+
+/*
+ * Destroy a ust app data structure and free its memory.
+ */
+void ust_app_destroy(struct ust_app *app)
+{
+ if (!app) {
+ return;
+ }
+
+ call_rcu(&app->pid_n.head, delete_ust_app_rcu);
+}
+
+/*
+ * Take a snapshot for a given UST session. The snapshot is sent to the given
+ * output.
+ *
+ * Returns LTTNG_OK on success or a LTTNG_ERR error code.
+ */
+enum lttng_error_code ust_app_snapshot_record(
+ const struct ltt_ust_session *usess,
+ const struct consumer_output *output, int wait,
+ uint64_t nb_packets_per_stream)
+{
+ int ret = 0;
+ enum lttng_error_code status = LTTNG_OK;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+ char *trace_path = NULL;
+
+ assert(usess);
+ assert(output);
+
+ rcu_read_lock();
+
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct buffer_reg_uid *reg;
+
+ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
+ struct buffer_reg_channel *reg_chan;
+ struct consumer_socket *socket;
+ char pathname[PATH_MAX];
+ size_t consumer_path_offset = 0;
+
+ if (!reg->registry->reg.ust->metadata_key) {
+ /* Skip since no metadata is present */
+ continue;
+ }
+
+ /* Get consumer socket to use to push the metadata.*/
+ socket = consumer_find_socket_by_bitness(reg->bits_per_long,
+ usess->consumer);
+ if (!socket) {
+ status = LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ memset(pathname, 0, sizeof(pathname));
+ ret = snprintf(pathname, sizeof(pathname),
+ DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH,
+ reg->uid, reg->bits_per_long);
+ if (ret < 0) {
+ PERROR("snprintf snapshot path");
+ status = LTTNG_ERR_INVALID;
+ goto error;
+ }
+ /* Free path allowed on previous iteration. */
+ free(trace_path);
+ trace_path = setup_channel_trace_path(usess->consumer, pathname,
+ &consumer_path_offset);
+ if (!trace_path) {
+ status = LTTNG_ERR_INVALID;
+ goto error;
+ }
+ /* Add the UST default trace dir to path. */
+ cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
+ reg_chan, node.node) {
+ status = consumer_snapshot_channel(socket,
+ reg_chan->consumer_key,
+ output, 0, usess->uid,
+ usess->gid, &trace_path[consumer_path_offset], wait,
+ nb_packets_per_stream);
+ if (status != LTTNG_OK) {
+ goto error;
+ }
+ }
+ status = consumer_snapshot_channel(socket,
+ reg->registry->reg.ust->metadata_key, output, 1,
+ usess->uid, usess->gid, &trace_path[consumer_path_offset],
+ wait, 0);
+ if (status != LTTNG_OK) {
+ goto error;
+ }
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct consumer_socket *socket;
+ struct lttng_ht_iter chan_iter;
+ struct ust_app_channel *ua_chan;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+ char pathname[PATH_MAX];
+ size_t consumer_path_offset = 0;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (!ua_sess) {
+ /* Session not associated with this app. */
+ continue;
+ }
+
+ /* Get the right consumer socket for the application. */
+ socket = consumer_find_socket_by_bitness(app->bits_per_long,
+ output);
+ if (!socket) {
+ status = LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Add the UST default trace dir to path. */
+ memset(pathname, 0, sizeof(pathname));
+ ret = snprintf(pathname, sizeof(pathname), DEFAULT_UST_TRACE_DIR "/%s",
+ ua_sess->path);
+ if (ret < 0) {
+ status = LTTNG_ERR_INVALID;
+ PERROR("snprintf snapshot path");
+ goto error;
+ }
+ /* Free path allowed on previous iteration. */
+ free(trace_path);
+ trace_path = setup_channel_trace_path(usess->consumer, pathname,
+ &consumer_path_offset);
+ if (!trace_path) {
+ status = LTTNG_ERR_INVALID;
+ goto error;
+ }
+ cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
+ ua_chan, node.node) {
+ status = consumer_snapshot_channel(socket,
