2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <sys/socket.h>
27 #include <sys/types.h>
32 #include <common/common.h>
33 #include <common/kernel-ctl/kernel-ctl.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35 #include <common/sessiond-comm/relayd.h>
36 #include <common/compat/fcntl.h>
37 #include <common/pipe.h>
38 #include <common/relayd/relayd.h>
39 #include <common/utils.h>
40 #include <common/consumer-stream.h>
42 #include "kernel-consumer.h"
44 extern struct lttng_consumer_global_data consumer_data
;
45 extern int consumer_poll_timeout
;
46 extern volatile int consumer_quit
;
49 * Take a snapshot for a specific fd
51 * Returns 0 on success, < 0 on error
53 int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
56 int infd
= stream
->wait_fd
;
58 ret
= kernctl_snapshot(infd
);
61 perror("Getting sub-buffer snapshot.");
68 * Get the produced position
70 * Returns 0 on success, < 0 on error
72 int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
76 int infd
= stream
->wait_fd
;
78 ret
= kernctl_snapshot_get_produced(infd
, pos
);
81 perror("kernctl_snapshot_get_produced");
88 * Get the consumerd position
90 * Returns 0 on success, < 0 on error
92 int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream
*stream
,
96 int infd
= stream
->wait_fd
;
98 ret
= kernctl_snapshot_get_consumed(infd
, pos
);
101 perror("kernctl_snapshot_get_consumed");
108 * Find a relayd and send the stream
110 * Returns 0 on success, < 0 on error
112 static int send_relayd_stream(struct lttng_consumer_stream
*stream
,
116 const char *stream_path
;
117 struct consumer_relayd_sock_pair
*relayd
;
120 assert(stream
->net_seq_idx
!= -1ULL);
125 stream_path
= stream
->chan
->pathname
;
128 /* The stream is not metadata. Get relayd reference if exists. */
130 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
131 if (relayd
!= NULL
) {
132 /* Add stream on the relayd */
133 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
134 ret
= relayd_add_stream(&relayd
->control_sock
, stream
->name
,
135 stream_path
, &stream
->relayd_stream_id
,
136 stream
->chan
->tracefile_size
, stream
->chan
->tracefile_count
);
137 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
141 uatomic_inc(&relayd
->refcount
);
143 ERR("Stream %" PRIu64
" relayd ID %" PRIu64
" unknown. Can't send it.",
144 stream
->key
, stream
->net_seq_idx
);
149 DBG("Stream %s with key %" PRIu64
" sent to relayd id %" PRIu64
,
150 stream
->name
, stream
->key
, stream
->net_seq_idx
);
158 * Find a relayd and close the stream
160 static void close_relayd_stream(struct lttng_consumer_stream
*stream
)
162 struct consumer_relayd_sock_pair
*relayd
;
164 /* The stream is not metadata. Get relayd reference if exists. */
166 relayd
= consumer_find_relayd(stream
->net_seq_idx
);
168 consumer_stream_relayd_close(stream
, relayd
);
174 * Take a snapshot of all the stream of a channel
176 * Returns 0 on success, < 0 on error
178 int lttng_kconsumer_snapshot_channel(uint64_t key
, char *path
,
179 uint64_t relayd_id
, struct lttng_consumer_local_data
*ctx
)
182 unsigned long consumed_pos
, produced_pos
;
183 struct lttng_consumer_channel
*channel
;
184 struct lttng_consumer_stream
*stream
;
186 DBG("Kernel consumer snapshot channel %lu", key
);
190 channel
= consumer_find_channel(key
);
192 ERR("No channel found for key %lu", key
);
197 /* Splice is not supported yet for channel snapshot. */
198 if (channel
->output
!= CONSUMER_CHANNEL_MMAP
) {
199 ERR("Unsupported output %d", channel
->output
);
204 cds_list_for_each_entry(stream
, &channel
->stream_no_monitor_list
.head
,
207 * Lock stream because we are about to change its state.
209 pthread_mutex_lock(&stream
->lock
);
212 * Assign the received relayd ID so we can use it for streaming. The streams
213 * are not visible to anyone so this is OK to change it.
