2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
4 * SPDX-License-Identifier: GPL-2.0-only
17 #include <sys/types.h>
20 #include <common/common.h>
21 #include <common/utils.h>
22 #include <common/trace-chunk.h>
23 #include <common/sessiond-comm/sessiond-comm.h>
24 #include <lttng/location-internal.h>
25 #include "lttng-sessiond.h"
30 #include "trace-ust.h"
34 struct ltt_session_destroy_notifier_element
{
35 ltt_session_destroy_notifier notifier
;
39 struct ltt_session_clear_notifier_element
{
40 ltt_session_clear_notifier notifier
;
47 * No ltt_session.lock is taken here because those data structure are widely
48 * spread across the lttng-tools code base so before calling functions below
49 * that can read/write a session, the caller MUST acquire the session lock
50 * using session_lock() and session_unlock().
54 * Init tracing session list.
56 * Please see session.h for more explanation and correct usage of the list.
58 static struct ltt_session_list ltt_session_list
= {
59 .head
= CDS_LIST_HEAD_INIT(ltt_session_list
.head
),
60 .lock
= PTHREAD_MUTEX_INITIALIZER
,
61 .removal_cond
= PTHREAD_COND_INITIALIZER
,
65 /* These characters are forbidden in a session name. Used by validate_name. */
66 static const char *forbidden_name_chars
= "/";
68 /* Global hash table to keep the sessions, indexed by id. */
69 static struct lttng_ht
*ltt_sessions_ht_by_id
= NULL
;
70 /* Global hash table to keep the sessions, indexed by name. */
71 static struct lttng_ht
*ltt_sessions_ht_by_name
= NULL
;
74 * Validate the session name for forbidden characters.
76 * Return 0 on success else -1 meaning a forbidden char. has been found.
78 static int validate_name(const char *name
)
85 tmp_name
= strdup(name
);
92 tok
= strpbrk(tmp_name
, forbidden_name_chars
);
94 DBG("Session name %s contains a forbidden character", name
);
95 /* Forbidden character has been found. */
107 * Add a ltt_session structure to the global list.
109 * The caller MUST acquire the session list lock before.
110 * Returns the unique identifier for the session.
112 static uint64_t add_session_list(struct ltt_session
*ls
)
116 cds_list_add(&ls
->list
, <t_session_list
.head
);
117 return ltt_session_list
.next_uuid
++;
121 * Delete a ltt_session structure to the global list.
123 * The caller MUST acquire the session list lock before.
125 static void del_session_list(struct ltt_session
*ls
)
129 cds_list_del(&ls
->list
);
133 * Return a pointer to the session list.
135 struct ltt_session_list
*session_get_list(void)
137 return <t_session_list
;
141 * Returns once the session list is empty.
143 void session_list_wait_empty(void)
145 pthread_mutex_lock(<t_session_list
.lock
);
146 while (!cds_list_empty(<t_session_list
.head
)) {
147 pthread_cond_wait(<t_session_list
.removal_cond
,
148 <t_session_list
.lock
);
150 pthread_mutex_unlock(<t_session_list
.lock
);
154 * Acquire session list lock
156 void session_lock_list(void)
158 pthread_mutex_lock(<t_session_list
.lock
);
162 * Try to acquire session list lock
164 int session_trylock_list(void)
166 return pthread_mutex_trylock(<t_session_list
.lock
);
170 * Release session list lock
172 void session_unlock_list(void)
174 pthread_mutex_unlock(<t_session_list
.lock
);
178 * Get the session's consumer destination type.
180 * The caller must hold the session lock.
182 enum consumer_dst_type
session_get_consumer_destination_type(
183 const struct ltt_session
*session
)
186 * The output information is duplicated in both of those session types.
187 * Hence, it doesn't matter from which it is retrieved. However, it is
188 * possible for only one of them to be set.
190 return session
->kernel_session
?
191 session
->kernel_session
->consumer
->type
:
192 session
->ust_session
->consumer
->type
;
196 * Get the session's consumer network hostname.
197 * The caller must ensure that the destination is of type "net".
199 * The caller must hold the session lock.
201 const char *session_get_net_consumer_hostname(const struct ltt_session
*session
)
203 const char *hostname
= NULL
;
204 const struct consumer_output
*output
;
206 output
= session
->kernel_session
?
207 session
->kernel_session
->consumer
:
208 session
->ust_session
->consumer
;
211 * hostname is assumed to be the same for both control and data
214 switch (output
->dst
.net
.control
.dtype
) {
216 hostname
= output
->dst
.net
.control
.dst
.ipv4
;
219 hostname
= output
->dst
.net
.control
.dst
.ipv6
;
228 * Get the session's consumer network control and data ports.
229 * The caller must ensure that the destination is of type "net".
231 * The caller must hold the session lock.
233 void session_get_net_consumer_ports(const struct ltt_session
*session
,
234 uint16_t *control_port
, uint16_t *data_port
)
236 const struct consumer_output
*output
;
238 output
= session
->kernel_session
?
