+end:
+ return ret;
+}
+
+/*
+ * Snapshot the whole metadata.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret = 0;
+ ssize_t write_len;
+ uint64_t total_len = 0;
+ struct lttng_consumer_channel *metadata_channel;
+ struct lttng_consumer_stream *metadata_stream;
+
+ assert(path);
+ assert(ctx);
+
+ DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
+ key, path);
+
+ rcu_read_lock();
+
+ metadata_channel = consumer_find_channel(key);
+ if (!metadata_channel) {
+ ERR("UST snapshot metadata channel not found for key %lu", key);
+ ret = -1;
+ goto error;
+ }
+ assert(!metadata_channel->monitor);
+
+ /*
+ * Ask the sessiond if we have new metadata waiting and update the
+ * consumer metadata cache.
+ */
+ ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * The metadata stream is NOT created in no monitor mode when the channel
+ * is created on a sessiond ask channel command.
+ */
+ ret = create_ust_streams(metadata_channel, ctx);
+ if (ret < 0) {
+ goto error;
+ }
+
+ metadata_stream = metadata_channel->metadata_stream;
+ assert(metadata_stream);
+
+ if (relayd_id != (uint64_t) -1ULL) {
+ metadata_stream->net_seq_idx = relayd_id;
+ ret = consumer_send_relayd_stream(metadata_stream, path);
+ if (ret < 0) {
+ goto error_stream;
+ }
+ } else {
+ ret = utils_create_stream_file(path, metadata_stream->name,
+ metadata_stream->chan->tracefile_size,
+ metadata_stream->tracefile_count_current,
+ metadata_stream->uid, metadata_stream->gid);
+ if (ret < 0) {
+ goto error_stream;
+ }
+ metadata_stream->out_fd = ret;
+ metadata_stream->tracefile_size_current = 0;
+ }
+
+ pthread_mutex_lock(&metadata_channel->metadata_cache->lock);
+ while (total_len < metadata_channel->metadata_cache->total_bytes_written) {
+ /*
+ * Write at most one packet of metadata into the channel
+ * to avoid blocking here.
+ */
+ write_len = ustctl_write_one_packet_to_channel(metadata_channel->uchan,
+ metadata_channel->metadata_cache->data,
+ metadata_channel->metadata_cache->total_bytes_written);
+ if (write_len < 0) {
+ ERR("UST consumer snapshot writing metadata packet");
+ ret = -1;
+ goto error_unlock;
+ }
+ total_len += write_len;
+
+ DBG("Written %" PRIu64 " bytes to metadata (left: %" PRIu64 ")",
+ write_len,
+ metadata_channel->metadata_cache->total_bytes_written - write_len);
+ ustctl_flush_buffer(metadata_stream->ustream, 1);
+ ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ }
+
+error_unlock:
+ pthread_mutex_unlock(&metadata_channel->metadata_cache->lock);
+
+error_stream:
+ /*
+ * Clean up the stream completly because the next snapshot will use a new
+ * metadata stream.
+ */
+ cds_list_del(&metadata_stream->send_node);
+ consumer_stream_destroy(metadata_stream, NULL);
+ metadata_channel->metadata_stream = NULL;
+
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Take a snapshot of all the stream of a channel.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret;
+ unsigned use_relayd = 0;
+ unsigned long consumed_pos, produced_pos;
+ struct lttng_consumer_channel *channel;
+ struct lttng_consumer_stream *stream;
+
+ assert(path);
+ assert(ctx);
+
+ rcu_read_lock();
+
+ if (relayd_id != (uint64_t) -1ULL) {
+ use_relayd = 1;
+ }
+
+ channel = consumer_find_channel(key);
+ if (!channel) {
+ ERR("UST snapshot channel not found for key %lu", key);
+ ret = -1;
+ goto error;
+ }
+ assert(!channel->monitor);
+ DBG("UST consumer snapshot channel %lu", key);
+
+ cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+ /* Lock stream because we are about to change its state. */
+ pthread_mutex_lock(&stream->lock);
+ stream->net_seq_idx = relayd_id;
+
+ if (use_relayd) {
+ ret = consumer_send_relayd_stream(stream, path);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ } else {
+ ret = utils_create_stream_file(path, stream->name,
+ stream->chan->tracefile_size,
+ stream->tracefile_count_current,
+ stream->uid, stream->gid);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ stream->out_fd = ret;
+ stream->tracefile_size_current = 0;
+
+ DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
+ stream->name, stream->key);
+ }
+
+ ustctl_flush_buffer(stream->ustream, 1);
+
+ ret = lttng_ustconsumer_take_snapshot(stream);
+ if (ret < 0) {
+ ERR("Taking UST snapshot");
+ goto error_unlock;
+ }
+
+ ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
+ if (ret < 0) {
+ ERR("Produced UST snapshot position");
+ goto error_unlock;
+ }
+
+ ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
+ if (ret < 0) {
+ ERR("Consumerd UST snapshot position");
+ goto error_unlock;
+ }
+
+ while (consumed_pos < produced_pos) {
+ ssize_t read_len;
+ unsigned long len, padded_len;
+
+ DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
+
+ ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
+ if (ret < 0) {
+ if (ret != -EAGAIN) {
+ PERROR("ustctl_get_subbuf snapshot");
+ goto error_close_stream;
+ }
+ DBG("UST consumer get subbuf failed. Skipping it.");
+ consumed_pos += stream->max_sb_size;
+ continue;
+ }
+
+ ret = ustctl_get_subbuf_size(stream->ustream, &len);
+ if (ret < 0) {
+ ERR("Snapshot ustctl_get_subbuf_size");
+ goto error_put_subbuf;
+ }
+
+ ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
+ if (ret < 0) {
+ ERR("Snapshot ustctl_get_padded_subbuf_size");
+ goto error_put_subbuf;
+ }
+
+ read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
+ padded_len - len);
+ if (use_relayd) {
+ if (read_len != len) {
+ ret = -1;
+ goto error_put_subbuf;
+ }
+ } else {
+ if (read_len != padded_len) {
+ ret = -1;
+ goto error_put_subbuf;
+ }
+ }
+
+ ret = ustctl_put_subbuf(stream->ustream);
+ if (ret < 0) {
+ ERR("Snapshot ustctl_put_subbuf");
+ goto error_close_stream;
+ }
+ consumed_pos += stream->max_sb_size;
+ }
+
+ /* Simply close the stream so we can use it on the next snapshot. */
+ consumer_stream_close(stream);
+ pthread_mutex_unlock(&stream->lock);
+ }
+
+ rcu_read_unlock();
+ return 0;
+
+error_put_subbuf:
+ if (ustctl_put_subbuf(stream->ustream) < 0) {
+ ERR("Snapshot ustctl_put_subbuf");
+ }
+error_close_stream:
+ consumer_stream_close(stream);
+error_unlock:
+ pthread_mutex_unlock(&stream->lock);
+error:
+ rcu_read_unlock();
projects / lttng-tools.git / commitdiff
