[lttng-tools.git] / src / bin / lttng-relayd / index.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 <assert.h>

#include <common/common.h>
#include <common/utils.h>

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

/*
 * Allocate a new relay index object. Pass the stream in which it is
 * contained as parameter. The sequence number will be used as the hash
 * table key.
 *
 * Called with stream mutex held.
 * Return allocated object or else NULL on error.
 */
static struct relay_index *relay_index_create(struct relay_stream *stream,
		uint64_t net_seq_num)
{
	struct relay_index *index;

	DBG2("Creating relay index for stream id %" PRIu64 " and seqnum %" PRIu64,
			stream->stream_handle, net_seq_num);

	index = zmalloc(sizeof(*index));
	if (!index) {
		PERROR("Relay index zmalloc");
		goto end;
	}
	if (!stream_get(stream)) {
		ERR("Cannot get stream");
		free(index);
		index = NULL;
		goto end;
	}
	index->stream = stream;

	lttng_ht_node_init_u64(&index->index_n, net_seq_num);
	pthread_mutex_init(&index->lock, NULL);
	pthread_mutex_init(&index->reflock, NULL);
	urcu_ref_init(&index->ref);

end:
	return index;
}

/*
 * Add unique relay index to the given hash table. In case of a collision, the
 * already existing object is put in the given _index variable.
 *
 * RCU read side lock MUST be acquired.
 */
static struct relay_index *relay_index_add_unique(struct relay_stream *stream,
		struct relay_index *index)
{
	struct cds_lfht_node *node_ptr;
	struct relay_index *_index;

	DBG2("Adding relay index with stream id %" PRIu64 " and seqnum %" PRIu64,
			stream->stream_handle, index->index_n.key);

	node_ptr = cds_lfht_add_unique(stream->indexes_ht->ht,
			stream->indexes_ht->hash_fct(&index->index_n, lttng_ht_seed),
			stream->indexes_ht->match_fct, &index->index_n,
			&index->index_n.node);
	if (node_ptr != &index->index_n.node) {
		_index = caa_container_of(node_ptr, struct relay_index,
				index_n.node);
	} else {
		_index = NULL;
	}
	return _index;
}

/*
 * Should be called with RCU read-side lock held.
 */
static bool relay_index_get(struct relay_index *index)
{
	bool has_ref = false;

	DBG2("index get for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
			index->stream->stream_handle, index->index_n.key,
			(int) index->ref.refcount);

	/* Confirm that the index refcount has not reached 0. */
	pthread_mutex_lock(&index->reflock);
	if (index->ref.refcount != 0) {
		has_ref = true;
		urcu_ref_get(&index->ref);
	}
	pthread_mutex_unlock(&index->reflock);

	return has_ref;
}

/*
 * Get a relayd index in within the given stream, or create it if not
 * present.
 *
 * Called with stream mutex held.
 * Return index object or else NULL on error.
 */
struct relay_index *relay_index_get_by_id_or_create(struct relay_stream *stream,
		 uint64_t net_seq_num)
{
	struct lttng_ht_node_u64 *node;
	struct lttng_ht_iter iter;
	struct relay_index *index = NULL;

	DBG3("Finding index for stream id %" PRIu64 " and seq_num %" PRIu64,
			stream->stream_handle, net_seq_num);

	rcu_read_lock();
	lttng_ht_lookup(stream->indexes_ht, &net_seq_num, &iter);
	node = lttng_ht_iter_get_node_u64(&iter);
	if (node) {
		index = caa_container_of(node, struct relay_index, index_n);
	} else {
		struct relay_index *oldindex;

		index = relay_index_create(stream, net_seq_num);
		if (!index) {
			ERR("Cannot create index for stream id %" PRIu64 " and seq_num %" PRIu64,
				stream->stream_handle, net_seq_num);
			goto end;
		}
		oldindex = relay_index_add_unique(stream, index);
		if (oldindex) {
			/* Added concurrently, keep old. */
			relay_index_put(index);
			index = oldindex;
			if (!relay_index_get(index)) {
				index = NULL;
			}
		} else {
			stream->indexes_in_flight++;
			index->in_hash_table = true;
		}
	}
end:
	rcu_read_unlock();
	DBG2("Index %sfound or created in HT for stream ID %" PRIu64 " and seqnum %" PRIu64,
			(index == NULL) ? "NOT " : "", stream->stream_handle, net_seq_num);
	return index;
}

