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 7622a22537738b2164f57d8fb15caf0b46963606..aae56f90cf8e0765f6b95d65a375f06a5f1891fe 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -480,7 +480,8 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                                msg.u.channel.tracefile_size,
                                msg.u.channel.tracefile_count, 0,
                                msg.u.channel.monitor,
-                               msg.u.channel.live_timer_interval);
+                               msg.u.channel.live_timer_interval,
+                               NULL, NULL);
                if (new_channel == NULL) {
                        lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
                        goto end_nosignal;
@@ -1218,7 +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;
                }