X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Flive.c;h=f1e440640aa465c9389f8061174e10657fa32a47;hb=4045de2805a4f5f980bbd0af9ca152aff4c691e3;hp=fe7c26d7221c83c1b4ceb06866a773899bde3154;hpb=7a962c33a9c457db2da39bd9834e45e523d78881;p=lttng-tools.git

diff --git a/src/bin/lttng-relayd/live.c b/src/bin/lttng-relayd/live.c
index fe7c26d72..f1e440640 100644
--- a/src/bin/lttng-relayd/live.c
+++ b/src/bin/lttng-relayd/live.c
@@ -374,7 +374,7 @@ static int make_viewer_streams(struct relay_session *relay_session,
 				 * chunk can be used safely.
 				 */
 				if ((relay_stream->ongoing_rotation.is_set ||
-						    relay_session->ongoing_rotation) &&
+						session_has_ongoing_rotation(relay_session)) &&
 						relay_stream->trace_chunk) {
 					viewer_stream_trace_chunk = lttng_trace_chunk_copy(
 							relay_stream->trace_chunk);
@@ -1165,12 +1165,27 @@ int viewer_get_new_streams(struct relay_connection *conn)
 	 * the viewer's point of view.
 	 */
 	pthread_mutex_lock(&session->lock);
+	/*
+	 * If a session rotation is ongoing, do not attempt to open any
+	 * stream, because the chunk can be in an intermediate state
+	 * due to directory renaming.
+	 */
+	if (session_has_ongoing_rotation(session)) {
+		DBG("Relay session %" PRIu64 " rotation ongoing", session_id);
+		response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_NO_NEW);
+		goto send_reply_unlock;
+	}
 	ret = make_viewer_streams(session,
 			conn->viewer_session,
 			LTTNG_VIEWER_SEEK_BEGINNING, &nb_total, &nb_unsent,
 			&nb_created, &closed);
 	if (ret < 0) {
-		goto error_unlock_session;
+		/*
+		 * This is caused by an internal error; propagate the negative
+		 * 'ret' to close the connection.
+		 */
+		response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_ERR);
+		goto send_reply;
 	}
 	send_streams = 1;
 	response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_OK);
@@ -1225,10 +1240,6 @@ end_put_session:
 	}
 error:
 	return ret;
-error_unlock_session:
-	pthread_mutex_unlock(&session->lock);
-	session_put(session);
-	return ret;
 }
 
 /*
@@ -1305,6 +1316,17 @@ int viewer_attach_session(struct relay_connection *conn)
 		goto send_reply;
 	}
 
+	/*
+	 * If a session rotation is ongoing, do not attempt to open any
+	 * stream, because the chunk can be in an intermediate state
+	 * due to directory renaming.
+	 */
+	if (session_has_ongoing_rotation(session)) {
+		DBG("Relay session %" PRIu64 " rotation ongoing", session_id);
+		send_streams = 0;
+		goto send_reply;
+	}
+
 	ret = make_viewer_streams(session,
 			conn->viewer_session, seek_type,
 			&nb_streams, NULL, NULL, &closed);
@@ -1609,6 +1631,13 @@ int viewer_get_next_index(struct relay_connection *conn)
 	metadata_viewer_stream =
 			ctf_trace_get_viewer_metadata_stream(ctf_trace);
 
+	/*
+	 * Hold the session lock to protect against concurrent changes
+	 * to the chunk files (e.g. rename done by clear), which are
+	 * protected by the session ongoing rotation state. Those are
+	 * synchronized with the session lock.
+	 */
+	pthread_mutex_lock(&rstream->trace->session->lock);
 	pthread_mutex_lock(&rstream->lock);
 
 	/*
@@ -1625,7 +1654,7 @@ int viewer_get_next_index(struct relay_connection *conn)
 		goto send_reply;
 	}
 
-	if (rstream->trace->session->ongoing_rotation) {
+	if (session_has_ongoing_rotation(rstream->trace->session)) {
 		/* Rotation is ongoing, try again later. */
 		viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_RETRY);
 		goto send_reply;
@@ -1659,9 +1688,9 @@ int viewer_get_next_index(struct relay_connection *conn)
 	 * This allows clients to consume all the packets of a trace chunk
 	 * after a session's destruction.
 	 */
-	if (conn->viewer_session->current_trace_chunk != vstream->stream_file.trace_chunk &&
+	if (!lttng_trace_chunk_ids_equal(conn->viewer_session->current_trace_chunk, vstream->stream_file.trace_chunk) &&
 			!(rstream->completed_rotation_count == vstream->last_seen_rotation_count + 1 && !rstream->trace_chunk)) {
-		DBG("Viewer session and viewer stream chunk differ: "
+		DBG("Viewer session and viewer stream chunk IDs differ: "
 				"vsession chunk %p vstream chunk %p",
 				conn->viewer_session->current_trace_chunk,
 				vstream->stream_file.trace_chunk);
@@ -1775,6 +1804,7 @@ int viewer_get_next_index(struct relay_connection *conn)
 send_reply:
 	if (rstream) {
 		pthread_mutex_unlock(&rstream->lock);
+		pthread_mutex_unlock(&rstream->trace->session->lock);
 	}
 
 	if (metadata_viewer_stream) {
@@ -1816,6 +1846,7 @@ end:
 
 error_put:
 	pthread_mutex_unlock(&rstream->lock);
+	pthread_mutex_unlock(&rstream->trace->session->lock);
 	if (metadata_viewer_stream) {
 		viewer_stream_put(metadata_viewer_stream);
 	}
@@ -2004,11 +2035,11 @@ int viewer_get_metadata(struct relay_connection *conn)
 		 * an error.
 		 */
 		if (vstream->metadata_sent > 0) {
-			vstream->stream->no_new_metadata_notified = true;
-			if (vstream->stream->closed) {
+			if (vstream->stream->closed && vstream->stream->no_new_metadata_notified) {
 				/* Release ownership for the viewer metadata stream. */
 				viewer_stream_put(vstream);
 			}
+			vstream->stream->no_new_metadata_notified = true;
 		}
 		goto send_reply;
 	}
@@ -2030,8 +2061,8 @@ int viewer_get_metadata(struct relay_connection *conn)
 	}
 
 	if (conn->viewer_session->current_trace_chunk &&
-			conn->viewer_session->current_trace_chunk !=
-					vstream->stream_file.trace_chunk) {
+			!lttng_trace_chunk_ids_equal(conn->viewer_session->current_trace_chunk,
+					vstream->stream_file.trace_chunk)) {
 		bool acquired_reference;
 
 		DBG("Viewer session and viewer stream chunk differ: "