Fix: unhandled prev_seq initial value

The previous sequence number of a stream is initialized to -1ULL
and comparing the current sequence number against it to perform
a rotation will yield unexepected results.

The assumption that the previous sequence number is less than
the current one is assert()'ed on elsewhere.

This case triggers whenever a rotation is performed before the
relay daemon has received a packet for a given stream.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index f68ecdfbcbfe6ab9248c8603676a6a811e59d9aa..e3c070f8ba0330c2c297983456b385be19ad0513 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -1722,7 +1722,8 @@ int try_rotate_stream(struct relay_stream *stream)
                goto end;
        }
 
-       if (stream->prev_seq < stream->rotate_at_seq_num) {
+       if (stream->prev_seq < stream->rotate_at_seq_num ||
+                       stream->prev_seq == -1ULL) {
                DBG("Stream %" PRIu64 " no yet ready for rotation",
                                stream->stream_handle);
                goto end;