215 stream
->net_seq_idx
= relayd_id
;
216 channel
->relayd_id
= relayd_id
;
217 if (relayd_id
!= (uint64_t) -1ULL) {
218 ret
= send_relayd_stream(stream
, path
);
220 ERR("sending stream to relayd");
224 ret
= utils_create_stream_file(path
, stream
->name
,
225 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
226 stream
->uid
, stream
->gid
);
228 ERR("utils_create_stream_file");
232 stream
->out_fd
= ret
;
233 stream
->tracefile_size_current
= 0;
235 DBG("Kernel consumer snapshot stream %s/%s (%lu)", path
,
236 stream
->name
, stream
->key
);
239 ret
= kernctl_buffer_flush(stream
->wait_fd
);
241 ERR("Failed to flush kernel metadata stream");
245 ret
= lttng_kconsumer_take_snapshot(stream
);
247 ERR("Taking kernel snapshot");
251 ret
= lttng_kconsumer_get_produced_snapshot(stream
, &produced_pos
);
253 ERR("Produced kernel snapshot position");
257 ret
= lttng_kconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
259 ERR("Consumerd kernel snapshot position");
263 if (stream
->max_sb_size
== 0) {
264 ret
= kernctl_get_max_subbuf_size(stream
->wait_fd
,
265 &stream
->max_sb_size
);
267 ERR("Getting kernel max_sb_size");
272 while (consumed_pos
< produced_pos
) {
274 unsigned long len
, padded_len
;
276 DBG("Kernel consumer taking snapshot at pos %lu", consumed_pos
);
278 ret
= kernctl_get_subbuf(stream
->wait_fd
, &consumed_pos
);
280 if (errno
!= EAGAIN
) {
281 PERROR("kernctl_get_subbuf snapshot");
284 DBG("Kernel consumer get subbuf failed. Skipping it.");
285 consumed_pos
+= stream
->max_sb_size
;
289 ret
= kernctl_get_subbuf_size(stream
->wait_fd
, &len
);
291 ERR("Snapshot kernctl_get_subbuf_size");
292 goto error_put_subbuf
;
295 ret
= kernctl_get_padded_subbuf_size(stream
->wait_fd
, &padded_len
);
297 ERR("Snapshot kernctl_get_padded_subbuf_size");
298 goto error_put_subbuf
;
301 read_len
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
,
304 * We write the padded len in local tracefiles but the data len
305 * when using a relay. Display the error but continue processing
306 * to try to release the subbuffer.
308 if (relayd_id
!= (uint64_t) -1ULL) {
309 if (read_len
!= len
) {
310 ERR("Error sending to the relay (ret: %zd != len: %lu)",
314 if (read_len
!= padded_len
) {
315 ERR("Error writing to tracefile (ret: %zd != len: %lu)",
316 read_len
, padded_len
);
320 ret
= kernctl_put_subbuf(stream
->wait_fd
);
322 ERR("Snapshot kernctl_put_subbuf");
325 consumed_pos
+= stream
->max_sb_size
;
328 if (relayd_id
== (uint64_t) -1ULL) {
329 ret
= close(stream
->out_fd
);
331 PERROR("Kernel consumer snapshot close out_fd");
336 close_relayd_stream(stream
);
337 stream
->net_seq_idx
= (uint64_t) -1ULL;
339 pthread_mutex_unlock(&stream
->lock
);
347 ret
= kernctl_put_subbuf(stream
->wait_fd
);
349 ERR("Snapshot kernctl_put_subbuf error path");
352 pthread_mutex_unlock(&stream
->lock
);
359 * Read the whole metadata available for a snapshot.
