X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=111d655881c7f35c915e83da4239d381df9e4970;hb=d6ef77b34f2ba071e280bc8c25936e95bf1094d9;hp=f23fc9c5711f18101e1b7b3fb6cd7245ea378cee;hpb=13886d2d433762b7cf54f8e812f747ec2829de57;p=lttng-tools.git

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index f23fc9c57..111d65588 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -16,7 +16,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 #include <poll.h>
 #include <pthread.h>
@@ -28,15 +28,25 @@
 #include <inttypes.h>
 #include <unistd.h>
 #include <sys/stat.h>
+#include <stdint.h>
 
+#include <bin/lttng-consumerd/health-consumerd.h>
 #include <common/common.h>
 #include <common/kernel-ctl/kernel-ctl.h>
 #include <common/sessiond-comm/sessiond-comm.h>
 #include <common/sessiond-comm/relayd.h>
 #include <common/compat/fcntl.h>
+#include <common/compat/endian.h>
 #include <common/pipe.h>
 #include <common/relayd/relayd.h>
 #include <common/utils.h>
+#include <common/consumer/consumer-stream.h>
+#include <common/index/index.h>
+#include <common/consumer/consumer-timer.h>
+#include <common/optional.h>
+#include <common/buffer-view.h>
+#include <common/consumer/consumer.h>
+#include <common/consumer/metadata-bucket.h>
 
 #include "kernel-consumer.h"
 
@@ -55,9 +65,12 @@ int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream)
 	int infd = stream->wait_fd;
 
 	ret = kernctl_snapshot(infd);
-	if (ret != 0) {
-		errno = -ret;
-		perror("Getting sub-buffer snapshot.");
+	/*
+	 * -EAGAIN is not an error, it just means that there is no data to
+	 *  be read.
+	 */
+	if (ret != 0 && ret != -EAGAIN) {
+		PERROR("Getting sub-buffer snapshot.");
 	}
 
