+ channel = consumer_find_channel(key);
+ if (!channel) {
+ ERR("Kernel consumer lost packets channel %"
+ PRIu64 " not found", key);
+ count = 0;
+ } else {
+ count = channel->lost_packets;
+ }
+
+ health_code_update();
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &count, sizeof(count));
+ if (ret < 0) {
+ PERROR("send lost packets");
+ goto error_fatal;
+ }
+
+ break;
+ }
+ case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE:
+ {
+ int channel_monitor_pipe;
+
+ ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ /* Successfully received the command's type. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ goto error_fatal;
+ }
+
+ ret = lttcomm_recv_fds_unix_sock(sock, &channel_monitor_pipe,
+ 1);
+ if (ret != sizeof(channel_monitor_pipe)) {
+ ERR("Failed to receive channel monitor pipe");
+ goto error_fatal;
+ }
+
+ DBG("Received channel monitor pipe (%d)", channel_monitor_pipe);
+ ret = consumer_timer_thread_set_channel_monitor_pipe(
+ channel_monitor_pipe);
+ if (!ret) {
+ int flags;
+
+ ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ /* Set the pipe as non-blocking. */
+ ret = fcntl(channel_monitor_pipe, F_GETFL, 0);
+ if (ret == -1) {
+ PERROR("fcntl get flags of the channel monitoring pipe");
+ goto error_fatal;
+ }
+ flags = ret;
+
+ ret = fcntl(channel_monitor_pipe, F_SETFL,
+ flags | O_NONBLOCK);
+ if (ret == -1) {
+ PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe");
+ goto error_fatal;
+ }
+ DBG("Channel monitor pipe set as non-blocking");
+ } else {
+ ret_code = LTTCOMM_CONSUMERD_ALREADY_SET;
+ }
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ goto error_fatal;
+ }
+ break;
+ }
+ case LTTNG_CONSUMER_ROTATE_CHANNEL:
+ {
+ struct lttng_consumer_channel *channel;
+ uint64_t key = msg.u.rotate_channel.key;
+
+ DBG("Consumer rotate channel %" PRIu64, key);
+
+ channel = consumer_find_channel(key);
+ if (!channel) {
+ ERR("Channel %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+ } else {
+ /*
+ * Sample the rotate position of all the streams in this channel.
+ */
+ ret = lttng_consumer_rotate_channel(channel, key,
+ msg.u.rotate_channel.pathname,
+ msg.u.rotate_channel.relayd_id,
+ msg.u.rotate_channel.metadata,
+ msg.u.rotate_channel.new_chunk_id,
+ ctx);
+ if (ret < 0) {
+ ERR("Rotate channel failed");
+ ret_code = LTTCOMM_CONSUMERD_ROTATION_FAIL;
+ }
+
+ health_code_update();
+ }
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ if (channel) {
+ /* Rotate the streams that are ready right now. */
+ ret = lttng_consumer_rotate_ready_streams(
+ channel, key, ctx);
+ if (ret < 0) {
+ ERR("Rotate ready streams failed");
+ }
+ }
+
+ break;
+ }
+ case LTTNG_CONSUMER_ROTATE_RENAME:
+ {
+ DBG("Consumer rename session %" PRIu64 " after rotation, old path = \"%s\", new path = \"%s\"",
+ msg.u.rotate_rename.session_id,
+ msg.u.rotate_rename.old_path,
+ msg.u.rotate_rename.new_path);
+ ret = lttng_consumer_rotate_rename(msg.u.rotate_rename.old_path,
+ msg.u.rotate_rename.new_path,
+ msg.u.rotate_rename.uid,
+ msg.u.rotate_rename.gid,
+ msg.u.rotate_rename.relayd_id);
+ if (ret < 0) {
+ ERR("Rotate rename failed");
+ ret_code = LTTCOMM_CONSUMERD_ROTATE_RENAME_FAILED;
+ }
+
+ health_code_update();
+
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ break;
+ }
+ case LTTNG_CONSUMER_CHECK_ROTATION_PENDING_LOCAL:
+ {
+ int pending;
+ uint32_t pending_reply;
+
+ DBG("Perform local check of pending rotation for session id %" PRIu64,
+ msg.u.check_rotation_pending_local.session_id);
+ pending = lttng_consumer_check_rotation_pending_local(
+ msg.u.check_rotation_pending_local.session_id,
+ msg.u.check_rotation_pending_local.chunk_id);
+ if (pending < 0) {
+ ERR("Local rotation pending check failed with code %i", pending);
+ ret_code = LTTCOMM_CONSUMERD_ROTATION_PENDING_LOCAL_FAILED;
+ } else {
+ pending_reply = !!pending;
+ }
+
+ health_code_update();
+
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
+ if (pending < 0) {
+ /*
+ * An error occured while running the command;
+ * don't send the 'pending' flag as the sessiond
+ * will not read it.
