+/*
+ * Copyright (C) 2011 Julien Desfossez <julien.desfossez@polymtl.ca>
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <lttng/ust-ctl.h>
+#include <lttng/ust-sigbus.h>
+#include <poll.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <urcu/list.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <bin/lttng-consumerd/health-consumerd.h>
+#include <common/common.h>
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/relayd/relayd.h>
+#include <common/compat/fcntl.h>
+#include <common/compat/endian.h>
+#include <common/consumer/consumer-metadata-cache.h>
+#include <common/consumer/consumer-stream.h>
+#include <common/consumer/consumer-timer.h>
+#include <common/utils.h>
+#include <common/index/index.h>
+#include <common/consumer/consumer.h>
+#include <common/shm.h>
+#include <common/optional.h>
+
+#include "ust-consumer.h"
+
+#define INT_MAX_STR_LEN 12 /* includes \0 */
+
+extern struct lttng_consumer_global_data the_consumer_data;
+extern int consumer_poll_timeout;
+
+LTTNG_EXPORT DEFINE_LTTNG_UST_SIGBUS_STATE();
+
+/*
+ * Free channel object and all streams associated with it. This MUST be used
+ * only and only if the channel has _NEVER_ been added to the global channel
+ * hash table.
+ */
+static void destroy_channel(struct lttng_consumer_channel *channel)
+{
+ struct lttng_consumer_stream *stream, *stmp;
+
+ LTTNG_ASSERT(channel);
+
+ DBG("UST consumer cleaning stream list");
+
+ cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
+ send_node) {
+
+ health_code_update();
+
+ cds_list_del(&stream->send_node);
+ lttng_ust_ctl_destroy_stream(stream->ustream);
+ lttng_trace_chunk_put(stream->trace_chunk);
+ free(stream);
+ }
+
+ /*
+ * If a channel is available meaning that was created before the streams
+ * were, delete it.
+ */
+ if (channel->uchan) {
+ lttng_ustconsumer_del_channel(channel);
+ lttng_ustconsumer_free_channel(channel);
+ }
+
+ if (channel->trace_chunk) {
+ lttng_trace_chunk_put(channel->trace_chunk);
+ }
+
+ free(channel);
+}
+
+/*
+ * Add channel to internal consumer state.
+ *
+ * Returns 0 on success or else a negative value.
+ */
+static int add_channel(struct lttng_consumer_channel *channel,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret = 0;
+
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(ctx);
+
+ if (ctx->on_recv_channel != NULL) {
+ ret = ctx->on_recv_channel(channel);
+ if (ret == 0) {
+ ret = consumer_add_channel(channel, ctx);
+ } else if (ret < 0) {
+ /* Most likely an ENOMEM. */
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
+ goto error;
+ }
+ } else {
+ ret = consumer_add_channel(channel, ctx);
+ }
+
+ DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
+
+error:
+ return ret;
+}
+
+/*
+ * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
+ * error value if applicable is set in it else it is kept untouched.
+ *
+ * Return NULL on error else the newly allocated stream object.
+ */
+static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
+ struct lttng_consumer_channel *channel,
+ struct lttng_consumer_local_data *ctx, int *_alloc_ret)
+{
+ int alloc_ret;
+ struct lttng_consumer_stream *stream = NULL;
+
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(ctx);
+
+ stream = consumer_stream_create(
+ channel,
+ channel->key,
+ key,
+ channel->name,
+ channel->relayd_id,
+ channel->session_id,
+ channel->trace_chunk,
+ cpu,
+ &alloc_ret,
+ channel->type,
+ channel->monitor);
+ if (stream == NULL) {
+ switch (alloc_ret) {
+ case -ENOENT:
+ /*
+ * We could not find the channel. Can happen if cpu hotplug
+ * happens while tearing down.
+ */
+ DBG3("Could not find channel");
+ break;
+ case -ENOMEM:
+ case -EINVAL:
+ default:
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
+ break;
+ }
+ goto error;
+ }
+
+ consumer_stream_update_channel_attributes(stream, channel);
+
+error:
+ if (_alloc_ret) {
+ *_alloc_ret = alloc_ret;
+ }
+ return stream;
+}
+
+/*
+ * Send the given stream pointer to the corresponding thread.
+ *
+ * Returns 0 on success else a negative value.
+ */
+static int send_stream_to_thread(struct lttng_consumer_stream *stream,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret;
+ struct lttng_pipe *stream_pipe;
+
+ /* Get the right pipe where the stream will be sent. */
+ if (stream->metadata_flag) {
+ consumer_add_metadata_stream(stream);
+ stream_pipe = ctx->consumer_metadata_pipe;
+ } else {
+ consumer_add_data_stream(stream);
+ stream_pipe = ctx->consumer_data_pipe;
+ }
+
+ /*
+ * From this point on, the stream's ownership has been moved away from
+ * the channel and it becomes globally visible. Hence, remove it from
+ * the local stream list to prevent the stream from being both local and
+ * global.
+ */
+ stream->globally_visible = 1;
+ cds_list_del(&stream->send_node);
+
+ ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
+ if (ret < 0) {
+ ERR("Consumer write %s stream to pipe %d",
+ stream->metadata_flag ? "metadata" : "data",
+ lttng_pipe_get_writefd(stream_pipe));
+ if (stream->metadata_flag) {
+ consumer_del_stream_for_metadata(stream);
+ } else {
+ consumer_del_stream_for_data(stream);
+ }
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+static
+int get_stream_shm_path(char *stream_shm_path, const char *shm_path, int cpu)
+{
+ char cpu_nr[INT_MAX_STR_LEN]; /* int max len */
+ int ret;
+
+ strncpy(stream_shm_path, shm_path, PATH_MAX);
+ stream_shm_path[PATH_MAX - 1] = '\0';
+ ret = snprintf(cpu_nr, INT_MAX_STR_LEN, "%i", cpu);
+ if (ret < 0) {
+ PERROR("snprintf");
+ goto end;
+ }
+ strncat(stream_shm_path, cpu_nr,
+ PATH_MAX - strlen(stream_shm_path) - 1);
+ ret = 0;
+end:
+ return ret;
+}
+
+/*
+ * Create streams for the given channel using liblttng-ust-ctl.
+ * The channel lock must be acquired by the caller.
+ *
+ * Return 0 on success else a negative value.
+ */
+static int create_ust_streams(struct lttng_consumer_channel *channel,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret, cpu = 0;
+ struct lttng_ust_ctl_consumer_stream *ustream;
+ struct lttng_consumer_stream *stream;
+ pthread_mutex_t *current_stream_lock = NULL;
+
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(ctx);
+
+ /*
+ * While a stream is available from ustctl. When NULL is returned, we've
+ * reached the end of the possible stream for the channel.
+ */
+ while ((ustream = lttng_ust_ctl_create_stream(channel->uchan, cpu))) {
+ int wait_fd;
+ int ust_metadata_pipe[2];
+
+ health_code_update();
+
+ if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
+ ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
+ if (ret < 0) {
+ ERR("Create ust metadata poll pipe");
+ goto error;
+ }
+ wait_fd = ust_metadata_pipe[0];
+ } else {
+ wait_fd = lttng_ust_ctl_stream_get_wait_fd(ustream);
+ }
+
+ /* Allocate consumer stream object. */
+ stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
+ if (!stream) {
+ goto error_alloc;
+ }
+ stream->ustream = ustream;
+ /*
+ * Store it so we can save multiple function calls afterwards since
+ * this value is used heavily in the stream threads. This is UST
+ * specific so this is why it's done after allocation.
+ */
+ stream->wait_fd = wait_fd;
+
+ /*
+ * Increment channel refcount since the channel reference has now been
+ * assigned in the allocation process above.
+ */
+ if (stream->chan->monitor) {
+ uatomic_inc(&stream->chan->refcount);
+ }
+
+ pthread_mutex_lock(&stream->lock);
+ current_stream_lock = &stream->lock;
+ /*
+ * Order is important this is why a list is used. On error, the caller
+ * should clean this list.
+ */
+ cds_list_add_tail(&stream->send_node, &channel->streams.head);
+
+ ret = lttng_ust_ctl_get_max_subbuf_size(stream->ustream,
+ &stream->max_sb_size);
+ if (ret < 0) {
+ ERR("lttng_ust_ctl_get_max_subbuf_size failed for stream %s",
+ stream->name);
+ goto error;
+ }
+
+ /* Do actions once stream has been received. */
+ if (ctx->on_recv_stream) {
+ ret = ctx->on_recv_stream(stream);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
+ stream->name, stream->key, stream->relayd_stream_id);
+
+ /* Set next CPU stream. */
+ channel->streams.count = ++cpu;
+
+ /* Keep stream reference when creating metadata. */
+ if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
+ channel->metadata_stream = stream;
+ if (channel->monitor) {
+ /* Set metadata poll pipe if we created one */
+ memcpy(stream->ust_metadata_poll_pipe,
+ ust_metadata_pipe,
+ sizeof(ust_metadata_pipe));
+ }
+ }
+ pthread_mutex_unlock(&stream->lock);
+ current_stream_lock = NULL;
+ }
+
+ return 0;
+
+error:
+error_alloc:
+ if (current_stream_lock) {
+ pthread_mutex_unlock(current_stream_lock);
+ }
+ return ret;
+}
+
+static int open_ust_stream_fd(struct lttng_consumer_channel *channel, int cpu,
+ const struct lttng_credentials *session_credentials)
+{
+ char shm_path[PATH_MAX];
+ int ret;
+
+ if (!channel->shm_path[0]) {
+ return shm_create_anonymous("ust-consumer");
+ }
+ ret = get_stream_shm_path(shm_path, channel->shm_path, cpu);
+ if (ret) {
+ goto error_shm_path;
+ }
+ return run_as_open(shm_path,
+ O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR,
+ lttng_credentials_get_uid(session_credentials),
+ lttng_credentials_get_gid(session_credentials));
+
+error_shm_path:
+ return -1;
+}
+
+/*
+ * Create an UST channel with the given attributes and send it to the session
+ * daemon using the ust ctl API.
+ *
+ * Return 0 on success or else a negative value.
+ */
+static int create_ust_channel(struct lttng_consumer_channel *channel,
+ struct lttng_ust_ctl_consumer_channel_attr *attr,
+ struct lttng_ust_ctl_consumer_channel **ust_chanp)
+{
+ int ret, nr_stream_fds, i, j;
+ int *stream_fds;
+ struct lttng_ust_ctl_consumer_channel *ust_channel;
+
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(attr);
+ LTTNG_ASSERT(ust_chanp);
+ LTTNG_ASSERT(channel->buffer_credentials.is_set);
+
+ DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
+ "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
+ "switch_timer_interval: %u, read_timer_interval: %u, "
+ "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
+ attr->num_subbuf, attr->switch_timer_interval,
+ attr->read_timer_interval, attr->output, attr->type);
+
+ if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA)
+ nr_stream_fds = 1;
+ else
+ nr_stream_fds = lttng_ust_ctl_get_nr_stream_per_channel();
+ stream_fds = (int *) zmalloc(nr_stream_fds * sizeof(*stream_fds));
+ if (!stream_fds) {
+ ret = -1;
+ goto error_alloc;
+ }
+ for (i = 0; i < nr_stream_fds; i++) {
+ stream_fds[i] = open_ust_stream_fd(channel, i,
+ &channel->buffer_credentials.value);
+ if (stream_fds[i] < 0) {
+ ret = -1;
+ goto error_open;
+ }
+ }
+ ust_channel = lttng_ust_ctl_create_channel(attr, stream_fds, nr_stream_fds);
+ if (!ust_channel) {
+ ret = -1;
+ goto error_create;
+ }
+ channel->nr_stream_fds = nr_stream_fds;
+ channel->stream_fds = stream_fds;
+ *ust_chanp = ust_channel;
+
+ return 0;
+
+error_create:
+error_open:
+ for (j = i - 1; j >= 0; j--) {
+ int closeret;
+
+ closeret = close(stream_fds[j]);
+ if (closeret) {
+ PERROR("close");
+ }
+ if (channel->shm_path[0]) {
+ char shm_path[PATH_MAX];
+
+ closeret = get_stream_shm_path(shm_path,
+ channel->shm_path, j);
+ if (closeret) {
+ ERR("Cannot get stream shm path");
+ }
+ closeret = run_as_unlink(shm_path,
+ lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+ channel->buffer_credentials)),
+ lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+ channel->buffer_credentials)));
+ if (closeret) {
+ PERROR("unlink %s", shm_path);
+ }
+ }
+ }
+ /* Try to rmdir all directories under shm_path root. */
+ if (channel->root_shm_path[0]) {
+ (void) run_as_rmdir_recursive(channel->root_shm_path,
+ lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+ channel->buffer_credentials)),
+ lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+ channel->buffer_credentials)),
+ LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG);
+ }
+ free(stream_fds);
+error_alloc:
+ return ret;
+}
+
+/*
+ * Send a single given stream to the session daemon using the sock.