int relay_index_set_fd(struct relay_index *index, struct stream_fd *index_fd,
		uint64_t data_offset)
{
	int ret = 0;

	pthread_mutex_lock(&index->lock);
	if (index->index_fd) {
		ret = -1;
		goto end;
	}
	stream_fd_get(index_fd);
	index->index_fd = index_fd;
	index->index_data.offset = data_offset;
end:
	pthread_mutex_unlock(&index->lock);
	return ret;
}

int relay_index_set_data(struct relay_index *index,
                const struct ctf_packet_index *data)
{
	int ret = 0;

	pthread_mutex_lock(&index->lock);
	if (index->has_index_data) {
		ret = -1;
		goto end;
	}
	/* Set everything except data_offset. */
	index->index_data.packet_size = data->packet_size;
	index->index_data.content_size = data->content_size;
	index->index_data.timestamp_begin = data->timestamp_begin;
	index->index_data.timestamp_end = data->timestamp_end;
	index->index_data.events_discarded = data->events_discarded;
	index->index_data.stream_id = data->stream_id;
	index->has_index_data = true;
end:
	pthread_mutex_unlock(&index->lock);
	return ret;
}

static void index_destroy(struct relay_index *index)
{
	free(index);
}

static void index_destroy_rcu(struct rcu_head *rcu_head)
{
	struct relay_index *index =
		caa_container_of(rcu_head, struct relay_index, rcu_node);

	index_destroy(index);
}

/* Stream lock must be held by the caller. */
static void index_release(struct urcu_ref *ref)
{
	struct relay_index *index = caa_container_of(ref, struct relay_index, ref);
	struct relay_stream *stream = index->stream;
	int ret;
	struct lttng_ht_iter iter;

	if (index->index_fd) {
		stream_fd_put(index->index_fd);
		index->index_fd = NULL;
	}
	if (index->in_hash_table) {
		/* Delete index from hash table. */
		iter.iter.node = &index->index_n.node;
		ret = lttng_ht_del(stream->indexes_ht, &iter);
		assert(!ret);
		stream->indexes_in_flight--;
	}

	stream_put(index->stream);
	index->stream = NULL;

	call_rcu(&index->rcu_node, index_destroy_rcu);
}

/*
 * Called with stream mutex held.
 *
 * Stream lock must be held by the caller.
 */
void relay_index_put(struct relay_index *index)
{
	DBG2("index put for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
			index->stream->stream_handle, index->index_n.key,
			(int) index->ref.refcount);
	/*
	 * Ensure existance of index->lock for index unlock.
	 */
	rcu_read_lock();
	/*
	 * Index lock ensures that concurrent test and update of stream
	 * ref is atomic.
	 */
	pthread_mutex_lock(&index->reflock);
	assert(index->ref.refcount != 0);
	urcu_ref_put(&index->ref, index_release);
	pthread_mutex_unlock(&index->reflock);
	rcu_read_unlock();
}

/*
 * Try to flush index to disk. Releases self-reference to index once
 * flush succeeds.
 *
 * Stream lock must be held by the caller.
 * Return 0 on successful flush, a negative value on error, or positive
 * value if no flush was performed.
 */
int relay_index_try_flush(struct relay_index *index)
{
	int ret = 1;
	bool flushed = false;
	int fd;

	pthread_mutex_lock(&index->lock);
	if (index->flushed) {
		goto skip;
	}
	/* Check if we are ready to flush. */
	if (!index->has_index_data || !index->index_fd) {
		goto skip;
	}
	fd = index->index_fd->fd;
	DBG2("Writing index for stream ID %" PRIu64 " and seq num %" PRIu64
			" on fd %d", index->stream->stream_handle,
			index->index_n.key, fd);
	flushed = true;
	index->flushed = true;
	ret = index_write(fd, &index->index_data, sizeof(index->index_data));
	if (ret == sizeof(index->index_data)) {
		ret = 0;
	} else {
		ret = -1;
	}
skip:
	pthread_mutex_unlock(&index->lock);

	if (flushed) {
		/* Put self-ref from index now that it has been flushed. */
		relay_index_put(index);
	}
	return ret;
}