239 session
->kernel_session
->consumer
:
240 session
->ust_session
->consumer
;
241 *control_port
= output
->dst
.net
.control
.port
;
242 *data_port
= output
->dst
.net
.data
.port
;
246 * Get the location of the latest trace archive produced by a rotation.
248 * The caller must hold the session lock.
250 struct lttng_trace_archive_location
*session_get_trace_archive_location(
251 const struct ltt_session
*session
)
254 struct lttng_trace_archive_location
*location
= NULL
;
255 char *chunk_path
= NULL
;
257 if (session
->rotation_state
!= LTTNG_ROTATION_STATE_COMPLETED
||
258 !session
->last_archived_chunk_name
) {
262 switch (session_get_consumer_destination_type(session
)) {
263 case CONSUMER_DST_LOCAL
:
264 ret
= asprintf(&chunk_path
,
265 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY
"/%s",
266 session_get_base_path(session
),
267 session
->last_archived_chunk_name
);
271 location
= lttng_trace_archive_location_local_create(
274 case CONSUMER_DST_NET
:
276 const char *hostname
;
277 uint16_t control_port
, data_port
;
279 hostname
= session_get_net_consumer_hostname(session
);
280 session_get_net_consumer_ports(session
,
283 location
= lttng_trace_archive_location_relay_create(
285 LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP
,
286 control_port
, data_port
, session
->last_chunk_path
);
298 * Allocate the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name HT.
300 * The session list lock must be held.
302 static int ltt_sessions_ht_alloc(void)
306 DBG("Allocating ltt_sessions_ht_by_id");
307 ltt_sessions_ht_by_id
= lttng_ht_new(0, LTTNG_HT_TYPE_U64
);
308 if (!ltt_sessions_ht_by_id
) {
310 ERR("Failed to allocate ltt_sessions_ht_by_id");
314 DBG("Allocating ltt_sessions_ht_by_name");
315 ltt_sessions_ht_by_name
= lttng_ht_new(0, LTTNG_HT_TYPE_STRING
);
316 if (!ltt_sessions_ht_by_name
) {
318 ERR("Failed to allocate ltt_sessions_ht_by_name");
327 * Destroy the ltt_sessions_ht_by_id HT.
329 * The session list lock must be held.
331 static void ltt_sessions_ht_destroy(void)
333 if (ltt_sessions_ht_by_id
) {
334 ht_cleanup_push(ltt_sessions_ht_by_id
);
335 ltt_sessions_ht_by_id
= NULL
;
338 if (ltt_sessions_ht_by_name
) {
339 ht_cleanup_push(ltt_sessions_ht_by_name
);
340 ltt_sessions_ht_by_name
= NULL
;
347 * Add a ltt_session to the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name.
348 * If unallocated, the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name. HTs
349 * are allocated. The session list lock must be held.
351 static void add_session_ht(struct ltt_session
*ls
)
357 if (!ltt_sessions_ht_by_id
) {
358 ret
= ltt_sessions_ht_alloc();
360 ERR("Error allocating the sessions HT");
365 /* Should always be present with ltt_sessions_ht_by_id. */
366 assert(ltt_sessions_ht_by_name
);
368 lttng_ht_node_init_u64(&ls
->node
, ls
->id
);
369 lttng_ht_add_unique_u64(ltt_sessions_ht_by_id
, &ls
->node
);
371 lttng_ht_node_init_str(&ls
->node_by_name
, ls
->name
);
372 lttng_ht_add_unique_str(ltt_sessions_ht_by_name
, &ls
->node_by_name
);
379 * Test if ltt_sessions_ht_by_id/name are empty.
380 * Return 1 if empty, 0 if not empty.
381 * The session list lock must be held.
383 static int ltt_sessions_ht_empty(void)
387 if (!ltt_sessions_ht_by_id
) {
392 assert(ltt_sessions_ht_by_name
);
394 count
= lttng_ht_get_count(ltt_sessions_ht_by_id
);
395 assert(count
== lttng_ht_get_count(ltt_sessions_ht_by_name
));
397 return count
? 0 : 1;
401 * Remove a ltt_session from the ltt_sessions_ht_by_id/name.
402 * If empty, the ltt_sessions_ht_by_id/name HTs are freed.
403 * The session list lock must be held.
