src/common/consumer/consumer-stream.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License, version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define _LGPL_SOURCE
  21 #include <assert.h>
  22 #include <inttypes.h>
  23 #include <sys/mman.h>
  24 #include <unistd.h>
  25
  26 #include <common/common.h>
  27 #include <common/index/index.h>
  28 #include <common/kernel-consumer/kernel-consumer.h>
  29 #include <common/relayd/relayd.h>
  30 #include <common/ust-consumer/ust-consumer.h>
  31 #include <common/utils.h>
  32
  33 #include "consumer-stream.h"
  34
  35 /*
  36  * RCU call to free stream. MUST only be used with call_rcu().
  37  */
  38 static void free_stream_rcu(struct rcu_head *head)
  39 {
  40         struct lttng_ht_node_u64 *node =
  41                 caa_container_of(head, struct lttng_ht_node_u64, head);
  42         struct lttng_consumer_stream *stream =
  43                 caa_container_of(node, struct lttng_consumer_stream, node);
  44
  45         pthread_mutex_destroy(&stream->lock);
  46         free(stream);
  47 }
  48
  49 /*
  50  * Close stream on the relayd side. This call can destroy a relayd if the
  51  * conditions are met.
  52  *
  53  * A RCU read side lock MUST be acquired if the relayd object was looked up in
  54  * a hash table before calling this.
  55  */
  56 void consumer_stream_relayd_close(struct lttng_consumer_stream *stream,
  57                 struct consumer_relayd_sock_pair *relayd)
  58 {
  59         int ret;
  60
  61         assert(stream);
  62         assert(relayd);
  63
  64         if (stream->sent_to_relayd) {
  65                 uatomic_dec(&relayd->refcount);
  66                 assert(uatomic_read(&relayd->refcount) >= 0);
  67         }
  68
  69         /* Closing streams requires to lock the control socket. */
  70         pthread_mutex_lock(&relayd->ctrl_sock_mutex);
  71         ret = relayd_send_close_stream(&relayd->control_sock,
  72                         stream->relayd_stream_id,
  73                         stream->next_net_seq_num - 1);
  74         pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
  75         if (ret < 0) {
  76                 ERR("Relayd send close stream failed. Cleaning up relayd %" PRIu64 ".", relayd->net_seq_idx);
  77                 lttng_consumer_cleanup_relayd(relayd);
  78         }
  79
  80         /* Both conditions are met, we destroy the relayd. */
  81         if (uatomic_read(&relayd->refcount) == 0 &&
  82                         uatomic_read(&relayd->destroy_flag)) {
  83                 consumer_destroy_relayd(relayd);
  84         }
  85         stream->net_seq_idx = (uint64_t) -1ULL;
  86         stream->sent_to_relayd = 0;
  87 }
  88
  89 /*
  90  * Close stream's file descriptors and, if needed, close stream also on the
  91  * relayd side.
  92  *
  93  * The consumer data lock MUST be acquired.
  94  * The stream lock MUST be acquired.
  95  */
  96 void consumer_stream_close(struct lttng_consumer_stream *stream)
  97 {
  98         int ret;
  99         struct consumer_relayd_sock_pair *relayd;
 100
 101         assert(stream);
 102
 103         switch (consumer_data.type) {
 104         case LTTNG_CONSUMER_KERNEL:
 105                 if (stream->mmap_base != NULL) {
 106                         ret = munmap(stream->mmap_base, stream->mmap_len);
 107                         if (ret != 0) {
 108                                 PERROR("munmap");
 109                         }
 110                 }
 111
 112                 if (stream->wait_fd >= 0) {
 113                         ret = close(stream->wait_fd);
 114                         if (ret) {
 115                                 PERROR("close");
 116                         }
 117                         stream->wait_fd = -1;
 118                 }
 119                 if (stream->chan->output == CONSUMER_CHANNEL_SPLICE) {
 120                         utils_close_pipe(stream->splice_pipe);
 121                 }
 122                 break;
 123         case LTTNG_CONSUMER32_UST:
 124         case LTTNG_CONSUMER64_UST:
 125         {
 126                 /*
 127                  * Special case for the metadata since the wait fd is an internal pipe
 128                  * polled in the metadata thread.
 129                  */
 130                 if (stream->metadata_flag && stream->chan->monitor) {
 131                         int rpipe = stream->ust_metadata_poll_pipe[0];
 132
 133                         /*
 134                          * This will stop the channel timer if one and close the write side
 135                          * of the metadata poll pipe.