+ */
+ break;
+ }
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &pending_reply,
+ sizeof(pending_reply));
+ if (ret < 0) {
+ PERROR("Failed to send rotation pending return code");
+ goto error_fatal;
+ }
+ break;
+ }
+ case LTTNG_CONSUMER_CHECK_ROTATION_PENDING_RELAY:
+ {
+ int pending;
+ uint32_t pending_reply;
+
+ DBG("Perform relayd check of pending rotation for session id %" PRIu64,
+ msg.u.check_rotation_pending_relay.session_id);
+ pending = lttng_consumer_check_rotation_pending_relay(
+ msg.u.check_rotation_pending_relay.session_id,
+ msg.u.check_rotation_pending_relay.relayd_id,
+ msg.u.check_rotation_pending_relay.chunk_id);
+ if (pending < 0) {
+ ERR("Relayd rotation pending check failed with code %i", pending);
+ ret_code = LTTCOMM_CONSUMERD_ROTATION_PENDING_RELAY_FAILED;
+ } else {
+ pending_reply = !!pending;
+ }
+
+ health_code_update();
+
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
+ if (pending < 0) {
+ /*
+ * An error occured while running the command;
+ * don't send the 'pending' flag as the sessiond
+ * will not read it.
+ */
+ break;
+ }
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &pending_reply,
+ sizeof(pending_reply));
+ if (ret < 0) {
+ PERROR("Failed to send rotation pending return code");
+ goto error_fatal;
+ }
+ break;
+ }
+ case LTTNG_CONSUMER_MKDIR:
+ {
+ DBG("Consumer mkdir %s in session %" PRIu64,
+ msg.u.mkdir.path,
+ msg.u.mkdir.session_id);
+ ret = lttng_consumer_mkdir(msg.u.mkdir.path,
+ msg.u.mkdir.uid,
+ msg.u.mkdir.gid,
+ msg.u.mkdir.relayd_id);
+ if (ret < 0) {
+ ERR("consumer mkdir failed");
+ ret_code = LTTCOMM_CONSUMERD_MKDIR_FAILED;
+ }
+
+ health_code_update();
+
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ break;
+ }
+ default:
+ goto end_nosignal;
+ }
+
+end_nosignal:
+ rcu_read_unlock();
+
+ /*
+ * Return 1 to indicate success since the 0 value can be a socket
+ * shutdown during the recv() or send() call.
+ */
+ health_code_update();
+ return 1;
+
+error_fatal:
+ rcu_read_unlock();
+ /* This will issue a consumer stop. */
+ return -1;
+}
+
+/*
+ * Populate index values of a kernel stream. Values are set in big endian order.
+ *
+ * Return 0 on success or else a negative value.