405 static void del_session_ht(struct ltt_session
*ls
)
407 struct lttng_ht_iter iter
;
411 assert(ltt_sessions_ht_by_id
);
412 assert(ltt_sessions_ht_by_name
);
414 iter
.iter
.node
= &ls
->node
.node
;
415 ret
= lttng_ht_del(ltt_sessions_ht_by_id
, &iter
);
418 iter
.iter
.node
= &ls
->node_by_name
.node
;
419 ret
= lttng_ht_del(ltt_sessions_ht_by_name
, &iter
);
422 if (ltt_sessions_ht_empty()) {
423 DBG("Empty ltt_sessions_ht_by_id/name, destroying hast tables");
424 ltt_sessions_ht_destroy();
429 * Acquire session lock
431 void session_lock(struct ltt_session
*session
)
435 pthread_mutex_lock(&session
->lock
);
439 * Release session lock
441 void session_unlock(struct ltt_session
*session
)
445 pthread_mutex_unlock(&session
->lock
);
449 int _session_set_trace_chunk_no_lock_check(struct ltt_session
*session
,
450 struct lttng_trace_chunk
*new_trace_chunk
,
451 struct lttng_trace_chunk
**_current_trace_chunk
)
454 unsigned int i
, refs_to_acquire
= 0, refs_acquired
= 0, refs_to_release
= 0;
455 struct cds_lfht_iter iter
;
456 struct consumer_socket
*socket
;
457 struct lttng_trace_chunk
*current_trace_chunk
;
459 enum lttng_trace_chunk_status chunk_status
;
463 * Ownership of current trace chunk is transferred to
464 * `current_trace_chunk`.
466 current_trace_chunk
= session
->current_trace_chunk
;
467 session
->current_trace_chunk
= NULL
;
468 if (session
->ust_session
) {
469 lttng_trace_chunk_put(
470 session
->ust_session
->current_trace_chunk
);
471 session
->ust_session
->current_trace_chunk
= NULL
;
473 if (session
->kernel_session
) {
474 lttng_trace_chunk_put(
475 session
->kernel_session
->current_trace_chunk
);
476 session
->kernel_session
->current_trace_chunk
= NULL
;
478 if (!new_trace_chunk
) {
482 chunk_status
= lttng_trace_chunk_get_id(new_trace_chunk
, &chunk_id
);
483 assert(chunk_status
== LTTNG_TRACE_CHUNK_STATUS_OK
);
486 refs_to_acquire
+= !!session
->ust_session
;
487 refs_to_acquire
+= !!session
->kernel_session
;
489 for (refs_acquired
= 0; refs_acquired
< refs_to_acquire
;
491 if (!lttng_trace_chunk_get(new_trace_chunk
)) {
492 ERR("Failed to acquire reference to new trace chunk of session \"%s\"",
498 if (session
->ust_session
) {
499 const uint64_t relayd_id
=
500 session
->ust_session
->consumer
->net_seq_index
;
501 const bool is_local_trace
=
502 session
->ust_session
->consumer
->type
==
505 session
->ust_session
->current_trace_chunk
= new_trace_chunk
;
506 if (is_local_trace
) {
507 enum lttng_error_code ret_error_code
;
509 ret_error_code
= ust_app_create_channel_subdirectories(
510 session
->ust_session
);
511 if (ret_error_code
!= LTTNG_OK
) {
515 cds_lfht_for_each_entry(
516 session
->ust_session
->consumer
->socks
->ht
,
517 &iter
, socket
, node
.node
) {
518 pthread_mutex_lock(socket
->lock
);
519 ret
= consumer_create_trace_chunk(socket
,
521 session
->id
, new_trace_chunk
,
522 DEFAULT_UST_TRACE_DIR
);
523 pthread_mutex_unlock(socket
->lock
);
529 if (session
->kernel_session
) {
530 const uint64_t relayd_id
=
531 session
->kernel_session
->consumer
->net_seq_index
;
532 const bool is_local_trace
=
533 session
->kernel_session
->consumer
->type
==
536 session
->kernel_session
->current_trace_chunk
= new_trace_chunk
;
537 if (is_local_trace
) {
538 enum lttng_error_code ret_error_code
;
540 ret_error_code
= kernel_create_channel_subdirectories(
541 session
->kernel_session
);
542 if (ret_error_code
!= LTTNG_OK
) {
546 cds_lfht_for_each_entry(
547 session
->kernel_session
->consumer
->socks
->ht
,
548 &iter
, socket
, node
.node
) {
549 pthread_mutex_lock(socket
->lock
);
550 ret
= consumer_create_trace_chunk(socket
,
552 session
->id
, new_trace_chunk
,
553 DEFAULT_KERNEL_TRACE_DIR
);
554 pthread_mutex_unlock(socket
->lock
);
562 * Update local current trace chunk state last, only if all remote
563 * creations succeeded.