361 * Returns 0 on success, < 0 on error
363 int lttng_kconsumer_snapshot_metadata(uint64_t key
, char *path
,
364 uint64_t relayd_id
, struct lttng_consumer_local_data
*ctx
)
366 struct lttng_consumer_channel
*metadata_channel
;
367 struct lttng_consumer_stream
*metadata_stream
;
370 DBG("Kernel consumer snapshot metadata with key %" PRIu64
" at path %s",
375 metadata_channel
= consumer_find_channel(key
);
376 if (!metadata_channel
) {
377 ERR("Snapshot kernel metadata channel not found for key %lu", key
);
382 metadata_stream
= metadata_channel
->metadata_stream
;
383 assert(metadata_stream
);
385 if (relayd_id
!= (uint64_t) -1ULL) {
386 ret
= send_relayd_stream(metadata_stream
, path
);
388 ERR("sending stream to relayd");
390 DBG("Stream %s sent to the relayd", metadata_stream
->name
);
392 ret
= utils_create_stream_file(path
, metadata_stream
->name
,
393 metadata_stream
->chan
->tracefile_size
,
394 metadata_stream
->tracefile_count_current
,
395 metadata_stream
->uid
, metadata_stream
->gid
);
399 metadata_stream
->out_fd
= ret
;
404 ret
= lttng_kconsumer_read_subbuffer(metadata_stream
, ctx
);
407 ERR("Kernel snapshot reading subbuffer");
410 /* "ret" is negative at this point so we will exit the loop. */
415 if (relayd_id
== (uint64_t) -1ULL) {
416 ret
= close(metadata_stream
->out_fd
);
418 PERROR("Kernel consumer snapshot close out_fd");
421 metadata_stream
->out_fd
= -1;
423 close_relayd_stream(metadata_stream
);
424 metadata_stream
->net_seq_idx
= (uint64_t) -1ULL;
434 * Receive command from session daemon and process it.
436 * Return 1 on success else a negative value or 0.
438 int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
439 int sock
, struct pollfd
*consumer_sockpoll
)
442 enum lttng_error_code ret_code
= LTTNG_OK
;
443 struct lttcomm_consumer_msg msg
;
445 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
446 if (ret
!= sizeof(msg
)) {
447 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
453 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
455 * Notify the session daemon that the command is completed.
457 * On transport layer error, the function call will print an error
458 * message so handling the returned code is a bit useless since we
459 * return an error code anyway.
461 (void) consumer_send_status_msg(sock
, ret_code
);
465 /* relayd needs RCU read-side protection */
468 switch (msg
.cmd_type
) {
469 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
471 /* Session daemon status message are handled in the following call. */
472 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
473 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
474 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
477 case LTTNG_CONSUMER_ADD_CHANNEL
:
479 struct lttng_consumer_channel
*new_channel
;
482 /* First send a status message before receiving the fds. */
483 ret
= consumer_send_status_msg(sock
, ret_code
);
485 /* Somehow, the session daemon is not responding anymore. */
488 DBG("consumer_add_channel %" PRIu64
, msg
.u
.channel
.channel_key
);
489 new_channel
= consumer_allocate_channel(msg
.u
.channel
.channel_key
,
490 msg
.u
.channel
.session_id
, msg
.u
.channel
.pathname
,
491 msg
.u
.channel
.name
, msg
.u
.channel
.uid
, msg
.u
.channel
.gid
,
492 msg
.u
.channel
.relayd_id
, msg
.u
.channel
.output
,
493 msg
.u
.channel
.tracefile_size
,
494 msg
.u
.channel
.tracefile_count
, 0,
495 msg
.u
.channel
.monitor
);
496 if (new_channel
== NULL
) {
497 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
500 new_channel
->nb_init_stream_left
= msg
.u
.channel
.nb_init_streams
;
501 switch (msg
.u
.channel
.output
) {
502 case LTTNG_EVENT_SPLICE
:
503 new_channel
->output
= CONSUMER_CHANNEL_SPLICE
;
505 case LTTNG_EVENT_MMAP
:
506 new_channel
->output
= CONSUMER_CHANNEL_MMAP
;
509 ERR("Channel output unknown %d", msg
.u
.channel
.output
);
513 /* Translate and save channel type. */
514 switch (msg
.u
.channel
.type
) {
515 case CONSUMER_CHANNEL_TYPE_DATA
:
516 case CONSUMER_CHANNEL_TYPE_METADATA
:
517 new_channel
->type
= msg
.u
.channel
.type
;
524 if (ctx
->on_recv_channel
!= NULL
) {
525 ret_recv
= ctx
->on_recv_channel(new_channel
);
527 ret
= consumer_add_channel(new_channel
, ctx
);
528 } else if (ret_recv
< 0) {
532 ret
= consumer_add_channel(new_channel
, ctx
);
535 /* If we received an error in add_channel, we need to report it. */
537 ret
= consumer_send_status_msg(sock
, ret
);
546 case LTTNG_CONSUMER_ADD_STREAM
:
549 struct lttng_pipe
*stream_pipe
;
550 struct lttng_consumer_stream
*new_stream
;
551 struct lttng_consumer_channel
*channel
;
555 * Get stream's channel reference. Needed when adding the stream to the
558 channel
= consumer_find_channel(msg
.u
.stream
.channel_key
);
561 * We could not find the channel. Can happen if cpu hotplug
562 * happens while tearing down.
