[lttng-tools.git] / src / bin / lttng-relayd / viewer-stream.c

/*
 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
 *                      David Goulet <dgoulet@efficios.com>
 *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License, version 2 only, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _LGPL_SOURCE
#include <common/common.h>
#include <common/index/index.h>
#include <common/compat/string.h>

#include "lttng-relayd.h"
#include "viewer-stream.h"

static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
{
	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
	free(vstream->path_name);
	free(vstream->channel_name);
	free(vstream);
}

static void viewer_stream_destroy_rcu(struct rcu_head *head)
{
	struct relay_viewer_stream *vstream =
		caa_container_of(head, struct relay_viewer_stream, rcu_node);

	viewer_stream_destroy(vstream);
}

struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
		struct lttng_trace_chunk *viewer_trace_chunk,
		enum lttng_viewer_seek seek_t)
{
	struct relay_viewer_stream *vstream = NULL;
	const bool acquired_reference = lttng_trace_chunk_get(
			viewer_trace_chunk);

	if (!acquired_reference) {
		goto error;
	}

	vstream = zmalloc(sizeof(*vstream));
	if (!vstream) {
		PERROR("relay viewer stream zmalloc");
		goto error;
	}

	vstream->stream_file.trace_chunk = viewer_trace_chunk;
	viewer_trace_chunk = NULL;
	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
	if (vstream->path_name == NULL) {
		PERROR("relay viewer path_name alloc");
		goto error;
	}
	vstream->channel_name = lttng_strndup(stream->channel_name,
			LTTNG_VIEWER_NAME_MAX);
	if (vstream->channel_name == NULL) {
		PERROR("relay viewer channel_name alloc");
		goto error;
	}

	if (!stream_get(stream)) {
		ERR("Cannot get stream");
		goto error;
	}
	vstream->stream = stream;

	pthread_mutex_lock(&stream->lock);

	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
		ERR("Cannot attach viewer metadata stream to trace (busy).");
		goto error_unlock;
	}

	switch (seek_t) {
	case LTTNG_VIEWER_SEEK_BEGINNING:
	{
		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);

		if (seq_tail == -1ULL) {
			/*
			 * Tail may not be initialized yet. Nonetheless, we know
			 * we want to send the first index once it becomes
			 * available.
			 */
			seq_tail = 0;
		}
		vstream->current_tracefile_id =
			tracefile_array_get_file_index_tail(stream->tfa);
		vstream->index_sent_seqcount = seq_tail;
		break;
	}
	case LTTNG_VIEWER_SEEK_LAST:
		vstream->current_tracefile_id =
			tracefile_array_get_read_file_index_head(stream->tfa);
		/*
		 * We seek at the very end of each stream, awaiting for
		 * a future packet to eventually come in.
		 *
		 * We don't need to check the head position for -1ULL since the
		 * increment will set it to 0.
		 */
		vstream->index_sent_seqcount =
				tracefile_array_get_seq_head(stream->tfa) + 1;
		break;
	default:
		goto error_unlock;
	}

	/*
	 * If we never received an index for the current stream, delay
	 * the opening of the index, otherwise open it right now.
	 */
	if (stream->index_received_seqcount == 0) {
		vstream->index_file = NULL;
	} else {
		const uint32_t connection_major = stream->trace->session->major;
		const uint32_t connection_minor = stream->trace->session->minor;

		vstream->index_file = lttng_index_file_create_from_trace_chunk_read_only(
				vstream->stream_file.trace_chunk,
				stream->path_name,
				stream->channel_name, stream->tracefile_size,
				vstream->current_tracefile_id,
				lttng_to_index_major(connection_major,
						connection_minor),
				lttng_to_index_minor(connection_major,
						connection_minor));
		if (!vstream->index_file) {
			goto error_unlock;
		}
	}

	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
		off_t lseek_ret;

		lseek_ret = lseek(vstream->index_file->fd, 0, SEEK_END);
		if (lseek_ret < 0) {
			goto error_unlock;
		}
	}
	if (stream->is_metadata) {
		rcu_assign_pointer(stream->trace->viewer_metadata_stream,
				vstream);
	}
	pthread_mutex_unlock(&stream->lock);