+ */
+static int get_index_values(struct ctf_packet_index *index, int infd)
+{
+ int ret;
+
+ ret = kernctl_get_timestamp_begin(infd, &index->timestamp_begin);
+ if (ret < 0) {
+ PERROR("kernctl_get_timestamp_begin");
+ goto error;
+ }
+ index->timestamp_begin = htobe64(index->timestamp_begin);
+
+ ret = kernctl_get_timestamp_end(infd, &index->timestamp_end);
+ if (ret < 0) {
+ PERROR("kernctl_get_timestamp_end");
+ goto error;
+ }
+ index->timestamp_end = htobe64(index->timestamp_end);
+
+ ret = kernctl_get_events_discarded(infd, &index->events_discarded);
+ if (ret < 0) {
+ PERROR("kernctl_get_events_discarded");
+ goto error;
+ }
+ index->events_discarded = htobe64(index->events_discarded);
+
+ ret = kernctl_get_content_size(infd, &index->content_size);
+ if (ret < 0) {
+ PERROR("kernctl_get_content_size");
+ goto error;
+ }
+ index->content_size = htobe64(index->content_size);
+
+ ret = kernctl_get_packet_size(infd, &index->packet_size);
+ if (ret < 0) {
+ PERROR("kernctl_get_packet_size");
+ goto error;
+ }
+ index->packet_size = htobe64(index->packet_size);
+
+ ret = kernctl_get_stream_id(infd, &index->stream_id);
+ if (ret < 0) {
+ PERROR("kernctl_get_stream_id");
+ goto error;
+ }
+ index->stream_id = htobe64(index->stream_id);
+
+ ret = kernctl_get_instance_id(infd, &index->stream_instance_id);
+ if (ret < 0) {
+ if (ret == -ENOTTY) {
+ /* Command not implemented by lttng-modules. */
+ index->stream_instance_id = -1ULL;
+ } else {
+ PERROR("kernctl_get_instance_id");
+ goto error;
+ }
+ }
+ index->stream_instance_id = htobe64(index->stream_instance_id);
+
+ ret = kernctl_get_sequence_number(infd, &index->packet_seq_num);
+ if (ret < 0) {
+ if (ret == -ENOTTY) {
+ /* Command not implemented by lttng-modules. */
+ index->packet_seq_num = -1ULL;
+ ret = 0;
+ } else {
+ PERROR("kernctl_get_sequence_number");
+ goto error;
+ }
+ }
+ index->packet_seq_num = htobe64(index->packet_seq_num);
+
+error:
+ return ret;
+}
+/*
+ * Sync metadata meaning request them to the session daemon and snapshot to the
+ * metadata thread can consumer them.
+ *
+ * Metadata stream lock MUST be acquired.
+ *
+ * Return 0 if new metadatda is available, EAGAIN if the metadata stream
+ * is empty or a negative value on error.
+ */
+int lttng_kconsumer_sync_metadata(struct lttng_consumer_stream *metadata)
+{
+ int ret;
+
+ assert(metadata);
+
+ ret = kernctl_buffer_flush(metadata->wait_fd);
+ if (ret < 0) {
+ ERR("Failed to flush kernel stream");
+ goto end;
+ }
+
+ ret = kernctl_snapshot(metadata->wait_fd);
+ if (ret < 0) {
+ if (ret != -EAGAIN) {
+ ERR("Sync metadata, taking kernel snapshot failed.");
+ goto end;
+ }
+ DBG("Sync metadata, no new kernel metadata");
+ /* No new metadata, exit. */
+ ret = ENODATA;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int update_stream_stats(struct lttng_consumer_stream *stream)
+{
+ int ret;
+ uint64_t seq, discarded;
+
+ ret = kernctl_get_sequence_number(stream->wait_fd, &seq);
+ if (ret < 0) {
+ if (ret == -ENOTTY) {
+ /* Command not implemented by lttng-modules. */
+ seq = -1ULL;
+ } else {
+ PERROR("kernctl_get_sequence_number");
+ goto end;
+ }
+ }
+
+ /*
+ * Start the sequence when we extract the first packet in case we don't
+ * start at 0 (for example if a consumer is not connected to the
+ * session immediately after the beginning).
+ */
+ if (stream->last_sequence_number == -1ULL) {
+ stream->last_sequence_number = seq;
+ } else if (seq > stream->last_sequence_number) {
+ stream->chan->lost_packets += seq -
+ stream->last_sequence_number - 1;
+ } else {
+ /* seq <= last_sequence_number */
+ ERR("Sequence number inconsistent : prev = %" PRIu64
+ ", current = %" PRIu64,
+ stream->last_sequence_number, seq);
+ ret = -1;
+ goto end;
+ }
+ stream->last_sequence_number = seq;
+
+ ret = kernctl_get_events_discarded(stream->wait_fd, &discarded);
+ if (ret < 0) {
+ PERROR("kernctl_get_events_discarded");
+ goto end;
+ }
+ if (discarded < stream->last_discarded_events) {
+ /*
+ * Overflow has occurred. We assume only one wrap-around
+ * has occurred.
+ */
+ stream->chan->discarded_events += (1ULL << (CAA_BITS_PER_LONG - 1)) -
+ stream->last_discarded_events + discarded;
+ } else {
+ stream->chan->discarded_events += discarded -
+ stream->last_discarded_events;
+ }
+ stream->last_discarded_events = discarded;
+ ret = 0;
+
+end:
+ return ret;
+}
+
+/*
+ * Check if the local version of the metadata stream matches with the version
+ * of the metadata stream in the kernel. If it was updated, set the reset flag
+ * on the stream.
