[lttng-tools.git] / src / bin / lttng-relayd / index.cpp

/*
 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#define _LGPL_SOURCE

#include "connection.hpp"
#include "index.hpp"
#include "lttng-relayd.hpp"
#include "stream.hpp"

#include <common/common.hpp>
#include <common/compat/endian.hpp>
#include <common/urcu.hpp>
#include <common/utils.hpp>

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

	lttng_ht_node_init_u64(&index->index_n, net_seq_num);
	pthread_mutex_init(&index->lock, nullptr);
	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;

	ASSERT_RCU_READ_LOCKED();

	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 = nullptr;
	}
	return _index;
}

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

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

	return urcu_ref_get_unless_zero(&index->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 = nullptr;

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

	lttng::urcu::read_lock_guard read_lock;
	lttng_ht_lookup(stream->indexes_ht, &net_seq_num, &iter);
	node = lttng_ht_iter_get_node_u64(&iter);
	if (node) {
		index = lttng::utils::container_of(node, &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 = nullptr;
			}
		} else {
			stream->indexes_in_flight++;
			index->in_hash_table = true;
		}
	}
end:
	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_file(struct relay_index *index,
			 struct lttng_index_file *index_file,
			 uint64_t data_offset)
{
	int ret = 0;

	pthread_mutex_lock(&index->lock);
	if (index->index_file) {
		ret = -1;
		goto end;
	}
	lttng_index_file_get(index_file);
	index->index_file = index_file;
	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 = lttng::utils::container_of(rcu_head, &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 = lttng::utils::container_of(ref, &relay_index::ref);
	struct relay_stream *stream = index->stream;
	int ret;
	struct lttng_ht_iter iter;

	if (index->index_file) {
		lttng_index_file_put(index->index_file);
		index->index_file = nullptr;
	}
	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);
		LTTNG_ASSERT(!ret);
		stream->indexes_in_flight--;
	}

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

	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 existence of index->lock for index unlock.
	 */
	lttng::urcu::read_lock_guard read_lock;
	/*
	 * Index lock ensures that concurrent test and update of stream
	 * ref is atomic.
	 */
	LTTNG_ASSERT(index->ref.refcount != 0);
	urcu_ref_put(&index->ref, index_release);
}

/*
 * 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;

	pthread_mutex_lock(&index->lock);
	if (index->flushed) {
		goto skip;
	}
	/* Check if we are ready to flush. */
	if (!index->has_index_data || !index->index_file) {
		goto skip;
	}

	DBG2("Writing index for stream ID %" PRIu64 " and seq num %" PRIu64,
	     index->stream->stream_handle,
	     index->index_n.key);
	flushed = true;
	index->flushed = true;
	ret = lttng_index_file_write(index->index_file, &index->index_data);
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;

	lttng::urcu::read_lock_guard 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);
	}
}

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

	lttng::urcu::read_lock_guard read_lock;

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

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;

	lttng::urcu::read_lock_guard 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;
		}
	}

	return net_seq_num;
}

/*
 * Update the index file of an already existing relay_index.
 * Offsets by 'removed_data_count' the offset field of an index.
 */
static int relay_index_switch_file(struct relay_index *index,
				   struct lttng_index_file *new_index_file,
				   uint64_t removed_data_count)
{
	int ret = 0;
	uint64_t offset;

	pthread_mutex_lock(&index->lock);
	if (!index->index_file) {
		ERR("No index_file");
		ret = 0;
		goto end;
	}

	lttng_index_file_put(index->index_file);
	lttng_index_file_get(new_index_file);
	index->index_file = new_index_file;
	offset = be64toh(index->index_data.offset);
	index->index_data.offset = htobe64(offset - removed_data_count);

end:
	pthread_mutex_unlock(&index->lock);
	return ret;
}

/*
 * Switch the index file of all pending indexes for a stream and update the
 * data offset by substracting the last safe position.
 * Stream lock must be held.
 */
int relay_index_switch_all_files(struct relay_stream *stream)
{
	struct lttng_ht_iter iter;
	struct relay_index *index;
	int ret = 0;

