34ad4a7436e344b178a1302bd9fd06c64b..18ef586d00c85d62e5b92bfbc083979dc32e5bf6 100644 (file)
--- a/src/bin/lttng-relayd/sessiond-trace-chunks.cpp
+++ b/src/bin/lttng-relayd/sessiond-trace-chunks.cpp
@@ -360,6 +360,7 @@ struct lttng_trace_chunk *sessiond_trace_chunk_registry_publish_chunk(
        char uuid_str[LTTNG_UUID_STR_LEN];
        char chunk_id_str[MAX_INT_DEC_LEN(typeof(chunk_id))] = "-1";
        struct lttng_trace_chunk *published_chunk = NULL;
+       bool trace_chunk_already_published;
 
        lttng_uuid_to_str(sessiond_uuid, uuid_str);
        lttng_uuid_copy(key.sessiond_uuid, sessiond_uuid);
@@ -394,20 +395,29 @@ 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);
+                       element->trace_chunk_registry, session_id, new_chunk,
+                       &trace_chunk_already_published);
        /*
-        * 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.
+        * When the trace chunk is first published, 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.
+        *
+        * In cases where the trace chunk had already been published,
+        * the reference belonging to the sessiond trace chunk
+        * registry instance has already been 'put'. We simply return
+        * the published trace chunk with a reference taken on behalf of the
+        * caller.
         */
-       lttng_trace_chunk_put(published_chunk);
+       if (!trace_chunk_already_published) {
+               lttng_trace_chunk_put(published_chunk);
+       }
 end:
        trace_chunk_registry_ht_element_put(element);
        return published_chunk;