+ *
+ * Return 0 on success else a negative value.
+ */
+static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(sock >= 0);
+
+ DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
+
+ /* Send stream to session daemon. */
+ ret = lttng_ust_ctl_send_stream_to_sessiond(sock, stream->ustream);
+ if (ret < 0) {
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Send channel to sessiond and relayd if applicable.
+ *
+ * Return 0 on success or else a negative value.
+ */
+static int send_channel_to_sessiond_and_relayd(int sock,
+ struct lttng_consumer_channel *channel,
+ struct lttng_consumer_local_data *ctx, int *relayd_error)
+{
+ int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ struct lttng_consumer_stream *stream;
+ uint64_t net_seq_idx = -1ULL;
+
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(ctx);
+ LTTNG_ASSERT(sock >= 0);
+
+ DBG("UST consumer sending channel %s to sessiond", channel->name);
+
+ if (channel->relayd_id != (uint64_t) -1ULL) {
+ cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+
+ health_code_update();
+
+ /* Try to send the stream to the relayd if one is available. */
+ DBG("Sending stream %" PRIu64 " of channel \"%s\" to relayd",
+ stream->key, channel->name);
+ ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
+ if (ret < 0) {
+ /*
+ * Flag that the relayd was the problem here probably due to a
+ * communicaton error on the socket.
+ */
+ if (relayd_error) {
+ *relayd_error = 1;
+ }
+ ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
+ }
+ if (net_seq_idx == -1ULL) {
+ net_seq_idx = stream->net_seq_idx;
+ }
+ }
+ }
+
+ /* Inform sessiond that we are about to send channel and streams. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
+ /*
+ * Either the session daemon is not responding or the relayd died so we
+ * stop now.
+ */
+ goto error;
+ }
+
+ /* Send channel to sessiond. */
+ ret = lttng_ust_ctl_send_channel_to_sessiond(sock, channel->uchan);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_ust_ctl_channel_close_wakeup_fd(channel->uchan);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* The channel was sent successfully to the sessiond at this point. */
+ cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+
+ health_code_update();
+
+ /* Send stream to session daemon. */
+ ret = send_sessiond_stream(sock, stream);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ /* Tell sessiond there is no more stream. */
+ ret = lttng_ust_ctl_send_stream_to_sessiond(sock, NULL);
+ if (ret < 0) {
+ goto error;
+ }
+
+ DBG("UST consumer NULL stream sent to sessiond");
+
+ return 0;
+
+error:
+ if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
+ ret = -1;
+ }
+ return ret;
+}
+
+/*
+ * Creates a channel and streams and add the channel it to the channel internal
+ * state. The created stream must ONLY be sent once the GET_CHANNEL command is
+ * received.
+ *
+ * Return 0 on success or else, a negative value is returned and the channel
+ * MUST be destroyed by consumer_del_channel().
+ */
+static int ask_channel(struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_channel *channel,
+ struct lttng_ust_ctl_consumer_channel_attr *attr)
+{
+ int ret;
+
+ LTTNG_ASSERT(ctx);
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(attr);
+
+ /*
+ * This value is still used by the kernel consumer since for the kernel,
+ * the stream ownership is not IN the consumer so we need to have the
+ * number of left stream that needs to be initialized so we can know when
+ * to delete the channel (see consumer.c).
+ *
+ * As for the user space tracer now, the consumer creates and sends the
+ * stream to the session daemon which only sends them to the application
+ * once every stream of a channel is received making this value useless
+ * because we they will be added to the poll thread before the application
+ * receives them. This ensures that a stream can not hang up during
+ * initilization of a channel.
+ */
+ channel->nb_init_stream_left = 0;
+
+ /* The reply msg status is handled in the following call. */
+ ret = create_ust_channel(channel, attr, &channel->uchan);
+ if (ret < 0) {
+ goto end;
+ }
+
+ channel->wait_fd = lttng_ust_ctl_channel_get_wait_fd(channel->uchan);
+
+ /*
+ * For the snapshots (no monitor), we create the metadata streams
+ * on demand, not during the channel creation.
+ */
+ if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
+ ret = 0;
+ goto end;
+ }
+
+ /* Open all streams for this channel. */
+ pthread_mutex_lock(&channel->lock);
+ ret = create_ust_streams(channel, ctx);
+ pthread_mutex_unlock(&channel->lock);
+ if (ret < 0) {
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+/*
+ * Send all stream of a channel to the right thread handling it.
+ *
+ * On error, return a negative value else 0 on success.
+ */
+static int send_streams_to_thread(struct lttng_consumer_channel *channel,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret = 0;
+ struct lttng_consumer_stream *stream, *stmp;
+
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(ctx);
+
+ /* Send streams to the corresponding thread. */
+ cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
+ send_node) {
+
+ health_code_update();
+
+ /* Sending the stream to the thread. */
+ ret = send_stream_to_thread(stream, ctx);
+ if (ret < 0) {
+ /*
+ * If we are unable to send the stream to the thread, there is
+ * a big problem so just stop everything.
+ */
+ goto error;
+ }
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Flush channel's streams using the given key to retrieve the channel.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int flush_channel(uint64_t chan_key)
+{
+ int ret = 0;
+ struct lttng_consumer_channel *channel;
+ struct lttng_consumer_stream *stream;
+ struct lttng_ht *ht;
+ struct lttng_ht_iter iter;
+
+ DBG("UST consumer flush channel key %" PRIu64, chan_key);
+
+ rcu_read_lock();
+ channel = consumer_find_channel(chan_key);
+ if (!channel) {
+ ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
+ ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ ht = the_consumer_data.stream_per_chan_id_ht;
+
+ /* For each stream of the channel id, flush it. */
+ cds_lfht_for_each_entry_duplicate(ht->ht,
+ ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
+ &channel->key, &iter.iter, stream, node_channel_id.node) {
+
+ health_code_update();
+
+ pthread_mutex_lock(&stream->lock);
+
+ /*
+ * Protect against concurrent teardown of a stream.
+ */
+ if (cds_lfht_is_node_deleted(&stream->node.node)) {
+ goto next;
+ }
+
+ if (!stream->quiescent) {
+ ret = lttng_ust_ctl_flush_buffer(stream->ustream, 0);
+ if (ret) {
+ ERR("Failed to flush buffer while flushing channel: channel key = %" PRIu64 ", channel name = '%s'",
+ chan_key, channel->name);
+ ret = LTTNG_ERR_BUFFER_FLUSH_FAILED;
+ pthread_mutex_unlock(&stream->lock);
+ goto error;
+ }
+ stream->quiescent = true;
+ }
+next:
+ pthread_mutex_unlock(&stream->lock);
+ }
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Clear quiescent state from channel's streams using the given key to
+ * retrieve the channel.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int clear_quiescent_channel(uint64_t chan_key)
+{
+ int ret = 0;
+ struct lttng_consumer_channel *channel;
+ struct lttng_consumer_stream *stream;
+ struct lttng_ht *ht;
+ struct lttng_ht_iter iter;
+
+ DBG("UST consumer clear quiescent channel key %" PRIu64, chan_key);
+
+ rcu_read_lock();
+ channel = consumer_find_channel(chan_key);
+ if (!channel) {
+ ERR("UST consumer clear quiescent channel %" PRIu64 " not found", chan_key);
+ ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ ht = the_consumer_data.stream_per_chan_id_ht;
+
+ /* For each stream of the channel id, clear quiescent state. */
+ cds_lfht_for_each_entry_duplicate(ht->ht,
+ ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
+ &channel->key, &iter.iter, stream, node_channel_id.node) {
+
+ health_code_update();
+
+ pthread_mutex_lock(&stream->lock);
+ stream->quiescent = false;
+ pthread_mutex_unlock(&stream->lock);
+ }
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Close metadata stream wakeup_fd using the given key to retrieve the channel.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int close_metadata(uint64_t chan_key)
+{
+ int ret = 0;
+ struct lttng_consumer_channel *channel;
+ unsigned int channel_monitor;
+
+ DBG("UST consumer close metadata key %" PRIu64, chan_key);
+
+ channel = consumer_find_channel(chan_key);
+ if (!channel) {
+ /*
+ * This is possible if the metadata thread has issue a delete because
+ * the endpoint point of the stream hung up. There is no way the
+ * session daemon can know about it thus use a DBG instead of an actual
+ * error.
+ */
+ DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
+ ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ pthread_mutex_lock(&the_consumer_data.lock);
+ pthread_mutex_lock(&channel->lock);
+ channel_monitor = channel->monitor;
+ if (cds_lfht_is_node_deleted(&channel->node.node)) {
+ goto error_unlock;
+ }
+
+ lttng_ustconsumer_close_metadata(channel);
+ pthread_mutex_unlock(&channel->lock);
+ pthread_mutex_unlock(&the_consumer_data.lock);
+
+ /*
+ * The ownership of a metadata channel depends on the type of
+ * session to which it belongs. In effect, the monitor flag is checked
+ * to determine if this metadata channel is in "snapshot" mode or not.
+ *
+ * In the non-snapshot case, the metadata channel is created along with
+ * a single stream which will remain present until the metadata channel
+ * is destroyed (on the destruction of its session). In this case, the
+ * metadata stream in "monitored" by the metadata poll thread and holds
+ * the ownership of its channel.
+ *
+ * Closing the metadata will cause the metadata stream's "metadata poll
+ * pipe" to be closed. Closing this pipe will wake-up the metadata poll
+ * thread which will teardown the metadata stream which, in return,
+ * deletes the metadata channel.
+ *
+ * In the snapshot case, the metadata stream is created and destroyed
+ * on every snapshot record. Since the channel doesn't have an owner
+ * other than the session daemon, it is safe to destroy it immediately
+ * on reception of the CLOSE_METADATA command.
+ */
+ if (!channel_monitor) {
+ /*
+ * The channel and consumer_data locks must be
+ * released before this call since consumer_del_channel
+ * re-acquires the channel and consumer_data locks to teardown
+ * the channel and queue its reclamation by the "call_rcu"
+ * worker thread.
+ */
+ consumer_del_channel(channel);
+ }
+
+ return ret;
+error_unlock:
+ pthread_mutex_unlock(&channel->lock);
+ pthread_mutex_unlock(&the_consumer_data.lock);
+error:
+ return ret;
+}
+
+/*
+ * RCU read side lock MUST be acquired before calling this function.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
+{
+ int ret;
+ struct lttng_consumer_channel *metadata;
+
+ DBG("UST consumer setup metadata key %" PRIu64, key);
+
+ metadata = consumer_find_channel(key);
+ if (!metadata) {
+ ERR("UST consumer push metadata %" PRIu64 " not found", key);
+ ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+ goto end;
+ }
+
+ /*
+ * In no monitor mode, the metadata channel has no stream(s) so skip the
+ * ownership transfer to the metadata thread.
+ */
+ if (!metadata->monitor) {
+ DBG("Metadata channel in no monitor");
+ ret = 0;
+ goto end;
+ }
+
+ /*
+ * Send metadata stream to relayd if one available. Availability is
+ * known if the stream is still in the list of the channel.
