Fix: consumer: put each chunk on teardown

[lttng-tools.git] / src / common / consumer / consumer.c

diff --git a/src/common/consumer/consumer.c b/src/common/consumer/consumer.c
index 82be751c40ef82e83e47e10e785caa0d131cffbe..a53b7383ec170b279211609043385c8104c6d861 100644 (file)
--- a/src/common/consumer/consumer.c
+++ b/src/common/consumer/consumer.c
@@ -1408,6 +1408,7 @@ void lttng_consumer_cleanup(void)
 {
        struct lttng_ht_iter iter;
        struct lttng_consumer_channel *channel;
+       unsigned int trace_chunks_left;
 
        rcu_read_lock();
 
@@ -1432,6 +1433,27 @@ void lttng_consumer_cleanup(void)
         */
        lttng_ht_destroy(consumer_data.stream_list_ht);
 
+       /*
+        * Trace chunks in the registry may still exist if the session
+        * daemon has encountered an internal error and could not
+        * tear down its sessions and/or trace chunks properly.
+        *
+        * Release the session daemon's implicit reference to any remaining
+        * trace chunk and print an error if any trace chunk was found. Note
+        * that there are _no_ legitimate cases for trace chunks to be left,
+        * it is a leak. However, it can happen following a crash of the
+        * session daemon and not emptying the registry would cause an assertion
+        * to hit.
+        */
+       trace_chunks_left = lttng_trace_chunk_registry_put_each_chunk(
+                       consumer_data.chunk_registry);
+       if (trace_chunks_left) {
+               ERR("%u trace chunks are leaked by lttng-consumerd. "
+                               "This can be caused by an internal error of the session daemon.",
+                               trace_chunks_left);
+       }
+       /* Run all callbacks freeing each chunk. */
+       rcu_barrier();
        lttng_trace_chunk_registry_destroy(consumer_data.chunk_registry);
 }