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/relayd/relayd.h>
38 #include <common/utils.h>
40 #include "kernel-consumer.h"
42 extern struct lttng_consumer_global_data consumer_data
;
43 extern int consumer_poll_timeout
;
44 extern volatile int consumer_quit
;
47 * Take a snapshot for a specific fd
49 * Returns 0 on success, < 0 on error
51 int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
54 int infd
= stream
->wait_fd
;
56 ret
= kernctl_snapshot(infd
);
59 perror("Getting sub-buffer snapshot.");
66 * Get the produced position
68 * Returns 0 on success, < 0 on error
70 int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
74 int infd
= stream
->wait_fd
;
76 ret
= kernctl_snapshot_get_produced(infd
, pos
);
79 perror("kernctl_snapshot_get_produced");
85 int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
86 int sock
, struct pollfd
*consumer_sockpoll
)
89 enum lttng_error_code ret_code
= LTTNG_OK
;
90 struct lttcomm_consumer_msg msg
;
92 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
93 if (ret
!= sizeof(msg
)) {
94 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
97 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
99 * Notify the session daemon that the command is completed.
101 * On transport layer error, the function call will print an error
102 * message so handling the returned code is a bit useless since we
103 * return an error code anyway.
105 (void) consumer_send_status_msg(sock
, ret_code
);
109 /* relayd needs RCU read-side protection */
112 switch (msg
.cmd_type
) {
113 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
115 /* Session daemon status message are handled in the following call. */
116 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
117 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
118 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
121 case LTTNG_CONSUMER_ADD_CHANNEL
:
123 struct lttng_consumer_channel
*new_channel
;
125 /* First send a status message before receiving the fds. */
126 ret
= consumer_send_status_msg(sock
, ret_code
);
128 /* Somehow, the session daemon is not responding anymore. */
132 DBG("consumer_add_channel %" PRIu64
, msg
.u
.channel
.channel_key
);
133 new_channel
= consumer_allocate_channel(msg
.u
.channel
.channel_key
,
134 msg
.u
.channel
.session_id
, msg
.u
.channel
.pathname
,
135 msg
.u
.channel
.name
, msg
.u
.channel
.uid
, msg
.u
.channel
.gid
,
136 msg
.u
.channel
.relayd_id
, msg
.u
.channel
.output
,
137 msg
.u
.channel
.tracefile_size
,
138 msg
.u
.channel
.tracefile_count
);
139 if (new_channel
== NULL
) {
140 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
143 new_channel
->nb_init_stream_left
= msg
.u
.channel
.nb_init_streams
;
145 /* Translate and save channel type. */
146 switch (msg
.u
.channel
.type
) {
147 case CONSUMER_CHANNEL_TYPE_DATA
:
148 case CONSUMER_CHANNEL_TYPE_METADATA
:
149 new_channel
->type
= msg
.u
.channel
.type
;
156 if (ctx
->on_recv_channel
!= NULL
) {
157 ret
= ctx
->on_recv_channel(new_channel
);
159 consumer_add_channel(new_channel
, ctx
);
160 } else if (ret
< 0) {
164 consumer_add_channel(new_channel
, ctx
);
168 case LTTNG_CONSUMER_ADD_STREAM
:
171 struct consumer_relayd_sock_pair
*relayd
= NULL
;
172 struct lttng_consumer_stream
*new_stream
;
173 struct lttng_consumer_channel
*channel
;
177 * Get stream's channel reference. Needed when adding the stream to the
180 channel
= consumer_find_channel(msg
.u
.stream
.channel_key
);
183 * We could not find the channel. Can happen if cpu hotplug
184 * happens while tearing down.
186 ERR("Unable to find channel key %" PRIu64
, msg
.u
.stream
.channel_key
);
187 ret_code
= LTTNG_ERR_KERN_CHAN_NOT_FOUND
;
190 /* First send a status message before receiving the fds. */
191 ret
= consumer_send_status_msg(sock
, ret_code
);
192 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
194 * Somehow, the session daemon is not responding anymore or the
195 * channel was not found.
201 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
206 /* Get stream file descriptor from socket */
207 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
208 if (ret
!= sizeof(fd
)) {
209 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_FD
);
215 * Send status code to session daemon only if the recv works. If the
216 * above recv() failed, the session daemon is notified through the
217 * error socket and the teardown is eventually done.