+ */
+ if (cds_list_empty(&metadata->streams.head)) {
+ ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
+ ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ goto error_no_stream;
+ }
+
+ /* Send metadata stream to relayd if needed. */
+ if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
+ ret = consumer_send_relayd_stream(metadata->metadata_stream,
+ metadata->pathname);
+ if (ret < 0) {
+ ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ goto error;
+ }
+ ret = consumer_send_relayd_streams_sent(
+ metadata->metadata_stream->net_seq_idx);
+ if (ret < 0) {
+ ret = LTTCOMM_CONSUMERD_RELAYD_FAIL;
+ goto error;
+ }
+ }
+
+ /*
+ * Ownership of metadata stream is passed along. Freeing is handled by
+ * the callee.
+ */
+ ret = send_streams_to_thread(metadata, ctx);
+ if (ret < 0) {
+ /*
+ * If we are unable to send the stream to the thread, there is
+ * a big problem so just stop everything.
+ */
+ ret = LTTCOMM_CONSUMERD_FATAL;
+ goto send_streams_error;
+ }
+ /* List MUST be empty after or else it could be reused. */
+ LTTNG_ASSERT(cds_list_empty(&metadata->streams.head));
+
+ ret = 0;
+ goto end;
+
+error:
+ /*
+ * Delete metadata channel on error. At this point, the metadata stream can
+ * NOT be monitored by the metadata thread thus having the guarantee that
+ * the stream is still in the local stream list of the channel. This call
+ * will make sure to clean that list.
+ */
+ consumer_stream_destroy(metadata->metadata_stream, NULL);
+ cds_list_del(&metadata->metadata_stream->send_node);
+ metadata->metadata_stream = NULL;
+send_streams_error:
+error_no_stream:
+end:
+ return ret;
+}
+
+/*
+ * Snapshot the whole metadata.
+ * RCU read-side lock must be held by the caller.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+static int snapshot_metadata(struct lttng_consumer_channel *metadata_channel,
+ uint64_t key, char *path, uint64_t relayd_id,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret = 0;
+ struct lttng_consumer_stream *metadata_stream;
+
+ LTTNG_ASSERT(path);
+ LTTNG_ASSERT(ctx);
+
+ DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
+ key, path);
+
+ rcu_read_lock();
+
+ LTTNG_ASSERT(!metadata_channel->monitor);
+
+ health_code_update();
+
+ /*
+ * Ask the sessiond if we have new metadata waiting and update the
+ * consumer metadata cache.
+ */
+ ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ health_code_update();
+
+ /*
+ * 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;
+ LTTNG_ASSERT(metadata_stream);
+
+ pthread_mutex_lock(&metadata_stream->lock);
+ if (relayd_id != (uint64_t) -1ULL) {
+ metadata_stream->net_seq_idx = relayd_id;
+ ret = consumer_send_relayd_stream(metadata_stream, path);
+ } else {
+ ret = consumer_stream_create_output_files(metadata_stream,
+ false);
+ }
+ pthread_mutex_unlock(&metadata_stream->lock);
+ if (ret < 0) {
+ goto error_stream;
+ }
+
+ do {
+ health_code_update();
+
+ ret = lttng_consumer_read_subbuffer(metadata_stream, ctx, true);
+ if (ret < 0) {
+ goto error_stream;
+ }
+ } while (ret > 0);
+
+error_stream:
+ /*
+ * Clean up the stream completly because the next snapshot will use a new
+ * metadata stream.
+ */
+ consumer_stream_destroy(metadata_stream, NULL);
+ cds_list_del(&metadata_stream->send_node);
+ metadata_channel->metadata_stream = NULL;
+
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+static
+int get_current_subbuf_addr(struct lttng_consumer_stream *stream,
+ const char **addr)
+{
+ int ret;
+ unsigned long mmap_offset;
+ const char *mmap_base;
+
+ mmap_base = (const char *) lttng_ust_ctl_get_mmap_base(stream->ustream);
+ if (!mmap_base) {
+ ERR("Failed to get mmap base for stream `%s`",
+ stream->name);
+ ret = -EPERM;
+ goto error;
+ }
+
+ ret = lttng_ust_ctl_get_mmap_read_offset(stream->ustream, &mmap_offset);
+ if (ret != 0) {
+ ERR("Failed to get mmap offset for stream `%s`", stream->name);
+ ret = -EINVAL;
+ goto error;
+ }
+
+ *addr = mmap_base + mmap_offset;
+error:
+ return ret;
+
+}
+
+/*
+ * Take a snapshot of all the stream of a channel.
+ * RCU read-side lock and the channel lock must be held by the caller.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+static int snapshot_channel(struct lttng_consumer_channel *channel,
+ uint64_t key, char *path, uint64_t relayd_id,
+ uint64_t nb_packets_per_stream,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret;
+ unsigned use_relayd = 0;
+ unsigned long consumed_pos, produced_pos;
+ struct lttng_consumer_stream *stream;
+
+ LTTNG_ASSERT(path);
+ LTTNG_ASSERT(ctx);
+
+ rcu_read_lock();
+
+ if (relayd_id != (uint64_t) -1ULL) {
+ use_relayd = 1;
+ }
+
+ LTTNG_ASSERT(!channel->monitor);
+ DBG("UST consumer snapshot channel %" PRIu64, key);
+
+ cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+ health_code_update();
+
+ /* Lock stream because we are about to change its state. */
+ pthread_mutex_lock(&stream->lock);
+ LTTNG_ASSERT(channel->trace_chunk);
+ if (!lttng_trace_chunk_get(channel->trace_chunk)) {
+ /*
+ * Can't happen barring an internal error as the channel
+ * holds a reference to the trace chunk.
+ */
+ ERR("Failed to acquire reference to channel's trace chunk");
+ ret = -1;
+ goto error_unlock;
+ }
+ LTTNG_ASSERT(!stream->trace_chunk);
+ stream->trace_chunk = channel->trace_chunk;
+
+ stream->net_seq_idx = relayd_id;
+
+ if (use_relayd) {
+ ret = consumer_send_relayd_stream(stream, path);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ } else {
+ ret = consumer_stream_create_output_files(stream,
+ false);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ DBG("UST consumer snapshot stream (%" PRIu64 ")",
+ stream->key);
+ }
+
+ /*
+ * If tracing is active, we want to perform a "full" buffer flush.
+ * Else, if quiescent, it has already been done by the prior stop.
+ */
+ if (!stream->quiescent) {
+ ret = lttng_ust_ctl_flush_buffer(stream->ustream, 0);
+ if (ret < 0) {
+ ERR("Failed to flush buffer during snapshot of channel: channel key = %" PRIu64 ", channel name = '%s'",
+ channel->key, channel->name);
+ goto error_unlock;
+ }
+ }
+
+ 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;
+ }
+
+ /*
+ * The original value is sent back if max stream size is larger than
+ * the possible size of the snapshot. Also, we assume that the session
+ * daemon should never send a maximum stream size that is lower than
+ * subbuffer size.
+ */
+ consumed_pos = consumer_get_consume_start_pos(consumed_pos,
+ produced_pos, nb_packets_per_stream,
+ stream->max_sb_size);
+
+ while ((long) (consumed_pos - produced_pos) < 0) {
+ ssize_t read_len;
+ unsigned long len, padded_len;
+ const char *subbuf_addr;
+ struct lttng_buffer_view subbuf_view;
+
+ health_code_update();
+
+ DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
+
+ ret = lttng_ust_ctl_get_subbuf(stream->ustream, &consumed_pos);
+ if (ret < 0) {
+ if (ret != -EAGAIN) {
+ PERROR("lttng_ust_ctl_get_subbuf snapshot");
+ goto error_close_stream;
+ }
+ DBG("UST consumer get subbuf failed. Skipping it.");
+ consumed_pos += stream->max_sb_size;
+ stream->chan->lost_packets++;
+ continue;
+ }
+
+ ret = lttng_ust_ctl_get_subbuf_size(stream->ustream, &len);
+ if (ret < 0) {
+ ERR("Snapshot lttng_ust_ctl_get_subbuf_size");
+ goto error_put_subbuf;
+ }
+
+ ret = lttng_ust_ctl_get_padded_subbuf_size(stream->ustream, &padded_len);
+ if (ret < 0) {
+ ERR("Snapshot lttng_ust_ctl_get_padded_subbuf_size");
+ goto error_put_subbuf;
+ }
+
+ ret = get_current_subbuf_addr(stream, &subbuf_addr);
+ if (ret) {
+ goto error_put_subbuf;
+ }
+
+ subbuf_view = lttng_buffer_view_init(
+ subbuf_addr, 0, padded_len);
+ read_len = lttng_consumer_on_read_subbuffer_mmap(
+ stream, &subbuf_view, padded_len - len);
+ if (use_relayd) {
+ if (read_len != len) {
+ ret = -EPERM;
+ goto error_put_subbuf;
+ }
+ } else {
+ if (read_len != padded_len) {
+ ret = -EPERM;
+ goto error_put_subbuf;
+ }
+ }
+
+ ret = lttng_ust_ctl_put_subbuf(stream->ustream);
+ if (ret < 0) {
+ ERR("Snapshot lttng_ust_ctl_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 (lttng_ust_ctl_put_subbuf(stream->ustream) < 0) {
+ ERR("Snapshot lttng_ust_ctl_put_subbuf");
+ }
+error_close_stream:
+ consumer_stream_close(stream);
+error_unlock:
+ pthread_mutex_unlock(&stream->lock);
+ rcu_read_unlock();
+ return ret;
+}
+
+static
+void metadata_stream_reset_cache_consumed_position(
+ struct lttng_consumer_stream *stream)
+{
+ ASSERT_LOCKED(stream->lock);
+
+ DBG("Reset metadata cache of session %" PRIu64,
+ stream->chan->session_id);
+ stream->ust_metadata_pushed = 0;
+}
+
+/*
+ * Receive the metadata updates from the sessiond. Supports receiving
+ * overlapping metadata, but is needs to always belong to a contiguous
+ * range starting from 0.
+ * Be careful about the locks held when calling this function: it needs
+ * the metadata cache flush to concurrently progress in order to
+ * complete.
+ */
+int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
+ uint64_t len, uint64_t version,
+ struct lttng_consumer_channel *channel, int timer, int wait)
+{
+ int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ char *metadata_str;
+ enum consumer_metadata_cache_write_status cache_write_status;
+
+ DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
+
+ metadata_str = (char *) zmalloc(len * sizeof(char));
+ if (!metadata_str) {
+ PERROR("zmalloc metadata string");
+ ret_code = LTTCOMM_CONSUMERD_ENOMEM;
+ goto end;
+ }
+
+ health_code_update();
+
+ /* Receive metadata string. */
+ ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
+ if (ret < 0) {
+ /* Session daemon is dead so return gracefully. */
+ ret_code = ret;
+ goto end_free;
+ }
+
+ health_code_update();
+
+ pthread_mutex_lock(&channel->metadata_cache->lock);
+ cache_write_status = consumer_metadata_cache_write(
+ channel->metadata_cache, offset, len, version,
+ metadata_str);
+ pthread_mutex_unlock(&channel->metadata_cache->lock);
+ switch (cache_write_status) {
+ case CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE:
+ /*
+ * The write entirely overlapped with existing contents of the
+ * same metadata version (same content); there is nothing to do.
+ */
+ break;
+ case CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED:
+ /*
+ * The metadata cache was invalidated (previously pushed
+ * content has been overwritten). Reset the stream's consumed
+ * metadata position to ensure the metadata poll thread consumes
+ * the whole cache.
+ */
+ pthread_mutex_lock(&channel->metadata_stream->lock);
+ metadata_stream_reset_cache_consumed_position(
+ channel->metadata_stream);
+ pthread_mutex_unlock(&channel->metadata_stream->lock);
+ /* Fall-through. */
+ case CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT:
+ /*
+ * In both cases, the metadata poll thread has new data to
+ * consume.
+ */
+ ret = consumer_metadata_wakeup_pipe(channel);
+ if (ret) {
+ ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ goto end_free;
+ }
+ break;
+ case CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR:
+ /* Unable to handle metadata. Notify session daemon. */
+ ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ /*
+ * Skip metadata flush on write error since the offset and len might
+ * not have been updated which could create an infinite loop below when
+ * waiting for the metadata cache to be flushed.