 	return ret;
@@ -76,36 +89,401 @@ int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 
 	ret = kernctl_snapshot_get_produced(infd, pos);
 	if (ret != 0) {
-		errno = -ret;
-		perror("kernctl_snapshot_get_produced");
+		PERROR("kernctl_snapshot_get_produced");
+	}
+
+	return ret;
+}
+
+/*
+ * Get the consumerd position
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream *stream,
+		unsigned long *pos)
+{
+	int ret;
+	int infd = stream->wait_fd;
+
+	ret = kernctl_snapshot_get_consumed(infd, pos);
+	if (ret != 0) {
+		PERROR("kernctl_snapshot_get_consumed");
+	}
+
+	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 = stream->mmap_base;
+
+	ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset);
+	if (ret < 0) {
+		PERROR("Failed to get mmap read offset");
+		goto error;
+	}
+
+	*addr = mmap_base + mmap_offset;
+error:
+	return ret;
+}
+
+/*
+ * Take a snapshot of all the stream of a channel
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
+		uint64_t relayd_id, uint64_t nb_packets_per_stream,
+		struct lttng_consumer_local_data *ctx)
+{
+	int ret;
+	struct lttng_consumer_channel *channel;
+	struct lttng_consumer_stream *stream;
+
+	DBG("Kernel consumer snapshot channel %" PRIu64, key);
+
+	rcu_read_lock();
+
+	channel = consumer_find_channel(key);
+	if (!channel) {
+		ERR("No channel found for key %" PRIu64, key);
+		ret = -1;
+		goto end;
+	}
+
+	/* Splice is not supported yet for channel snapshot. */
+	if (channel->output != CONSUMER_CHANNEL_MMAP) {
+		ERR("Unsupported output %d", channel->output);
+		ret = -1;
+		goto end;
+	}
+
+	cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+		unsigned long consumed_pos, produced_pos;
+
+		health_code_update();
+
+		/*
+		 * Lock stream because we are about to change its state.
+		 */
+		pthread_mutex_lock(&stream->lock);
+
+		/*
+		 * Assign the received relayd ID so we can use it for streaming. The streams
+		 * are not visible to anyone so this is OK to change it.
+		 */
+		stream->relayd_id = relayd_id;
+		channel->relayd_id = relayd_id;
+		if (relayd_id != (uint64_t) -1ULL) {
+			ret = consumer_send_relayd_stream(stream, path);
+			if (ret < 0) {
+				ERR("sending stream to relayd");
+				goto end_unlock;
+			}
+		} else {
+			ret = utils_create_stream_file(path, stream->name,
+					stream->chan->tracefile_size,
+					stream->tracefile_count_current,
+					stream->uid, stream->gid, NULL);
+			if (ret < 0) {
+				ERR("utils_create_stream_file");
+				goto end_unlock;
+			}
+
+			stream->out_fd = ret;
+			stream->tracefile_size_current = 0;
+
+			DBG("Kernel consumer snapshot stream %s/%s (%" PRIu64 ")",
+					path, stream->name, stream->key);
+		}
+		if (relayd_id != -1ULL) {
+			ret = consumer_send_relayd_streams_sent(relayd_id);
+			if (ret < 0) {
+				ERR("sending streams sent to relayd");
+				goto end_unlock;
+			}
+			channel->streams_sent_to_relayd = true;
+		}
+
+		ret = kernctl_buffer_flush_empty(stream->wait_fd);
+		if (ret < 0) {
+			/*
+			 * Doing a buffer flush which does not take into
+			 * account empty packets. This is not perfect
+			 * for stream intersection, but required as a
+			 * fall-back when "flush_empty" is not
+			 * implemented by lttng-modules.
+			 */
+			ret = kernctl_buffer_flush(stream->wait_fd);
+			if (ret < 0) {
+				ERR("Failed to flush kernel stream");
+				goto end_unlock;
+			}
+			goto end_unlock;
+		}
+
+		ret = lttng_kconsumer_take_snapshot(stream);
+		if (ret < 0) {
+			ERR("Taking kernel snapshot");
+			goto end_unlock;
+		}
+
+		ret = lttng_kconsumer_get_produced_snapshot(stream, &produced_pos);
+		if (ret < 0) {
+			ERR("Produced kernel snapshot position");
+			goto end_unlock;
+		}
+
+		ret = lttng_kconsumer_get_consumed_snapshot(stream, &consumed_pos);
+		if (ret < 0) {
+			ERR("Consumerd kernel snapshot position");
+			goto end_unlock;
+		}
+
+		if (stream->max_sb_size == 0) {
+			ret = kernctl_get_max_subbuf_size(stream->wait_fd,
+					&stream->max_sb_size);
+			if (ret < 0) {
+				ERR("Getting kernel max_sb_size");
+				goto end_unlock;
+			}
+		}
+
+		consumed_pos = consumer_get_consume_start_pos(consumed_pos,
+				produced_pos, nb_packets_per_stream,
+				stream->max_sb_size);
+
+		while (consumed_pos < produced_pos) {
+			ssize_t read_len;
+			unsigned long len, padded_len;
+			const char *subbuf_addr;
+			struct lttng_buffer_view subbuf_view;
+
+			health_code_update();
+			DBG("Kernel consumer taking snapshot at pos %lu", consumed_pos);
+
+			ret = kernctl_get_subbuf(stream->wait_fd, &consumed_pos);
+			if (ret < 0) {
+				if (ret != -EAGAIN) {
+					PERROR("kernctl_get_subbuf snapshot");
+					goto end_unlock;
+				}
+				DBG("Kernel consumer get subbuf failed. Skipping it.");
+				consumed_pos += stream->max_sb_size;
+				stream->chan->lost_packets++;
+				continue;
+			}
+
+			ret = kernctl_get_subbuf_size(stream->wait_fd, &len);
+			if (ret < 0) {
+				ERR("Snapshot kernctl_get_subbuf_size");
+				goto error_put_subbuf;
+			}
+
+			ret = kernctl_get_padded_subbuf_size(stream->wait_fd, &padded_len);
+			if (ret < 0) {
+				ERR("Snapshot kernctl_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);
+			/*
+			 * We write the padded len in local tracefiles but the data len
+			 * when using a relay. Display the error but continue processing
+			 * to try to release the subbuffer.
+			 */
+			if (relayd_id != (uint64_t) -1ULL) {
+				if (read_len != len) {
+					ERR("Error sending to the relay (ret: %zd != len: %lu)",
+							read_len, len);
+				}
+			} else {
+				if (read_len != padded_len) {
+					ERR("Error writing to tracefile (ret: %zd != len: %lu)",
+							read_len, padded_len);
+				}
+			}
+
+			ret = kernctl_put_subbuf(stream->wait_fd);
+			if (ret < 0) {
+				ERR("Snapshot kernctl_put_subbuf");
+				goto end_unlock;
+			}
+			consumed_pos += stream->max_sb_size;
+		}
+
+		if (relayd_id == (uint64_t) -1ULL) {
+			if (stream->out_fd >= 0) {
+				ret = close(stream->out_fd);
+				if (ret < 0) {
+					PERROR("Kernel consumer snapshot close out_fd");
+					goto end_unlock;
+				}
+				stream->out_fd = -1;
+			}
+		} else {
+			close_relayd_stream(stream);
+			stream->relayd_id = (uint64_t) -1ULL;
+		}
+		pthread_mutex_unlock(&stream->lock);
+	}
+
+	/* All good! */
+	ret = 0;
+	goto end;
+
+error_put_subbuf:
+	ret = kernctl_put_subbuf(stream->wait_fd);
+	if (ret < 0) {
+		ERR("Snapshot kernctl_put_subbuf error path");
+	}
+end_unlock:
+	pthread_mutex_unlock(&stream->lock);
+end:
+	rcu_read_unlock();
+	return ret;
+}
+
+/*
+ * Read the whole metadata available for a snapshot.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+static int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
+		uint64_t relayd_id, struct lttng_consumer_local_data *ctx)
+{
+	int ret, use_relayd = 0;
+	ssize_t ret_read;
+	struct lttng_consumer_channel *metadata_channel;
+	struct lttng_consumer_stream *metadata_stream;
+
+	assert(ctx);
+
+	DBG("Kernel consumer snapshot metadata with key %" PRIu64 " at path %s",
+			key, path);
+
+	rcu_read_lock();
+
+	metadata_channel = consumer_find_channel(key);
+	if (!metadata_channel) {
+		ERR("Kernel snapshot metadata not found for key %" PRIu64, key);
+		ret = -1;
+		goto error_no_channel;
+	}
+
+	metadata_stream = metadata_channel->metadata_stream;
+	assert(metadata_stream);
+	pthread_mutex_lock(&metadata_stream->lock);
+
+	/* Flag once that we have a valid relayd for the stream. */
+	if (relayd_id != (uint64_t) -1ULL) {
+		use_relayd = 1;
+	}
+
+	if (use_relayd) {
+		ret = consumer_send_relayd_stream(metadata_stream, path);
+		if (ret < 0) {
+			goto error_snapshot;
+		}
+	} else {
+		ret = utils_create_stream_file(path, metadata_stream->name,
+				metadata_stream->chan->tracefile_size,
+				metadata_stream->tracefile_count_current,
+				metadata_stream->uid, metadata_stream->gid, NULL);
+		if (ret < 0) {
+			goto error_snapshot;
+		}
+		metadata_stream->out_fd = ret;
+	}
+
+	do {
+		health_code_update();
+
+		ret_read = lttng_consumer_read_subbuffer(metadata_stream, ctx, true);
+		if (ret_read < 0) {
+			if (ret_read != -EAGAIN) {
+				ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
+						ret_read);
+				ret = ret_read;
+				goto error_snapshot;
+			}
+			/* ret_read is negative at this point so we will exit the loop. */
+			continue;
+		}
+	} while (ret_read >= 0);
+
+	if (use_relayd) {
+		close_relayd_stream(metadata_stream);
+		metadata_stream->relayd_id = (uint64_t) -1ULL;
+	} else {
+		if (metadata_stream->out_fd >= 0) {
+			ret = close(metadata_stream->out_fd);
+			if (ret < 0) {
+				PERROR("Kernel consumer snapshot metadata close out_fd");
+				/*
+				 * Don't go on error here since the snapshot was successful at this
+				 * point but somehow the close failed.
+				 */
+			}
+			metadata_stream->out_fd = -1;
+		}
 	}
 