+ ua_chan->key, output, 0,
+ lttng_credentials_get_uid(&ua_sess->effective_credentials),
+ lttng_credentials_get_gid(&ua_sess->effective_credentials),
+ &trace_path[consumer_path_offset], wait,
+ nb_packets_per_stream);
+ switch (status) {
+ case LTTNG_OK:
+ break;
+ case LTTNG_ERR_CHAN_NOT_FOUND:
+ continue;
+ default:
+ goto error;
+ }
+ }
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Skip application.");
+ continue;
+ }
+ status = consumer_snapshot_channel(socket,
+ registry->metadata_key, output, 1,
+ lttng_credentials_get_uid(&ua_sess->effective_credentials),
+ lttng_credentials_get_gid(&ua_sess->effective_credentials),
+ &trace_path[consumer_path_offset], wait, 0);
+ switch (status) {
+ case LTTNG_OK:
+ break;
+ case LTTNG_ERR_CHAN_NOT_FOUND:
+ continue;
+ default:
+ goto error;
+ }
+ }
+ break;
+ }
+ default:
+ assert(0);
+ break;
+ }
+
+error:
+ free(trace_path);
+ rcu_read_unlock();
+ return status;
+}
+
+/*
+ * Return the size taken by one more packet per stream.
+ */
+uint64_t ust_app_get_size_one_more_packet_per_stream(
+ const struct ltt_ust_session *usess, uint64_t cur_nr_packets)
+{
+ uint64_t tot_size = 0;
+ struct ust_app *app;
+ struct lttng_ht_iter iter;
+
+ assert(usess);
+
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct buffer_reg_uid *reg;
+
+ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
+ struct buffer_reg_channel *reg_chan;
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
+ reg_chan, node.node) {
+ if (cur_nr_packets >= reg_chan->num_subbuf) {
+ /*
+ * Don't take channel into account if we
+ * already grab all its packets.
+ */
+ continue;
+ }
+ tot_size += reg_chan->subbuf_size * reg_chan->stream_count;
+ }
+ rcu_read_unlock();
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct ust_app_channel *ua_chan;
+ struct ust_app_session *ua_sess;
+ struct lttng_ht_iter chan_iter;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (!ua_sess) {
+ /* Session not associated with this app. */
+ continue;
+ }
+
+ cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
+ ua_chan, node.node) {
+ if (cur_nr_packets >= ua_chan->attr.num_subbuf) {
+ /*
+ * Don't take channel into account if we
+ * already grab all its packets.
+ */
+ continue;
+ }
+ tot_size += ua_chan->attr.subbuf_size * ua_chan->streams.count;
+ }
+ }
+ rcu_read_unlock();
+ break;
+ }
+ default:
+ assert(0);
+ break;
+ }
+
+ return tot_size;
+}
+
+int ust_app_uid_get_channel_runtime_stats(uint64_t ust_session_id,
+ struct cds_list_head *buffer_reg_uid_list,
+ struct consumer_output *consumer, uint64_t uchan_id,
+ int overwrite, uint64_t *discarded, uint64_t *lost)
+{
+ int ret;
+ uint64_t consumer_chan_key;
+
+ *discarded = 0;
+ *lost = 0;
+
+ ret = buffer_reg_uid_consumer_channel_key(
+ buffer_reg_uid_list, uchan_id, &consumer_chan_key);
+ if (ret < 0) {
+ /* Not found */
+ ret = 0;
+ goto end;
+ }
+
+ if (overwrite) {
+ ret = consumer_get_lost_packets(ust_session_id,
+ consumer_chan_key, consumer, lost);
+ } else {
+ ret = consumer_get_discarded_events(ust_session_id,
+ consumer_chan_key, consumer, discarded);
+ }
+
+end:
+ return ret;
+}
+
+int ust_app_pid_get_channel_runtime_stats(struct ltt_ust_session *usess,
+ struct ltt_ust_channel *uchan,
+ struct consumer_output *consumer, int overwrite,
+ uint64_t *discarded, uint64_t *lost)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_str *ua_chan_node;
+ struct ust_app *app;
+ struct ust_app_session *ua_sess;
+ struct ust_app_channel *ua_chan;
+
+ *discarded = 0;
+ *lost = 0;
+
+ rcu_read_lock();
+ /*
+ * Iterate over every registered applications. Sum counters for
+ * all applications containing requested session and channel.