 136                          */
 137                         lttng_ustconsumer_close_metadata(stream->chan);
 138                         if (rpipe >= 0) {
 139                                 ret = close(rpipe);
 140                                 if (ret < 0) {
 141                                         PERROR("closing metadata pipe read side");
 142                                 }
 143                                 stream->ust_metadata_poll_pipe[0] = -1;
 144                         }
 145                 }
 146                 break;
 147         }
 148         default:
 149                 ERR("Unknown consumer_data type");
 150                 assert(0);
 151         }
 152
 153         /* Close output fd. Could be a socket or local file at this point. */
 154         if (stream->out_fd >= 0) {
 155                 ret = close(stream->out_fd);
 156                 if (ret) {
 157                         PERROR("close");
 158                 }
 159                 stream->out_fd = -1;
 160         }
 161
 162         if (stream->index_file) {
 163                 lttng_index_file_put(stream->index_file);
 164                 stream->index_file = NULL;
 165         }
 166
 167         lttng_trace_chunk_put(stream->trace_chunk);
 168         stream->trace_chunk = NULL;
 169
 170         /* Check and cleanup relayd if needed. */
 171         rcu_read_lock();
 172         relayd = consumer_find_relayd(stream->net_seq_idx);
 173         if (relayd != NULL) {
 174                 consumer_stream_relayd_close(stream, relayd);
 175         }
 176         rcu_read_unlock();
 177 }
 178
 179 /*
 180  * Delete the stream from all possible hash tables.
 181  *
 182  * The consumer data lock MUST be acquired.
 183  * The stream lock MUST be acquired.
 184  */
 185 void consumer_stream_delete(struct lttng_consumer_stream *stream,
 186                 struct lttng_ht *ht)
 187 {
 188         int ret;
 189         struct lttng_ht_iter iter;
 190
 191         assert(stream);
 192         /* Should NEVER be called not in monitor mode. */
 193         assert(stream->chan->monitor);
 194
 195         rcu_read_lock();
 196
 197         if (ht) {
 198                 iter.iter.node = &stream->node.node;
 199                 ret = lttng_ht_del(ht, &iter);
 200                 assert(!ret);
 201         }
 202
 203         /* Delete from stream per channel ID hash table. */
 204         iter.iter.node = &stream->node_channel_id.node;
 205         /*
 206          * The returned value is of no importance. Even if the node is NOT in the
 207          * hash table, we continue since we may have been called by a code path
 208          * that did not add the stream to a (all) hash table. Same goes for the
 209          * next call ht del call.
 210          */
 211         (void) lttng_ht_del(consumer_data.stream_per_chan_id_ht, &iter);
 212
 213         /* Delete from the global stream list. */
 214         iter.iter.node = &stream->node_session_id.node;
 215         /* See the previous ht del on why we ignore the returned value. */
 216         (void) lttng_ht_del(consumer_data.stream_list_ht, &iter);
 217
 218         rcu_read_unlock();
 219
 220         if (!stream->metadata_flag) {
 221                 /* Decrement the stream count of the global consumer data. */
 222                 assert(consumer_data.stream_count > 0);
 223                 consumer_data.stream_count--;
 224         }
 225 }
 226
 227 /*
 228  * Free the given stream within a RCU call.
 229  */
 230 void consumer_stream_free(struct lttng_consumer_stream *stream)
 231 {
 232         assert(stream);
 233
 234         call_rcu(&stream->node.head, free_stream_rcu);
 235 }
 236
 237 /*
 238  * Destroy the stream's buffers of the tracer.
 239  */
 240 void consumer_stream_destroy_buffers(struct lttng_consumer_stream *stream)
 241 {
 242         assert(stream);
 243
 244         switch (consumer_data.type) {
 245         case LTTNG_CONSUMER_KERNEL:
 246                 break;
 247         case LTTNG_CONSUMER32_UST:
 248         case LTTNG_CONSUMER64_UST:
 249                 lttng_ustconsumer_del_stream(stream);
 250                 break;
 251         default:
 252                 ERR("Unknown consumer_data type");
 253                 assert(0);
 254         }
 255 }
 256
 257 /*
 258  * Destroy and close a already created stream.
 259  */
 260 static void destroy_close_stream(struct lttng_consumer_stream *stream)
 261 {
 262         assert(stream);
 263
 264         DBG("Consumer stream destroy monitored key: %" PRIu64, stream->key);
 265
 266         /* Destroy tracer buffers of the stream. */
 267         consumer_stream_destroy_buffers(stream);
 268         /* Close down everything including the relayd if one. */
 269         consumer_stream_close(stream);
 270 }
 271
 272 /*
 273  * Decrement the stream's channel refcount and if down to 0, return the channel
 274  * pointer so it can be destroyed by the caller or NULL if not.