+	ret = 0;
+error_snapshot:
+	pthread_mutex_unlock(&metadata_stream->lock);
+	cds_list_del(&metadata_stream->send_node);
+	consumer_stream_destroy(metadata_stream, NULL);
+	metadata_channel->metadata_stream = NULL;
+error_no_channel:
+	rcu_read_unlock();
 	return ret;
 }
 
+/*
+ * Receive command from session daemon and process it.
+ *
+ * Return 1 on success else a negative value or 0.
+ */
 int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 		int sock, struct pollfd *consumer_sockpoll)
 {
 	ssize_t ret;
-	enum lttng_error_code ret_code = LTTNG_OK;
+	enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
 	struct lttcomm_consumer_msg msg;
 
+	health_code_update();
+
 	ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
 	if (ret != sizeof(msg)) {
-		lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
+		if (ret > 0) {
+			lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
+			ret = -1;
+		}
 		return ret;
 	}
-	if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
-		/*
-		 * Notify the session daemon that the command is completed.
-		 *
-		 * On transport layer error, the function call will print an error
-		 * message so handling the returned code is a bit useless since we
-		 * return an error code anyway.
-		 */
-		(void) consumer_send_status_msg(sock, ret_code);
-		return -ENOENT;
-	}
+
+	health_code_update();
+
+	/* Deprecated command */
+	assert(msg.cmd_type != LTTNG_CONSUMER_STOP);
+
+	health_code_update();
 
 	/* relayd needs RCU read-side protection */
 	rcu_read_lock();
@@ -114,34 +492,55 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 	case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
 	{
 		/* Session daemon status message are handled in the following call. */
-		ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
+		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.sock, msg.u.relayd_sock.session_id,
+				msg.u.relayd_sock.relayd_session_id);
 		goto end_nosignal;
 	}
 	case LTTNG_CONSUMER_ADD_CHANNEL:
 	{
 		struct lttng_consumer_channel *new_channel;
+		int ret_recv;
+
+		health_code_update();
 
 		/* First send a status message before receiving the fds. */
 		ret = consumer_send_status_msg(sock, ret_code);
 		if (ret < 0) {
 			/* Somehow, the session daemon is not responding anymore. */
-			goto end_nosignal;
+			goto error_fatal;
 		}
 
+		health_code_update();
+
 		DBG("consumer_add_channel %" PRIu64, msg.u.channel.channel_key);
 		new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
 				msg.u.channel.session_id, msg.u.channel.pathname,
 				msg.u.channel.name, msg.u.channel.uid, msg.u.channel.gid,
 				msg.u.channel.relayd_id, msg.u.channel.output,
 				msg.u.channel.tracefile_size,
-				msg.u.channel.tracefile_count);
+				msg.u.channel.tracefile_count, 0,
+				msg.u.channel.monitor,
+				msg.u.channel.live_timer_interval,
+				msg.u.channel.is_live,
+				NULL, NULL);
 		if (new_channel == NULL) {
 			lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
 			goto end_nosignal;
 		}
 		new_channel->nb_init_stream_left = msg.u.channel.nb_init_streams;
+		switch (msg.u.channel.output) {
+		case LTTNG_EVENT_SPLICE:
+			new_channel->output = CONSUMER_CHANNEL_SPLICE;
+			break;
+		case LTTNG_EVENT_MMAP:
+			new_channel->output = CONSUMER_CHANNEL_MMAP;
+			break;
+		default:
+			ERR("Channel output unknown %d", msg.u.channel.output);
+			goto end_nosignal;
+		}
 
 		/* Translate and save channel type. */
 		switch (msg.u.channel.type) {
@@ -154,22 +553,40 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 			goto end_nosignal;
 		};
 
+		health_code_update();
+
 		if (ctx->on_recv_channel != NULL) {
-			ret = ctx->on_recv_channel(new_channel);
-			if (ret == 0) {
-				consumer_add_channel(new_channel, ctx);
-			} else if (ret < 0) {
+			ret_recv = ctx->on_recv_channel(new_channel);
+			if (ret_recv == 0) {
+				ret = consumer_add_channel(new_channel, ctx);
+			} else if (ret_recv < 0) {
 				goto end_nosignal;
 			}
 		} else {
-			consumer_add_channel(new_channel, ctx);
+			ret = consumer_add_channel(new_channel, ctx);
+		}
+		if (CONSUMER_CHANNEL_TYPE_DATA) {
+			consumer_timer_live_start(new_channel,
+					msg.u.channel.live_timer_interval);
+		}
+
+		health_code_update();
+
+		/* If we received an error in add_channel, we need to report it. */
+		if (ret < 0) {
+			ret = consumer_send_status_msg(sock, ret);
+			if (ret < 0) {
+				goto error_fatal;
+			}
+			goto end_nosignal;
 		}
+
 		goto end_nosignal;
 	}
 	case LTTNG_CONSUMER_ADD_STREAM:
 	{
-		int fd, stream_pipe;
-		struct consumer_relayd_sock_pair *relayd = NULL;
+		int fd;
+		struct lttng_pipe *stream_pipe;
 		struct lttng_consumer_stream *new_stream;
 		struct lttng_consumer_channel *channel;
 		int alloc_ret = 0;
@@ -185,25 +602,35 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 			 * happens while tearing down.
 			 */
 			ERR("Unable to find channel key %" PRIu64, msg.u.stream.channel_key);
-			ret_code = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
+			ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
 		}
 