/*
 * Close every relay index within a given stream, without flushing
 * them.
 */
void relay_index_close_all(struct relay_stream *stream)
{
	struct lttng_ht_iter iter;
	struct relay_index *index;

	rcu_read_lock();
	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
			index, index_n.node) {
		/* Put self-ref from index. */
		relay_index_put(index);
	}
	rcu_read_unlock();
}

void relay_index_close_partial_fd(struct relay_stream *stream)
{
	struct lttng_ht_iter iter;
	struct relay_index *index;

	rcu_read_lock();
	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
			index, index_n.node) {
		if (!index->index_fd) {
			continue;
		}
		/*
		 * Partial index has its index_fd: we have only
		 * received its info from the data socket.
		 * Put self-ref from index.
		 */
		relay_index_put(index);
	}
	rcu_read_unlock();
}

uint64_t relay_index_find_last(struct relay_stream *stream)
{
	struct lttng_ht_iter iter;
	struct relay_index *index;
	uint64_t net_seq_num = -1ULL;

	rcu_read_lock();
	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
			index, index_n.node) {
		if (net_seq_num == -1ULL ||
				index->index_n.key > net_seq_num) {
			net_seq_num = index->index_n.key;
		}
	}
	rcu_read_unlock();
	return net_seq_num;
}
Commit	Line	Data
1c20f0e2 JD	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>
1c20f0e2 JD	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
1c20f0e2 JD	21	#include <assert.h>
	22
	23	#include <common/common.h>
	24	#include <common/utils.h>
	25
0a6518b0	26	#include "lttng-relayd.h"
7591bab1	27	#include "stream.h"
1c20f0e2 JD	28	#include "index.h"
	29
	30	/*
7591bab1 MD	31	* Allocate a new relay index object. Pass the stream in which it is
	32	* contained as parameter. The sequence number will be used as the hash
	33	* table key.
	34	*
	35	* Called with stream mutex held.
	36	* Return allocated object or else NULL on error.
1c20f0e2	37	*/
7591bab1 MD	38	static struct relay_index relay_index_create(struct relay_stream stream,
7591bab1 MD	39	uint64_t net_seq_num)
1c20f0e2	40	{
7591bab1	41	struct relay_index *index;
1c20f0e2	42
7591bab1 MD	43	DBG2("Creating relay index for stream id %" PRIu64 " and seqnum %" PRIu64,
7591bab1 MD	44	stream->stream_handle, net_seq_num);
1c20f0e2	45
7591bab1 MD	46	index = zmalloc(sizeof(*index));
	47	if (!index) {
	48	PERROR("Relay index zmalloc");
	49	goto end;
	50	}
	51	if (!stream_get(stream)) {
	52	ERR("Cannot get stream");
	53	free(index);
	54	index = NULL;
	55	goto end;
1c20f0e2	56	}
7591bab1	57	index->stream = stream;
1c20f0e2	58
7591bab1 MD	59	lttng_ht_node_init_u64(&index->index_n, net_seq_num);
	60	pthread_mutex_init(&index->lock, NULL);
	61	pthread_mutex_init(&index->reflock, NULL);
	62	urcu_ref_init(&index->ref);
	63
	64	end:
	65	return index;
1c20f0e2 JD	66	}
	67
	68	/*
7591bab1 MD	69	* Add unique relay index to the given hash table. In case of a collision, the
7591bab1 MD	70	* already existing object is put in the given _index variable.
1c20f0e2	71	*
7591bab1	72	* RCU read side lock MUST be acquired.
1c20f0e2	73	*/
7591bab1 MD	74	static struct relay_index relay_index_add_unique(struct relay_stream stream,
7591bab1 MD	75	struct relay_index *index)