565 session
->current_trace_chunk
= new_trace_chunk
;
566 LTTNG_OPTIONAL_SET(&session
->most_recent_chunk_id
, chunk_id
);
568 if (_current_trace_chunk
) {
569 *_current_trace_chunk
= current_trace_chunk
;
570 current_trace_chunk
= NULL
;
574 lttng_trace_chunk_put(current_trace_chunk
);
577 if (session
->ust_session
) {
578 session
->ust_session
->current_trace_chunk
= NULL
;
580 if (session
->kernel_session
) {
581 session
->kernel_session
->current_trace_chunk
= NULL
;
584 * Release references taken in the case where all references could not
587 refs_to_release
= refs_to_acquire
- refs_acquired
;
588 for (i
= 0; i
< refs_to_release
; i
++) {
589 lttng_trace_chunk_put(new_trace_chunk
);
595 struct lttng_trace_chunk
*session_create_new_trace_chunk(
596 const struct ltt_session
*session
,
597 const struct consumer_output
*consumer_output_override
,
598 const char *session_base_path_override
,
599 const char *chunk_name_override
)
602 struct lttng_trace_chunk
*trace_chunk
= NULL
;
603 enum lttng_trace_chunk_status chunk_status
;
604 const time_t chunk_creation_ts
= time(NULL
);
606 const char *base_path
;
607 struct lttng_directory_handle
*session_output_directory
= NULL
;
608 const struct lttng_credentials session_credentials
= {
609 .uid
= LTTNG_OPTIONAL_INIT_VALUE(session
->uid
),
610 .gid
= LTTNG_OPTIONAL_INIT_VALUE(session
->gid
),
612 uint64_t next_chunk_id
;
613 const struct consumer_output
*output
;
614 const char *new_path
;
616 if (consumer_output_override
) {
617 output
= consumer_output_override
;
619 assert(session
->ust_session
|| session
->kernel_session
);
620 output
= session
->ust_session
?
621 session
->ust_session
->consumer
:
622 session
->kernel_session
->consumer
;
625 is_local_trace
= output
->type
== CONSUMER_DST_LOCAL
;
626 base_path
= session_base_path_override
? :
627 consumer_output_get_base_path(output
);
629 if (chunk_creation_ts
== (time_t) -1) {
630 PERROR("Failed to sample time while creation session \"%s\" trace chunk",
635 next_chunk_id
= session
->most_recent_chunk_id
.is_set
?
636 session
->most_recent_chunk_id
.value
+ 1 : 0;
638 if (session
->current_trace_chunk
&&
639 !lttng_trace_chunk_get_name_overridden(session
->current_trace_chunk
)) {
640 chunk_status
= lttng_trace_chunk_rename_path(session
->current_trace_chunk
,
641 DEFAULT_CHUNK_TMP_OLD_DIRECTORY
);
642 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
646 if (!session
->current_trace_chunk
) {
647 if (!session
->rotated
) {
653 new_path
= DEFAULT_CHUNK_TMP_NEW_DIRECTORY
;
656 trace_chunk
= lttng_trace_chunk_create(next_chunk_id
,
657 chunk_creation_ts
, new_path
);
662 if (chunk_name_override
) {
663 chunk_status
= lttng_trace_chunk_override_name(trace_chunk
,
664 chunk_name_override
);
665 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
670 if (!is_local_trace
) {
672 * No need to set crendentials and output directory
673 * for remote trace chunks.
678 chunk_status
= lttng_trace_chunk_set_credentials(trace_chunk
,
679 &session_credentials
);
680 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
684 DBG("Creating base output directory of session \"%s\" at %s",
685 session
->name
, base_path
);
686 ret
= utils_mkdir_recursive(base_path
, S_IRWXU
| S_IRWXG
,
687 session
->uid
, session
->gid
);
691 session_output_directory
= lttng_directory_handle_create(base_path
);
692 if (!session_output_directory
) {
695 chunk_status
= lttng_trace_chunk_set_as_owner(trace_chunk
,
696 session_output_directory
);
697 lttng_directory_handle_put(session_output_directory
);
698 session_output_directory
= NULL
;
699 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
705 lttng_directory_handle_put(session_output_directory
);
706 lttng_trace_chunk_put(trace_chunk
);
711 int session_close_trace_chunk(struct ltt_session
*session
,
712 struct lttng_trace_chunk
*trace_chunk
,
713 enum lttng_trace_chunk_command_type close_command
,
714 char *closed_trace_chunk_path
)
717 bool error_occurred
= false;
718 struct cds_lfht_iter iter
;
719 struct consumer_socket
*socket
;
720 enum lttng_trace_chunk_status chunk_status
;
721 const time_t chunk_close_timestamp
= time(NULL
);
722 const char *new_path
;
724 chunk_status
= lttng_trace_chunk_set_close_command(
725 trace_chunk
, close_command
);
726 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
731 if (chunk_close_timestamp
== (time_t) -1) {
732 ERR("Failed to sample the close timestamp of the current trace chunk of session \"%s\"",
738 if (close_command
== LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE
&& !session
->rotated
) {
739 /* New chunk stays in session output directory. */
742 /* Use chunk name for new chunk. */
745 if (session
->current_trace_chunk
&&
746 !lttng_trace_chunk_get_name_overridden(session
->current_trace_chunk
)) {
747 /* Rename new chunk path. */
748 chunk_status
= lttng_trace_chunk_rename_path(session
->current_trace_chunk