+		health_code_update();
+
 		/* First send a status message before receiving the fds. */
 		ret = consumer_send_status_msg(sock, ret_code);
-		if (ret < 0 || ret_code != LTTNG_OK) {
-			/*
-			 * Somehow, the session daemon is not responding anymore or the
-			 * channel was not found.
-			 */
+		if (ret < 0) {
+			/* Somehow, the session daemon is not responding anymore. */
+			goto error_fatal;
+		}
+
+		health_code_update();
+
+		if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
+			/* Channel was not found. */
 			goto end_nosignal;
 		}
 
-		/* block */
-		if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
-			rcu_read_unlock();
-			return -EINTR;
+		/* Blocking call */
+		health_poll_entry();
+		ret = lttng_consumer_poll_socket(consumer_sockpoll);
+		health_poll_exit();
+		if (ret) {
+			goto error_fatal;
 		}
 
+		health_code_update();
+
 		/* Get stream file descriptor from socket */
 		ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
 		if (ret != sizeof(fd)) {
@@ -212,6 +639,8 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 			return ret;
 		}
 
+		health_code_update();
+
 		/*
 		 * Send status code to session daemon only if the recv works. If the
 		 * above recv() failed, the session daemon is notified through the
@@ -223,7 +652,12 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 			goto end_nosignal;
 		}
 
-		new_stream = consumer_allocate_stream(channel->key,
+		health_code_update();
+
+		pthread_mutex_lock(&channel->lock);
+		new_stream = consumer_stream_create(
+				channel,
+				channel->key,
 				fd,
 				LTTNG_CONSUMER_ACTIVE_STREAM,
 				channel->name,
@@ -233,7 +667,8 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				channel->session_id,
 				msg.u.stream.cpu,
 				&alloc_ret,
-				channel->type);
+				channel->type,
+				channel->monitor);
 		if (new_stream == NULL) {
 			switch (alloc_ret) {
 			case -ENOMEM:
@@ -242,10 +677,29 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
 				break;
 			}
+			pthread_mutex_unlock(&channel->lock);
 			goto end_nosignal;
 		}
-		new_stream->chan = channel;
+
 		new_stream->wait_fd = fd;
+		ret = kernctl_get_max_subbuf_size(new_stream->wait_fd,
+				&new_stream->max_sb_size);
+		if (ret < 0) {
+			pthread_mutex_unlock(&channel->lock);
+			ERR("Failed to get kernel maximal subbuffer size");
+			goto end_nosignal;
+		}
+
+		/*
+		 * We've just assigned the channel to the stream so increment the
+		 * refcount right now. We don't need to increment the refcount for
+		 * streams in no monitor because we handle manually the cleanup of
+		 * those. It is very important to make sure there is NO prior
+		 * consumer_del_stream() calls or else the refcount will be unbalanced.
+		 */
+		if (channel->monitor) {
+			uatomic_inc(&new_stream->chan->refcount);
+		}
 
 		/*
 		 * The buffer flush is done on the session daemon side for the kernel
@@ -256,51 +710,94 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 		 */
 		new_stream->hangup_flush_done = 0;
 
-		/* The stream is not metadata. Get relayd reference if exists. */
-		relayd = consumer_find_relayd(new_stream->net_seq_idx);
-		if (relayd != NULL) {
-			/* Add stream on the relayd */
-			pthread_mutex_lock(&relayd->ctrl_sock_mutex);
-			ret = relayd_add_stream(&relayd->control_sock,
-					new_stream->name, new_stream->chan->pathname,
-					&new_stream->relayd_stream_id,
-					new_stream->chan->tracefile_size,
-					new_stream->chan->tracefile_count);
-			pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+		health_code_update();
+
+		if (ctx->on_recv_stream) {
+			ret = ctx->on_recv_stream(new_stream);
 			if (ret < 0) {
-				consumer_del_stream(new_stream, NULL);
+				consumer_stream_free(new_stream);
 				goto end_nosignal;
 			}
-		} else if (new_stream->net_seq_idx != (uint64_t) -1ULL) {
-			ERR("Network sequence index %" PRIu64 " unknown. Not adding stream.",
-					new_stream->net_seq_idx);
-			consumer_del_stream(new_stream, NULL);
-			goto end_nosignal;
 		}
 
-		if (ctx->on_recv_stream) {
-			ret = ctx->on_recv_stream(new_stream);
+		health_code_update();
+
+		if (new_stream->metadata_flag) {
+			channel->metadata_stream = new_stream;
+		}
+
+		/* Do not monitor this stream. */
+		if (!channel->monitor) {
+			DBG("Kernel consumer add stream %s in no monitor mode with "
+					"relayd id %" PRIu64, new_stream->name,
+					new_stream->relayd_id);
+			cds_list_add(&new_stream->send_node, &channel->streams.head);
+			pthread_mutex_unlock(&channel->lock);
+			break;
+		}
+
+		/* Send stream to relayd if the stream has an ID. */
+		if (new_stream->relayd_id != (uint64_t) -1ULL) {
+			ret = consumer_send_relayd_stream(new_stream,
+					new_stream->chan->pathname);
 			if (ret < 0) {
-				consumer_del_stream(new_stream, NULL);
+				pthread_mutex_unlock(&channel->lock);
+				consumer_stream_free(new_stream);
 				goto end_nosignal;
 			}
+
+			/*
+			 * If adding an extra stream to an already
+			 * existing channel (e.g. cpu hotplug), we need
+			 * to send the "streams_sent" command to relayd.
+			 */
+			if (channel->streams_sent_to_relayd) {
+				ret = consumer_send_relayd_streams_sent(
+						new_stream->relayd_id);
+				if (ret < 0) {
+					pthread_mutex_unlock(&channel->lock);
+					goto end_nosignal;
+				}
+			}
 		}
+		pthread_mutex_unlock(&channel->lock);
 