	lttng::urcu::read_lock_guard read_lock;

	cds_lfht_for_each_entry (stream->indexes_ht->ht, &iter.iter, index, index_n.node) {
		ret = relay_index_switch_file(
			index, stream->index_file, stream->pos_after_last_complete_data_index);
		if (ret) {
			return ret;
		}
	}

	return ret;
}

/*
 * Set index data from the control port to a given index object.
 */
int relay_index_set_control_data(struct relay_index *index,
				 const struct lttcomm_relayd_index *data,
				 unsigned int minor_version)
{
	/* The index on disk is encoded in big endian. */
	ctf_packet_index index_data{};

	index_data.packet_size = htobe64(data->packet_size);
	index_data.content_size = htobe64(data->content_size);
	index_data.timestamp_begin = htobe64(data->timestamp_begin);
	index_data.timestamp_end = htobe64(data->timestamp_end);
	index_data.events_discarded = htobe64(data->events_discarded);
	index_data.stream_id = htobe64(data->stream_id);

	if (minor_version >= 8) {
		index->index_data.stream_instance_id = htobe64(data->stream_instance_id);
		index->index_data.packet_seq_num = htobe64(data->packet_seq_num);
	} else {
		uint64_t unset_value = -1ULL;

		index->index_data.stream_instance_id = htobe64(unset_value);
		index->index_data.packet_seq_num = htobe64(unset_value);
	}