 275  */
 276 static struct lttng_consumer_channel *unref_channel(
 277                 struct lttng_consumer_stream *stream)
 278 {
 279         struct lttng_consumer_channel *free_chan = NULL;
 280
 281         assert(stream);
 282         assert(stream->chan);
 283
 284         /* Update refcount of channel and see if we need to destroy it. */
 285         if (!uatomic_sub_return(&stream->chan->refcount, 1)
 286                         && !uatomic_read(&stream->chan->nb_init_stream_left)) {
 287                 free_chan = stream->chan;
 288         }
 289
 290         return free_chan;
 291 }
 292
 293 /*
 294  * Destroy a stream completely. This will delete, close and free the stream.
 295  * Once return, the stream is NO longer usable. Its channel may get destroyed
 296  * if conditions are met for a monitored stream.
 297  *
 298  * This MUST be called WITHOUT the consumer data and stream lock acquired if
 299  * the stream is in _monitor_ mode else it does not matter.
 300  */
 301 void consumer_stream_destroy(struct lttng_consumer_stream *stream,
 302                 struct lttng_ht *ht)
 303 {
 304         assert(stream);
 305
 306         /* Stream is in monitor mode. */
 307         if (stream->monitor) {
 308                 struct lttng_consumer_channel *free_chan = NULL;
 309
 310                 /*
 311                  * This means that the stream was successfully removed from the streams
 312                  * list of the channel and sent to the right thread managing this
 313                  * stream thus being globally visible.
 314                  */
 315                 if (stream->globally_visible) {
 316                         pthread_mutex_lock(&consumer_data.lock);
 317                         pthread_mutex_lock(&stream->chan->lock);
 318                         pthread_mutex_lock(&stream->lock);
 319                         /* Remove every reference of the stream in the consumer. */
 320                         consumer_stream_delete(stream, ht);
 321
 322                         destroy_close_stream(stream);
 323
 324                         /* Update channel's refcount of the stream. */
 325                         free_chan = unref_channel(stream);
 326
 327                         /* Indicates that the consumer data state MUST be updated after this. */
 328                         consumer_data.need_update = 1;
 329
 330                         pthread_mutex_unlock(&stream->lock);
 331                         pthread_mutex_unlock(&stream->chan->lock);
 332                         pthread_mutex_unlock(&consumer_data.lock);
 333                 } else {
 334                         /*
 335                          * If the stream is not visible globally, this needs to be done
 336                          * outside of the consumer data lock section.
 337                          */
 338                         free_chan = unref_channel(stream);
 339                 }
 340
 341                 if (free_chan) {
 342                         consumer_del_channel(free_chan);
 343                 }
 344         } else {
 345                 destroy_close_stream(stream);
 346         }
 347
 348         /* Free stream within a RCU call. */
 349         lttng_trace_chunk_put(stream->trace_chunk);
 350         stream->trace_chunk = NULL;
 351         consumer_stream_free(stream);
 352 }
 353
 354 /*
 355  * Write index of a specific stream either on the relayd or local disk.
 356  *
 357  * Return 0 on success or else a negative value.
 358  */
 359 int consumer_stream_write_index(struct lttng_consumer_stream *stream,
 360                 struct ctf_packet_index *element)
 361 {
 362         int ret;
 363
 364         assert(stream);
 365         assert(element);
 366
 367         rcu_read_lock();
 368         if (stream->net_seq_idx != (uint64_t) -1ULL) {
 369                 struct consumer_relayd_sock_pair *relayd;
 370                 relayd = consumer_find_relayd(stream->net_seq_idx);
 371                 if (relayd) {
 372                         pthread_mutex_lock(&relayd->ctrl_sock_mutex);
 373                         ret = relayd_send_index(&relayd->control_sock, element,
 374                                 stream->relayd_stream_id, stream->next_net_seq_num - 1);
 375                         if (ret < 0) {
 376                                 /*
 377                                  * Communication error with lttng-relayd,
 378                                  * perform cleanup now
 379                                  */
 380                                 ERR("Relayd send index failed. Cleaning up relayd %" PRIu64 ".", relayd->net_seq_idx);
 381                                 lttng_consumer_cleanup_relayd(relayd);
 382                                 ret = -1;
 383                         }
 384                         pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
 385                 } else {
 386                         ERR("Stream %" PRIu64 " relayd ID %" PRIu64 " unknown. Can't write index.",
 387                                         stream->key, stream->net_seq_idx);
 388                         ret = -1;
 389                 }
 390         } else {
 391                 if (lttng_index_file_write(stream->index_file, element)) {
 392                         ret = -1;
 393                 } else {
 394                         ret = 0;
 395                 }
 396         }
 397         if (ret < 0) {
 398                 goto error;
 399         }
 400
 401 error:
 402         rcu_read_unlock();
 403         return ret;
 404 }
 405
 406 /*
 407  * Actually do the metadata sync using the given metadata stream.