 		/* Get the right pipe where the stream will be sent. */
 		if (new_stream->metadata_flag) {
-			stream_pipe = lttng_pipe_get_writefd(ctx->consumer_metadata_pipe);
+			ret = consumer_add_metadata_stream(new_stream);
+			if (ret) {
+				ERR("Consumer add metadata stream %" PRIu64 " failed. Continuing",
+						new_stream->key);
+				consumer_stream_free(new_stream);
+				goto end_nosignal;
+			}
+			stream_pipe = ctx->consumer_metadata_pipe;
 		} else {
-			stream_pipe = lttng_pipe_get_writefd(ctx->consumer_data_pipe);
+			ret = consumer_add_data_stream(new_stream);
+			if (ret) {
+				ERR("Consumer add stream %" PRIu64 " failed. Continuing",
+						new_stream->key);
+				consumer_stream_free(new_stream);
+				goto end_nosignal;
+			}
+			stream_pipe = ctx->consumer_data_pipe;
 		}
 
-		do {
-			ret = write(stream_pipe, &new_stream, sizeof(new_stream));
-		} while (ret < 0 && errno == EINTR);
+		/* Vitible to other threads */
+		new_stream->globally_visible = 1;
+
+		health_code_update();
+
+		ret = lttng_pipe_write(stream_pipe, &new_stream, sizeof(new_stream));
 		if (ret < 0) {
-			PERROR("Consumer write %s stream to pipe %d",
+			ERR("Consumer write %s stream to pipe %d",
 					new_stream->metadata_flag ? "metadata" : "data",
-					stream_pipe);
-			consumer_del_stream(new_stream, NULL);
+					lttng_pipe_get_writefd(stream_pipe));
+			if (new_stream->metadata_flag) {
+				consumer_del_stream_for_metadata(new_stream);
+			} else {
+				consumer_del_stream_for_data(new_stream);
+			}
 			goto end_nosignal;
 		}
 
@@ -308,6 +805,58 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				new_stream->name, fd, new_stream->relayd_stream_id);
 		break;
 	}
+	case LTTNG_CONSUMER_STREAMS_SENT:
+	{
+		struct lttng_consumer_channel *channel;
+
+		/*
+		 * Get stream's channel reference. Needed when adding the stream to the
+		 * global hash table.
+		 */
+		channel = consumer_find_channel(msg.u.sent_streams.channel_key);
+		if (!channel) {
+			/*
+			 * We could not find the channel. Can happen if cpu hotplug
+			 * happens while tearing down.
+			 */
+			ERR("Unable to find channel key %" PRIu64,
+					msg.u.sent_streams.channel_key);
+			ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+		}
+
+		health_code_update();
+
+		/*
+		 * Send status code to session daemon.
+		 */
+		ret = consumer_send_status_msg(sock, ret_code);
+		if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
+			/* Somehow, the session daemon is not responding anymore. */
+			goto end_nosignal;
+		}
+
+		health_code_update();
+
+		/*
+		 * We should not send this message if we don't monitor the
+		 * streams in this channel.
+		 */
+		if (!channel->monitor) {
+			break;
+		}
+
+		health_code_update();
+		/* Send stream to relayd if the stream has an ID. */
+		if (msg.u.sent_streams.net_seq_idx != (uint64_t) -1ULL) {
+			ret = consumer_send_relayd_streams_sent(
+					msg.u.sent_streams.net_seq_idx);
+			if (ret < 0) {
+				goto end_nosignal;
+			}
+			channel->streams_sent_to_relayd = true;
+		}
+		break;
+	}
 	case LTTNG_CONSUMER_UPDATE_STREAM:
 	{
 		rcu_read_unlock();
@@ -324,7 +873,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 		relayd = consumer_find_relayd(index);
 		if (relayd == NULL) {
 			DBG("Unable to find relayd %" PRIu64, index);
-			ret_code = LTTNG_ERR_NO_CONSUMER;
+			ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
 		}
 
 		/*
@@ -341,10 +890,12 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 			consumer_flag_relayd_for_destroy(relayd);
 		}
 
+		health_code_update();
+
 		ret = consumer_send_status_msg(sock, ret_code);
 		if (ret < 0) {
 			/* Somehow, the session daemon is not responding anymore. */
-			goto end_nosignal;
+			goto error_fatal;
 		}
 
 		goto end_nosignal;
@@ -358,10 +909,13 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 
 		ret = consumer_data_pending(id);
 
+		health_code_update();
+
 		/* Send back returned value to session daemon */
 		ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
 		if (ret < 0) {
 			PERROR("send data pending ret code");
+			goto error_fatal;
 		}
 