+ */
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct lttng_ht_iter uiter;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ continue;
+ }
+
+ /* Get channel */
+ lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &uiter);
+ ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
+ /* If the session is found for the app, the channel must be there */
+ assert(ua_chan_node);
+
+ ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
+
+ if (overwrite) {
+ uint64_t _lost;
+
+ ret = consumer_get_lost_packets(usess->id, ua_chan->key,
+ consumer, &_lost);
+ if (ret < 0) {
+ break;
+ }
+ (*lost) += _lost;
+ } else {
+ uint64_t _discarded;
+
+ ret = consumer_get_discarded_events(usess->id,
+ ua_chan->key, consumer, &_discarded);
+ if (ret < 0) {
+ break;
+ }
+ (*discarded) += _discarded;
+ }
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+
+static
+int ust_app_regenerate_statedump(struct ltt_ust_session *usess,
+ struct ust_app *app)
+{
+ int ret = 0;
+ struct ust_app_session *ua_sess;
+
+ DBG("Regenerating the metadata for ust app pid %d", app->pid);
+
+ rcu_read_lock();
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ /* The session is in teardown process. Ignore and continue. */
+ goto end;
+ }
+
+ pthread_mutex_lock(&ua_sess->lock);
+
+ if (ua_sess->deleted) {
+ goto end_unlock;
+ }
+
+ pthread_mutex_lock(&app->sock_lock);
+ ret = ustctl_regenerate_statedump(app->sock, ua_sess->handle);
+ pthread_mutex_unlock(&app->sock_lock);
+
+end_unlock:
+ pthread_mutex_unlock(&ua_sess->lock);
+
+end:
+ rcu_read_unlock();
+ health_code_update();
+ return ret;
+}
+
+/*
+ * Regenerate the statedump for each app in the session.
+ */
+int ust_app_regenerate_statedump_all(struct ltt_ust_session *usess)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ DBG("Regenerating the metadata for all UST apps");
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ if (!app->compatible) {
+ continue;
+ }
+
+ ret = ust_app_regenerate_statedump(usess, app);
+ if (ret < 0) {
+ /* Continue to the next app even on error */
+ continue;
+ }
+ }
+
+ rcu_read_unlock();
+
+ return 0;
+}
+
+/*
+ * Rotate all the channels of a session.
+ *
+ * Return LTTNG_OK on success or else an LTTng error code.