	/* Globally visible after the add unique. */
	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);

	urcu_ref_init(&vstream->ref);

	return vstream;

error_unlock:
	pthread_mutex_unlock(&stream->lock);
error:
	if (vstream) {
		viewer_stream_destroy(vstream);
	}
	if (viewer_trace_chunk && acquired_reference) {
		lttng_trace_chunk_put(viewer_trace_chunk);
	}
	return NULL;
}

static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
{
	int ret;
	struct lttng_ht_iter iter;

	iter.iter.node = &vstream->stream_n.node;
	ret = lttng_ht_del(viewer_streams_ht, &iter);
	assert(!ret);
}

static void viewer_stream_release(struct urcu_ref *ref)
{
	struct relay_viewer_stream *vstream = caa_container_of(ref,
			struct relay_viewer_stream, ref);

	if (vstream->stream->is_metadata) {
		rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
	}

	viewer_stream_unpublish(vstream);

	if (vstream->stream_file.fd) {
		stream_fd_put(vstream->stream_file.fd);
		vstream->stream_file.fd = NULL;
	}
	if (vstream->index_file) {
		lttng_index_file_put(vstream->index_file);
		vstream->index_file = NULL;
	}
	if (vstream->stream) {
		stream_put(vstream->stream);
		vstream->stream = NULL;
	}

	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
}

/* Must be called with RCU read-side lock held. */
bool viewer_stream_get(struct relay_viewer_stream *vstream)
{
	return urcu_ref_get_unless_zero(&vstream->ref);
}

/*
 * Get viewer stream by id.
 *
 * Return viewer stream if found else NULL.
 */
struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
{
	struct lttng_ht_node_u64 *node;
	struct lttng_ht_iter iter;
	struct relay_viewer_stream *vstream = NULL;

	rcu_read_lock();
	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	node = lttng_ht_iter_get_node_u64(&iter);
	if (!node) {
		DBG("Relay viewer stream %" PRIu64 " not found", id);
		goto end;
	}
	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	if (!viewer_stream_get(vstream)) {
		vstream = NULL;
	}
end:
	rcu_read_unlock();
	return vstream;
}

void viewer_stream_put(struct relay_viewer_stream *vstream)
{
	rcu_read_lock();
	urcu_ref_put(&vstream->ref, viewer_stream_release);
	rcu_read_unlock();
}

/*
 * Rotate a stream to the next tracefile.
 *
 * Must be called with the rstream lock held.
 * Returns 0 on success, 1 on EOF, a negative value on error.
 */
int viewer_stream_rotate(struct relay_viewer_stream *vstream)
{
	int ret;
	uint64_t new_id;
	const struct relay_stream *stream = vstream->stream;
	const uint32_t connection_major = stream->trace->session->major;
	const uint32_t connection_minor = stream->trace->session->minor;

	/* Detect the last tracefile to open. */
	if (stream->index_received_seqcount
			== vstream->index_sent_seqcount
			&& stream->trace->session->connection_closed) {
		ret = 1;
		goto end;
	}

	if (stream->tracefile_count == 0) {
		/* Ignore rotation, there is none to do. */
		ret = 0;
		goto end;
	}

	/*
	 * Try to move to the next file.
	 */
	new_id = (vstream->current_tracefile_id + 1)
			% stream->tracefile_count;
	if (tracefile_array_seq_in_file(stream->tfa, new_id,
			vstream->index_sent_seqcount)) {
		vstream->current_tracefile_id = new_id;
	} else {
		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);