1c20f0e2	76	{
7591bab1 MD	77	struct cds_lfht_node *node_ptr;
7591bab1 MD	78	struct relay_index *_index;
1c20f0e2	79
7591bab1 MD	80	DBG2("Adding relay index with stream id %" PRIu64 " and seqnum %" PRIu64,
7591bab1 MD	81	stream->stream_handle, index->index_n.key);
1c20f0e2	82
7591bab1 MD	83	node_ptr = cds_lfht_add_unique(stream->indexes_ht->ht,
	84	stream->indexes_ht->hash_fct(&index->index_n, lttng_ht_seed),
	85	stream->indexes_ht->match_fct, &index->index_n,
	86	&index->index_n.node);
	87	if (node_ptr != &index->index_n.node) {
	88	_index = caa_container_of(node_ptr, struct relay_index,
	89	index_n.node);
	90	} else {
	91	_index = NULL;
1c20f0e2	92	}
7591bab1 MD	93	return _index;
	94	}
	95
	96	/*
	97	* Should be called with RCU read-side lock held.
	98	*/
	99	static bool relay_index_get(struct relay_index *index)
	100	{
	101	bool has_ref = false;
1c20f0e2	102
7591bab1 MD	103	DBG2("index get for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
	104	index->stream->stream_handle, index->index_n.key,
	105	(int) index->ref.refcount);
1c20f0e2	106
7591bab1 MD	107	/* Confirm that the index refcount has not reached 0. */
	108	pthread_mutex_lock(&index->reflock);
	109	if (index->ref.refcount != 0) {
	110	has_ref = true;
	111	urcu_ref_get(&index->ref);
	112	}
	113	pthread_mutex_unlock(&index->reflock);
	114
	115	return has_ref;
1c20f0e2 JD	116	}
	117
	118	/*
7591bab1 MD	119	* Get a relayd index in within the given stream, or create it if not
7591bab1 MD	120	* present.
1c20f0e2	121	*
7591bab1	122	* Called with stream mutex held.
1c20f0e2 JD	123	* Return index object or else NULL on error.
1c20f0e2 JD	124	*/
7591bab1 MD	125	struct relay_index relay_index_get_by_id_or_create(struct relay_stream stream,
7591bab1 MD	126	uint64_t net_seq_num)
1c20f0e2	127	{
7591bab1	128	struct lttng_ht_node_u64 *node;
1c20f0e2	129	struct lttng_ht_iter iter;
1c20f0e2 JD	130	struct relay_index *index = NULL;
1c20f0e2 JD	131
1c20f0e2	132	DBG3("Finding index for stream id %" PRIu64 " and seq_num %" PRIu64,
7591bab1	133	stream->stream_handle, net_seq_num);
1c20f0e2	134
7591bab1 MD	135	rcu_read_lock();
	136	lttng_ht_lookup(stream->indexes_ht, &net_seq_num, &iter);
	137	node = lttng_ht_iter_get_node_u64(&iter);
	138	if (node) {
	139	index = caa_container_of(node, struct relay_index, index_n);
	140	} else {
	141	struct relay_index *oldindex;
	142
	143	index = relay_index_create(stream, net_seq_num);
	144	if (!index) {
	145	ERR("Cannot create index for stream id %" PRIu64 " and seq_num %" PRIu64,
811a4037	146	stream->stream_handle, net_seq_num);
7591bab1 MD	147	goto end;
	148	}
	149	oldindex = relay_index_add_unique(stream, index);
	150	if (oldindex) {
	151	/* Added concurrently, keep old. */
	152	relay_index_put(index);
	153	index = oldindex;
	154	if (!relay_index_get(index)) {
	155	index = NULL;
	156	}
	157	} else {
	158	stream->indexes_in_flight++;
	159	index->in_hash_table = true;
	160	}
1c20f0e2	161	}
1c20f0e2	162	end:
7591bab1 MD	163	rcu_read_unlock();
7591bab1 MD	164	DBG2("Index %sfound or created in HT for stream ID %" PRIu64 " and seqnum %" PRIu64,
719155c2	165	(index == NULL) ? "NOT " : "", stream->stream_handle, net_seq_num);