+ */
+enum lttng_error_code ust_app_rotate_session(struct ltt_session *session)
+{
+ int ret;
+ enum lttng_error_code cmd_ret = LTTNG_OK;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+ struct ltt_ust_session *usess = session->ust_session;
+
+ assert(usess);
+
+ rcu_read_lock();
+
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct buffer_reg_uid *reg;
+
+ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
+ struct buffer_reg_channel *reg_chan;
+ struct consumer_socket *socket;
+
+ if (!reg->registry->reg.ust->metadata_key) {
+ /* Skip since no metadata is present */
+ continue;
+ }
+
+ /* Get consumer socket to use to push the metadata.*/
+ socket = consumer_find_socket_by_bitness(reg->bits_per_long,
+ usess->consumer);
+ if (!socket) {
+ cmd_ret = LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Rotate the data channels. */
+ cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
+ reg_chan, node.node) {
+ ret = consumer_rotate_channel(socket,
+ reg_chan->consumer_key,
+ usess->uid, usess->gid,
+ usess->consumer,
+ /* is_metadata_channel */ false);
+ if (ret < 0) {
+ cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
+ goto error;
+ }
+ }
+
+ (void) push_metadata(reg->registry->reg.ust, usess->consumer);
+
+ ret = consumer_rotate_channel(socket,
+ reg->registry->reg.ust->metadata_key,
+ usess->uid, usess->gid,
+ usess->consumer,
+ /* is_metadata_channel */ true);
+ if (ret < 0) {
+ cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
+ goto error;
+ }
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct consumer_socket *socket;
+ struct lttng_ht_iter chan_iter;
+ struct ust_app_channel *ua_chan;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (!ua_sess) {
+ /* Session not associated with this app. */
+ continue;
+ }
+
+ /* Get the right consumer socket for the application. */
+ socket = consumer_find_socket_by_bitness(app->bits_per_long,
+ usess->consumer);
+ if (!socket) {
+ cmd_ret = LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Skip application.");
+ continue;
+ }
+
+ /* Rotate the data channels. */
+ cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
+ ua_chan, node.node) {
+ ret = consumer_rotate_channel(socket,
+ ua_chan->key,
+ lttng_credentials_get_uid(&ua_sess->effective_credentials),
+ lttng_credentials_get_gid(&ua_sess->effective_credentials),
+ ua_sess->consumer,
+ /* is_metadata_channel */ false);
+ if (ret < 0) {
+ /* Per-PID buffer and application going away. */
+ if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
+ continue;
+ cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
+ goto error;
+ }
+ }
+
+ /* Rotate the metadata channel. */
+ (void) push_metadata(registry, usess->consumer);
+ ret = consumer_rotate_channel(socket,
+ registry->metadata_key,
+ lttng_credentials_get_uid(&ua_sess->effective_credentials),
+ lttng_credentials_get_gid(&ua_sess->effective_credentials),
+ ua_sess->consumer,
+ /* is_metadata_channel */ true);
+ if (ret < 0) {
+ /* Per-PID buffer and application going away. */
+ if (ret == -LTTNG_ERR_CHAN_NOT_FOUND)
+ continue;
+ cmd_ret = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
+ goto error;
+ }
+ }
+ break;
+ }
+ default:
+ assert(0);
+ break;
+ }
+
+ cmd_ret = LTTNG_OK;
+
+error:
+ rcu_read_unlock();
+ return cmd_ret;
+}
+
+enum lttng_error_code ust_app_create_channel_subdirectories(
+ const struct ltt_ust_session *usess)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ struct lttng_ht_iter iter;
+ enum lttng_trace_chunk_status chunk_status;
+ char *pathname_index;
+ int fmt_ret;
+
+ assert(usess->current_trace_chunk);
+ rcu_read_lock();
+
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct buffer_reg_uid *reg;
+
+ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
+ fmt_ret = asprintf(&pathname_index,
+ DEFAULT_UST_TRACE_DIR "/" DEFAULT_UST_TRACE_UID_PATH "/" DEFAULT_INDEX_DIR,
+ reg->uid, reg->bits_per_long);
+ if (fmt_ret < 0) {
+ ERR("Failed to format channel index directory");
+ ret = LTTNG_ERR_CREATE_DIR_FAIL;
+ goto error;
+ }
+
+ /*
+ * Create the index subdirectory which will take care
+ * of implicitly creating the channel's path.
+ */
+ chunk_status = lttng_trace_chunk_create_subdirectory(
+ usess->current_trace_chunk,
+ pathname_index);
+ free(pathname_index);
+ if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+ ret = LTTNG_ERR_CREATE_DIR_FAIL;
+ goto error;
+ }
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ struct ust_app *app;
+
+ /*
+ * Create the toplevel ust/ directory in case no apps are running.