,
750 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
755 if (!lttng_trace_chunk_get_name_overridden(trace_chunk
) &&
756 close_command
== LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION
) {
757 const char *old_path
;
759 if (!session
->rotated
) {
764 /* We need to move back the .tmp_old_chunk to its rightful place. */
765 chunk_status
= lttng_trace_chunk_rename_path(trace_chunk
,
767 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
772 if (close_command
== LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED
) {
773 session
->rotated
= true;
775 chunk_status
= lttng_trace_chunk_set_close_timestamp(trace_chunk
,
776 chunk_close_timestamp
);
777 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
778 ERR("Failed to set the close timestamp of the current trace chunk of session \"%s\"",
784 if (session
->ust_session
) {
785 const uint64_t relayd_id
=
786 session
->ust_session
->consumer
->net_seq_index
;
788 cds_lfht_for_each_entry(
789 session
->ust_session
->consumer
->socks
->ht
,
790 &iter
, socket
, node
.node
) {
791 pthread_mutex_lock(socket
->lock
);
792 ret
= consumer_close_trace_chunk(socket
,
795 trace_chunk
, closed_trace_chunk_path
);
796 pthread_mutex_unlock(socket
->lock
);
798 ERR("Failed to close trace chunk on user space consumer");
799 error_occurred
= true;
803 if (session
->kernel_session
) {
804 const uint64_t relayd_id
=
805 session
->kernel_session
->consumer
->net_seq_index
;
807 cds_lfht_for_each_entry(
808 session
->kernel_session
->consumer
->socks
->ht
,
809 &iter
, socket
, node
.node
) {
810 pthread_mutex_lock(socket
->lock
);
811 ret
= consumer_close_trace_chunk(socket
,
814 trace_chunk
, closed_trace_chunk_path
);
815 pthread_mutex_unlock(socket
->lock
);
817 ERR("Failed to close trace chunk on kernel consumer");
818 error_occurred
= true;
822 ret
= error_occurred
? -1 : 0;
828 * This function skips the metadata channel as the begin/end timestamps of a
829 * metadata packet are useless.
831 * Moreover, opening a packet after a "clear" will cause problems for live
832 * sessions as it will introduce padding that was not part of the first trace
833 * chunk. The relay daemon expects the content of the metadata stream of
834 * successive metadata trace chunks to be strict supersets of one another.
836 * For example, flushing a packet at the beginning of the metadata stream of
837 * a trace chunk resulting from a "clear" session command will cause the
838 * size of the metadata stream of the new trace chunk to not match the size of
839 * the metadata stream of the original chunk. This will confuse the relay
840 * daemon as the same "offset" in a metadata stream will no longer point
841 * to the same content.
844 enum lttng_error_code
session_kernel_open_packets(struct ltt_session
*session
)
846 enum lttng_error_code ret
= LTTNG_OK
;
847 struct consumer_socket
*socket
;
848 struct lttng_ht_iter iter
;
849 struct cds_lfht_node
*node
;
850 struct ltt_kernel_channel
*chan
;
854 cds_lfht_first(session
->kernel_session
->consumer
->socks
->ht
, &iter
.iter
);
855 node
= cds_lfht_iter_get_node(&iter
.iter
);
856 socket
= container_of(node
, typeof(*socket
), node
.node
);
858 cds_list_for_each_entry(chan
,
859 &session
->kernel_session
->channel_list
.head
, list
) {
862 DBG("Open packet of kernel channel: channel key = %" PRIu64
863 ", session name = %s, session_id = %" PRIu64
,
864 chan
->key
, session
->name
, session
->id
);
866 open_ret
= consumer_open_channel_packets(socket
, chan
->key
);
868 /* General error (no known error expected). */
879 enum lttng_error_code
session_open_packets(struct ltt_session
*session
)
881 enum lttng_error_code ret
= LTTNG_OK
;
883 DBG("Opening packets of session channels: session name = %s, session id = %" PRIu64
,
884 session
->name
, session
->id
);
886 if (session
->ust_session
) {
887 ret
= ust_app_open_packets(session
);
888 if (ret
!= LTTNG_OK
) {
893 if (session
->kernel_session
) {
894 ret
= session_kernel_open_packets(session
);
895 if (ret
!= LTTNG_OK
) {
905 * Set a session's current trace chunk.
907 * Must be called with the session lock held.
909 int session_set_trace_chunk(struct ltt_session
*session
,
910 struct lttng_trace_chunk
*new_trace_chunk
,
911 struct lttng_trace_chunk
**current_trace_chunk
)
913 ASSERT_LOCKED(session
->lock
);
914 return _session_set_trace_chunk_no_lock_check(session
, new_trace_chunk
,
915 current_trace_chunk
);
919 void session_notify_destruction(const struct ltt_session
*session
)
922 const size_t count
= lttng_dynamic_array_get_count(
923 &session
->destroy_notifiers
);
925 for (i
= 0; i
< count
; i
++) {
926 const struct ltt_session_destroy_notifier_element
*element
=
927 lttng_dynamic_array_get_element(
928 &session
->destroy_notifiers
, i
);
930 element
->notifier(session
, element
->user_data
);
935 * Fire each clear notifier once, and remove them from the array.