	return relay_index_set_data(index, &index_data);
}
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
	3	* Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
	4	* Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* SPDX-License-Identifier: GPL-2.0-only
	7	*
	8	*/
	9
	10	#define _LGPL_SOURCE
	11
	12	#include "connection.hpp"
	13	#include "index.hpp"
	14	#include "lttng-relayd.hpp"
	15	#include "stream.hpp"
	16
	17	#include <common/common.hpp>
	18	#include <common/compat/endian.hpp>
	19	#include <common/urcu.hpp>
	20	#include <common/utils.hpp>
	21
	22	/*
	23	* Allocate a new relay index object. Pass the stream in which it is
	24	* contained as parameter. The sequence number will be used as the hash
	25	* table key.
	26	*
	27	* Called with stream mutex held.
	28	* Return allocated object or else NULL on error.
	29	*/
	30	static struct relay_index relay_index_create(struct relay_stream stream, uint64_t net_seq_num)
	31	{
	32	struct relay_index *index;
	33
	34	DBG2("Creating relay index for stream id %" PRIu64 " and seqnum %" PRIu64,
	35	stream->stream_handle,
	36	net_seq_num);
	37
	38	index = zmalloc<relay_index>();
	39	if (!index) {
	40	PERROR("Relay index zmalloc");
	41	goto end;
	42	}
	43	if (!stream_get(stream)) {
	44	ERR("Cannot get stream");
	45	free(index);
	46	index = nullptr;
	47	goto end;
	48	}
	49	index->stream = stream;
	50
	51	lttng_ht_node_init_u64(&index->index_n, net_seq_num);
	52	pthread_mutex_init(&index->lock, nullptr);
	53	urcu_ref_init(&index->ref);
	54
	55	end:
	56	return index;
	57	}
	58
	59	/*
	60	* Add unique relay index to the given hash table. In case of a collision, the
	61	* already existing object is put in the given _index variable.
	62	*
	63	* RCU read side lock MUST be acquired.
	64	*/
	65	static struct relay_index relay_index_add_unique(struct relay_stream stream,
	66	struct relay_index *index)
	67	{
	68	struct cds_lfht_node *node_ptr;
	69	struct relay_index *_index;
	70
	71	ASSERT_RCU_READ_LOCKED();
	72
	73	DBG2("Adding relay index with stream id %" PRIu64 " and seqnum %" PRIu64,
	74	stream->stream_handle,
	75	index->index_n.key);
	76
	77	node_ptr = cds_lfht_add_unique(stream->indexes_ht->ht,
	78	stream->indexes_ht->hash_fct(&index->index_n, lttng_ht_seed),
	79	stream->indexes_ht->match_fct,
	80	&index->index_n,
	81	&index->index_n.node);
	82	if (node_ptr != &index->index_n.node) {
	83	_index = caa_container_of(node_ptr, struct relay_index, index_n.node);
	84	} else {
	85	_index = nullptr;
	86	}
	87	return _index;
	88	}
	89
	90	/*
	91	* Should be called with RCU read-side lock held.
	92	*/
	93	static bool relay_index_get(struct relay_index *index)
	94	{
	95	ASSERT_RCU_READ_LOCKED();
	96
	97	DBG2("index get for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
	98	index->stream->stream_handle,
	99	index->index_n.key,
	100	(int) index->ref.refcount);
	101
	102	return urcu_ref_get_unless_zero(&index->ref);
	103	}
	104
	105	/*
	106	* Get a relayd index in within the given stream, or create it if not
	107	* present.
	108	*
	109	* Called with stream mutex held.
	110	* Return index object or else NULL on error.
	111	*/
	112	struct relay_index relay_index_get_by_id_or_create(struct relay_stream stream,
	113	uint64_t net_seq_num)
	114	{
	115	struct lttng_ht_node_u64 *node;
	116	struct lttng_ht_iter iter;
	117	struct relay_index *index = nullptr;
	118
	119	DBG3("Finding index for stream id %" PRIu64 " and seq_num %" PRIu64,
	120	stream->stream_handle,
	121	net_seq_num);
	122
	123	lttng::urcu::read_lock_guard read_lock;
	124	lttng_ht_lookup(stream->indexes_ht, &net_seq_num, &iter);
	125	node = lttng_ht_iter_get_node_u64(&iter);
	126	if (node) {
	127	index = lttng::utils::container_of(node, &relay_index::index_n);
	128	} else {
	129	struct relay_index *oldindex;
	130
	131	index = relay_index_create(stream, net_seq_num);
	132	if (!index) {
	133	ERR("Cannot create index for stream id %" PRIu64 " and seq_num %" PRIu64,
	134	stream->stream_handle,
	135	net_seq_num);
	136	goto end;
	137	}
	138	oldindex = relay_index_add_unique(stream, index);
	139	if (oldindex) {
	140	/* Added concurrently, keep old. */
	141	relay_index_put(index);
	142	index = oldindex;
	143	if (!relay_index_get(index)) {
	144	index = nullptr;
	145	}
	146	} else {
