Fix: sessiond vs consumerd push/get metadata deadlock

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

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index e30d21b1ac59e77437ed983e39b5a8ada2e17dff..aae56f90cf8e0765f6b95d65a375f06a5f1891fe 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -1219,7 +1219,22 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                /*
                 * In live, block until all the metadata is sent.
                 */
+               pthread_mutex_lock(&stream->metadata_timer_lock);
+               assert(!stream->missed_metadata_flush);
+               stream->waiting_on_metadata = true;
+               pthread_mutex_unlock(&stream->metadata_timer_lock);
+
                err = consumer_stream_sync_metadata(ctx, stream->session_id);
+
+               pthread_mutex_lock(&stream->metadata_timer_lock);
+               stream->waiting_on_metadata = false;
+               if (stream->missed_metadata_flush) {
+                       stream->missed_metadata_flush = false;
+                       pthread_mutex_unlock(&stream->metadata_timer_lock);
+                       (void) consumer_flush_kernel_index(stream);
+               } else {
+                       pthread_mutex_unlock(&stream->metadata_timer_lock);
+               }
                if (err < 0) {
                        goto end;
                }