+ */
+ goto end_free;
+ default:
+ abort();
+ }
+
+ if (!wait) {
+ goto end_free;
+ }
+ while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
+ DBG("Waiting for metadata to be flushed");
+
+ health_code_update();
+
+ usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
+ }
+
+end_free:
+ free(metadata_str);
+end:
+ return ret_code;
+}
+
+/*
+ * Receive command from session daemon and process it.
+ *
+ * Return 1 on success else a negative value or 0.
+ */
+int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
+ int sock, struct pollfd *consumer_sockpoll)
+{
+ int ret_func;
+ enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ struct lttcomm_consumer_msg msg;
+ struct lttng_consumer_channel *channel = NULL;
+
+ health_code_update();
+
+ {
+ ssize_t ret_recv;
+
+ ret_recv = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
+ if (ret_recv != sizeof(msg)) {
+ DBG("Consumer received unexpected message size %zd (expects %zu)",
+ ret_recv, sizeof(msg));
+ /*
+ * The ret value might 0 meaning an orderly shutdown but this is ok
+ * since the caller handles this.
+ */
+ if (ret_recv > 0) {
+ lttng_consumer_send_error(ctx,
+ LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
+ ret_recv = -1;
+ }
+ return ret_recv;
+ }
+ }
+
+ health_code_update();
+
+ /* deprecated */
+ LTTNG_ASSERT(msg.cmd_type != LTTNG_CONSUMER_STOP);
+
+ health_code_update();
+
+ /* relayd needs RCU read-side lock */
+ rcu_read_lock();
+
+ switch (msg.cmd_type) {
+ case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
+ {
+ /* Session daemon status message are handled in the following call. */
+ consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
+ msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
+ &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id,
+ msg.u.relayd_sock.relayd_session_id);
+ goto end_nosignal;
+ }
+ case LTTNG_CONSUMER_DESTROY_RELAYD:
+ {
+ uint64_t index = msg.u.destroy_relayd.net_seq_idx;
+ struct consumer_relayd_sock_pair *relayd;
+
+ DBG("UST consumer destroying relayd %" PRIu64, index);
+
+ /* Get relayd reference if exists. */
+ relayd = consumer_find_relayd(index);
+ if (relayd == NULL) {
+ DBG("Unable to find relayd %" PRIu64, index);
+ ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
+ }
+
+ /*
+ * Each relayd socket pair has a refcount of stream attached to it
+ * which tells if the relayd is still active or not depending on the
+ * refcount value.
+ *
+ * This will set the destroy flag of the relayd object and destroy it
+ * if the refcount reaches zero when called.
+ *
+ * The destroy can happen either here or when a stream fd hangs up.
+ */
+ if (relayd) {
+ consumer_flag_relayd_for_destroy(relayd);
+ }
+
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_UPDATE_STREAM:
+ {
+ rcu_read_unlock();
+ return -ENOSYS;
+ }
+ case LTTNG_CONSUMER_DATA_PENDING:
+ {
+ int is_data_pending;
+ ssize_t ret_send;
+ uint64_t id = msg.u.data_pending.session_id;
+
+ DBG("UST consumer data pending command for id %" PRIu64, id);
+
+ is_data_pending = consumer_data_pending(id);
+
+ /* Send back returned value to session daemon */
+ ret_send = lttcomm_send_unix_sock(sock, &is_data_pending,
+ sizeof(is_data_pending));
+ if (ret_send < 0) {
+ DBG("Error when sending the data pending ret code: %zd",
+ ret_send);
+ goto error_fatal;
+ }
+
+ /*
+ * No need to send back a status message since the data pending
+ * returned value is the response.
+ */
+ break;
+ }
+ case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
+ {
+ int ret_ask_channel, ret_add_channel, ret_send;
+ struct lttng_ust_ctl_consumer_channel_attr attr;
+ const uint64_t chunk_id = msg.u.ask_channel.chunk_id.value;
+ const struct lttng_credentials buffer_credentials = {
+ .uid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.ask_channel.buffer_credentials.uid),
+ .gid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.ask_channel.buffer_credentials.gid),
+ };
+
+ /* Create a plain object and reserve a channel key. */
+ channel = consumer_allocate_channel(
+ msg.u.ask_channel.key,
+ msg.u.ask_channel.session_id,
+ msg.u.ask_channel.chunk_id.is_set ?
+ &chunk_id : NULL,
+ msg.u.ask_channel.pathname,
+ msg.u.ask_channel.name,
+ msg.u.ask_channel.relayd_id,
+ (enum lttng_event_output) msg.u.ask_channel.output,
+ msg.u.ask_channel.tracefile_size,
+ msg.u.ask_channel.tracefile_count,
+ msg.u.ask_channel.session_id_per_pid,
+ msg.u.ask_channel.monitor,
+ msg.u.ask_channel.live_timer_interval,
+ msg.u.ask_channel.is_live,
+ msg.u.ask_channel.root_shm_path,
+ msg.u.ask_channel.shm_path);
+ if (!channel) {
+ goto end_channel_error;
+ }
+
+ LTTNG_OPTIONAL_SET(&channel->buffer_credentials,
+ buffer_credentials);
+
+ /*
+ * Assign UST application UID to the channel. This value is ignored for
+ * per PID buffers. This is specific to UST thus setting this after the
+ * allocation.
+ */
+ channel->ust_app_uid = msg.u.ask_channel.ust_app_uid;
+
+ /* Build channel attributes from received message. */
+ attr.subbuf_size = msg.u.ask_channel.subbuf_size;
+ attr.num_subbuf = msg.u.ask_channel.num_subbuf;
+ attr.overwrite = msg.u.ask_channel.overwrite;
+ attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
+ attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
+ attr.chan_id = msg.u.ask_channel.chan_id;
+ memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
+ attr.blocking_timeout= msg.u.ask_channel.blocking_timeout;
+
+ /* Match channel buffer type to the UST abi. */
+ switch (msg.u.ask_channel.output) {
+ case LTTNG_EVENT_MMAP:
+ default:
+ attr.output = LTTNG_UST_ABI_MMAP;
+ break;
+ }
+
+ /* Translate and save channel type. */
+ switch (msg.u.ask_channel.type) {
+ case LTTNG_UST_ABI_CHAN_PER_CPU:
+ channel->type = CONSUMER_CHANNEL_TYPE_DATA;
+ attr.type = LTTNG_UST_ABI_CHAN_PER_CPU;
+ /*
+ * Set refcount to 1 for owner. Below, we will
+ * pass ownership to the
+ * consumer_thread_channel_poll() thread.
+ */
+ channel->refcount = 1;
+ break;
+ case LTTNG_UST_ABI_CHAN_METADATA:
+ channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
+ attr.type = LTTNG_UST_ABI_CHAN_METADATA;
+ break;
+ default:
+ abort();
+ goto error_fatal;
+ };
+
+ health_code_update();
+
+ ret_ask_channel = ask_channel(ctx, channel, &attr);
+ if (ret_ask_channel < 0) {
+ goto end_channel_error;
+ }
+
+ if (msg.u.ask_channel.type == LTTNG_UST_ABI_CHAN_METADATA) {
+ int ret_allocate;
+
+ ret_allocate = consumer_metadata_cache_allocate(
+ channel);
+ if (ret_allocate < 0) {
+ ERR("Allocating metadata cache");
+ goto end_channel_error;
+ }
+ consumer_timer_switch_start(channel, attr.switch_timer_interval);
+ attr.switch_timer_interval = 0;
+ } else {
+ int monitor_start_ret;
+
+ consumer_timer_live_start(channel,
+ msg.u.ask_channel.live_timer_interval);
+ monitor_start_ret = consumer_timer_monitor_start(
+ channel,
+ msg.u.ask_channel.monitor_timer_interval);
+ if (monitor_start_ret < 0) {
+ ERR("Starting channel monitoring timer failed");
+ goto end_channel_error;
+ }
+ }
+
+ health_code_update();
+
+ /*
+ * Add the channel to the internal state AFTER all streams were created
+ * and successfully sent to session daemon. This way, all streams must
+ * be ready before this channel is visible to the threads.
+ * If add_channel succeeds, ownership of the channel is
+ * passed to consumer_thread_channel_poll().
+ */
+ ret_add_channel = add_channel(channel, ctx);
+ if (ret_add_channel < 0) {
+ if (msg.u.ask_channel.type == LTTNG_UST_ABI_CHAN_METADATA) {
+ if (channel->switch_timer_enabled == 1) {
+ consumer_timer_switch_stop(channel);
+ }
+ consumer_metadata_cache_destroy(channel);
+ }
+ if (channel->live_timer_enabled == 1) {
+ consumer_timer_live_stop(channel);
+ }
+ if (channel->monitor_timer_enabled == 1) {
+ consumer_timer_monitor_stop(channel);
+ }
+ goto end_channel_error;
+ }
+
+ health_code_update();
+
+ /*
+ * Channel and streams are now created. Inform the session daemon that
+ * everything went well and should wait to receive the channel and
+ * streams with ustctl API.
+ */
+ ret_send = consumer_send_status_channel(sock, channel);
+ if (ret_send < 0) {
+ /*
+ * There is probably a problem on the socket.
+ */
+ goto error_fatal;
+ }
+
+ break;
+ }
+ case LTTNG_CONSUMER_GET_CHANNEL:
+ {
+ int ret, relayd_err = 0;
+ uint64_t key = msg.u.get_channel.key;
+ struct lttng_consumer_channel *found_channel;
+
+ found_channel = consumer_find_channel(key);
+ if (!found_channel) {
+ ERR("UST consumer get channel key %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+ goto end_get_channel;
+ }
+
+ health_code_update();
+
+ /* Send the channel to sessiond (and relayd, if applicable). */
+ ret = send_channel_to_sessiond_and_relayd(
+ sock, found_channel, ctx, &relayd_err);
+ if (ret < 0) {
+ if (relayd_err) {
+ /*
+ * We were unable to send to the relayd the stream so avoid
+ * sending back a fatal error to the thread since this is OK
+ * and the consumer can continue its work. The above call
+ * has sent the error status message to the sessiond.
+ */
+ goto end_get_channel_nosignal;
+ }
+ /*
+ * The communicaton was broken hence there is a bad state between
+ * the consumer and sessiond so stop everything.
+ */
+ goto error_get_channel_fatal;
+ }
+
+ health_code_update();
+
+ /*
+ * In no monitor mode, the streams ownership is kept inside the channel
+ * so don't send them to the data thread.
+ */
+ if (!found_channel->monitor) {
+ goto end_get_channel;
+ }
+
+ ret = send_streams_to_thread(found_channel, ctx);
+ if (ret < 0) {
+ /*
+ * If we are unable to send the stream to the thread, there is
+ * a big problem so just stop everything.
+ */
+ goto error_get_channel_fatal;
+ }
+ /* List MUST be empty after or else it could be reused. */
+ LTTNG_ASSERT(cds_list_empty(&found_channel->streams.head));
+end_get_channel:
+ goto end_msg_sessiond;
+error_get_channel_fatal:
+ goto error_fatal;
+end_get_channel_nosignal:
+ goto end_nosignal;
+ }
+ case LTTNG_CONSUMER_DESTROY_CHANNEL:
+ {
+ uint64_t key = msg.u.destroy_channel.key;
+
+ /*
+ * Only called if streams have not been sent to stream
+ * manager thread. However, channel has been sent to
+ * channel manager thread.
+ */
+ notify_thread_del_channel(ctx, key);
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_CLOSE_METADATA:
+ {
+ int ret;
+
+ ret = close_metadata(msg.u.close_metadata.key);
+ if (ret != 0) {
+ ret_code = (lttcomm_return_code) ret;
+ }
+
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_FLUSH_CHANNEL:
+ {
+ int ret;
+
+ ret = flush_channel(msg.u.flush_channel.key);
+ if (ret != 0) {
+ ret_code = (lttcomm_return_code) ret;
+ }
+
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL:
+ {
+ int ret;
+
+ ret = clear_quiescent_channel(
+ msg.u.clear_quiescent_channel.key);
+ if (ret != 0) {
+ ret_code = (lttcomm_return_code) ret;
+ }
+
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_PUSH_METADATA:
+ {
+ int ret;
+ uint64_t len = msg.u.push_metadata.len;
+ uint64_t key = msg.u.push_metadata.key;
+ uint64_t offset = msg.u.push_metadata.target_offset;
+ uint64_t version = msg.u.push_metadata.version;
+ struct lttng_consumer_channel *found_channel;
+
+ DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
+ len);
+
+ found_channel = consumer_find_channel(key);
+ if (!found_channel) {
+ /*
+ * This is possible if the metadata creation on the consumer side
+ * is in flight vis-a-vis a concurrent push metadata from the
+ * session daemon. Simply return that the channel failed and the
+ * session daemon will handle that message correctly considering
+ * that this race is acceptable thus the DBG() statement here.