1c20f0e2 JD	166	return index;
	167	}
	168
7591bab1 MD	169	int relay_index_set_fd(struct relay_index index, struct stream_fd index_fd,
7591bab1 MD	170	uint64_t data_offset)
1c20f0e2	171	{
7591bab1	172	int ret = 0;
1c20f0e2	173
7591bab1 MD	174	pthread_mutex_lock(&index->lock);
	175	if (index->index_fd) {
	176	ret = -1;
	177	goto end;
	178	}
	179	stream_fd_get(index_fd);
	180	index->index_fd = index_fd;
	181	index->index_data.offset = data_offset;
	182	end:
	183	pthread_mutex_unlock(&index->lock);
	184	return ret;
	185	}
1c20f0e2	186
7591bab1 MD	187	int relay_index_set_data(struct relay_index *index,
	188	const struct ctf_packet_index *data)
	189	{
	190	int ret = 0;
1c20f0e2	191
7591bab1 MD	192	pthread_mutex_lock(&index->lock);
	193	if (index->has_index_data) {
	194	ret = -1;
	195	goto end;
1c20f0e2	196	}
7591bab1 MD	197	/* Set everything except data_offset. */
	198	index->index_data.packet_size = data->packet_size;
	199	index->index_data.content_size = data->content_size;
	200	index->index_data.timestamp_begin = data->timestamp_begin;
	201	index->index_data.timestamp_end = data->timestamp_end;
	202	index->index_data.events_discarded = data->events_discarded;
	203	index->index_data.stream_id = data->stream_id;
	204	index->has_index_data = true;
	205	end:
	206	pthread_mutex_unlock(&index->lock);
	207	return ret;
1c20f0e2 JD	208	}
1c20f0e2 JD	209
7591bab1	210	static void index_destroy(struct relay_index *index)
1c20f0e2	211	{
7591bab1 MD	212	free(index);
7591bab1 MD	213	}
1c20f0e2	214
7591bab1 MD	215	static void index_destroy_rcu(struct rcu_head *rcu_head)
	216	{
	217	struct relay_index *index =
	218	caa_container_of(rcu_head, struct relay_index, rcu_node);
1c20f0e2	219
7591bab1	220	index_destroy(index);
1c20f0e2 JD	221	}
1c20f0e2 JD	222
7591bab1 MD	223	/* Stream lock must be held by the caller. */
7591bab1 MD	224	static void index_release(struct urcu_ref *ref)
1c20f0e2	225	{
7591bab1 MD	226	struct relay_index *index = caa_container_of(ref, struct relay_index, ref);
	227	struct relay_stream *stream = index->stream;
	228	int ret;
	229	struct lttng_ht_iter iter;
	230
	231	if (index->index_fd) {
	232	stream_fd_put(index->index_fd);
	233	index->index_fd = NULL;
	234	}
	235	if (index->in_hash_table) {
	236	/* Delete index from hash table. */
	237	iter.iter.node = &index->index_n.node;
	238	ret = lttng_ht_del(stream->indexes_ht, &iter);
	239	assert(!ret);
	240	stream->indexes_in_flight--;
	241	}
	242
	243	stream_put(index->stream);
	244	index->stream = NULL;
	245
	246	call_rcu(&index->rcu_node, index_destroy_rcu);
1c20f0e2 JD	247	}
	248
	249	/*
7591bab1 MD	250	* Called with stream mutex held.
	251	*
	252	* Stream lock must be held by the caller.
1c20f0e2	253	*/
7591bab1	254	void relay_index_put(struct relay_index *index)
1c20f0e2	255	{
7591bab1 MD	256	DBG2("index put for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
	257	index->stream->stream_handle, index->index_n.key,
	258	(int) index->ref.refcount);
	259	/*
	260	* Ensure existance of index->lock for index unlock.
	261	*/
	262	rcu_read_lock();
	263	/*
	264	* Index lock ensures that concurrent test and update of stream