+ */
+ chunk_status = lttng_trace_chunk_create_subdirectory(
+ usess->current_trace_chunk,
+ DEFAULT_UST_TRACE_DIR);
+ if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+ ret = LTTNG_ERR_CREATE_DIR_FAIL;
+ goto error;
+ }
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
+ pid_n.node) {
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (!ua_sess) {
+ /* Session not associated with this app. */
+ continue;
+ }
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Skip application.");
+ continue;
+ }
+
+ fmt_ret = asprintf(&pathname_index,
+ DEFAULT_UST_TRACE_DIR "/%s/" DEFAULT_INDEX_DIR,
+ ua_sess->path);
+ if (fmt_ret < 0) {
+ ERR("Failed to format channel index directory");
+ ret = LTTNG_ERR_CREATE_DIR_FAIL;
+ goto error;
+ }
+ /*
+ * Create the index subdirectory which will take care
+ * of implicitly creating the channel's path.
+ */
+ chunk_status = lttng_trace_chunk_create_subdirectory(
+ usess->current_trace_chunk,
+ pathname_index);
+ free(pathname_index);
+ if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+ ret = LTTNG_ERR_CREATE_DIR_FAIL;
+ goto error;
+ }
+ }
+ break;
+ }
+ default:
+ abort();
+ }
+
+ ret = LTTNG_OK;
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Clear all the channels of a session.
+ *
+ * Return LTTNG_OK on success or else an LTTng error code.
+ */
+enum lttng_error_code ust_app_clear_session(struct ltt_session *session)
+{
+ int ret;
+ enum lttng_error_code cmd_ret = LTTNG_OK;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+ struct ltt_ust_session *usess = session->ust_session;
+
+ assert(usess);
+
+ rcu_read_lock();
+
+ if (usess->active) {
+ ERR("Expecting inactive session %s (%" PRIu64 ")", session->name, session->id);
+ cmd_ret = LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct buffer_reg_uid *reg;
+
+ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
+ struct buffer_reg_channel *reg_chan;
+ struct consumer_socket *socket;
+
+ /* Get consumer socket to use to push the metadata.*/
+ socket = consumer_find_socket_by_bitness(reg->bits_per_long,
+ usess->consumer);
+ if (!socket) {
+ cmd_ret = LTTNG_ERR_INVALID;
+ goto error_socket;
+ }
+
+ /* Clear the data channels. */
+ cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
+ reg_chan, node.node) {
+ ret = consumer_clear_channel(socket,
+ reg_chan->consumer_key);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ (void) push_metadata(reg->registry->reg.ust, usess->consumer);
+
+ /*
+ * Clear the metadata channel.
+ * Metadata channel is not cleared per se but we still need to
+ * perform a rotation operation on it behind the scene.
+ */
+ ret = consumer_clear_channel(socket,
+ reg->registry->reg.ust->metadata_key);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct consumer_socket *socket;
+ struct lttng_ht_iter chan_iter;
+ struct ust_app_channel *ua_chan;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (!ua_sess) {
+ /* Session not associated with this app. */
+ continue;
+ }
+
+ /* Get the right consumer socket for the application. */
+ socket = consumer_find_socket_by_bitness(app->bits_per_long,
+ usess->consumer);
+ if (!socket) {
+ cmd_ret = LTTNG_ERR_INVALID;
+ goto error_socket;
+ }
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Skip application.");
+ continue;
+ }
+
+ /* Clear the data channels. */
+ cds_lfht_for_each_entry(ua_sess->channels->ht, &chan_iter.iter,
+ ua_chan, node.node) {
+ ret = consumer_clear_channel(socket, ua_chan->key);
+ if (ret < 0) {
+ /* Per-PID buffer and application going away. */
+ if (ret == -LTTNG_ERR_CHAN_NOT_FOUND) {
+ continue;
+ }
+ goto error;
+ }
+ }
+
+ (void) push_metadata(registry, usess->consumer);
+
+ /*
+ * Clear the metadata channel.
+ * Metadata channel is not cleared per se but we still need to
+ * perform rotation operation on it behind the scene.