		/*
		 * This can only be reached on overwrite, which implies there
		 * has been data written at some point, which will have set the
		 * tail.
		 */
		assert(seq_tail != -1ULL);
		/*
		 * We need to resync because we lag behind tail.
		 */
		vstream->current_tracefile_id =
			tracefile_array_get_file_index_tail(stream->tfa);
		vstream->index_sent_seqcount = seq_tail;
	}

	if (vstream->index_file) {
		lttng_index_file_put(vstream->index_file);
		vstream->index_file = NULL;
	}
	if (vstream->stream_file.fd) {
		stream_fd_put(vstream->stream_file.fd);
		vstream->stream_file.fd = NULL;
	}
	vstream->index_file =
			lttng_index_file_create_from_trace_chunk_read_only(
					vstream->stream_file.trace_chunk,
					stream->path_name,
					stream->channel_name,
					stream->tracefile_size,
					vstream->current_tracefile_id,
					lttng_to_index_major(connection_major,
							connection_minor),
					lttng_to_index_minor(connection_major,
							connection_minor));
	if (!vstream->index_file) {
		ret = -1;
		goto end;
	} else {
		ret = 0;
	}
end:
	return ret;
}

void print_viewer_streams(void)
{
	struct lttng_ht_iter iter;
	struct relay_viewer_stream *vstream;