937 void session_notify_clear(struct ltt_session
*session
)
940 const size_t count
= lttng_dynamic_array_get_count(
941 &session
->clear_notifiers
);
943 for (i
= 0; i
< count
; i
++) {
944 const struct ltt_session_clear_notifier_element
*element
=
945 lttng_dynamic_array_get_element(
946 &session
->clear_notifiers
, i
);
948 element
->notifier(session
, element
->user_data
);
950 lttng_dynamic_array_clear(&session
->clear_notifiers
);
954 void session_release(struct urcu_ref
*ref
)
957 struct ltt_ust_session
*usess
;
958 struct ltt_kernel_session
*ksess
;
959 struct ltt_session
*session
= container_of(ref
, typeof(*session
), ref
);
960 const bool session_published
= session
->published
;
962 assert(!session
->chunk_being_archived
);
964 usess
= session
->ust_session
;
965 ksess
= session
->kernel_session
;
967 /* Clean kernel session teardown, keeping data for destroy notifier. */
968 kernel_destroy_session(ksess
);
970 /* UST session teardown, keeping data for destroy notifier. */
972 /* Close any relayd session */
973 consumer_output_send_destroy_relayd(usess
->consumer
);
975 /* Destroy every UST application related to this session. */
976 ret
= ust_app_destroy_trace_all(usess
);
978 ERR("Error in ust_app_destroy_trace_all");
981 /* Clean up the rest, keeping destroy notifier data. */
982 trace_ust_destroy_session(usess
);
986 * Must notify the kernel thread here to update it's poll set in order to
987 * remove the channel(s)' fd just destroyed.
989 ret
= notify_thread_pipe(the_kernel_poll_pipe
[1]);
991 PERROR("write kernel poll pipe");
994 DBG("Destroying session %s (id %" PRIu64
")", session
->name
, session
->id
);
996 snapshot_destroy(&session
->snapshot
);
998 pthread_mutex_destroy(&session
->lock
);
1000 if (session_published
) {
1001 ASSERT_LOCKED(ltt_session_list
.lock
);
1002 del_session_list(session
);
1003 del_session_ht(session
);
1005 session_notify_destruction(session
);
1007 consumer_output_put(session
->consumer
);
1008 kernel_free_session(ksess
);
1009 session
->kernel_session
= NULL
;
1011 trace_ust_free_session(usess
);
1012 session
->ust_session
= NULL
;
1014 lttng_dynamic_array_reset(&session
->destroy_notifiers
);
1015 lttng_dynamic_array_reset(&session
->clear_notifiers
);
1016 free(session
->last_archived_chunk_name
);
1017 free(session
->base_path
);
1019 if (session_published
) {
1021 * Broadcast after free-ing to ensure the memory is
1022 * reclaimed before the main thread exits.
1024 ASSERT_LOCKED(ltt_session_list
.lock
);
1025 pthread_cond_broadcast(<t_session_list
.removal_cond
);
1030 * Acquire a reference to a session.
1031 * This function may fail (return false); its return value must be checked.
1033 bool session_get(struct ltt_session
*session
)
1035 return urcu_ref_get_unless_zero(&session
->ref
);
1039 * Release a reference to a session.
1041 void session_put(struct ltt_session
*session
)
1047 * The session list lock must be held as any session_put()
1048 * may cause the removal of the session from the session_list.
1050 ASSERT_LOCKED(ltt_session_list
.lock
);
1051 assert(session
->ref
.refcount
);
1052 urcu_ref_put(&session
->ref
, session_release
);
1056 * Destroy a session.
1058 * This method does not immediately release/free the session as other
1059 * components may still hold a reference to the session. However,
1060 * the session should no longer be presented to the user.
1062 * Releases the session list's reference to the session
1063 * and marks it as destroyed. Iterations on the session list should be
1064 * mindful of the "destroyed" flag.
1066 void session_destroy(struct ltt_session
*session
)
1068 assert(!session
->destroyed
);
1069 session
->destroyed
= true;
1070 session_put(session
);
1073 int session_add_destroy_notifier(struct ltt_session
*session
,
1074 ltt_session_destroy_notifier notifier
, void *user_data
)
1076 const struct ltt_session_destroy_notifier_element element
= {
1077 .notifier
= notifier
,
1078 .user_data
= user_data
1081 return lttng_dynamic_array_add_element(&session
->destroy_notifiers
,
1085 int session_add_clear_notifier(struct ltt_session
*session
,
1086 ltt_session_clear_notifier notifier
, void *user_data
)
1088 const struct ltt_session_clear_notifier_element element
= {
1089 .notifier
= notifier
,
1090 .user_data
= user_data
1093 return lttng_dynamic_array_add_element(&session
->clear_notifiers
,
1098 * Return a ltt_session structure ptr that matches name. If no session found,
1099 * NULL is returned. This must be called with the session list lock held using
1100 * session_lock_list and session_unlock_list.
