From mboxrd@z Thu Jan 1 00:00:00 1970 From: mathieu.desnoyers@efficios.com (Mathieu Desnoyers) Date: Thu, 5 Dec 2019 01:58:09 -0500 Subject: [lttng-dev] [PATCH babeltrace-1.5 6/6] Fix: lttng-live format: do not error out on empty streams hang up In-Reply-To: <20191205065809.16728-1-mathieu.desnoyers@efficios.com> References: <20191205065809.16728-1-mathieu.desnoyers@efficios.com> Message-ID: <20191205065809.16728-7-mathieu.desnoyers@efficios.com> Attaching to a stream hung up before providing any trace packet causes ctf_open_mmap_stream_read() to return an error. This kind of scenario can happen with the upcoming "lttng clear" feature. Signed-off-by: Mathieu Desnoyers --- formats/ctf/ctf.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/formats/ctf/ctf.c b/formats/ctf/ctf.c index 980ebc9a..1ba9017f 100644 --- a/formats/ctf/ctf.c +++ b/formats/ctf/ctf.c @@ -2571,8 +2571,13 @@ int ctf_open_mmap_stream_read(struct ctf_trace *td, } ret = prepare_mmap_stream_definition(td, file_stream, packet_seek); - if (ret) + if (ret) { + /* We need to check for EOF here for empty files. */ + if (unlikely(file_stream->pos.offset == EOF)) { + ret = 0; + } goto error_index; + } /* * For now, only a single clock per trace is supported. -- 2.17.1