+ */
+ DBG("UST consumer push metadata %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
+ goto end_push_metadata_msg_sessiond;
+ }
+
+ health_code_update();
+
+ if (!len) {
+ /*
+ * There is nothing to receive. We have simply
+ * checked whether the channel can be found.
+ */
+ ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ goto end_push_metadata_msg_sessiond;
+ }
+
+ /* Tell session daemon we are ready to receive the metadata. */
+ ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto error_push_metadata_fatal;
+ }
+
+ health_code_update();
+
+ /* Wait for more data. */
+ health_poll_entry();
+ ret = lttng_consumer_poll_socket(consumer_sockpoll);
+ health_poll_exit();
+ if (ret) {
+ goto error_push_metadata_fatal;
+ }
+
+ health_code_update();
+
+ ret = lttng_ustconsumer_recv_metadata(sock, key, offset, len,
+ version, found_channel, 0, 1);
+ if (ret < 0) {
+ /* error receiving from sessiond */
+ goto error_push_metadata_fatal;
+ } else {
+ ret_code = (lttcomm_return_code) ret;
+ goto end_push_metadata_msg_sessiond;
+ }
+end_push_metadata_msg_sessiond:
+ goto end_msg_sessiond;
+error_push_metadata_fatal:
+ goto error_fatal;
+ }
+ case LTTNG_CONSUMER_SETUP_METADATA:
+ {
+ int ret;
+
+ ret = setup_metadata(ctx, msg.u.setup_metadata.key);
+ if (ret) {
+ ret_code = (lttcomm_return_code) ret;
+ }
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
+ {
+ struct lttng_consumer_channel *found_channel;
+ uint64_t key = msg.u.snapshot_channel.key;
+ int ret_send;
+
+ found_channel = consumer_find_channel(key);
+ if (!found_channel) {
+ DBG("UST snapshot channel not found for key %" PRIu64, key);
+ ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+ } else {
+ if (msg.u.snapshot_channel.metadata) {
+ int ret_snapshot;
+
+ ret_snapshot = snapshot_metadata(found_channel,
+ key,
+ msg.u.snapshot_channel.pathname,
+ msg.u.snapshot_channel.relayd_id,
+ ctx);
+ if (ret_snapshot < 0) {
+ ERR("Snapshot metadata failed");
+ ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED;
+ }
+ } else {
+ int ret_snapshot;
+
+ ret_snapshot = snapshot_channel(found_channel,
+ key,
+ msg.u.snapshot_channel.pathname,
+ msg.u.snapshot_channel.relayd_id,
+ msg.u.snapshot_channel
+ .nb_packets_per_stream,
+ ctx);
+ if (ret_snapshot < 0) {
+ ERR("Snapshot channel failed");
+ ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED;
+ }
+ }
+ }
+ health_code_update();
+ ret_send = consumer_send_status_msg(sock, ret_code);
+ if (ret_send < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ health_code_update();
+ break;
+ }
+ case LTTNG_CONSUMER_DISCARDED_EVENTS:
+ {
+ int ret = 0;
+ uint64_t discarded_events;
+ struct lttng_ht_iter iter;
+ struct lttng_ht *ht;
+ struct lttng_consumer_stream *stream;
+ uint64_t id = msg.u.discarded_events.session_id;
+ uint64_t key = msg.u.discarded_events.channel_key;
+
+ DBG("UST consumer discarded events command for session id %"
+ PRIu64, id);
+ rcu_read_lock();
+ pthread_mutex_lock(&the_consumer_data.lock);
+
+ ht = the_consumer_data.stream_list_ht;
+
+ /*
+ * We only need a reference to the channel, but they are not
+ * directly indexed, so we just use the first matching stream
+ * to extract the information we need, we default to 0 if not
+ * found (no events are dropped if the channel is not yet in
+ * use).
+ */
+ discarded_events = 0;
+ cds_lfht_for_each_entry_duplicate(ht->ht,
+ ht->hash_fct(&id, lttng_ht_seed),
+ ht->match_fct, &id,
+ &iter.iter, stream, node_session_id.node) {
+ if (stream->chan->key == key) {
+ discarded_events = stream->chan->discarded_events;
+ break;
+ }
+ }
+ pthread_mutex_unlock(&the_consumer_data.lock);
+ rcu_read_unlock();
+
+ DBG("UST consumer discarded events command for session id %"
+ PRIu64 ", channel key %" PRIu64, id, key);
+
+ health_code_update();
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &discarded_events, sizeof(discarded_events));
+ if (ret < 0) {
+ PERROR("send discarded events");
+ goto error_fatal;
+ }
+
+ break;
+ }
+ case LTTNG_CONSUMER_LOST_PACKETS:
+ {
+ int ret;
+ uint64_t lost_packets;
+ struct lttng_ht_iter iter;
+ struct lttng_ht *ht;
+ struct lttng_consumer_stream *stream;
+ uint64_t id = msg.u.lost_packets.session_id;
+ uint64_t key = msg.u.lost_packets.channel_key;
+
+ DBG("UST consumer lost packets command for session id %"
+ PRIu64, id);
+ rcu_read_lock();
+ pthread_mutex_lock(&the_consumer_data.lock);
+
+ ht = the_consumer_data.stream_list_ht;
+
+ /*
+ * We only need a reference to the channel, but they are not
+ * directly indexed, so we just use the first matching stream
+ * to extract the information we need, we default to 0 if not
+ * found (no packets lost if the channel is not yet in use).
+ */
+ lost_packets = 0;
+ cds_lfht_for_each_entry_duplicate(ht->ht,
+ ht->hash_fct(&id, lttng_ht_seed),
+ ht->match_fct, &id,
+ &iter.iter, stream, node_session_id.node) {
+ if (stream->chan->key == key) {
+ lost_packets = stream->chan->lost_packets;
+ break;
+ }
+ }
+ pthread_mutex_unlock(&the_consumer_data.lock);
+ rcu_read_unlock();
+
+ DBG("UST consumer lost packets command for session id %"
+ PRIu64 ", channel key %" PRIu64, id, key);
+
+ health_code_update();
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &lost_packets,
+ sizeof(lost_packets));
+ if (ret < 0) {
+ PERROR("send lost packets");
+ goto error_fatal;
+ }
+
+ break;
+ }
+ case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE:
+ {
+ int channel_monitor_pipe, ret_send,
+ ret_set_channel_monitor_pipe;
+ ssize_t ret_recv;
+
+ ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ /* Successfully received the command's type. */
+ ret_send = consumer_send_status_msg(sock, ret_code);
+ if (ret_send < 0) {
+ goto error_fatal;
+ }
+
+ ret_recv = lttcomm_recv_fds_unix_sock(
+ sock, &channel_monitor_pipe, 1);
+ if (ret_recv != sizeof(channel_monitor_pipe)) {
+ ERR("Failed to receive channel monitor pipe");
+ goto error_fatal;
+ }
+
+ DBG("Received channel monitor pipe (%d)", channel_monitor_pipe);
+ ret_set_channel_monitor_pipe =
+ consumer_timer_thread_set_channel_monitor_pipe(
+ channel_monitor_pipe);
+ if (!ret_set_channel_monitor_pipe) {
+ int flags;
+ int ret_fcntl;
+
+ ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ /* Set the pipe as non-blocking. */
+ ret_fcntl = fcntl(channel_monitor_pipe, F_GETFL, 0);
+ if (ret_fcntl == -1) {
+ PERROR("fcntl get flags of the channel monitoring pipe");
+ goto error_fatal;
+ }
+ flags = ret_fcntl;
+
+ ret_fcntl = fcntl(channel_monitor_pipe, F_SETFL,
+ flags | O_NONBLOCK);
+ if (ret_fcntl == -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;
+ }
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_ROTATE_CHANNEL:
+ {
+ struct lttng_consumer_channel *found_channel;
+ uint64_t key = msg.u.rotate_channel.key;
+ int ret_send_status;
+
+ found_channel = consumer_find_channel(key);
+ if (!found_channel) {
+ DBG("Channel %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+ } else {
+ int rotate_channel;
+
+ /*
+ * Sample the rotate position of all the streams in
+ * this channel.
+ */
+ rotate_channel = lttng_consumer_rotate_channel(
+ found_channel, key,
+ msg.u.rotate_channel.relayd_id,
+ msg.u.rotate_channel.metadata, ctx);
+ if (rotate_channel < 0) {
+ ERR("Rotate channel failed");
+ ret_code = LTTCOMM_CONSUMERD_ROTATION_FAIL;
+ }
+
+ health_code_update();
+ }
+
+ ret_send_status = consumer_send_status_msg(sock, ret_code);
+ if (ret_send_status < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_rotate_channel_nosignal;
+ }
+
+ /*
+ * Rotate the streams that are ready right now.
+ * FIXME: this is a second consecutive iteration over the
+ * streams in a channel, there is probably a better way to
+ * handle this, but it needs to be after the
+ * consumer_send_status_msg() call.
+ */
+ if (found_channel) {
+ int ret_rotate_read_streams;
+
+ ret_rotate_read_streams =
+ lttng_consumer_rotate_ready_streams(
+ found_channel, key,
+ ctx);
+ if (ret_rotate_read_streams < 0) {
+ ERR("Rotate channel failed");
+ }
+ }
+ break;
+end_rotate_channel_nosignal:
+ goto end_nosignal;
+ }
+ case LTTNG_CONSUMER_CLEAR_CHANNEL:
+ {
+ struct lttng_consumer_channel *found_channel;
+ uint64_t key = msg.u.clear_channel.key;
+ int ret_send_status;
+
+ found_channel = consumer_find_channel(key);
+ if (!found_channel) {
+ DBG("Channel %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+ } else {
+ int ret_clear_channel;
+
+ ret_clear_channel = lttng_consumer_clear_channel(
+ found_channel);
+ if (ret_clear_channel) {
+ ERR("Clear channel failed key %" PRIu64, key);
+ ret_code = (lttcomm_return_code) ret_clear_channel;
+ }
+
+ health_code_update();
+ }
+ ret_send_status = consumer_send_status_msg(sock, ret_code);
+ if (ret_send_status < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ break;
+ }
+ case LTTNG_CONSUMER_INIT:
+ {
+ int ret_send_status;
+
+ ret_code = lttng_consumer_init_command(ctx,
+ msg.u.init.sessiond_uuid);
+ health_code_update();
+ ret_send_status = consumer_send_status_msg(sock, ret_code);
+ if (ret_send_status < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ break;
+ }
+ case LTTNG_CONSUMER_CREATE_TRACE_CHUNK:
+ {
+ const struct lttng_credentials credentials = {
+ .uid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.create_trace_chunk.credentials.value.uid),
+ .gid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.create_trace_chunk.credentials.value.gid),
+ };
+ const bool is_local_trace =
+ !msg.u.create_trace_chunk.relayd_id.is_set;
+ const uint64_t relayd_id =
+ msg.u.create_trace_chunk.relayd_id.value;
+ const char *chunk_override_name =
+ *msg.u.create_trace_chunk.override_name ?
+ msg.u.create_trace_chunk.override_name :
+ NULL;
+ struct lttng_directory_handle *chunk_directory_handle = NULL;
+
+ /*
+ * The session daemon will only provide a chunk directory file
+ * descriptor for local traces.
+ */
+ if (is_local_trace) {
+ int chunk_dirfd;
+ int ret_send_status;
+ ssize_t ret_recv;
+
+ /* Acnowledge the reception of the command. */
+ ret_send_status = consumer_send_status_msg(
+ sock, LTTCOMM_CONSUMERD_SUCCESS);
+ if (ret_send_status < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
+ /*
+ * Receive trace chunk domain dirfd.