219 ret
= consumer_send_status_msg(sock
, ret_code
);
221 /* Somehow, the session daemon is not responding anymore. */
225 new_stream
= consumer_allocate_stream(channel
->key
,
227 LTTNG_CONSUMER_ACTIVE_STREAM
,
236 if (new_stream
== NULL
) {
241 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
246 new_stream
->chan
= channel
;
247 new_stream
->wait_fd
= fd
;
250 * The buffer flush is done on the session daemon side for the kernel
251 * so no need for the stream "hangup_flush_done" variable to be
252 * tracked. This is important for a kernel stream since we don't rely
253 * on the flush state of the stream to read data. It's not the case for
254 * user space tracing.
256 new_stream
->hangup_flush_done
= 0;
258 /* The stream is not metadata. Get relayd reference if exists. */
259 relayd
= consumer_find_relayd(new_stream
->net_seq_idx
);
260 if (relayd
!= NULL
) {
261 /* Add stream on the relayd */
262 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
263 ret
= relayd_add_stream(&relayd
->control_sock
,
264 new_stream
->name
, new_stream
->chan
->pathname
,
265 &new_stream
->relayd_stream_id
);
266 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
268 consumer_del_stream(new_stream
, NULL
);
271 } else if (new_stream
->net_seq_idx
!= (uint64_t) -1ULL) {
272 ERR("Network sequence index %" PRIu64
" unknown. Not adding stream.",
273 new_stream
->net_seq_idx
);
274 consumer_del_stream(new_stream
, NULL
);
278 if (ctx
->on_recv_stream
) {
279 ret
= ctx
->on_recv_stream(new_stream
);
281 consumer_del_stream(new_stream
, NULL
);
286 /* Get the right pipe where the stream will be sent. */
287 if (new_stream
->metadata_flag
) {
288 stream_pipe
= ctx
->consumer_metadata_pipe
[1];
290 stream_pipe
= ctx
->consumer_data_pipe
[1];
294 ret
= write(stream_pipe
, &new_stream
, sizeof(new_stream
));
295 } while (ret
< 0 && errno
== EINTR
);
297 PERROR("Consumer write %s stream to pipe %d",
298 new_stream
->metadata_flag
? "metadata" : "data",
300 consumer_del_stream(new_stream
, NULL
);
304 DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64
,
305 new_stream
->name
, fd
, new_stream
->relayd_stream_id
);
308 case LTTNG_CONSUMER_UPDATE_STREAM
:
313 case LTTNG_CONSUMER_DESTROY_RELAYD
:
315 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
316 struct consumer_relayd_sock_pair
*relayd
;
318 DBG("Kernel consumer destroying relayd %" PRIu64
, index
);
320 /* Get relayd reference if exists. */
321 relayd
= consumer_find_relayd(index
);
322 if (relayd
== NULL
) {
323 DBG("Unable to find relayd %" PRIu64
, index
);
324 ret_code
= LTTNG_ERR_NO_CONSUMER
;
328 * Each relayd socket pair has a refcount of stream attached to it
329 * which tells if the relayd is still active or not depending on the
332 * This will set the destroy flag of the relayd object and destroy it
333 * if the refcount reaches zero when called.
335 * The destroy can happen either here or when a stream fd hangs up.
338 consumer_flag_relayd_for_destroy(relayd
);
341 ret
= consumer_send_status_msg(sock
, ret_code
);
343 /* Somehow, the session daemon is not responding anymore. */
349 case LTTNG_CONSUMER_DATA_PENDING
:
352 uint64_t id
= msg
.u
.data_pending
.session_id
;
354 DBG("Kernel consumer data pending command for id %" PRIu64
, id
);
356 ret
= consumer_data_pending(id
);
358 /* Send back returned value to session daemon */
359 ret
= lttcomm_send_unix_sock(sock
, &ret
, sizeof(ret
));
361 PERROR("send data pending ret code");
365 * No need to send back a status message since the data pending
366 * returned value is the response.
378 * Return 1 to indicate success since the 0 value can be a socket
379 * shutdown during the recv() or send() call.
385 * Consume data on a file descriptor and write it on a trace file.