1101 * A reference to the session is implicitly acquired by this function.
1103 struct ltt_session
*session_find_by_name(const char *name
)
1105 struct ltt_session
*iter
;
1108 ASSERT_LOCKED(ltt_session_list
.lock
);
1110 DBG2("Trying to find session by name %s", name
);
1112 cds_list_for_each_entry(iter
, <t_session_list
.head
, list
) {
1113 if (!strncmp(iter
->name
, name
, NAME_MAX
) &&
1121 return session_get(iter
) ? iter
: NULL
;
1125 * Return an ltt_session that matches the id. If no session is found,
1126 * NULL is returned. This must be called with rcu_read_lock and
1127 * session list lock held (to guarantee the lifetime of the session).
1129 struct ltt_session
*session_find_by_id(uint64_t id
)
1131 struct lttng_ht_node_u64
*node
;
1132 struct lttng_ht_iter iter
;
1133 struct ltt_session
*ls
;
1135 ASSERT_LOCKED(ltt_session_list
.lock
);
1137 if (!ltt_sessions_ht_by_id
) {
1141 lttng_ht_lookup(ltt_sessions_ht_by_id
, &id
, &iter
);
1142 node
= lttng_ht_iter_get_node_u64(&iter
);
1146 ls
= caa_container_of(node
, struct ltt_session
, node
);
1148 DBG3("Session %" PRIu64
" found by id.", id
);
1149 return session_get(ls
) ? ls
: NULL
;
1152 DBG3("Session %" PRIu64
" NOT found by id", id
);
1157 * Create a new session and add it to the session list.
1158 * Session list lock must be held by the caller.
1160 enum lttng_error_code
session_create(const char *name
, uid_t uid
, gid_t gid
,
1161 struct ltt_session
**out_session
)
1164 enum lttng_error_code ret_code
;
1165 struct ltt_session
*new_session
= NULL
;
1167 ASSERT_LOCKED(ltt_session_list
.lock
);
1169 struct ltt_session
*clashing_session
;
1171 clashing_session
= session_find_by_name(name
);
1172 if (clashing_session
) {
1173 session_put(clashing_session
);
1174 ret_code
= LTTNG_ERR_EXIST_SESS
;
1178 new_session
= zmalloc(sizeof(struct ltt_session
));
1180 PERROR("Failed to allocate an ltt_session structure");
1181 ret_code
= LTTNG_ERR_NOMEM
;
1185 lttng_dynamic_array_init(&new_session
->destroy_notifiers
,
1186 sizeof(struct ltt_session_destroy_notifier_element
),
1188 lttng_dynamic_array_init(&new_session
->clear_notifiers
,
1189 sizeof(struct ltt_session_clear_notifier_element
),
1191 urcu_ref_init(&new_session
->ref
);
1192 pthread_mutex_init(&new_session
->lock
, NULL
);
1194 new_session
->creation_time
= time(NULL
);
1195 if (new_session
->creation_time
== (time_t) -1) {
1196 PERROR("Failed to sample session creation time");
1197 ret_code
= LTTNG_ERR_SESSION_FAIL
;
1201 /* Create default consumer output. */
1202 new_session
->consumer
= consumer_create_output(CONSUMER_DST_LOCAL
);
1203 if (new_session
->consumer
== NULL
) {
1204 ret_code
= LTTNG_ERR_NOMEM
;
1209 ret
= lttng_strncpy(new_session
->name
, name
, sizeof(new_session
->name
));
1211 ret_code
= LTTNG_ERR_SESSION_INVALID_CHAR
;
1214 ret
= validate_name(name
);
1216 ret_code
= LTTNG_ERR_SESSION_INVALID_CHAR
;
1221 bool found_name
= false;
1223 struct tm
*timeinfo
;
1225 timeinfo
= localtime(&new_session
->creation_time
);
1227 ret_code
= LTTNG_ERR_SESSION_FAIL
;
1230 strftime(datetime
, sizeof(datetime
), "%Y%m%d-%H%M%S", timeinfo
);
1231 for (i
= 0; i
< INT_MAX
; i
++) {
1232 struct ltt_session
*clashing_session
;
1235 ret
= snprintf(new_session
->name
,
1236 sizeof(new_session
->name
),
1238 DEFAULT_SESSION_NAME
,
1241 ret
= snprintf(new_session
->name
,
1242 sizeof(new_session
->name
),
1244 DEFAULT_SESSION_NAME
, i
,
1247 new_session
->name_contains_creation_time
= true;
1248 if (ret
== -1 || ret
>= sizeof(new_session
->name
)) {
1250 * Null-terminate in case the name is used
1251 * in logging statements.