 408  *
 409  * Return 0 on success else a negative value. ENODATA can be returned also
 410  * indicating that there is no metadata available for that stream.
 411  */
 412 static int do_sync_metadata(struct lttng_consumer_stream *metadata,
 413                 struct lttng_consumer_local_data *ctx)
 414 {
 415         int ret;
 416
 417         assert(metadata);
 418         assert(metadata->metadata_flag);
 419         assert(ctx);
 420
 421         /*
 422          * In UST, since we have to write the metadata from the cache packet
 423          * by packet, we might need to start this procedure multiple times
 424          * until all the metadata from the cache has been extracted.
 425          */
 426         do {
 427                 /*
 428                  * Steps :
 429                  * - Lock the metadata stream
 430                  * - Check if metadata stream node was deleted before locking.
 431                  *   - if yes, release and return success
 432                  * - Check if new metadata is ready (flush + snapshot pos)
 433                  * - If nothing : release and return.
 434                  * - Lock the metadata_rdv_lock
 435                  * - Unlock the metadata stream
 436                  * - cond_wait on metadata_rdv to wait the wakeup from the
 437                  *   metadata thread
 438                  * - Unlock the metadata_rdv_lock
 439                  */
 440                 pthread_mutex_lock(&metadata->lock);
 441
 442                 /*
 443                  * There is a possibility that we were able to acquire a reference on the
 444                  * stream from the RCU hash table but between then and now, the node might
 445                  * have been deleted just before the lock is acquired. Thus, after locking,
 446                  * we make sure the metadata node has not been deleted which means that the
 447                  * buffers are closed.
 448                  *
 449                  * In that case, there is no need to sync the metadata hence returning a
 450                  * success return code.
 451                  */
 452                 ret = cds_lfht_is_node_deleted(&metadata->node.node);
 453                 if (ret) {
 454                         ret = 0;
 455                         goto end_unlock_mutex;
 456                 }
 457
 458                 switch (ctx->type) {
 459                 case LTTNG_CONSUMER_KERNEL:
 460                         /*
 461                          * Empty the metadata cache and flush the current stream.
 462                          */
 463                         ret = lttng_kconsumer_sync_metadata(metadata);
 464                         break;
 465                 case LTTNG_CONSUMER32_UST:
 466                 case LTTNG_CONSUMER64_UST:
 467                         /*
 468                          * Ask the sessiond if we have new metadata waiting and update the
 469                          * consumer metadata cache.
 470                          */
 471                         ret = lttng_ustconsumer_sync_metadata(ctx, metadata);
 472                         break;
 473                 default:
 474                         assert(0);
 475                         ret = -1;
 476                         break;
 477                 }
 478                 /*
 479                  * Error or no new metadata, we exit here.
 480                  */
 481                 if (ret <= 0 || ret == ENODATA) {
 482                         goto end_unlock_mutex;
 483                 }
 484
 485                 /*
 486                  * At this point, new metadata have been flushed, so we wait on the
 487                  * rendez-vous point for the metadata thread to wake us up when it
 488                  * finishes consuming the metadata and continue execution.
 489                  */
 490
 491                 pthread_mutex_lock(&metadata->metadata_rdv_lock);
 492
 493                 /*
 494                  * Release metadata stream lock so the metadata thread can process it.
 495                  */
 496                 pthread_mutex_unlock(&metadata->lock);
 497
 498                 /*
 499                  * Wait on the rendez-vous point. Once woken up, it means the metadata was
 500                  * consumed and thus synchronization is achieved.
 501                  */
 502                 pthread_cond_wait(&metadata->metadata_rdv, &metadata->metadata_rdv_lock);
 503                 pthread_mutex_unlock(&metadata->metadata_rdv_lock);
 504         } while (ret == EAGAIN);
 505
 506         /* Success */
 507         return 0;
 508
 509 end_unlock_mutex:
 510         pthread_mutex_unlock(&metadata->lock);
 511         return ret;
 512 }
 513
 514 /*
 515  * Synchronize the metadata using a given session ID. A successful acquisition
 516  * of a metadata stream will trigger a request to the session daemon and a
 517  * snapshot so the metadata thread can consume it.