	if (!viewer_streams_ht) {
		return;
	}

	rcu_read_lock();
	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
			stream_n.node) {
		if (!viewer_stream_get(vstream)) {
			continue;
		}
		DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
			" session %" PRIu64,
			vstream,
			vstream->ref.refcount,
			vstream->stream->stream_handle,
			vstream->stream->trace->id,
			vstream->stream->trace->session->id);
		viewer_stream_put(vstream);
	}
	rcu_read_unlock();
}
Commit	Line	Data
2f8f53af DG	1	/*
	2	* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
	3	* David Goulet <dgoulet@efficios.com>
7591bab1	4	* 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2f8f53af DG	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License, version 2 only, as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along with
	16	* this program; if not, write to the Free Software Foundation, Inc., 51
	17	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	18	*/
	19
6c1c0768	20	#define _LGPL_SOURCE
2f8f53af DG	21	#include <common/common.h>
2f8f53af DG	22	#include <common/index/index.h>
f5436bfc	23	#include <common/compat/string.h>
2f8f53af DG	24
	25	#include "lttng-relayd.h"
	26	#include "viewer-stream.h"
	27
7591bab1	28	static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
2f8f53af	29	{
dc3bfa8d	30	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
7591bab1 MD	31	free(vstream->path_name);
	32	free(vstream->channel_name);
	33	free(vstream);
2f8f53af DG	34	}
2f8f53af DG	35
7591bab1	36	static void viewer_stream_destroy_rcu(struct rcu_head *head)
2f8f53af	37	{
7591bab1	38	struct relay_viewer_stream *vstream =
2f8f53af DG	39	caa_container_of(head, struct relay_viewer_stream, rcu_node);
2f8f53af DG	40
7591bab1	41	viewer_stream_destroy(vstream);
2f8f53af DG	42	}
	43
	44	struct relay_viewer_stream viewer_stream_create(struct relay_stream stream,
b66a15d1	45	struct lttng_trace_chunk *viewer_trace_chunk,
7591bab1	46	enum lttng_viewer_seek seek_t)
2f8f53af	47	{
ebb29c10 JG	48	struct relay_viewer_stream *vstream = NULL;
ebb29c10 JG	49	const bool acquired_reference = lttng_trace_chunk_get(
b66a15d1	50	viewer_trace_chunk);
ebb29c10 JG	51
	52	if (!acquired_reference) {
	53	goto error;
	54	}
2f8f53af	55
2f8f53af DG	56	vstream = zmalloc(sizeof(*vstream));
	57	if (!vstream) {
	58	PERROR("relay viewer stream zmalloc");
	59	goto error;
	60	}
	61
b66a15d1 JG	62	vstream->stream_file.trace_chunk = viewer_trace_chunk;
b66a15d1 JG	63	viewer_trace_chunk = NULL;
f5436bfc	64	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
b272577e MD	65	if (vstream->path_name == NULL) {
	66	PERROR("relay viewer path_name alloc");
	67	goto error;
	68	}
f5436bfc	69	vstream->channel_name = lttng_strndup(stream->channel_name,
2f8f53af	70	LTTNG_VIEWER_NAME_MAX);
b272577e MD	71	if (vstream->channel_name == NULL) {
	72	PERROR("relay viewer channel_name alloc");
	73	goto error;
	74	}
2f8f53af	75
a44ca2ca MD	76	if (!stream_get(stream)) {
	77	ERR("Cannot get stream");
	78	goto error;
	79	}
	80	vstream->stream = stream;
	81
	82	pthread_mutex_lock(&stream->lock);
	83
	84	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
	85	ERR("Cannot attach viewer metadata stream to trace (busy).");
	86	goto error_unlock;
	87	}
	88
2f8f53af	89	switch (seek_t) {
c4e361a4	90	case LTTNG_VIEWER_SEEK_BEGINNING:
a44ca2ca MD	91	{
	92	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	93
	94	if (seq_tail == -1ULL) {
	95	/*
	96	* Tail may not be initialized yet. Nonetheless, we know
	97	* we want to send the first index once it becomes
	98	* available.
	99	*/
	100	seq_tail = 0;
	101	}
	102	vstream->current_tracefile_id =
	103	tracefile_array_get_file_index_tail(stream->tfa);
	104	vstream->index_sent_seqcount = seq_tail;
2f8f53af	105	break;
a44ca2ca	106	}
c4e361a4	107	case LTTNG_VIEWER_SEEK_LAST:
a44ca2ca	108	vstream->current_tracefile_id =
78118e3b	109	tracefile_array_get_read_file_index_head(stream->tfa);
a44ca2ca MD	110	/*
	111	* We seek at the very end of each stream, awaiting for
	112	* a future packet to eventually come in.
	113	*
	114	* We don't need to check the head position for -1ULL since the
	115	* increment will set it to 0.
	116	*/