564 ERR("Unable to find channel key %" PRIu64
, msg
.u
.stream
.channel_key
);
565 ret_code
= LTTNG_ERR_KERN_CHAN_NOT_FOUND
;
568 /* First send a status message before receiving the fds. */
569 ret
= consumer_send_status_msg(sock
, ret_code
);
572 * Somehow, the session daemon is not responding
577 if (ret_code
!= LTTNG_OK
) {
579 * Channel was not found.
585 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
590 /* Get stream file descriptor from socket */
591 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
592 if (ret
!= sizeof(fd
)) {
593 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_FD
);
599 * Send status code to session daemon only if the recv works. If the
600 * above recv() failed, the session daemon is notified through the
601 * error socket and the teardown is eventually done.
603 ret
= consumer_send_status_msg(sock
, ret_code
);
605 /* Somehow, the session daemon is not responding anymore. */
609 new_stream
= consumer_allocate_stream(channel
->key
,
611 LTTNG_CONSUMER_ACTIVE_STREAM
,
620 if (new_stream
== NULL
) {
625 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
630 new_stream
->chan
= channel
;
631 new_stream
->wait_fd
= fd
;
632 switch (channel
->output
) {
633 case CONSUMER_CHANNEL_SPLICE
:
634 new_stream
->output
= LTTNG_EVENT_SPLICE
;
636 case CONSUMER_CHANNEL_MMAP
:
637 new_stream
->output
= LTTNG_EVENT_MMAP
;
640 ERR("Stream output unknown %d", channel
->output
);
645 * We've just assigned the channel to the stream so increment the
646 * refcount right now. We don't need to increment the refcount for
647 * streams in no monitor because we handle manually the cleanup of
648 * those. It is very important to make sure there is NO prior
649 * consumer_del_stream() calls or else the refcount will be unbalanced.
651 if (channel
->monitor
) {
652 uatomic_inc(&new_stream
->chan
->refcount
);
656 * The buffer flush is done on the session daemon side for the kernel
657 * so no need for the stream "hangup_flush_done" variable to be
658 * tracked. This is important for a kernel stream since we don't rely
659 * on the flush state of the stream to read data. It's not the case for
660 * user space tracing.