+ */
+ ret = consumer_clear_channel(socket, registry->metadata_key);
+ if (ret < 0) {
+ /* Per-PID buffer and application going away. */
+ if (ret == -LTTNG_ERR_CHAN_NOT_FOUND) {
+ continue;
+ }
+ goto error;
+ }
+ }
+ break;
+ }
+ default:
+ assert(0);
+ break;
+ }
+
+ cmd_ret = LTTNG_OK;
+ goto end;
+
+error:
+ switch (-ret) {
+ case LTTCOMM_CONSUMERD_RELAYD_CLEAR_DISALLOWED:
+ cmd_ret = LTTNG_ERR_CLEAR_RELAY_DISALLOWED;
+ break;
+ default:
+ cmd_ret = LTTNG_ERR_CLEAR_FAIL_CONSUMER;
+ }
+
+error_socket:
+end:
+ rcu_read_unlock();
+ return cmd_ret;
+}
+
+/*
+ * This function skips the metadata channel as the begin/end timestamps of a
+ * metadata packet are useless.
+ *
+ * Moreover, opening a packet after a "clear" will cause problems for live
+ * sessions as it will introduce padding that was not part of the first trace
+ * chunk. The relay daemon expects the content of the metadata stream of
+ * successive metadata trace chunks to be strict supersets of one another.
+ *
+ * For example, flushing a packet at the beginning of the metadata stream of
+ * a trace chunk resulting from a "clear" session command will cause the
+ * size of the metadata stream of the new trace chunk to not match the size of
+ * the metadata stream of the original chunk. This will confuse the relay
+ * daemon as the same "offset" in a metadata stream will no longer point
+ * to the same content.
+ */
+enum lttng_error_code ust_app_open_packets(struct ltt_session *session)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ struct lttng_ht_iter iter;
+ struct ltt_ust_session *usess = session->ust_session;
+
+ assert(usess);
+
+ rcu_read_lock();
+
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct buffer_reg_uid *reg;
+
+ cds_list_for_each_entry (
+ reg, &usess->buffer_reg_uid_list, lnode) {
+ struct buffer_reg_channel *reg_chan;
+ struct consumer_socket *socket;
+
+ socket = consumer_find_socket_by_bitness(
+ reg->bits_per_long, usess->consumer);
+ if (!socket) {
+ ret = LTTNG_ERR_FATAL;
+ goto error;
+ }
+
+ cds_lfht_for_each_entry(reg->registry->channels->ht,
+ &iter.iter, reg_chan, node.node) {
+ const int open_ret =
+ consumer_open_channel_packets(
+ socket,
+ reg_chan->consumer_key);
+
+ if (open_ret < 0) {
+ ret = LTTNG_ERR_UNK;
+ goto error;
+ }
+ }
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ struct ust_app *app;
+
+ cds_lfht_for_each_entry (
+ ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ struct consumer_socket *socket;
+ struct lttng_ht_iter chan_iter;
+ struct ust_app_channel *ua_chan;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (!ua_sess) {
+ /* Session not associated with this app. */
+ continue;
+ }
+
+ /* Get the right consumer socket for the application. */
+ socket = consumer_find_socket_by_bitness(
+ app->bits_per_long, usess->consumer);
+ if (!socket) {
+ ret = LTTNG_ERR_FATAL;
+ goto error;
+ }
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Skip application.");
+ continue;
+ }
+
+ cds_lfht_for_each_entry(ua_sess->channels->ht,
+ &chan_iter.iter, ua_chan, node.node) {
+ const int open_ret =
+ consumer_open_channel_packets(
+ socket,
+ ua_chan->key);
+
+ if (open_ret < 0) {
+ /*
+ * Per-PID buffer and application going
+ * away.
+ */
+ if (open_ret == -LTTNG_ERR_CHAN_NOT_FOUND) {
+ continue;
+ }
+
+ ret = LTTNG_ERR_UNK;
+ goto error;
+ }
+ }
+ }
+ break;
+ }
+ default:
+ abort();
+ break;
+ }
+
+error:
+ rcu_read_unlock();
+ return ret;
+}