	117	vstream->index_sent_seqcount =
	118	tracefile_array_get_seq_head(stream->tfa) + 1;
2f8f53af DG	119	break;
2f8f53af DG	120	default:
a44ca2ca	121	goto error_unlock;
2f8f53af	122	}
2f8f53af	123
2f8f53af	124	/*
a44ca2ca MD	125	* If we never received an index for the current stream, delay
a44ca2ca MD	126	* the opening of the index, otherwise open it right now.
2f8f53af	127	*/
a44ca2ca	128	if (stream->index_received_seqcount == 0) {
f8f3885c	129	vstream->index_file = NULL;
2f8f53af	130	} else {
ebb29c10 JG	131	const uint32_t connection_major = stream->trace->session->major;
	132	const uint32_t connection_minor = stream->trace->session->minor;
	133
	134	vstream->index_file = lttng_index_file_create_from_trace_chunk_read_only(
b66a15d1 JG	135	vstream->stream_file.trace_chunk,
b66a15d1 JG	136	stream->path_name,
ebb29c10 JG	137	stream->channel_name, stream->tracefile_size,
	138	vstream->current_tracefile_id,
	139	lttng_to_index_major(connection_major,
	140	connection_minor),
	141	lttng_to_index_minor(connection_major,
	142	connection_minor));
f8f3885c	143	if (!vstream->index_file) {
7591bab1	144	goto error_unlock;
2f8f53af	145	}
2f8f53af DG	146	}
2f8f53af DG	147
f8f3885c	148	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
2f8f53af DG	149	off_t lseek_ret;
2f8f53af DG	150
f8f3885c	151	lseek_ret = lseek(vstream->index_file->fd, 0, SEEK_END);
2f8f53af	152	if (lseek_ret < 0) {
7591bab1	153	goto error_unlock;
2f8f53af	154	}
7591bab1	155	}
7591bab1 MD	156	if (stream->is_metadata) {
	157	rcu_assign_pointer(stream->trace->viewer_metadata_stream,
	158	vstream);
2f8f53af	159	}
a44ca2ca	160	pthread_mutex_unlock(&stream->lock);
2f8f53af	161
7591bab1 MD	162	/* Globally visible after the add unique. */
	163	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
	164	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
	165
7591bab1 MD	166	urcu_ref_init(&vstream->ref);
7591bab1 MD	167
2f8f53af DG	168	return vstream;
2f8f53af DG	169
7591bab1 MD	170	error_unlock:
7591bab1 MD	171	pthread_mutex_unlock(&stream->lock);
2f8f53af DG	172	error:
2f8f53af DG	173	if (vstream) {
7591bab1	174	viewer_stream_destroy(vstream);
2f8f53af	175	}
e4650a96	176	if (viewer_trace_chunk && acquired_reference) {
b66a15d1 JG	177	lttng_trace_chunk_put(viewer_trace_chunk);
b66a15d1 JG	178	}
2f8f53af DG	179	return NULL;
	180	}
	181
7591bab1	182	static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
2f8f53af DG	183	{
	184	int ret;
	185	struct lttng_ht_iter iter;
	186
7591bab1	187	iter.iter.node = &vstream->stream_n.node;
2f8f53af DG	188	ret = lttng_ht_del(viewer_streams_ht, &iter);
	189	assert(!ret);
	190	}
	191
7591bab1	192	static void viewer_stream_release(struct urcu_ref *ref)
2f8f53af	193	{
7591bab1 MD	194	struct relay_viewer_stream *vstream = caa_container_of(ref,
7591bab1 MD	195	struct relay_viewer_stream, ref);
2a174661	196
7591bab1 MD	197	if (vstream->stream->is_metadata) {
7591bab1 MD	198	rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
2a174661	199	}
2f8f53af	200
7591bab1 MD	201	viewer_stream_unpublish(vstream);
7591bab1 MD	202
ebb29c10 JG	203	if (vstream->stream_file.fd) {
	204	stream_fd_put(vstream->stream_file.fd);
	205	vstream->stream_file.fd = NULL;
2f8f53af	206	}
f8f3885c MD	207	if (vstream->index_file) {
	208	lttng_index_file_put(vstream->index_file);
	209	vstream->index_file = NULL;
7591bab1 MD	210	}
	211	if (vstream->stream) {
	212	stream_put(vstream->stream);
	213	vstream->stream = NULL;
	214	}
dc3bfa8d	215
7591bab1 MD	216	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
	217	}
	218
	219	/* Must be called with RCU read-side lock held. */
	220	bool viewer_stream_get(struct relay_viewer_stream *vstream)
	221	{
ce4d4083	222	return urcu_ref_get_unless_zero(&vstream->ref);
2f8f53af DG	223	}
	224
	225	/*
7591bab1	226	* Get viewer stream by id.
2f8f53af	227	*
7591bab1	228	* Return viewer stream if found else NULL.
2f8f53af	229	*/
7591bab1	230	struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
2f8f53af DG	231	{
	232	struct lttng_ht_node_u64 *node;
	233	struct lttng_ht_iter iter;
7591bab1	234	struct relay_viewer_stream *vstream = NULL;
2f8f53af	235
7591bab1	236	rcu_read_lock();