662 new_stream
->hangup_flush_done
= 0;
664 if (ctx
->on_recv_stream
) {
665 ret
= ctx
->on_recv_stream(new_stream
);
667 consumer_del_stream(new_stream
, NULL
);
672 if (new_stream
->metadata_flag
) {
673 channel
->metadata_stream
= new_stream
;
676 /* Do not monitor this stream. */
677 if (!channel
->monitor
) {
678 DBG("Kernel consumer add stream %s in no monitor mode with "
679 "relayd id %" PRIu64
, new_stream
->name
,
680 new_stream
->net_seq_idx
);
681 cds_list_add(&new_stream
->no_monitor_node
,
682 &channel
->stream_no_monitor_list
.head
);
686 ret
= send_relayd_stream(new_stream
, NULL
);
688 consumer_del_stream(new_stream
, NULL
);
692 /* Get the right pipe where the stream will be sent. */
693 if (new_stream
->metadata_flag
) {
694 stream_pipe
= ctx
->consumer_metadata_pipe
;
696 stream_pipe
= ctx
->consumer_data_pipe
;
699 ret
= lttng_pipe_write(stream_pipe
, &new_stream
, sizeof(new_stream
));
701 ERR("Consumer write %s stream to pipe %d",
702 new_stream
->metadata_flag
? "metadata" : "data",
703 lttng_pipe_get_writefd(stream_pipe
));
704 consumer_del_stream(new_stream
, NULL
);
708 DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64
,
709 new_stream
->name
, fd
, new_stream
->relayd_stream_id
);
712 case LTTNG_CONSUMER_UPDATE_STREAM
:
717 case LTTNG_CONSUMER_DESTROY_RELAYD
:
719 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
720 struct consumer_relayd_sock_pair
*relayd
;
722 DBG("Kernel consumer destroying relayd %" PRIu64
, index
);
724 /* Get relayd reference if exists. */
725 relayd
= consumer_find_relayd(index
);
726 if (relayd
== NULL
) {
727 DBG("Unable to find relayd %" PRIu64
, index
);
728 ret_code
= LTTNG_ERR_NO_CONSUMER
;
732 * Each relayd socket pair has a refcount of stream attached to it
733 * which tells if the relayd is still active or not depending on the
736 * This will set the destroy flag of the relayd object and destroy it
737 * if the refcount reaches zero when called.
739 * The destroy can happen either here or when a stream fd hangs up.
742 consumer_flag_relayd_for_destroy(relayd
);
745 ret
= consumer_send_status_msg(sock
, ret_code
);
747 /* Somehow, the session daemon is not responding anymore. */
753 case LTTNG_CONSUMER_DATA_PENDING
:
756 uint64_t id
= msg
.u
.data_pending
.session_id
;
758 DBG("Kernel consumer data pending command for id %" PRIu64
, id
);
760 ret
= consumer_data_pending(id
);
762 /* Send back returned value to session daemon */
763 ret
= lttcomm_send_unix_sock(sock
, &ret
, sizeof(ret
));
765 PERROR("send data pending ret code");
770 * No need to send back a status message since the data pending
771 * returned value is the response.
775 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
777 if (msg
.u
.snapshot_channel
.metadata
== 1) {
778 ret
= lttng_kconsumer_snapshot_metadata(msg
.u
.snapshot_channel
.key
,
779 msg
.u
.snapshot_channel
.pathname
,
780 msg
.u
.snapshot_channel
.relayd_id
, ctx
);
782 ERR("Snapshot metadata failed");
783 ret_code
= LTTNG_ERR_KERN_META_FAIL
;
786 ret
= lttng_kconsumer_snapshot_channel(msg
.u
.snapshot_channel
.key
,
787 msg
.u
.snapshot_channel
.pathname
,
788 msg
.u
.snapshot_channel
.relayd_id
, ctx
);
790 ERR("Snapshot channel failed");
791 ret_code
= LTTNG_ERR_KERN_CHAN_FAIL
;
795 ret
= consumer_send_status_msg(sock
, ret_code
);
797 /* Somehow, the session daemon is not responding anymore. */
802 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
804 uint64_t key
= msg
.u
.destroy_channel
.key
;
805 struct lttng_consumer_channel
*channel
;
807 channel
= consumer_find_channel(key
);
809 ERR("Kernel consumer destroy channel %" PRIu64
" not found", key
);
810 ret_code
= LTTNG_ERR_KERN_CHAN_NOT_FOUND
;
813 ret
= consumer_send_status_msg(sock
, ret_code
);
815 /* Somehow, the session daemon is not responding anymore. */
820 * This command should ONLY be issued for channel with streams set in
823 assert(!channel
->monitor
);
826 * The refcount should ALWAYS be 0 in the case of a channel in no
829 assert(!uatomic_sub_return(&channel
->refcount
, 1));
831 consumer_del_channel(channel
);
843 * Return 1 to indicate success since the 0 value can be a socket
844 * shutdown during the recv() or send() call.
850 /* This will issue a consumer stop. */
855 * Consume data on a file descriptor and write it on a trace file.