1253 new_session
->name
[sizeof(new_session
->name
) - 1] = '\0';
1254 ret_code
= LTTNG_ERR_SESSION_FAIL
;
1259 session_find_by_name(new_session
->name
);
1260 session_put(clashing_session
);
1261 if (!clashing_session
) {
1267 DBG("Generated session name \"%s\"", new_session
->name
);
1268 new_session
->has_auto_generated_name
= true;
1270 ERR("Failed to auto-generate a session name");
1271 ret_code
= LTTNG_ERR_SESSION_FAIL
;
1276 ret
= gethostname(new_session
->hostname
, sizeof(new_session
->hostname
));
1278 if (errno
== ENAMETOOLONG
) {
1279 new_session
->hostname
[sizeof(new_session
->hostname
) - 1] = '\0';
1280 ERR("Hostname exceeds the maximal permitted length and has been truncated to %s",
1281 new_session
->hostname
);
1283 ret_code
= LTTNG_ERR_SESSION_FAIL
;
1288 new_session
->uid
= uid
;
1289 new_session
->gid
= gid
;
1291 ret
= snapshot_init(&new_session
->snapshot
);
1293 ret_code
= LTTNG_ERR_NOMEM
;
1297 new_session
->rotation_state
= LTTNG_ROTATION_STATE_NO_ROTATION
;
1299 /* Add new session to the session list. */
1300 new_session
->id
= add_session_list(new_session
);
1303 * Add the new session to the ltt_sessions_ht_by_id.
1304 * No ownership is taken by the hash table; it is merely
1305 * a wrapper around the session list used for faster access
1308 add_session_ht(new_session
);
1309 new_session
->published
= true;
1312 * Consumer is left to NULL since the create_session_uri command will
1313 * set it up and, if valid, assign it to the session.
1315 DBG("Tracing session %s created with ID %" PRIu64
" by uid = %d, gid = %d",
1316 new_session
->name
, new_session
->id
, new_session
->uid
,
1318 ret_code
= LTTNG_OK
;
1321 (void) session_get(new_session
);
1322 *out_session
= new_session
;
1326 session_put(new_session
);
1332 * Check if the UID matches the session. Root user has access to all
1335 bool session_access_ok(struct ltt_session
*session
, uid_t uid
)
1338 return (uid
== session
->uid
) || uid
== 0;
1342 * Set a session's rotation state and reset all associated state.
1344 * This function resets the rotation state (check timers, pending
1345 * flags, etc.) and sets the result of the last rotation. The result
1346 * can be queries by a liblttng-ctl client.
1348 * Be careful of the result passed to this function. For instance,
1349 * on failure to launch a rotation, a client will expect the rotation
1350 * state to be set to "NO_ROTATION". If an error occurred while the
1351 * rotation was "ONGOING", result should be set to "ERROR", which will
1352 * allow a client to report it.
1354 * Must be called with the session and session_list locks held.
1356 int session_reset_rotation_state(struct ltt_session
*session
,
1357 enum lttng_rotation_state result
)
1361 ASSERT_LOCKED(ltt_session_list
.lock
);
1362 ASSERT_LOCKED(session
->lock
);
1364 session
->rotation_state
= result
;
1365 if (session
->rotation_pending_check_timer_enabled
) {
1366 ret
= timer_session_rotation_pending_check_stop(session
);
1368 if (session
->chunk_being_archived
) {
1370 enum lttng_trace_chunk_status chunk_status
;
1372 chunk_status
= lttng_trace_chunk_get_id(
1373 session
->chunk_being_archived
,
1375 assert(chunk_status
== LTTNG_TRACE_CHUNK_STATUS_OK
);
1376 LTTNG_OPTIONAL_SET(&session
->last_archived_chunk_id
,
1378 lttng_trace_chunk_put(session
->chunk_being_archived
);
1379 session
->chunk_being_archived
= NULL
;
1381 * Fire the clear reply notifiers if we are completing a clear
1384 session_notify_clear(session
);
1390 * Sample the id of a session looked up via its name.
1391 * Here the term "sampling" hint the caller that this return the id at a given
1392 * point in time with no guarantee that the session for which the id was
1393 * sampled still exist at that point.
1395 * Return 0 when the session is not found,
1396 * Return 1 when the session is found and set `id`.
1398 bool sample_session_id_by_name(const char *name
, uint64_t *id
)
1401 struct lttng_ht_node_str
*node
;
1402 struct lttng_ht_iter iter
;
1403 struct ltt_session
*ls
;
1407 if (!ltt_sessions_ht_by_name
) {
1412 lttng_ht_lookup(ltt_sessions_ht_by_name
, name
, &iter
);
1413 node
= lttng_ht_iter_get_node_str(&iter
);
1419 ls
= caa_container_of(node
, struct ltt_session
, node_by_name
);
1423 DBG3("Session id `%" PRIu64
"` sampled for session `%s", *id
, name
);