+ */
+ ret_recv = lttcomm_recv_fds_unix_sock(
+ sock, &chunk_dirfd, 1);
+ if (ret_recv != sizeof(chunk_dirfd)) {
+ ERR("Failed to receive trace chunk domain directory file descriptor");
+ goto error_fatal;
+ }
+
+ DBG("Received trace chunk domain directory fd (%d)",
+ chunk_dirfd);
+ chunk_directory_handle = lttng_directory_handle_create_from_dirfd(
+ chunk_dirfd);
+ if (!chunk_directory_handle) {
+ ERR("Failed to initialize chunk domain directory handle from directory file descriptor");
+ if (close(chunk_dirfd)) {
+ PERROR("Failed to close chunk directory file descriptor");
+ }
+ goto error_fatal;
+ }
+ }
+
+ ret_code = lttng_consumer_create_trace_chunk(
+ !is_local_trace ? &relayd_id : NULL,
+ msg.u.create_trace_chunk.session_id,
+ msg.u.create_trace_chunk.chunk_id,
+ (time_t) msg.u.create_trace_chunk
+ .creation_timestamp,
+ chunk_override_name,
+ msg.u.create_trace_chunk.credentials.is_set ?
+ &credentials :
+ NULL,
+ chunk_directory_handle);
+ lttng_directory_handle_put(chunk_directory_handle);
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_CLOSE_TRACE_CHUNK:
+ {
+ enum lttng_trace_chunk_command_type close_command =
+ (lttng_trace_chunk_command_type)
+ msg.u.close_trace_chunk.close_command.value;
+ const uint64_t relayd_id =
+ msg.u.close_trace_chunk.relayd_id.value;
+ struct lttcomm_consumer_close_trace_chunk_reply reply;
+ char closed_trace_chunk_path[LTTNG_PATH_MAX] = {};
+ int ret;
+
+ ret_code = lttng_consumer_close_trace_chunk(
+ msg.u.close_trace_chunk.relayd_id.is_set ?
+ &relayd_id :
+ NULL,
+ msg.u.close_trace_chunk.session_id,
+ msg.u.close_trace_chunk.chunk_id,
+ (time_t) msg.u.close_trace_chunk.close_timestamp,
+ msg.u.close_trace_chunk.close_command.is_set ?
+ &close_command :
+ NULL, closed_trace_chunk_path);
+ reply.ret_code = ret_code;
+ reply.path_length = strlen(closed_trace_chunk_path) + 1;
+ ret = lttcomm_send_unix_sock(sock, &reply, sizeof(reply));
+ if (ret != sizeof(reply)) {
+ goto error_fatal;
+ }
+ ret = lttcomm_send_unix_sock(sock, closed_trace_chunk_path,
+ reply.path_length);
+ if (ret != reply.path_length) {
+ goto error_fatal;
+ }
+ goto end_nosignal;
+ }
+ case LTTNG_CONSUMER_TRACE_CHUNK_EXISTS:
+ {
+ const uint64_t relayd_id =
+ msg.u.trace_chunk_exists.relayd_id.value;
+
+ ret_code = lttng_consumer_trace_chunk_exists(
+ msg.u.trace_chunk_exists.relayd_id.is_set ?
+ &relayd_id : NULL,
+ msg.u.trace_chunk_exists.session_id,
+ msg.u.trace_chunk_exists.chunk_id);
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_OPEN_CHANNEL_PACKETS:
+ {
+ const uint64_t key = msg.u.open_channel_packets.key;
+ struct lttng_consumer_channel *found_channel =
+ consumer_find_channel(key);
+
+ if (found_channel) {
+ pthread_mutex_lock(&found_channel->lock);
+ ret_code = lttng_consumer_open_channel_packets(
+ found_channel);
+ pthread_mutex_unlock(&found_channel->lock);
+ } else {
+ /*
+ * The channel could have disappeared in per-pid
+ * buffering mode.
+ */
+ DBG("Channel %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+ }
+
+ health_code_update();
+ goto end_msg_sessiond;
+ }
+ default:
+ break;
+ }
+
+end_nosignal:
+ /*
+ * Return 1 to indicate success since the 0 value can be a socket
+ * shutdown during the recv() or send() call.
+ */
+ ret_func = 1;
+ goto end;
+
+end_msg_sessiond:
+ /*
+ * The returned value here is not useful since either way we'll return 1 to
+ * the caller because the session daemon socket management is done
+ * elsewhere. Returning a negative code or 0 will shutdown the consumer.
+ */
+ {
+ int ret_send_status;
+
+ ret_send_status = consumer_send_status_msg(sock, ret_code);
+ if (ret_send_status < 0) {
+ goto error_fatal;
+ }
+ }
+
+ ret_func = 1;
+ goto end;
+
+end_channel_error:
+ if (channel) {
+ /*
+ * Free channel here since no one has a reference to it. We don't
+ * free after that because a stream can store this pointer.
+ */
+ destroy_channel(channel);
+ }
+ /* We have to send a status channel message indicating an error. */
+ {
+ int ret_send_status;
+
+ ret_send_status = consumer_send_status_channel(sock, NULL);
+ if (ret_send_status < 0) {
+ /* Stop everything if session daemon can not be notified. */
+ goto error_fatal;
+ }
+ }
+
+ ret_func = 1;
+ goto end;
+
+error_fatal:
+ /* This will issue a consumer stop. */
+ ret_func = -1;
+ goto end;
+
+end:
+ rcu_read_unlock();
+ health_code_update();
+ return ret_func;
+}
+
+int lttng_ust_flush_buffer(struct lttng_consumer_stream *stream,
+ int producer_active)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ return lttng_ust_ctl_flush_buffer(stream->ustream, producer_active);
+}
+
+/*
+ * Take a snapshot for a specific stream.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ return lttng_ust_ctl_snapshot(stream->ustream);
+}
+
+/*
+ * Sample consumed and produced positions for a specific stream.
+ *
+ * Returns 0 on success, < 0 on error.
+ */
+int lttng_ustconsumer_sample_snapshot_positions(
+ struct lttng_consumer_stream *stream)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ return lttng_ust_ctl_snapshot_sample_positions(stream->ustream);
+}
+
+/*
+ * Get the produced position
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_ustconsumer_get_produced_snapshot(
+ struct lttng_consumer_stream *stream, unsigned long *pos)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+ LTTNG_ASSERT(pos);
+
+ return lttng_ust_ctl_snapshot_get_produced(stream->ustream, pos);
+}
+
+/*
+ * Get the consumed position
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_ustconsumer_get_consumed_snapshot(
+ struct lttng_consumer_stream *stream, unsigned long *pos)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+ LTTNG_ASSERT(pos);
+
+ return lttng_ust_ctl_snapshot_get_consumed(stream->ustream, pos);
+}
+
+int lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream,
+ int producer)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ return lttng_ust_ctl_flush_buffer(stream->ustream, producer);
+}
+
+int lttng_ustconsumer_clear_buffer(struct lttng_consumer_stream *stream)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ return lttng_ust_ctl_clear_buffer(stream->ustream);
+}
+
+int lttng_ustconsumer_get_current_timestamp(
+ struct lttng_consumer_stream *stream, uint64_t *ts)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+ LTTNG_ASSERT(ts);
+
+ return lttng_ust_ctl_get_current_timestamp(stream->ustream, ts);
+}
+
+int lttng_ustconsumer_get_sequence_number(
+ struct lttng_consumer_stream *stream, uint64_t *seq)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+ LTTNG_ASSERT(seq);
+
+ return lttng_ust_ctl_get_sequence_number(stream->ustream, seq);
+}
+
+/*
+ * Called when the stream signals the consumer that it has hung up.
+ */
+void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ pthread_mutex_lock(&stream->lock);
+ if (!stream->quiescent) {
+ if (lttng_ust_ctl_flush_buffer(stream->ustream, 0) < 0) {
+ ERR("Failed to flush buffer on stream hang-up");
+ } else {
+ stream->quiescent = true;
+ }
+ }
+ pthread_mutex_unlock(&stream->lock);
+ stream->hangup_flush_done = 1;
+}
+
+void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
+{
+ int i;
+
+ LTTNG_ASSERT(chan);
+ LTTNG_ASSERT(chan->uchan);
+ LTTNG_ASSERT(chan->buffer_credentials.is_set);
+
+ if (chan->switch_timer_enabled == 1) {
+ consumer_timer_switch_stop(chan);
+ }
+ for (i = 0; i < chan->nr_stream_fds; i++) {
+ int ret;
+
+ ret = close(chan->stream_fds[i]);
+ if (ret) {
+ PERROR("close");
+ }
+ if (chan->shm_path[0]) {
+ char shm_path[PATH_MAX];
+
+ ret = get_stream_shm_path(shm_path, chan->shm_path, i);
+ if (ret) {
+ ERR("Cannot get stream shm path");
+ }
+ ret = run_as_unlink(shm_path,
+ lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+ chan->buffer_credentials)),
+ lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+ chan->buffer_credentials)));
+ if (ret) {
+ PERROR("unlink %s", shm_path);
+ }
+ }
+ }
+}
+
+void lttng_ustconsumer_free_channel(struct lttng_consumer_channel *chan)
+{
+ LTTNG_ASSERT(chan);
+ LTTNG_ASSERT(chan->uchan);
+ LTTNG_ASSERT(chan->buffer_credentials.is_set);
+
+ consumer_metadata_cache_destroy(chan);
+ lttng_ust_ctl_destroy_channel(chan->uchan);
+ /* Try to rmdir all directories under shm_path root. */
+ if (chan->root_shm_path[0]) {
+ (void) run_as_rmdir_recursive(chan->root_shm_path,
+ lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR(
+ chan->buffer_credentials)),
+ lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR(
+ chan->buffer_credentials)),
+ LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG);
+ }
+ free(chan->stream_fds);
+}
+
+void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ if (stream->chan->switch_timer_enabled == 1) {
+ consumer_timer_switch_stop(stream->chan);
+ }
+ lttng_ust_ctl_destroy_stream(stream->ustream);
+}
+
+int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ return lttng_ust_ctl_stream_get_wakeup_fd(stream->ustream);
+}
+
+int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+
+ return lttng_ust_ctl_stream_close_wakeup_fd(stream->ustream);
+}
+
+/*
+ * Write up to one packet from the metadata cache to the channel.
+ *
+ * Returns the number of bytes pushed from the cache into the ring buffer, or a
+ * negative value on error.
+ */
+static
+int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
+{
+ ssize_t write_len;
+ int ret;
+
+ pthread_mutex_lock(&stream->chan->metadata_cache->lock);
+ if (stream->chan->metadata_cache->contents.size ==
+ stream->ust_metadata_pushed) {
+ /*
+ * In the context of a user space metadata channel, a
+ * change in version can be detected in two ways:
+ * 1) During the pre-consume of the `read_subbuffer` loop,
+ * 2) When populating the metadata ring buffer (i.e. here).
+ *
+ * This function is invoked when there is no metadata
+ * available in the ring-buffer. If all data was consumed
+ * up to the size of the metadata cache, there is no metadata
+ * to insert in the ring-buffer.
+ *
+ * However, the metadata version could still have changed (a
+ * regeneration without any new data will yield the same cache
+ * size).
+ *
+ * The cache's version is checked for a version change and the
+ * consumed position is reset if one occurred.
+ *
+ * This check is only necessary for the user space domain as
+ * it has to manage the cache explicitly. If this reset was not
+ * performed, no metadata would be consumed (and no reset would
+ * occur as part of the pre-consume) until the metadata size
+ * exceeded the cache size.