857 ssize_t
lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
858 struct lttng_consumer_local_data
*ctx
)
860 unsigned long len
, subbuf_size
, padding
;
863 int infd
= stream
->wait_fd
;
865 DBG("In read_subbuffer (infd : %d)", infd
);
866 /* Get the next subbuffer */
867 err
= kernctl_get_next_subbuf(infd
);
871 * This is a debug message even for single-threaded consumer,
872 * because poll() have more relaxed criterions than get subbuf,
873 * so get_subbuf may fail for short race windows where poll()
874 * would issue wakeups.
876 DBG("Reserving sub buffer failed (everything is normal, "
877 "it is due to concurrency)");
881 /* Get the full subbuffer size including padding */
882 err
= kernctl_get_padded_subbuf_size(infd
, &len
);
885 perror("Getting sub-buffer len failed.");
890 switch (stream
->chan
->output
) {
891 case CONSUMER_CHANNEL_SPLICE
:
893 * XXX: The lttng-modules splice "actor" does not handle copying
894 * partial pages hence only using the subbuffer size without the
895 * padding makes the splice fail.
900 /* splice the subbuffer to the tracefile */
901 ret
= lttng_consumer_on_read_subbuffer_splice(ctx
, stream
, subbuf_size
,
904 * XXX: Splice does not support network streaming so the return value
905 * is simply checked against subbuf_size and not like the mmap() op.
907 if (ret
!= subbuf_size
) {
909 * display the error but continue processing to try
910 * to release the subbuffer
912 ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
916 case CONSUMER_CHANNEL_MMAP
:
917 /* Get subbuffer size without padding */
918 err
= kernctl_get_subbuf_size(infd
, &subbuf_size
);
921 perror("Getting sub-buffer len failed.");
926 /* Make sure the tracer is not gone mad on us! */
927 assert(len
>= subbuf_size
);
929 padding
= len
- subbuf_size
;
931 /* write the subbuffer to the tracefile */
932 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
,
935 * The mmap operation should write subbuf_size amount of data when
936 * network streaming or the full padding (len) size when we are _not_
939 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
940 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
942 * Display the error but continue processing to try to release the
945 ERR("Error writing to tracefile "
946 "(ret: %zd != len: %lu != subbuf_size: %lu)",
947 ret
, len
, subbuf_size
);
951 ERR("Unknown output method");
955 err
= kernctl_put_next_subbuf(infd
);
958 if (errno
== EFAULT
) {
959 perror("Error in unreserving sub buffer\n");
960 } else if (errno
== EIO
) {
961 /* Should never happen with newer LTTng versions */
962 perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
973 int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
980 * Don't create anything if this is set for streaming or should not be
983 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
) {
984 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
985 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
986 stream
->uid
, stream
->gid
);
990 stream
->out_fd
= ret
;
991 stream
->tracefile_size_current
= 0;
994 if (stream
->output
== LTTNG_EVENT_MMAP
) {
995 /* get the len of the mmap region */
996 unsigned long mmap_len
;
998 ret
= kernctl_get_mmap_len(stream
->wait_fd
, &mmap_len
);
1001 PERROR("kernctl_get_mmap_len");
1002 goto error_close_fd
;
1004 stream
->mmap_len
= (size_t) mmap_len
;
1006 stream
->mmap_base
= mmap(NULL
, stream
->mmap_len
, PROT_READ
,
1007 MAP_PRIVATE
, stream
->wait_fd
, 0);
1008 if (stream
->mmap_base
== MAP_FAILED
) {
1009 PERROR("Error mmaping");
1011 goto error_close_fd
;
1015 /* we return 0 to let the library handle the FD internally */
1022 err
= close(stream
->out_fd
);
1030 * Check if data is still being extracted from the buffers for a specific
1031 * stream. Consumer data lock MUST be acquired before calling this function
1032 * and the stream lock.
1034 * Return 1 if the traced data are still getting read else 0 meaning that the
1035 * data is available for trace viewer reading.
1037 int lttng_kconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1043 ret
= kernctl_get_next_subbuf(stream
->wait_fd
);
1045 /* There is still data so let's put back this subbuffer. */
1046 ret
= kernctl_put_subbuf(stream
->wait_fd
);
1048 ret
= 1; /* Data is pending */
1052 /* Data is NOT pending and ready to be read. */