 		/*
@@ -370,6 +924,139 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 		 */
 		break;
 	}
+	case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
+	{
+		if (msg.u.snapshot_channel.metadata == 1) {
+			ret = lttng_kconsumer_snapshot_metadata(msg.u.snapshot_channel.key,
+					msg.u.snapshot_channel.pathname,
+					msg.u.snapshot_channel.relayd_id, ctx);
+			if (ret < 0) {
+				ERR("Snapshot metadata failed");
+				ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
+			}
+		} else {
+			ret = lttng_kconsumer_snapshot_channel(msg.u.snapshot_channel.key,
+					msg.u.snapshot_channel.pathname,
+					msg.u.snapshot_channel.relayd_id,
+					msg.u.snapshot_channel.nb_packets_per_stream,
+					ctx);
+			if (ret < 0) {
+				ERR("Snapshot channel failed");
+				ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+			}
+		}
+
+		health_code_update();
+
+		ret = consumer_send_status_msg(sock, ret_code);
+		if (ret < 0) {
+			/* Somehow, the session daemon is not responding anymore. */
+			goto end_nosignal;
+		}
+		break;
+	}
+	case LTTNG_CONSUMER_DESTROY_CHANNEL:
+	{
+		uint64_t key = msg.u.destroy_channel.key;
+		struct lttng_consumer_channel *channel;
+
+		channel = consumer_find_channel(key);
+		if (!channel) {
+			ERR("Kernel consumer destroy channel %" PRIu64 " not found", key);
+			ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+		}
+
+		health_code_update();
+
+		ret = consumer_send_status_msg(sock, ret_code);
+		if (ret < 0) {
+			/* Somehow, the session daemon is not responding anymore. */
+			goto end_nosignal;
+		}
+
+		health_code_update();
+
+		/* Stop right now if no channel was found. */
+		if (!channel) {
+			goto end_nosignal;
+		}
+
+		/*
+		 * This command should ONLY be issued for channel with streams set in
+		 * no monitor mode.
+		 */
+		assert(!channel->monitor);
+
+		/*
+		 * The refcount should ALWAYS be 0 in the case of a channel in no
+		 * monitor mode.
+		 */
+		assert(!uatomic_sub_return(&channel->refcount, 1));
+
+		consumer_del_channel(channel);
+
+		goto end_nosignal;
+	}
+	case LTTNG_CONSUMER_DISCARDED_EVENTS:
+	{
+		uint64_t ret;
+		struct lttng_consumer_channel *channel;
+		uint64_t id = msg.u.discarded_events.session_id;
+		uint64_t key = msg.u.discarded_events.channel_key;
+
+		DBG("Kernel consumer discarded events command for session id %"
+				PRIu64 ", channel key %" PRIu64, id, key);
+
+		channel = consumer_find_channel(key);
+		if (!channel) {
+			ERR("Kernel consumer discarded events channel %"
+					PRIu64 " not found", key);
+			ret = 0;
+		} else {
+			ret = channel->discarded_events;
+		}
+
+		health_code_update();
+
+		/* Send back returned value to session daemon */
+		ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
+		if (ret < 0) {
+			PERROR("send discarded events");
+			goto error_fatal;
+		}
+
+		break;
+	}
+	case LTTNG_CONSUMER_LOST_PACKETS:
+	{
+		uint64_t ret;
+		struct lttng_consumer_channel *channel;
+		uint64_t id = msg.u.lost_packets.session_id;
+		uint64_t key = msg.u.lost_packets.channel_key;
+
+		DBG("Kernel consumer lost packets command for session id %"
+				PRIu64 ", channel key %" PRIu64, id, key);
+
+		channel = consumer_find_channel(key);
+		if (!channel) {
+			ERR("Kernel consumer lost packets channel %"
+					PRIu64 " not found", key);
+			ret = 0;
+		} else {
+			ret = channel->lost_packets;
+		}
+
+		health_code_update();
+
+		/* Send back returned value to session daemon */
+		ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
+		if (ret < 0) {
+			PERROR("send lost packets");
+			goto error_fatal;
+		}
+
+		break;
+	}
 	default:
 		goto end_nosignal;
 	}
@@ -381,125 +1068,347 @@ end_nosignal:
 	 * Return 1 to indicate success since the 0 value can be a socket
 	 * shutdown during the recv() or send() call.
 	 */
+	health_code_update();
 	return 1;
+
+error_fatal:
+	rcu_read_unlock();
+	/* This will issue a consumer stop. */
+	return -1;
 }
 
 /*
- * Consume data on a file descriptor and write it on a trace file.
+ * Sync metadata meaning request them to the session daemon and snapshot to the
+ * metadata thread can consumer them.
+ *
+ * Metadata stream lock MUST be acquired.
+ *
+ * Return 0 if new metadatda is available, EAGAIN if the metadata stream
+ * is empty or a negative value on error.
  */
-ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
-		struct lttng_consumer_local_data *ctx)
+int lttng_kconsumer_sync_metadata(struct lttng_consumer_stream *metadata)
 {
-	unsigned long len, subbuf_size, padding;
-	int err;
-	ssize_t ret = 0;
-	int infd = stream->wait_fd;
+	int ret;
 
-	DBG("In read_subbuffer (infd : %d)", infd);
-	/* Get the next subbuffer */
-	err = kernctl_get_next_subbuf(infd);
-	if (err != 0) {
-		ret = err;
-		/*
-		 * This is a debug message even for single-threaded consumer,
-		 * because poll() have more relaxed criterions than get subbuf,
-		 * so get_subbuf may fail for short race windows where poll()
-		 * would issue wakeups.
-		 */
-		DBG("Reserving sub buffer failed (everything is normal, "
-				"it is due to concurrency)");
+	assert(metadata);
+
+	ret = kernctl_buffer_flush(metadata->wait_fd);
+	if (ret < 0) {
+		ERR("Failed to flush kernel stream");
 		goto end;
 	}
 
-	/* Get the full subbuffer size including padding */
-	err = kernctl_get_padded_subbuf_size(infd, &len);
-	if (err != 0) {
-		errno = -err;
-		perror("Getting sub-buffer len failed.");
-		ret = err;
+	ret = kernctl_snapshot(metadata->wait_fd);
+	if (ret < 0) {
+		if (ret != -EAGAIN) {
+			ERR("Sync metadata, taking kernel snapshot failed.");
+			goto end;
+		}
+		DBG("Sync metadata, no new kernel metadata");
+		/* No new metadata, exit. */
+		ret = ENODATA;
 		goto end;
 	}
 
-	switch (stream->chan->output) {
-	case LTTNG_EVENT_SPLICE:
+end:
+	return ret;
+}
 
-		/*
-		 * XXX: The lttng-modules splice "actor" does not handle copying
-		 * partial pages hence only using the subbuffer size without the
-		 * padding makes the splice fail.
-		 */
-		subbuf_size = len;
-		padding = 0;
+static
+int extract_common_subbuffer_info(struct lttng_consumer_stream *stream,
+		struct stream_subbuffer *subbuf)
+{
+	int ret;
 
