common: index and trace-chunk file creation/open API change

[lttng-tools.git] / src / bin / lttng-relayd / live.c

diff --git a/src/bin/lttng-relayd/live.c b/src/bin/lttng-relayd/live.c
index 3ca1797ed9b07b12468840f0bcd963709f72a92b..250d85c6fb39fde7558004f95c198b216b009a6d 100644 (file)
--- a/src/bin/lttng-relayd/live.c
+++ b/src/bin/lttng-relayd/live.c
@@ -309,6 +309,7 @@ static int make_viewer_streams(struct relay_session *session,
        rcu_read_lock();
        cds_lfht_for_each_entry(session->ctf_traces_ht->ht, &iter.iter, ctf_trace,
                        node.node) {
+               bool trace_has_metadata_stream = false;
                struct relay_stream *stream;
 
                health_code_update();
@@ -317,6 +318,30 @@ static int make_viewer_streams(struct relay_session *session,
                        continue;
                }
 
+               /*
+                * Iterate over all the streams of the trace to see if we have a
+                * metadata stream.
+                */
+               cds_list_for_each_entry_rcu(
+                               stream, &ctf_trace->stream_list, stream_node)
+               {
+                       if (stream->is_metadata) {
+                               trace_has_metadata_stream = true;
+                               break;
+                       }
+               }
+
+               /*
+                * If there is no metadata stream in this trace at the moment
+                * and we never sent one to the viewer, skip the trace. We
+                * accept that the viewer will not see this trace at all.
+                */
+               if (!trace_has_metadata_stream &&
+                               !ctf_trace->metadata_stream_sent_to_viewer) {
+                       ctf_trace_put(ctf_trace);
+                       continue;
+               }
+
                cds_list_for_each_entry_rcu(stream, &ctf_trace->stream_list, stream_node) {
                        struct relay_viewer_stream *vstream;
 
@@ -331,6 +356,15 @@ static int make_viewer_streams(struct relay_session *session,
                        }
                        vstream = viewer_stream_get_by_id(stream->stream_handle);
                        if (!vstream) {
+                               /*
+                                * Save that we sent the metadata stream to the
+                                * viewer. So that we know what trace the viewer
+                                * is aware of.
+                                */
+                               if (stream->is_metadata) {
+                                       ctf_trace->metadata_stream_sent_to_viewer =
+                                                       true;
+                               }
                                vstream = viewer_stream_create(stream,
                                                viewer_trace_chunk, seek_t);
                                if (!vstream) {
@@ -1188,6 +1222,7 @@ static int try_open_index(struct relay_viewer_stream *vstream,
        int ret = 0;
        const uint32_t connection_major = rstream->trace->session->major;
        const uint32_t connection_minor = rstream->trace->session->minor;
+       enum lttng_trace_chunk_status chunk_status;
 
        if (vstream->index_file) {
                goto end;
@@ -1200,14 +1235,19 @@ static int try_open_index(struct relay_viewer_stream *vstream,
                ret = -ENOENT;
                goto end;
        }
-       vstream->index_file = lttng_index_file_create_from_trace_chunk_read_only(
+       chunk_status = lttng_index_file_create_from_trace_chunk_read_only(
                        vstream->stream_file.trace_chunk, rstream->path_name,
                        rstream->channel_name, rstream->tracefile_size,
                        vstream->current_tracefile_id,
                        lttng_to_index_major(connection_major, connection_minor),
-                       lttng_to_index_minor(connection_major, connection_minor));
-       if (!vstream->index_file) {
-               ret = -1;
+                       lttng_to_index_minor(connection_major, connection_minor),
+                       true, &vstream->index_file);
+       if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+               if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NO_FILE) {
+                       ret = -ENOENT;
+               } else {
+                       ret = -1;
+               }
        }
 
 end:
@@ -1426,9 +1466,14 @@ int viewer_get_next_index(struct relay_connection *conn)
                        goto error_put;
                }
 
+               /*
+                * It is possible the the file we are trying to open is
+                * missing if the stream has been closed (application exits with
+                * per-pid buffers) and a clear command has been performed.
+                */
                status = lttng_trace_chunk_open_file(
                                vstream->stream_file.trace_chunk,
-                               file_path, O_RDONLY, 0, &fd);
+                               file_path, O_RDONLY, 0, &fd, true);
                if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
                        PERROR("Failed to open trace file for viewer stream");
                        goto error_put;
@@ -1690,7 +1735,23 @@ int viewer_get_metadata(struct relay_connection *conn)
 
        len = vstream->stream->metadata_received - vstream->metadata_sent;
        if (len == 0) {
+               /*
+                * The live viewers expect to receive a NO_NEW_METADATA
+                * status before a stream disappears, otherwise they abort the
+                * entire live connection when receiving an error status.
+                */
                reply.status = htobe32(LTTNG_VIEWER_NO_NEW_METADATA);
+               /*
+                * The live viewer considers a closed 0 byte metadata stream as
+                * an error.
+                */
+               if (vstream->metadata_sent > 0) {
+                       vstream->stream->no_new_metadata_notified = true;
+                       if (vstream->stream->closed) {
+                               /* Release ownership for the viewer metadata stream. */
+                               viewer_stream_put(vstream);
+                       }
+               }
                goto send_reply;
        }
 
@@ -1709,9 +1770,14 @@ int viewer_get_metadata(struct relay_connection *conn)
                        goto error;
                }
 
+               /*
+                * It is possible the the metadata file we are trying to open is
+                * missing if the stream has been closed (application exits with
+                * per-pid buffers) and a clear command has been performed.
+                */
                status = lttng_trace_chunk_open_file(
                                vstream->stream_file.trace_chunk,
-                               file_path, O_RDONLY, 0, &fd);
+                               file_path, O_RDONLY, 0, &fd, true);
                if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
                        PERROR("Failed to open metadata file for viewer stream");
                        goto error;
@@ -1738,12 +1804,6 @@ int viewer_get_metadata(struct relay_connection *conn)
                goto error;
        }
        vstream->metadata_sent += read_len;
-       if (vstream->metadata_sent == vstream->stream->metadata_received
-                       && vstream->stream->closed) {
-               /* Release ownership for the viewer metadata stream. */
-               viewer_stream_put(vstream);
-       }
-
        reply.status = htobe32(LTTNG_VIEWER_METADATA_OK);
 
        goto send_reply;