 518  *
 519  * This function call is a rendez-vous point between the metadata thread and
 520  * the data thread.
 521  *
 522  * Return 0 on success or else a negative value.
 523  */
 524 int consumer_stream_sync_metadata(struct lttng_consumer_local_data *ctx,
 525                 uint64_t session_id)
 526 {
 527         int ret;
 528         struct lttng_consumer_stream *stream = NULL;
 529         struct lttng_ht_iter iter;
 530         struct lttng_ht *ht;
 531
 532         assert(ctx);
 533
 534         /* Ease our life a bit. */
 535         ht = consumer_data.stream_list_ht;
 536
 537         rcu_read_lock();
 538
 539         /* Search the metadata associated with the session id of the given stream. */
 540
 541         cds_lfht_for_each_entry_duplicate(ht->ht,
 542                         ht->hash_fct(&session_id, lttng_ht_seed), ht->match_fct,
 543                         &session_id, &iter.iter, stream, node_session_id.node) {
 544                 if (!stream->metadata_flag) {
 545                         continue;
 546                 }
 547
 548                 ret = do_sync_metadata(stream, ctx);
 549                 if (ret < 0) {
 550                         goto end;
 551                 }
 552         }
 553
 554         /*
 555          * Force return code to 0 (success) since ret might be ENODATA for instance
 556          * which is not an error but rather that we should come back.
 557          */
 558         ret = 0;
 559
 560 end:
 561         rcu_read_unlock();
 562         return ret;
 563 }
 564
 565 int consumer_stream_create_output_files(struct lttng_consumer_stream *stream,
 566                 bool create_index)
 567 {
 568         int ret;
 569         enum lttng_trace_chunk_status chunk_status;
 570         const int flags = O_WRONLY | O_CREAT | O_TRUNC;
 571         const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
 572         char stream_path[LTTNG_PATH_MAX];
 573
 574         ASSERT_LOCKED(stream->lock);
 575         assert(stream->trace_chunk);
 576
 577         ret = utils_stream_file_path(stream->chan->pathname, stream->name,
 578                         stream->chan->tracefile_size,
 579                         stream->tracefile_count_current, NULL,
 580                         stream_path, sizeof(stream_path));
 581         if (ret < 0) {
 582                 goto end;
 583         }
 584
 585         if (stream->out_fd >= 0) {
 586                 ret = close(stream->out_fd);
 587                 if (ret < 0) {
 588                         PERROR("Failed to close stream file \"%s\"",
 589                                         stream->name);
 590                         goto end;
 591                 }
 592                 stream->out_fd = -1;
 593         }
 594
 595         DBG("Opening stream output file \"%s\"", stream_path);
 596         chunk_status = lttng_trace_chunk_open_file(stream->trace_chunk, stream_path,
 597                         flags, mode, &stream->out_fd);
 598         if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 599                 ERR("Failed to open stream file \"%s\"", stream->name);
 600                 ret = -1;
 601                 goto end;
 602         }
 603
 604         if (!stream->metadata_flag && (create_index || stream->index_file)) {
 605                 if (stream->index_file) {
 606                         lttng_index_file_put(stream->index_file);
 607                 }
 608                 stream->index_file = lttng_index_file_create_from_trace_chunk(
 609                                 stream->trace_chunk,
 610                                 stream->chan->pathname,
 611                                 stream->name,
 612                                 stream->chan->tracefile_size,
 613                                 stream->tracefile_count_current,
 614                                 CTF_INDEX_MAJOR, CTF_INDEX_MINOR,
 615                                 false);
 616                 if (!stream->index_file) {
 617                         ret = -1;
 618                         goto end;
 619                 }
 620         }
 621
 622         /* Reset current size because we just perform a rotation. */
 623         stream->tracefile_size_current = 0;
 624         stream->out_fd_offset = 0;
 625 end:
 626         return ret;
 627 }
 628
 629 int consumer_stream_rotate_output_files(struct lttng_consumer_stream *stream)
 630 {
 631         int ret;
 632
 633         stream->tracefile_count_current++;
 634         if (stream->chan->tracefile_count > 0) {
 635                 stream->tracefile_count_current %=
 636                                 stream->chan->tracefile_count;
 637         }
 638
 639         DBG("Rotating output files of stream \"%s\"", stream->name);
 640         ret = consumer_stream_create_output_files(stream, true);
 641         if (ret) {
 642                 goto end;
 643         }
 644
 645 end:
 646         return ret;
 647 }