-		/* splice the subbuffer to the tracefile */
-		ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, subbuf_size,
-				padding);
-		/*
-		 * XXX: Splice does not support network streaming so the return value
-		 * is simply checked against subbuf_size and not like the mmap() op.
-		 */
-		if (ret != subbuf_size) {
-			/*
-			 * display the error but continue processing to try
-			 * to release the subbuffer
-			 */
-			ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
-					ret, subbuf_size);
+	ret = kernctl_get_subbuf_size(
+			stream->wait_fd, &subbuf->info.data.subbuf_size);
+	if (ret) {
+		goto end;
+	}
+
+	ret = kernctl_get_padded_subbuf_size(
+			stream->wait_fd, &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;
+	}
+
+	ret = kernctl_get_metadata_version(
+			stream->wait_fd, &subbuf->info.metadata.version);
+	if (ret) {
+		goto end;
+	}
+
+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 = kernctl_get_packet_size(
+			stream->wait_fd, &subbuf->info.data.packet_size);
+	if (ret < 0) {
+		PERROR("Failed to get sub-buffer packet size");
+		goto end;
+	}
+
+	ret = kernctl_get_content_size(
+			stream->wait_fd, &subbuf->info.data.content_size);
+	if (ret < 0) {
+		PERROR("Failed to get sub-buffer content size");
+		goto end;
+	}
+
+	ret = kernctl_get_timestamp_begin(
+			stream->wait_fd, &subbuf->info.data.timestamp_begin);
+	if (ret < 0) {
+		PERROR("Failed to get sub-buffer begin timestamp");
+		goto end;
+	}
+
+	ret = kernctl_get_timestamp_end(
+			stream->wait_fd, &subbuf->info.data.timestamp_end);
+	if (ret < 0) {
+		PERROR("Failed to get sub-buffer end timestamp");
+		goto end;
+	}
+
+	ret = kernctl_get_events_discarded(
+			stream->wait_fd, &subbuf->info.data.events_discarded);
+	if (ret) {
+		PERROR("Failed to get sub-buffer events discarded count");
+		goto end;
+	}
+
+	ret = kernctl_get_sequence_number(stream->wait_fd,
+			&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;
 		}
-		break;
-	case LTTNG_EVENT_MMAP:
-		/* Get subbuffer size without padding */
-		err = kernctl_get_subbuf_size(infd, &subbuf_size);
-		if (err != 0) {
-			errno = -err;
-			perror("Getting sub-buffer len failed.");
-			ret = err;
+	} else {
+		subbuf->info.data.sequence_number.is_set = true;
+	}
+
+	ret = kernctl_get_stream_id(
+			stream->wait_fd, &subbuf->info.data.stream_id);
+	if (ret < 0) {
+		PERROR("Failed to get stream id");
+		goto end;
+	}
+
+	ret = kernctl_get_instance_id(stream->wait_fd,
+			&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;
+}
 
-		/* Make sure the tracer is not gone mad on us! */
-		assert(len >= subbuf_size);
+static
+int get_subbuffer_common(struct lttng_consumer_stream *stream,
+		struct stream_subbuffer *subbuffer)
+{
+	int ret;
 
-		padding = len - subbuf_size;
+	ret = kernctl_get_next_subbuf(stream->wait_fd);
+	if (ret) {
+		goto end;
+	}
 
-		/* write the subbuffer to the tracefile */
-		ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size,
-				padding);
-		/*
-		 * The mmap operation should write subbuf_size amount of data when
-		 * network streaming or the full padding (len) size when we are _not_
-		 * streaming.
-		 */
-		if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
-				(ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
+	ret = stream->read_subbuffer_ops.extract_subbuffer_info(
+			stream, subbuffer);
+end:
+	return ret;
+}
+
+static
+int get_next_subbuffer_splice(struct lttng_consumer_stream *stream,
+		struct stream_subbuffer *subbuffer)
+{
+	int ret;
+
+	ret = get_subbuffer_common(stream, subbuffer);
+	if (ret) {
+		goto end;
+	}
+
+	subbuffer->buffer.fd = stream->wait_fd;
+end:
+	return ret;
+}
+
+static
+int get_next_subbuffer_mmap(struct lttng_consumer_stream *stream,
+		struct stream_subbuffer *subbuffer)
+{
+	int ret;
+	const char *addr;
+
+	ret = get_subbuffer_common(stream, subbuffer);
+	if (ret) {
+		goto end;
+	}
+
+	ret = get_current_subbuf_addr(stream, &addr);
+	if (ret) {
+		goto end;
+	}
+
+	subbuffer->buffer.buffer = lttng_buffer_view_init(
+			addr, 0, subbuffer->info.data.padded_subbuf_size);
+end:
+	return ret;
+}
+
+static
+int get_next_subbuffer_metadata_check(struct lttng_consumer_stream *stream,
+		struct stream_subbuffer *subbuffer)
+{
+	int ret;
+	const char *addr;
+	bool coherent;
+
+	ret = kernctl_get_next_subbuf_metadata_check(stream->wait_fd,
+			&coherent);
+	if (ret) {
+		goto end;
+	}
+
+	ret = stream->read_subbuffer_ops.extract_subbuffer_info(
+			stream, subbuffer);
+	if (ret) {
+		goto end;
+	}
+
+	LTTNG_OPTIONAL_SET(&subbuffer->info.metadata.coherent, coherent);
+
+	ret = get_current_subbuf_addr(stream, &addr);
+	if (ret) {
+		goto end;
+	}
+
+	subbuffer->buffer.buffer = lttng_buffer_view_init(
+			addr, 0, subbuffer->info.data.padded_subbuf_size);
+	DBG("Got metadata packet with padded_subbuf_size = %lu, coherent = %s",
+			subbuffer->info.metadata.padded_subbuf_size,
+			coherent ? "true" : "false");
+end:
+	return ret;
+}
+
+static
+int put_next_subbuffer(struct lttng_consumer_stream *stream,
+		struct stream_subbuffer *subbuffer)
+{
+	const int ret = kernctl_put_next_subbuf(stream->wait_fd);
+
+	if (ret) {
+		if (ret == -EFAULT) {
+			PERROR("Error in unreserving sub buffer");
+		} else if (ret == -EIO) {
+			/* Should never happen with newer LTTng versions */
+			PERROR("Reader has been pushed by the writer, last sub-buffer corrupted");
+		}
+	}
+
+	return ret;
+}
+
+static
+bool is_get_next_check_metadata_available(int tracer_fd)
+{
+	return kernctl_get_next_subbuf_metadata_check(tracer_fd, NULL) !=
+			-ENOTTY;
+}
+
+static
+int lttng_kconsumer_set_stream_ops(
+		struct lttng_consumer_stream *stream)
+{
+	int ret = 0;
+
+	if (stream->metadata_flag && stream->chan->is_live) {
+		DBG("Attempting to enable metadata bucketization for live consumers");
+		if (is_get_next_check_metadata_available(stream->wait_fd)) {
+			DBG("Kernel tracer supports get_next_subbuffer_metadata_check, metadata will be accumulated until a coherent state is reached");
+			stream->read_subbuffer_ops.get_next_subbuffer =
+					get_next_subbuffer_metadata_check;
+			ret = consumer_stream_enable_metadata_bucketization(
+					stream);
+			if (ret) {
+				goto end;
+			}
+		} else {
 			/*
-			 * Display the error but continue processing to try to release the
-			 * subbuffer
+			 * The kernel tracer version is too old to indicate
+			 * when the metadata stream has reached a "coherent"
+			 * (parseable) point.
+			 *
+			 * This means that a live viewer may see an incoherent
+			 * sequence of metadata and fail to parse it.
 			 */
-			ERR("Error writing to tracefile "
-					"(ret: %zd != len: %lu != subbuf_size: %lu)",
-					ret, len, subbuf_size);
+			WARN("Kernel tracer does not support get_next_subbuffer_metadata_check which may cause live clients to fail to parse the metadata stream");
+			metadata_bucket_destroy(stream->metadata_bucket);
+			stream->metadata_bucket = NULL;
 		}
-		break;
-	default:
-		ERR("Unknown output method");
-		ret = -1;
 	}
 