+ */
+ if (stream->metadata_version !=
+ stream->chan->metadata_cache->version) {
+ metadata_stream_reset_cache_consumed_position(stream);
+ consumer_stream_metadata_set_version(stream,
+ stream->chan->metadata_cache->version);
+ } else {
+ ret = 0;
+ goto end;
+ }
+ }
+
+ write_len = lttng_ust_ctl_write_one_packet_to_channel(stream->chan->uchan,
+ &stream->chan->metadata_cache->contents.data[stream->ust_metadata_pushed],
+ stream->chan->metadata_cache->contents.size -
+ stream->ust_metadata_pushed);
+ LTTNG_ASSERT(write_len != 0);
+ if (write_len < 0) {
+ ERR("Writing one metadata packet");
+ ret = write_len;
+ goto end;
+ }
+ stream->ust_metadata_pushed += write_len;
+
+ LTTNG_ASSERT(stream->chan->metadata_cache->contents.size >=
+ stream->ust_metadata_pushed);
+ ret = write_len;
+
+ /*
+ * Switch packet (but don't open the next one) on every commit of
+ * a metadata packet. Since the subbuffer is fully filled (with padding,
+ * if needed), the stream is "quiescent" after this commit.
+ */
+ if (lttng_ust_ctl_flush_buffer(stream->ustream, 1)) {
+ ERR("Failed to flush buffer while commiting one metadata packet");
+ ret = -EIO;
+ } else {
+ stream->quiescent = true;
+ }
+end:
+ pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
+ return ret;
+}
+
+
+/*
+ * Sync metadata meaning request them to the session daemon and snapshot to the
+ * metadata thread can consumer them.
+ *
+ * Metadata stream lock is held here, but we need to release it when
+ * interacting with sessiond, else we cause a deadlock with live
+ * awaiting on metadata to be pushed out.
+ *
+ * The RCU read side lock must be held by the caller.
+ */
+enum sync_metadata_status lttng_ustconsumer_sync_metadata(
+ struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *metadata_stream)
+{
+ int ret;
+ enum sync_metadata_status status;
+ struct lttng_consumer_channel *metadata_channel;
+
+ LTTNG_ASSERT(ctx);
+ LTTNG_ASSERT(metadata_stream);
+
+ metadata_channel = metadata_stream->chan;
+ pthread_mutex_unlock(&metadata_stream->lock);
+ /*
+ * Request metadata from the sessiond, but don't wait for the flush
+ * because we locked the metadata thread.
+ */
+ ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 0);
+ pthread_mutex_lock(&metadata_stream->lock);
+ if (ret < 0) {
+ status = SYNC_METADATA_STATUS_ERROR;
+ goto end;
+ }
+
+ /*
+ * The metadata stream and channel can be deleted while the
+ * metadata stream lock was released. The streamed is checked
+ * for deletion before we use it further.
+ *
+ * Note that it is safe to access a logically-deleted stream since its
+ * existence is still guaranteed by the RCU read side lock. However,
+ * it should no longer be used. The close/deletion of the metadata
+ * channel and stream already guarantees that all metadata has been
+ * consumed. Therefore, there is nothing left to do in this function.
+ */
+ if (consumer_stream_is_deleted(metadata_stream)) {
+ DBG("Metadata stream %" PRIu64 " was deleted during the metadata synchronization",
+ metadata_stream->key);
+ status = SYNC_METADATA_STATUS_NO_DATA;
+ goto end;
+ }
+
+ ret = commit_one_metadata_packet(metadata_stream);
+ if (ret < 0) {
+ status = SYNC_METADATA_STATUS_ERROR;
+ goto end;
+ } else if (ret > 0) {
+ status = SYNC_METADATA_STATUS_NEW_DATA;
+ } else /* ret == 0 */ {
+ status = SYNC_METADATA_STATUS_NO_DATA;
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_snapshot(metadata_stream->ustream);
+ if (ret < 0) {
+ ERR("Failed to take a snapshot of the metadata ring-buffer positions, ret = %d", ret);
+ status = SYNC_METADATA_STATUS_ERROR;
+ goto end;
+ }
+
+end:
+ return status;
+}
+
+/*
+ * Return 0 on success else a negative value.
+ */
+static int notify_if_more_data(struct lttng_consumer_stream *stream,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret;
+ struct lttng_ust_ctl_consumer_stream *ustream;
+
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(ctx);
+
+ ustream = stream->ustream;
+
+ /*
+ * First, we are going to check if there is a new subbuffer available
+ * before reading the stream wait_fd.
+ */
+ /* Get the next subbuffer */
+ ret = lttng_ust_ctl_get_next_subbuf(ustream);
+ if (ret) {
+ /* No more data found, flag the stream. */
+ stream->has_data = 0;
+ ret = 0;
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_put_subbuf(ustream);
+ LTTNG_ASSERT(!ret);
+
+ /* This stream still has data. Flag it and wake up the data thread. */
+ stream->has_data = 1;
+
+ if (stream->monitor && !stream->hangup_flush_done && !ctx->has_wakeup) {
+ ssize_t writelen;
+
+ writelen = lttng_pipe_write(ctx->consumer_wakeup_pipe, "!", 1);
+ if (writelen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
+ ret = writelen;
+ goto end;
+ }
+
+ /* The wake up pipe has been notified. */
+ ctx->has_wakeup = 1;
+ }
+ ret = 0;
+
+end:
+ return ret;
+}
+
+static int consumer_stream_ust_on_wake_up(struct lttng_consumer_stream *stream)
+{
+ int ret = 0;
+
+ /*
+ * We can consume the 1 byte written into the wait_fd by
+ * UST. Don't trigger error if we cannot read this one byte
+ * (read returns 0), or if the error is EAGAIN or EWOULDBLOCK.
+ *
+ * This is only done when the stream is monitored by a thread,
+ * before the flush is done after a hangup and if the stream
+ * is not flagged with data since there might be nothing to
+ * consume in the wait fd but still have data available
+ * flagged by the consumer wake up pipe.
+ */
+ if (stream->monitor && !stream->hangup_flush_done && !stream->has_data) {
+ char dummy;
+ ssize_t readlen;
+
+ readlen = lttng_read(stream->wait_fd, &dummy, 1);
+ if (readlen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
+ ret = readlen;
+ }
+ }
+
+ return ret;
+}
+
+static int extract_common_subbuffer_info(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuf)
+{
+ int ret;
+
+ ret = lttng_ust_ctl_get_subbuf_size(
+ stream->ustream, &subbuf->info.data.subbuf_size);
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_padded_subbuf_size(
+ stream->ustream, &subbuf->info.data.padded_subbuf_size);
+ if (ret) {
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static int extract_metadata_subbuffer_info(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuf)
+{
+ int ret;
+
+ ret = extract_common_subbuffer_info(stream, subbuf);
+ if (ret) {
+ goto end;
+ }
+
+ subbuf->info.metadata.version = stream->metadata_version;
+
+end:
+ return ret;
+}
+
+static int extract_data_subbuffer_info(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuf)
+{
+ int ret;
+
+ ret = extract_common_subbuffer_info(stream, subbuf);
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_packet_size(
+ stream->ustream, &subbuf->info.data.packet_size);
+ if (ret < 0) {
+ PERROR("Failed to get sub-buffer packet size");
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_content_size(
+ stream->ustream, &subbuf->info.data.content_size);
+ if (ret < 0) {
+ PERROR("Failed to get sub-buffer content size");
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_timestamp_begin(
+ stream->ustream, &subbuf->info.data.timestamp_begin);
+ if (ret < 0) {
+ PERROR("Failed to get sub-buffer begin timestamp");
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_timestamp_end(
+ stream->ustream, &subbuf->info.data.timestamp_end);
+ if (ret < 0) {
+ PERROR("Failed to get sub-buffer end timestamp");
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_events_discarded(
+ stream->ustream, &subbuf->info.data.events_discarded);
+ if (ret) {
+ PERROR("Failed to get sub-buffer events discarded count");
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_sequence_number(stream->ustream,
+ &subbuf->info.data.sequence_number.value);
+ if (ret) {
+ /* May not be supported by older LTTng-modules. */
+ if (ret != -ENOTTY) {
+ PERROR("Failed to get sub-buffer sequence number");
+ goto end;
+ }
+ } else {
+ subbuf->info.data.sequence_number.is_set = true;
+ }
+
+ ret = lttng_ust_ctl_get_stream_id(
+ stream->ustream, &subbuf->info.data.stream_id);
+ if (ret < 0) {
+ PERROR("Failed to get stream id");
+ goto end;
+ }
+
+ ret = lttng_ust_ctl_get_instance_id(stream->ustream,
+ &subbuf->info.data.stream_instance_id.value);
+ if (ret) {
+ /* May not be supported by older LTTng-modules. */
+ if (ret != -ENOTTY) {
+ PERROR("Failed to get stream instance id");
+ goto end;
+ }
+ } else {
+ subbuf->info.data.stream_instance_id.is_set = true;
+ }
+end:
+ return ret;
+}
+
+static int get_next_subbuffer_common(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ int ret;
+ const char *addr;
+
+ ret = stream->read_subbuffer_ops.extract_subbuffer_info(
+ 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);
+ LTTNG_ASSERT(subbuffer->buffer.buffer.data != NULL);
+end:
+ return ret;
+}
+
+static enum get_next_subbuffer_status get_next_subbuffer(
+ struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ int ret;
+ enum get_next_subbuffer_status status;
+
+ ret = lttng_ust_ctl_get_next_subbuf(stream->ustream);
+ switch (ret) {
+ case 0:
+ status = GET_NEXT_SUBBUFFER_STATUS_OK;
+ break;
+ case -ENODATA:
+ case -EAGAIN:
+ /*
+ * The caller only expects -ENODATA when there is no data to
+ * read, but the kernel tracer returns -EAGAIN when there is
+ * currently no data for a non-finalized stream, and -ENODATA
+ * when there is no data for a finalized stream. Those can be
+ * combined into a -ENODATA return value.
+ */
+ status = GET_NEXT_SUBBUFFER_STATUS_NO_DATA;
+ goto end;
+ default:
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ }
+
+ ret = get_next_subbuffer_common(stream, subbuffer);
+ if (ret) {
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ }
+end:
+ return status;
+}
+
+static enum get_next_subbuffer_status get_next_subbuffer_metadata(
+ struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ int ret;
+ bool cache_empty;
+ bool got_subbuffer;
+ bool coherent;
+ bool buffer_empty;
+ unsigned long consumed_pos, produced_pos;
+ enum get_next_subbuffer_status status;
+
+ do {
+ ret = lttng_ust_ctl_get_next_subbuf(stream->ustream);
+ if (ret == 0) {
+ got_subbuffer = true;
+ } else {
+ got_subbuffer = false;
+ if (ret != -EAGAIN) {
+ /* Fatal error. */
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ }
+ }
+
+ /*
+ * Determine if the cache is empty and ensure that a sub-buffer
+ * is made available if the cache is not empty.
+ */
+ if (!got_subbuffer) {
+ ret = commit_one_metadata_packet(stream);
+ if (ret < 0 && ret != -ENOBUFS) {
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ } else if (ret == 0) {
+ /* Not an error, the cache is empty. */
+ cache_empty = true;
+ status = GET_NEXT_SUBBUFFER_STATUS_NO_DATA;
+ goto end;
+ } else {
+ cache_empty = false;
+ }
+ } else {
+ pthread_mutex_lock(&stream->chan->metadata_cache->lock);
+ cache_empty = stream->chan->metadata_cache->contents.size ==
+ stream->ust_metadata_pushed;
+ pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
+ }
+ } while (!got_subbuffer);
+
+ /* Populate sub-buffer infos and view. */
+ ret = get_next_subbuffer_common(stream, subbuffer);
+ if (ret) {
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ }
+
+ ret = lttng_ustconsumer_sample_snapshot_positions(stream);
+ if (ret < 0) {
+ /*
+ * -EAGAIN is not expected since we got a sub-buffer and haven't
+ * pushed the consumption position yet (on put_next).
+ */
+ PERROR("Failed to take a snapshot of metadata buffer positions");
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ }
+
+ ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
+ if (ret) {
+ PERROR("Failed to get metadata consumed position");
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ }
+
+ ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
+ if (ret) {
+ PERROR("Failed to get metadata produced position");
+ status = GET_NEXT_SUBBUFFER_STATUS_ERROR;
+ goto end;
+ }
+
+ /* Last sub-buffer of the ring buffer ? */
+ buffer_empty = (consumed_pos + stream->max_sb_size) == produced_pos;
+
+ /*
+ * The sessiond registry lock ensures that coherent units of metadata
+ * are pushed to the consumer daemon at once. Hence, if a sub-buffer is
+ * acquired, the cache is empty, and it is the only available sub-buffer
+ * available, it is safe to assume that it is "coherent".
