+ } else {
+ subbuf->info.data.stream_instance_id.is_set = true;
+ }
+end:
+ return ret;
+}
+
+static
+int get_subbuffer_common(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ int ret;
+
+ ret = kernctl_get_next_subbuf(stream->wait_fd);
+ if (ret) {
+ goto end;
+ }
+
+ ret = stream->read_subbuffer_ops.extract_subbuffer_info(
+ stream, subbuffer);
+end:
+ return ret;
+}
+
+static
+int get_next_subbuffer_splice(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ int ret;
+
+ ret = get_subbuffer_common(stream, subbuffer);
+ if (ret) {
+ goto end;
+ }
+
+ subbuffer->buffer.fd = stream->wait_fd;
+end:
+ return ret;
+}
+
+static
+int get_next_subbuffer_mmap(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ int ret;
+ const char *addr;
+
+ ret = get_subbuffer_common(stream, subbuffer);
+ if (ret) {
+ goto end;
+ }
+
+ ret = get_current_subbuf_addr(stream, &addr);
+ if (ret) {
+ goto end;
+ }
+
+ subbuffer->buffer.buffer = lttng_buffer_view_init(
+ addr, 0, subbuffer->info.data.padded_subbuf_size);
+end:
+ return ret;
+}
+
+static
+int get_next_subbuffer_metadata_check(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ int ret;
+ const char *addr;
+ bool coherent;
+
+ ret = kernctl_get_next_subbuf_metadata_check(stream->wait_fd,
+ &coherent);
+ if (ret) {
+ goto end;
+ }
+
+ ret = stream->read_subbuffer_ops.extract_subbuffer_info(
+ stream, subbuffer);
+ if (ret) {
+ goto end;
+ }
+
+ LTTNG_OPTIONAL_SET(&subbuffer->info.metadata.coherent, coherent);
+
+ ret = get_current_subbuf_addr(stream, &addr);
+ if (ret) {
+ goto end;
+ }
+
+ subbuffer->buffer.buffer = lttng_buffer_view_init(
+ addr, 0, subbuffer->info.data.padded_subbuf_size);
+ DBG("Got metadata packet with padded_subbuf_size = %lu, coherent = %s",
+ subbuffer->info.metadata.padded_subbuf_size,
+ coherent ? "true" : "false");
+end:
+ return ret;
+}
+
+static
+int put_next_subbuffer(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ const int ret = kernctl_put_next_subbuf(stream->wait_fd);
+
+ if (ret) {
+ if (ret == -EFAULT) {
+ PERROR("Error in unreserving sub buffer");
+ } else if (ret == -EIO) {
+ /* Should never happen with newer LTTng versions */
+ PERROR("Reader has been pushed by the writer, last sub-buffer corrupted");
+ }
+ }