	147	stream->indexes_in_flight++;
	148	index->in_hash_table = true;
	149	}
	150	}
	151	end:
	152	DBG2("Index %sfound or created in HT for stream ID %" PRIu64 " and seqnum %" PRIu64,
	153	(index == NULL) ? "NOT " : "",
	154	stream->stream_handle,
	155	net_seq_num);
	156	return index;
	157	}
	158
	159	int relay_index_set_file(struct relay_index *index,
	160	struct lttng_index_file *index_file,
	161	uint64_t data_offset)
	162	{
	163	int ret = 0;
	164
	165	pthread_mutex_lock(&index->lock);
	166	if (index->index_file) {
	167	ret = -1;
	168	goto end;
	169	}
	170	lttng_index_file_get(index_file);
	171	index->index_file = index_file;
	172	index->index_data.offset = data_offset;
	173	end:
	174	pthread_mutex_unlock(&index->lock);
	175	return ret;
	176	}
	177
	178	int relay_index_set_data(struct relay_index index, const struct ctf_packet_index data)
	179	{
	180	int ret = 0;
	181
	182	pthread_mutex_lock(&index->lock);
	183	if (index->has_index_data) {
	184	ret = -1;
	185	goto end;
	186	}
	187	/* Set everything except data_offset. */
	188	index->index_data.packet_size = data->packet_size;
	189	index->index_data.content_size = data->content_size;
	190	index->index_data.timestamp_begin = data->timestamp_begin;
	191	index->index_data.timestamp_end = data->timestamp_end;
	192	index->index_data.events_discarded = data->events_discarded;
	193	index->index_data.stream_id = data->stream_id;
	194	index->has_index_data = true;
	195	end:
	196	pthread_mutex_unlock(&index->lock);
	197	return ret;
	198	}
	199
	200	static void index_destroy(struct relay_index *index)
	201	{
	202	free(index);
	203	}
	204
	205	static void index_destroy_rcu(struct rcu_head *rcu_head)
	206	{
	207	struct relay_index *index = lttng::utils::container_of(rcu_head, &relay_index::rcu_node);
	208
	209	index_destroy(index);
	210	}
	211
	212	/* Stream lock must be held by the caller. */
	213	static void index_release(struct urcu_ref *ref)
	214	{
	215	struct relay_index *index = lttng::utils::container_of(ref, &relay_index::ref);
	216	struct relay_stream *stream = index->stream;
	217	int ret;
	218	struct lttng_ht_iter iter;
	219
	220	if (index->index_file) {
	221	lttng_index_file_put(index->index_file);
	222	index->index_file = nullptr;
	223	}
	224	if (index->in_hash_table) {
	225	/* Delete index from hash table. */
	226	iter.iter.node = &index->index_n.node;
	227	ret = lttng_ht_del(stream->indexes_ht, &iter);
	228	LTTNG_ASSERT(!ret);
	229	stream->indexes_in_flight--;
	230	}
	231
	232	stream_put(index->stream);
	233	index->stream = nullptr;
	234
	235	call_rcu(&index->rcu_node, index_destroy_rcu);
	236	}
	237
	238	/*
	239	* Called with stream mutex held.
	240	*
	241	* Stream lock must be held by the caller.
	242	*/
	243	void relay_index_put(struct relay_index *index)
	244	{
	245	DBG2("index put for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
	246	index->stream->stream_handle,
	247	index->index_n.key,
	248	(int) index->ref.refcount);
	249	/*
	250	* Ensure existence of index->lock for index unlock.
	251	*/
	252	lttng::urcu::read_lock_guard read_lock;
	253	/*
	254	* Index lock ensures that concurrent test and update of stream
	255	* ref is atomic.
	256	*/
	257	LTTNG_ASSERT(index->ref.refcount != 0);
	258	urcu_ref_put(&index->ref, index_release);
	259	}
	260
	261	/*
	262	* Try to flush index to disk. Releases self-reference to index once
	263	* flush succeeds.
	264	*
	265	* Stream lock must be held by the caller.
	266	* Return 0 on successful flush, a negative value on error, or positive
	267	* value if no flush was performed.
	268	*/
	269	int relay_index_try_flush(struct relay_index *index)
	270	{
	271	int ret = 1;
	272	bool flushed = false;
	273
	274	pthread_mutex_lock(&index->lock);
	275	if (index->flushed) {
	276	goto skip;
	277	}
	278	/* Check if we are ready to flush. */
	279	if (!index->has_index_data \|\| !index->index_file) {
	280	goto skip;
	281	}
	282
	283	DBG2("Writing index for stream ID %" PRIu64 " and seq num %" PRIu64,
	284	index->stream->stream_handle,
	285	index->index_n.key);
	286	flushed = true;
	287	index->flushed = true;
	288	ret = lttng_index_file_write(index->index_file, &index->index_data);
	289	skip:
	290	pthread_mutex_unlock(&index->lock);
	291
	292	if (flushed) {