-	err = kernctl_put_next_subbuf(infd);
-	if (err != 0) {
-		errno = -err;
-		if (errno == EFAULT) {
-			perror("Error in unreserving sub buffer\n");
-		} else if (errno == EIO) {
-			/* Should never happen with newer LTTng versions */
-			perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
+	if (!stream->read_subbuffer_ops.get_next_subbuffer) {
+		if (stream->chan->output == CONSUMER_CHANNEL_MMAP) {
+			stream->read_subbuffer_ops.get_next_subbuffer =
+					get_next_subbuffer_mmap;
+		} else {
+			stream->read_subbuffer_ops.get_next_subbuffer =
+					get_next_subbuffer_splice;
 		}
+	}
 
-		ret = -err;
-		goto end;
+	if (stream->metadata_flag) {
+		stream->read_subbuffer_ops.extract_subbuffer_info =
+				extract_metadata_subbuffer_info;
+	} else {
+		stream->read_subbuffer_ops.extract_subbuffer_info =
+				extract_data_subbuffer_info;
+		if (stream->chan->is_live) {
+			stream->read_subbuffer_ops.send_live_beacon =
+					consumer_flush_kernel_index;
+		}
 	}
 
+	stream->read_subbuffer_ops.put_next_subbuffer = put_next_subbuffer;
 end:
 	return ret;
 }
@@ -510,16 +1419,33 @@ int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 
 	assert(stream);
 
-	/* Don't create anything if this is set for streaming. */
-	if (stream->net_seq_idx == (uint64_t) -1ULL) {
+	/*
+	 * Don't create anything if this is set for streaming or should not be
+	 * monitored.
+	 */
+	if (stream->relayd_id == (uint64_t) -1ULL && stream->chan->monitor) {
 		ret = utils_create_stream_file(stream->chan->pathname, stream->name,
 				stream->chan->tracefile_size, stream->tracefile_count_current,
-				stream->uid, stream->gid);
+				stream->uid, stream->gid, NULL);
 		if (ret < 0) {
 			goto error;
 		}
 		stream->out_fd = ret;
 		stream->tracefile_size_current = 0;
+
+		if (!stream->metadata_flag) {
+			struct lttng_index_file *index_file;
+
+			index_file = lttng_index_file_create(stream->chan->pathname,
+					stream->name, stream->uid, stream->gid,
+					stream->chan->tracefile_size,
+					stream->tracefile_count_current,
+					CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
+			if (!index_file) {
+				goto error;
+			}
+			stream->index_file = index_file;
+		}
 	}
 
 	if (stream->output == LTTNG_EVENT_MMAP) {
@@ -528,7 +1454,6 @@ int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 
 		ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len);
 		if (ret != 0) {
-			errno = -ret;
 			PERROR("kernctl_get_mmap_len");
 			goto error_close_fd;
 		}
@@ -543,15 +1468,21 @@ int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 		}
 	}
 
+	ret = lttng_kconsumer_set_stream_ops(stream);
+	if (ret) {
+		goto error_close_fd;
+	}
+
 	/* we return 0 to let the library handle the FD internally */
 	return 0;
 
 error_close_fd:
-	{
+	if (stream->out_fd >= 0) {
 		int err;
 
 		err = close(stream->out_fd);
 		assert(!err);
+		stream->out_fd = -1;
 	}
 error:
 	return ret;
@@ -571,6 +1502,11 @@ int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream)
 
 	assert(stream);
 
+	if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
+		ret = 0;
+		goto end;
+	}
+
 	ret = kernctl_get_next_subbuf(stream->wait_fd);
 	if (ret == 0) {
 		/* There is still data so let's put back this subbuffer. */