	265	* ref is atomic.
	266	*/
	267	pthread_mutex_lock(&index->reflock);
	268	assert(index->ref.refcount != 0);
	269	urcu_ref_put(&index->ref, index_release);
	270	pthread_mutex_unlock(&index->reflock);
	271	rcu_read_unlock();
1c20f0e2 JD	272	}
	273
	274	/*
7591bab1 MD	275	* Try to flush index to disk. Releases self-reference to index once
7591bab1 MD	276	* flush succeeds.
1c20f0e2	277	*
7591bab1 MD	278	* Stream lock must be held by the caller.
	279	* Return 0 on successful flush, a negative value on error, or positive
	280	* value if no flush was performed.
1c20f0e2	281	*/
7591bab1	282	int relay_index_try_flush(struct relay_index *index)
1c20f0e2	283	{
7591bab1 MD	284	int ret = 1;
	285	bool flushed = false;
	286	int fd;
1c20f0e2	287
7591bab1 MD	288	pthread_mutex_lock(&index->lock);
	289	if (index->flushed) {
	290	goto skip;
	291	}
	292	/* Check if we are ready to flush. */
	293	if (!index->has_index_data \|\| !index->index_fd) {
	294	goto skip;
	295	}
	296	fd = index->index_fd->fd;
	297	DBG2("Writing index for stream ID %" PRIu64 " and seq num %" PRIu64
	298	" on fd %d", index->stream->stream_handle,
	299	index->index_n.key, fd);
	300	flushed = true;
	301	index->flushed = true;
	302	ret = index_write(fd, &index->index_data, sizeof(index->index_data));
	303	if (ret == sizeof(index->index_data)) {
	304	ret = 0;
	305	} else {
	306	ret = -1;
	307	}
	308	skip:
	309	pthread_mutex_unlock(&index->lock);
1c20f0e2	310
7591bab1 MD	311	if (flushed) {
	312	/* Put self-ref from index now that it has been flushed. */
	313	relay_index_put(index);
	314	}
	315	return ret;
1c20f0e2 JD	316	}
	317
	318	/*
7591bab1 MD	319	* Close every relay index within a given stream, without flushing
7591bab1 MD	320	* them.
1c20f0e2	321	*/
7591bab1	322	void relay_index_close_all(struct relay_stream *stream)
1c20f0e2 JD	323	{
	324	struct lttng_ht_iter iter;
	325	struct relay_index *index;
	326
1c20f0e2	327	rcu_read_lock();
7591bab1 MD	328	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
	329	index, index_n.node) {
	330	/* Put self-ref from index. */
	331	relay_index_put(index);
1c20f0e2 JD	332	}
	333	rcu_read_unlock();
	334	}
3d07a857 MD	335
	336	void relay_index_close_partial_fd(struct relay_stream *stream)
	337	{
	338	struct lttng_ht_iter iter;
	339	struct relay_index *index;
	340
	341	rcu_read_lock();
	342	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
	343	index, index_n.node) {
	344	if (!index->index_fd) {
	345	continue;
	346	}
	347	/*
	348	* Partial index has its index_fd: we have only
	349	* received its info from the data socket.
	350	* Put self-ref from index.
	351	*/
	352	relay_index_put(index);
	353	}
	354	rcu_read_unlock();
	355	}
	356
	357	uint64_t relay_index_find_last(struct relay_stream *stream)
	358	{
	359	struct lttng_ht_iter iter;
	360	struct relay_index *index;
	361	uint64_t net_seq_num = -1ULL;
	362
	363	rcu_read_lock();
	364	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
	365	index, index_n.node) {
	366	if (net_seq_num == -1ULL \|\|
	367	index->index_n.key > net_seq_num) {
	368	net_seq_num = index->index_n.key;
	369	}
	370	}
	371	rcu_read_unlock();
	372	return net_seq_num;
	373	}