	293	/* Put self-ref from index now that it has been flushed. */
	294	relay_index_put(index);
	295	}
	296	return ret;
	297	}
	298
	299	/*
	300	* Close every relay index within a given stream, without flushing
	301	* them.
	302	*/
	303	void relay_index_close_all(struct relay_stream *stream)
	304	{
	305	struct lttng_ht_iter iter;
	306	struct relay_index *index;
	307
	308	lttng::urcu::read_lock_guard read_lock;
	309
	310	cds_lfht_for_each_entry (stream->indexes_ht->ht, &iter.iter, index, index_n.node) {
	311	/* Put self-ref from index. */
	312	relay_index_put(index);
	313	}
	314	}
	315
	316	void relay_index_close_partial_fd(struct relay_stream *stream)
	317	{
	318	struct lttng_ht_iter iter;
	319	struct relay_index *index;
	320
	321	lttng::urcu::read_lock_guard read_lock;
	322
	323	cds_lfht_for_each_entry (stream->indexes_ht->ht, &iter.iter, index, index_n.node) {
	324	if (!index->index_file) {
	325	continue;
	326	}
	327	/*
	328	* Partial index has its index_file: we have only
	329	* received its info from the data socket.
	330	* Put self-ref from index.
	331	*/
	332	relay_index_put(index);
	333	}
	334	}
	335
	336	uint64_t relay_index_find_last(struct relay_stream *stream)
	337	{
	338	struct lttng_ht_iter iter;
	339	struct relay_index *index;
	340	uint64_t net_seq_num = -1ULL;
	341
	342	lttng::urcu::read_lock_guard read_lock;
	343
	344	cds_lfht_for_each_entry (stream->indexes_ht->ht, &iter.iter, index, index_n.node) {
	345	if (net_seq_num == -1ULL \|\| index->index_n.key > net_seq_num) {
	346	net_seq_num = index->index_n.key;
	347	}
	348	}
	349
	350	return net_seq_num;
	351	}
	352
	353	/*
	354	* Update the index file of an already existing relay_index.
	355	* Offsets by 'removed_data_count' the offset field of an index.
	356	*/
	357	static int relay_index_switch_file(struct relay_index *index,
	358	struct lttng_index_file *new_index_file,
	359	uint64_t removed_data_count)
	360	{
	361	int ret = 0;
	362	uint64_t offset;
	363
	364	pthread_mutex_lock(&index->lock);
	365	if (!index->index_file) {
	366	ERR("No index_file");
	367	ret = 0;
	368	goto end;
	369	}
	370
	371	lttng_index_file_put(index->index_file);
	372	lttng_index_file_get(new_index_file);
	373	index->index_file = new_index_file;
	374	offset = be64toh(index->index_data.offset);
	375	index->index_data.offset = htobe64(offset - removed_data_count);
	376
	377	end:
	378	pthread_mutex_unlock(&index->lock);
	379	return ret;
	380	}
	381
	382	/*
	383	* Switch the index file of all pending indexes for a stream and update the
	384	* data offset by substracting the last safe position.
	385	* Stream lock must be held.
	386	*/
	387	int relay_index_switch_all_files(struct relay_stream *stream)
	388	{
	389	struct lttng_ht_iter iter;
	390	struct relay_index *index;
	391	int ret = 0;
	392
	393	lttng::urcu::read_lock_guard read_lock;
	394
	395	cds_lfht_for_each_entry (stream->indexes_ht->ht, &iter.iter, index, index_n.node) {
	396	ret = relay_index_switch_file(
	397	index, stream->index_file, stream->pos_after_last_complete_data_index);
	398	if (ret) {
	399	return ret;
	400	}
	401	}
	402
	403	return ret;
	404	}
	405
	406	/*
	407	* Set index data from the control port to a given index object.
	408	*/
	409	int relay_index_set_control_data(struct relay_index *index,
	410	const struct lttcomm_relayd_index *data,
	411	unsigned int minor_version)
	412	{
	413	/* The index on disk is encoded in big endian. */
	414	ctf_packet_index index_data{};
	415
	416	index_data.packet_size = htobe64(data->packet_size);
	417	index_data.content_size = htobe64(data->content_size);
	418	index_data.timestamp_begin = htobe64(data->timestamp_begin);
	419	index_data.timestamp_end = htobe64(data->timestamp_end);
	420	index_data.events_discarded = htobe64(data->events_discarded);
	421	index_data.stream_id = htobe64(data->stream_id);
	422
	423	if (minor_version >= 8) {
	424	index->index_data.stream_instance_id = htobe64(data->stream_instance_id);
	425	index->index_data.packet_seq_num = htobe64(data->packet_seq_num);
	426	} else {
	427	uint64_t unset_value = -1ULL;
	428
	429	index->index_data.stream_instance_id = htobe64(unset_value);
	430	index->index_data.packet_seq_num = htobe64(unset_value);
	431	}
	432
	433	return relay_index_set_data(index, &index_data);
	434	}