2f8f53af DG	237	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	238	node = lttng_ht_iter_get_node_u64(&iter);
	239	if (!node) {
	240	DBG("Relay viewer stream %" PRIu64 " not found", id);
	241	goto end;
	242	}
7591bab1 MD	243	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	244	if (!viewer_stream_get(vstream)) {
	245	vstream = NULL;
	246	}
2f8f53af	247	end:
7591bab1 MD	248	rcu_read_unlock();
	249	return vstream;
	250	}
	251
	252	void viewer_stream_put(struct relay_viewer_stream *vstream)
	253	{
	254	rcu_read_lock();
7591bab1	255	urcu_ref_put(&vstream->ref, viewer_stream_release);
7591bab1 MD	256	rcu_read_unlock();
	257	}
	258
2f8f53af DG	259	/*
	260	* Rotate a stream to the next tracefile.
	261	*
7591bab1	262	* Must be called with the rstream lock held.
2f8f53af DG	263	* Returns 0 on success, 1 on EOF, a negative value on error.
2f8f53af DG	264	*/
7591bab1	265	int viewer_stream_rotate(struct relay_viewer_stream *vstream)
2f8f53af DG	266	{
2f8f53af DG	267	int ret;
a44ca2ca	268	uint64_t new_id;
ebb29c10 JG	269	const struct relay_stream *stream = vstream->stream;
	270	const uint32_t connection_major = stream->trace->session->major;
	271	const uint32_t connection_minor = stream->trace->session->minor;
2f8f53af	272
7591bab1	273	/* Detect the last tracefile to open. */
a44ca2ca MD	274	if (stream->index_received_seqcount
a44ca2ca MD	275	== vstream->index_sent_seqcount
7591bab1 MD	276	&& stream->trace->session->connection_closed) {
7591bab1 MD	277	ret = 1;
2a174661 DG	278	goto end;
2a174661 DG	279	}
2f8f53af	280
7591bab1 MD	281	if (stream->tracefile_count == 0) {
	282	/* Ignore rotation, there is none to do. */
	283	ret = 0;
2f8f53af DG	284	goto end;
	285	}
	286
a44ca2ca MD	287	/*
	288	* Try to move to the next file.
	289	*/
	290	new_id = (vstream->current_tracefile_id + 1)
	291	% stream->tracefile_count;
	292	if (tracefile_array_seq_in_file(stream->tfa, new_id,
	293	vstream->index_sent_seqcount)) {
	294	vstream->current_tracefile_id = new_id;
2f8f53af	295	} else {
a44ca2ca MD	296	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	297
	298	/*
	299	* This can only be reached on overwrite, which implies there
	300	* has been data written at some point, which will have set the
	301	* tail.
	302	*/
	303	assert(seq_tail != -1ULL);
	304	/*
	305	* We need to resync because we lag behind tail.
	306	*/
7591bab1	307	vstream->current_tracefile_id =
a44ca2ca MD	308	tracefile_array_get_file_index_tail(stream->tfa);
a44ca2ca MD	309	vstream->index_sent_seqcount = seq_tail;
2f8f53af	310	}
2f8f53af	311
f8f3885c MD	312	if (vstream->index_file) {
	313	lttng_index_file_put(vstream->index_file);
	314	vstream->index_file = NULL;
2f8f53af	315	}
ebb29c10 JG	316	if (vstream->stream_file.fd) {
	317	stream_fd_put(vstream->stream_file.fd);
	318	vstream->stream_file.fd = NULL;
2f8f53af	319	}
ebb29c10 JG	320	vstream->index_file =
ebb29c10 JG	321	lttng_index_file_create_from_trace_chunk_read_only(
b66a15d1 JG	322	vstream->stream_file.trace_chunk,
b66a15d1 JG	323	stream->path_name,
ebb29c10 JG	324	stream->channel_name,
	325	stream->tracefile_size,
	326	vstream->current_tracefile_id,
	327	lttng_to_index_major(connection_major,
	328	connection_minor),
	329	lttng_to_index_minor(connection_major,
	330	connection_minor));
f8f3885c MD	331	if (!vstream->index_file) {
f8f3885c MD	332	ret = -1;
7591bab1	333	goto end;
7591bab1	334	} else {
f8f3885c	335	ret = 0;
2f8f53af	336	}
2f8f53af	337	end:
2f8f53af DG	338	return ret;
2f8f53af DG	339	}
7591bab1 MD	340
	341	void print_viewer_streams(void)
	342	{
	343	struct lttng_ht_iter iter;
	344	struct relay_viewer_stream *vstream;
	345
ce3f3ba3 JG	346	if (!viewer_streams_ht) {
	347	return;
	348	}
	349
7591bab1 MD	350	rcu_read_lock();
	351	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
	352	stream_n.node) {
	353	if (!viewer_stream_get(vstream)) {
	354	continue;
	355	}
	356	DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
	357	" session %" PRIu64,
	358	vstream,
	359	vstream->ref.refcount,
	360	vstream->stream->stream_handle,
	361	vstream->stream->trace->id,
	362	vstream->stream->trace->session->id);
	363	viewer_stream_put(vstream);
	364	}
	365	rcu_read_unlock();
	366	}