387 ssize_t
lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
388 struct lttng_consumer_local_data
*ctx
)
390 unsigned long len
, subbuf_size
, padding
;
393 int infd
= stream
->wait_fd
;
395 DBG("In read_subbuffer (infd : %d)", infd
);
396 /* Get the next subbuffer */
397 err
= kernctl_get_next_subbuf(infd
);
401 * This is a debug message even for single-threaded consumer,
402 * because poll() have more relaxed criterions than get subbuf,
403 * so get_subbuf may fail for short race windows where poll()
404 * would issue wakeups.
406 DBG("Reserving sub buffer failed (everything is normal, "
407 "it is due to concurrency)");
411 /* Get the full subbuffer size including padding */
412 err
= kernctl_get_padded_subbuf_size(infd
, &len
);
415 perror("Getting sub-buffer len failed.");
420 switch (stream
->chan
->output
) {
421 case LTTNG_EVENT_SPLICE
:
424 * XXX: The lttng-modules splice "actor" does not handle copying
425 * partial pages hence only using the subbuffer size without the
426 * padding makes the splice fail.
431 /* splice the subbuffer to the tracefile */
432 ret
= lttng_consumer_on_read_subbuffer_splice(ctx
, stream
, subbuf_size
,
435 * XXX: Splice does not support network streaming so the return value
436 * is simply checked against subbuf_size and not like the mmap() op.
438 if (ret
!= subbuf_size
) {
440 * display the error but continue processing to try
441 * to release the subbuffer
443 ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
447 case LTTNG_EVENT_MMAP
:
448 /* Get subbuffer size without padding */
449 err
= kernctl_get_subbuf_size(infd
, &subbuf_size
);
452 perror("Getting sub-buffer len failed.");
457 /* Make sure the tracer is not gone mad on us! */
458 assert(len
>= subbuf_size
);
460 padding
= len
- subbuf_size
;
462 /* write the subbuffer to the tracefile */
463 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
,
466 * The mmap operation should write subbuf_size amount of data when
467 * network streaming or the full padding (len) size when we are _not_
470 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
471 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
473 * Display the error but continue processing to try to release the
476 ERR("Error writing to tracefile "
477 "(ret: %zd != len: %lu != subbuf_size: %lu)",
478 ret
, len
, subbuf_size
);
482 ERR("Unknown output method");
486 err
= kernctl_put_next_subbuf(infd
);
489 if (errno
== EFAULT
) {
490 perror("Error in unreserving sub buffer\n");
491 } else if (errno
== EIO
) {
492 /* Should never happen with newer LTTng versions */
493 perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
504 int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
510 /* Don't create anything if this is set for streaming. */
511 if (stream
->net_seq_idx
== (uint64_t) -1ULL) {
512 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
513 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
514 stream
->uid
, stream
->gid
);
518 stream
->out_fd
= ret
;
519 stream
->tracefile_size_current
= 0;
522 if (stream
->output
== LTTNG_EVENT_MMAP
) {
523 /* get the len of the mmap region */
524 unsigned long mmap_len
;
526 ret
= kernctl_get_mmap_len(stream
->wait_fd
, &mmap_len
);
529 PERROR("kernctl_get_mmap_len");
532 stream
->mmap_len
= (size_t) mmap_len
;
534 stream
->mmap_base
= mmap(NULL
, stream
->mmap_len
, PROT_READ
,
535 MAP_PRIVATE
, stream
->wait_fd
, 0);
536 if (stream
->mmap_base
== MAP_FAILED
) {
537 PERROR("Error mmaping");
543 /* we return 0 to let the library handle the FD internally */
550 err
= close(stream
->out_fd
);
558 * Check if data is still being extracted from the buffers for a specific
559 * stream. Consumer data lock MUST be acquired before calling this function
560 * and the stream lock.
562 * Return 1 if the traced data are still getting read else 0 meaning that the
563 * data is available for trace viewer reading.
565 int lttng_kconsumer_data_pending(struct lttng_consumer_stream
*stream
)
571 ret
= kernctl_get_next_subbuf(stream
->wait_fd
);
573 /* There is still data so let's put back this subbuffer. */
574 ret
= kernctl_put_subbuf(stream
->wait_fd
);
576 ret
= 1; /* Data is pending */
580 /* Data is NOT pending and ready to be read. */