+ */
+ coherent = got_subbuffer && cache_empty && buffer_empty;
+
+ LTTNG_OPTIONAL_SET(&subbuffer->info.metadata.coherent, coherent);
+ status = GET_NEXT_SUBBUFFER_STATUS_OK;
+end:
+ return status;
+}
+
+static int put_next_subbuffer(struct lttng_consumer_stream *stream,
+ struct stream_subbuffer *subbuffer)
+{
+ const int ret = lttng_ust_ctl_put_next_subbuf(stream->ustream);
+
+ LTTNG_ASSERT(ret == 0);
+ return ret;
+}
+
+static int signal_metadata(struct lttng_consumer_stream *stream,
+ struct lttng_consumer_local_data *ctx)
+{
+ ASSERT_LOCKED(stream->metadata_rdv_lock);
+ return pthread_cond_broadcast(&stream->metadata_rdv) ? -errno : 0;
+}
+
+static int lttng_ustconsumer_set_stream_ops(
+ struct lttng_consumer_stream *stream)
+{
+ int ret = 0;
+
+ stream->read_subbuffer_ops.on_wake_up = consumer_stream_ust_on_wake_up;
+ if (stream->metadata_flag) {
+ stream->read_subbuffer_ops.get_next_subbuffer =
+ get_next_subbuffer_metadata;
+ stream->read_subbuffer_ops.extract_subbuffer_info =
+ extract_metadata_subbuffer_info;
+ stream->read_subbuffer_ops.reset_metadata =
+ metadata_stream_reset_cache_consumed_position;
+ if (stream->chan->is_live) {
+ stream->read_subbuffer_ops.on_sleep = signal_metadata;
+ ret = consumer_stream_enable_metadata_bucketization(
+ stream);
+ if (ret) {
+ goto end;
+ }
+ }
+ } else {
+ stream->read_subbuffer_ops.get_next_subbuffer =
+ get_next_subbuffer;
+ stream->read_subbuffer_ops.extract_subbuffer_info =
+ extract_data_subbuffer_info;
+ stream->read_subbuffer_ops.on_sleep = notify_if_more_data;
+ if (stream->chan->is_live) {
+ stream->read_subbuffer_ops.send_live_beacon =
+ consumer_flush_ust_index;
+ }
+ }
+
+ stream->read_subbuffer_ops.put_next_subbuffer = put_next_subbuffer;
+end:
+ return ret;
+}
+
+/*
+ * Called when a stream is created.
+ *
+ * Return 0 on success or else a negative value.
+ */
+int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ LTTNG_ASSERT(stream);
+
+ /*
+ * Don't create anything if this is set for streaming or if there is
+ * no current trace chunk on the parent channel.
+ */
+ if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor &&
+ stream->chan->trace_chunk) {
+ ret = consumer_stream_create_output_files(stream, true);
+ if (ret) {
+ goto error;
+ }
+ }
+
+ lttng_ustconsumer_set_stream_ops(stream);
+ ret = 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Check if data is still being extracted from the buffers for a specific
+ * stream. Consumer data lock MUST be acquired before calling this function
+ * and the stream lock.
+ *
+ * Return 1 if the traced data are still getting read else 0 meaning that the
+ * data is available for trace viewer reading.
+ */
+int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream->ustream);
+ ASSERT_LOCKED(stream->lock);
+
+ DBG("UST consumer checking data pending");
+
+ if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
+ ret = 0;
+ goto end;
+ }
+
+ if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
+ uint64_t contiguous, pushed;
+
+ /* Ease our life a bit. */
+ pthread_mutex_lock(&stream->chan->metadata_cache->lock);
+ contiguous = stream->chan->metadata_cache->contents.size;
+ pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
+ pushed = stream->ust_metadata_pushed;
+
+ /*
+ * We can simply check whether all contiguously available data
+ * has been pushed to the ring buffer, since the push operation
+ * is performed within get_next_subbuf(), and because both
+ * get_next_subbuf() and put_next_subbuf() are issued atomically
+ * thanks to the stream lock within
+ * lttng_ustconsumer_read_subbuffer(). This basically means that
+ * whetnever ust_metadata_pushed is incremented, the associated
+ * metadata has been consumed from the metadata stream.
+ */
+ DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
+ contiguous, pushed);
+ LTTNG_ASSERT(((int64_t) (contiguous - pushed)) >= 0);
+ if ((contiguous != pushed) ||
+ (((int64_t) contiguous - pushed) > 0 || contiguous == 0)) {
+ ret = 1; /* Data is pending */
+ goto end;
+ }
+ } else {
+ ret = lttng_ust_ctl_get_next_subbuf(stream->ustream);
+ if (ret == 0) {
+ /*
+ * There is still data so let's put back this
+ * subbuffer.
+ */
+ ret = lttng_ust_ctl_put_subbuf(stream->ustream);
+ LTTNG_ASSERT(ret == 0);
+ ret = 1; /* Data is pending */
+ goto end;
+ }
+ }
+
+ /* Data is NOT pending so ready to be read. */
+ ret = 0;
+
+end:
+ return ret;
+}
+
+/*
+ * Stop a given metadata channel timer if enabled and close the wait fd which
+ * is the poll pipe of the metadata stream.
+ *
+ * This MUST be called with the metadata channel lock acquired.
+ */
+void lttng_ustconsumer_close_metadata(struct lttng_consumer_channel *metadata)
+{
+ int ret;
+
+ LTTNG_ASSERT(metadata);
+ LTTNG_ASSERT(metadata->type == CONSUMER_CHANNEL_TYPE_METADATA);
+
+ DBG("Closing metadata channel key %" PRIu64, metadata->key);
+
+ if (metadata->switch_timer_enabled == 1) {
+ consumer_timer_switch_stop(metadata);
+ }
+
+ if (!metadata->metadata_stream) {
+ goto end;
+ }
+
+ /*
+ * Closing write side so the thread monitoring the stream wakes up if any
+ * and clean the metadata stream.
+ */
+ if (metadata->metadata_stream->ust_metadata_poll_pipe[1] >= 0) {
+ ret = close(metadata->metadata_stream->ust_metadata_poll_pipe[1]);
+ if (ret < 0) {
+ PERROR("closing metadata pipe write side");
+ }
+ metadata->metadata_stream->ust_metadata_poll_pipe[1] = -1;
+ }
+
+end:
+ return;
+}
+
+/*
+ * Close every metadata stream wait fd of the metadata hash table. This
+ * function MUST be used very carefully so not to run into a race between the
+ * metadata thread handling streams and this function closing their wait fd.
+ *
+ * For UST, this is used when the session daemon hangs up. Its the metadata
+ * producer so calling this is safe because we are assured that no state change
+ * can occur in the metadata thread for the streams in the hash table.
+ */
+void lttng_ustconsumer_close_all_metadata(struct lttng_ht *metadata_ht)
+{
+ struct lttng_ht_iter iter;
+ struct lttng_consumer_stream *stream;
+
+ LTTNG_ASSERT(metadata_ht);
+ LTTNG_ASSERT(metadata_ht->ht);
+
+ DBG("UST consumer closing all metadata streams");
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
+ node.node) {
+
+ health_code_update();
+
+ pthread_mutex_lock(&stream->chan->lock);
+ lttng_ustconsumer_close_metadata(stream->chan);
+ pthread_mutex_unlock(&stream->chan->lock);
+
+ }
+ rcu_read_unlock();
+}
+
+void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ ret = lttng_ust_ctl_stream_close_wakeup_fd(stream->ustream);
+ if (ret < 0) {
+ ERR("Unable to close wakeup fd");
+ }
+}
+
+/*
+ * Please refer to consumer-timer.c before adding any lock within this
+ * function or any of its callees. Timers have a very strict locking
+ * semantic with respect to teardown. Failure to respect this semantic
+ * introduces deadlocks.
+ *
+ * DON'T hold the metadata lock when calling this function, else this
+ * can cause deadlock involving consumer awaiting for metadata to be
+ * pushed out due to concurrent interaction with the session daemon.
+ */
+int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_channel *channel, int timer, int wait)
+{
+ struct lttcomm_metadata_request_msg request;
+ struct lttcomm_consumer_msg msg;
+ enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ uint64_t len, key, offset, version;
+ int ret;
+
+ LTTNG_ASSERT(channel);
+ LTTNG_ASSERT(channel->metadata_cache);
+
+ memset(&request, 0, sizeof(request));
+
+ /* send the metadata request to sessiond */
+ switch (the_consumer_data.type) {
+ case LTTNG_CONSUMER64_UST:
+ request.bits_per_long = 64;
+ break;
+ case LTTNG_CONSUMER32_UST:
+ request.bits_per_long = 32;
+ break;
+ default:
+ request.bits_per_long = 0;
+ break;
+ }
+
+ request.session_id = channel->session_id;
+ request.session_id_per_pid = channel->session_id_per_pid;
+ /*
+ * Request the application UID here so the metadata of that application can
+ * be sent back. The channel UID corresponds to the user UID of the session
+ * used for the rights on the stream file(s).
+ */
+ request.uid = channel->ust_app_uid;
+ request.key = channel->key;
+
+ DBG("Sending metadata request to sessiond, session id %" PRIu64
+ ", per-pid %" PRIu64 ", app UID %u and channel key %" PRIu64,
+ request.session_id, request.session_id_per_pid, request.uid,
+ request.key);
+
+ pthread_mutex_lock(&ctx->metadata_socket_lock);
+
+ health_code_update();
+
+ ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
+ sizeof(request));
+ if (ret < 0) {
+ ERR("Asking metadata to sessiond");
+ goto end;
+ }
+
+ health_code_update();
+
+ /* Receive the metadata from sessiond */
+ ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
+ sizeof(msg));
+ if (ret != sizeof(msg)) {
+ DBG("Consumer received unexpected message size %d (expects %zu)",
+ ret, sizeof(msg));
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
+ /*
+ * The ret value might 0 meaning an orderly shutdown but this is ok
+ * since the caller handles this.
+ */
+ goto end;
+ }
+
+ health_code_update();
+
+ if (msg.cmd_type == LTTNG_ERR_UND) {
+ /* No registry found */
+ (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
+ ret_code);
+ ret = 0;
+ goto end;
+ } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
+ ERR("Unexpected cmd_type received %d", msg.cmd_type);
+ ret = -1;
+ goto end;
+ }
+
+ len = msg.u.push_metadata.len;
+ key = msg.u.push_metadata.key;
+ offset = msg.u.push_metadata.target_offset;
+ version = msg.u.push_metadata.version;
+
+ LTTNG_ASSERT(key == channel->key);
+ if (len == 0) {
+ DBG("No new metadata to receive for key %" PRIu64, key);
+ }
+
+ health_code_update();
+
+ /* Tell session daemon we are ready to receive the metadata. */
+ ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
+ LTTCOMM_CONSUMERD_SUCCESS);
+ if (ret < 0 || len == 0) {
+ /*
+ * Somehow, the session daemon is not responding anymore or there is
+ * nothing to receive.
+ */
+ goto end;
+ }
+
+ health_code_update();
+
+ ret = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
+ key, offset, len, version, channel, timer, wait);
+ if (ret >= 0) {
+ /*
+ * Only send the status msg if the sessiond is alive meaning a positive
+ * ret code.
+ */
+ (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret);
+ }
+ ret = 0;
+
+end:
+ health_code_update();
+
+ pthread_mutex_unlock(&ctx->metadata_socket_lock);
+ return ret;
+}
+
+/*
+ * Return the ustctl call for the get stream id.
+ */
+int lttng_ustconsumer_get_stream_id(struct lttng_consumer_stream *stream,
+ uint64_t *stream_id)
+{
+ LTTNG_ASSERT(stream);
+ LTTNG_ASSERT(stream_id);
+
+ return lttng_ust_ctl_get_stream_id(stream->ustream, stream_id);
+}
+
+void lttng_ustconsumer_sigbus_handle(void *addr)
+{
+ lttng_ust_ctl_sigbus_handle(addr);
+}
projects / lttng-tools.git / blobdiff