+ */
+static
+int metadata_stream_check_version(int infd, struct lttng_consumer_stream *stream)
+{
+ int ret;
+ uint64_t cur_version;
+
+ ret = kernctl_get_metadata_version(infd, &cur_version);
+ if (ret < 0) {
+ if (ret == -ENOTTY) {
+ /*
+ * LTTng-modules does not implement this
+ * command.
+ */
+ ret = 0;
+ goto end;
+ }
+ ERR("Failed to get the metadata version");
+ goto end;
+ }
+
+ if (stream->metadata_version == cur_version) {
+ ret = 0;
+ goto end;
+ }
+
+ DBG("New metadata version detected");
+ stream->metadata_version = cur_version;
+ stream->reset_metadata_flag = 1;
+ ret = 0;
+
+end:
+ return ret;
+}
+
+/*
+ * Consume data on a file descriptor and write it on a trace file.
+ */
+ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
+ struct lttng_consumer_local_data *ctx, bool *rotated)
+{
+ unsigned long len, subbuf_size, padding;
+ int err, write_index = 1, rotation_ret;
+ ssize_t ret = 0;
+ int infd = stream->wait_fd;
+ struct ctf_packet_index index;
+
+ DBG("In read_subbuffer (infd : %d)", infd);
+
+ /*
+ * If the stream was flagged to be ready for rotation before we extract the
+ * next packet, rotate it now.
+ */
+ if (stream->rotate_ready) {
+ DBG("Rotate stream before extracting data");
+ rotation_ret = lttng_consumer_rotate_stream(ctx, stream, rotated);
+ if (rotation_ret < 0) {
+ ERR("Stream rotation error");
+ ret = -1;
+ goto error;
+ }
+ }
+
+ /* Get the next subbuffer */
+ err = kernctl_get_next_subbuf(infd);
+ if (err != 0) {
+ /*
+ * This is a debug message even for single-threaded consumer,
+ * because poll() have more relaxed criterions than get subbuf,
+ * so get_subbuf may fail for short race windows where poll()
+ * would issue wakeups.
+ */
+ DBG("Reserving sub buffer failed (everything is normal, "
+ "it is due to concurrency)");
+ ret = err;
+ goto error;
+ }
+
+ /* Get the full subbuffer size including padding */
+ err = kernctl_get_padded_subbuf_size(infd, &len);
+ if (err != 0) {
+ PERROR("Getting sub-buffer len failed.");
+ err = kernctl_put_subbuf(infd);
+ if (err != 0) {
+ if (err == -EFAULT) {
+ PERROR("Error in unreserving sub buffer\n");
+ } else if (err == -EIO) {
+ /* Should never happen with newer LTTng versions */
+ PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
+ }
+ ret = err;
+ goto error;
+ }
+ ret = err;
+ goto error;
+ }
+
+ if (!stream->metadata_flag) {
+ ret = get_index_values(&index, infd);
+ if (ret < 0) {
+ err = kernctl_put_subbuf(infd);
+ if (err != 0) {
+ if (err == -EFAULT) {
+ PERROR("Error in unreserving sub buffer\n");
+ } else if (err == -EIO) {
+ /* Should never happen with newer LTTng versions */
+ PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
+ }
+ ret = err;
+ goto error;
+ }
+ goto error;
+ }
+ ret = update_stream_stats(stream);
+ if (ret < 0) {
+ err = kernctl_put_subbuf(infd);
+ if (err != 0) {
+ if (err == -EFAULT) {
+ PERROR("Error in unreserving sub buffer\n");
+ } else if (err == -EIO) {
+ /* Should never happen with newer LTTng versions */
+ PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
+ }
+ ret = err;
+ goto error;
+ }
+ goto error;
+ }
+ } else {
+ write_index = 0;
+ ret = metadata_stream_check_version(infd, stream);
+ if (ret < 0) {
+ err = kernctl_put_subbuf(infd);
+ if (err != 0) {
+ if (err == -EFAULT) {
+ PERROR("Error in unreserving sub buffer\n");
+ } else if (err == -EIO) {
+ /* Should never happen with newer LTTng versions */
+ PERROR("Reader has been pushed by the writer, last sub-buffer corrupted.");
+ }
+ ret = err;
+ goto error;
+ }
+ goto error;
+ }
+ }
+
+ switch (stream->chan->output) {
+ case CONSUMER_CHANNEL_SPLICE:
+ /*
+ * XXX: The lttng-modules splice "actor" does not handle copying
+ * partial pages hence only using the subbuffer size without the
+ * padding makes the splice fail.