src/bin/lttng-relayd/stream.cpp

   1 /*
   2  * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   4  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  *
   7  * SPDX-License-Identifier: GPL-2.0-only
   8  *
   9  */
  10
  11 #define _LGPL_SOURCE
  12 #include "index.hpp"
  13 #include "lttng-relayd.hpp"
  14 #include "stream.hpp"
  15 #include "viewer-stream.hpp"
  16
  17 #include <common/common.hpp>
  18 #include <common/defaults.hpp>
  19 #include <common/fs-handle.hpp>
  20 #include <common/sessiond-comm/relayd.hpp>
  21 #include <common/urcu.hpp>
  22 #include <common/utils.hpp>
  23
  24 #include <algorithm>
  25 #include <fcntl.h>
  26 #include <sys/stat.h>
  27 #include <sys/types.h>
  28 #include <urcu/rculist.h>
  29
  30 #define FILE_IO_STACK_BUFFER_SIZE 65536
  31
  32 /* Should be called with RCU read-side lock held. */
  33 bool stream_get(struct relay_stream *stream)
  34 {
  35         ASSERT_RCU_READ_LOCKED();
  36
  37         return urcu_ref_get_unless_zero(&stream->ref);
  38 }
  39
  40 /*
  41  * Get stream from stream id from the streams hash table. Return stream
  42  * if found else NULL. A stream reference is taken when a stream is
  43  * returned. stream_put() must be called on that stream.
  44  */
  45 struct relay_stream *stream_get_by_id(uint64_t stream_id)
  46 {
  47         struct lttng_ht_node_u64 *node;
  48         struct lttng_ht_iter iter;
  49         struct relay_stream *stream = nullptr;
  50
  51         lttng::urcu::read_lock_guard read_lock;
  52         lttng_ht_lookup(relay_streams_ht, &stream_id, &iter);
  53         node = lttng_ht_iter_get_node_u64(&iter);
  54         if (!node) {
  55                 DBG("Relay stream %" PRIu64 " not found", stream_id);
  56                 goto end;
  57         }
  58         stream = lttng::utils::container_of(node, &relay_stream::node);
  59         if (!stream_get(stream)) {
  60                 stream = nullptr;
  61         }
  62 end:
  63         return stream;
  64 }
  65
  66 static void stream_complete_rotation(struct relay_stream *stream)
  67 {
  68         DBG("Rotation completed for stream %" PRIu64, stream->stream_handle);
  69         if (stream->ongoing_rotation.value.next_trace_chunk) {
  70                 tracefile_array_reset(stream->tfa);
  71                 tracefile_array_commit_seq(stream->tfa, stream->index_received_seqcount);
  72         }
  73         lttng_trace_chunk_put(stream->trace_chunk);
  74         stream->trace_chunk = stream->ongoing_rotation.value.next_trace_chunk;
  75         stream->ongoing_rotation = LTTNG_OPTIONAL_INIT_UNSET;
  76         stream->completed_rotation_count++;
  77 }
  78
  79 static int stream_create_data_output_file_from_trace_chunk(struct relay_stream *stream,
  80                                                            struct lttng_trace_chunk *trace_chunk,
  81                                                            bool force_unlink,
  82                                                            struct fs_handle **out_file)
  83 {
  84         int ret;
  85         char stream_path[LTTNG_PATH_MAX];
  86         enum lttng_trace_chunk_status status;
  87         const int flags = O_RDWR | O_CREAT | O_TRUNC;
  88         const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
  89
  90         ASSERT_LOCKED(stream->lock);
  91
  92         ret = utils_stream_file_path(stream->path_name,
  93                                      stream->channel_name,
  94                                      stream->tracefile_size,
  95                                      stream->tracefile_current_index,
  96                                      nullptr,
  97                                      stream_path,
  98                                      sizeof(stream_path));
  99         if (ret < 0) {
 100                 goto end;
 101         }
 102
 103         if (stream->tracefile_wrapped_around || force_unlink) {
 104                 /*
 105                  * The on-disk ring-buffer has wrapped around.
 106                  * Newly created stream files will replace existing files. Since
 107                  * live clients may be consuming existing files, the file about
 108                  * to be replaced is unlinked in order to not overwrite its
 109                  * content.
 110                  */
 111                 status = (lttng_trace_chunk_status) lttng_trace_chunk_unlink_file(trace_chunk,
 112                                                                                   stream_path);
 113                 if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 114                         PERROR("Failed to unlink stream file \"%s\" during trace file rotation",
 115                                stream_path);
 116                         /*
 117                          * Don't abort if the file doesn't exist, it is
 118                          * unexpected, but should not be a fatal error.
 119                          */
 120                         if (errno != ENOENT) {
 121                                 ret = -1;
 122                                 goto end;
 123                         }
 124                 }
 125         }
 126
 127         status = lttng_trace_chunk_open_fs_handle(
 128                 trace_chunk, stream_path, flags, mode, out_file, false);
 129         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 130                 ERR("Failed to open stream file \"%s\"", stream->channel_name);
 131                 ret = -1;
 132                 goto end;
 133         }
 134 end:
 135         return ret;
 136 }
 137
 138 static int stream_rotate_data_file(struct relay_stream *stream)
 139 {
 140         int ret = 0;
 141
 142         DBG("Rotating stream %" PRIu64 " data file with size %" PRIu64,
 143             stream->stream_handle,
 144             stream->tracefile_size_current);
 145
 146         if (stream->file) {
 147                 fs_handle_close(stream->file);
 148                 stream->file = nullptr;
 149         }
 150
 151         stream->tracefile_wrapped_around = false;
 152         stream->tracefile_current_index = 0;
 153
 154         if (stream->ongoing_rotation.value.next_trace_chunk) {
 155                 enum lttng_trace_chunk_status chunk_status;
 156
 157                 chunk_status = lttng_trace_chunk_create_subdirectory(
 158                         stream->ongoing_rotation.value.next_trace_chunk, stream->path_name);
 159                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 160                         ret = -1;
 161                         goto end;
 162                 }
 163
 164                 /* Rotate the data file. */
 165                 ret = stream_create_data_output_file_from_trace_chunk(
 166                         stream,
 167                         stream->ongoing_rotation.value.next_trace_chunk,
 168                         false,
 169                         &stream->file);
 170                 if (ret < 0) {
 171                         ERR("Failed to rotate stream data file");
 172                         goto end;
 173                 }
 174         }
 175         DBG("%s: reset tracefile_size_current for stream %" PRIu64 " was %" PRIu64,
 176             __func__,
 177             stream->stream_handle,
 178             stream->tracefile_size_current);
 179         stream->tracefile_size_current = 0;
 180         stream->pos_after_last_complete_data_index = 0;
 181         stream->ongoing_rotation.value.data_rotated = true;
 182
 183         if (stream->ongoing_rotation.value.index_rotated) {
 184                 /* Rotation completed; reset its state. */
 185                 stream_complete_rotation(stream);
 186         }
 187 end:
 188         return ret;
 189 }
 190
 191 /*
 192  * If too much data has been written in a tracefile before we received the
 193  * rotation command, we have to move the excess data to the new tracefile and
 194  * perform the rotation. This can happen because the control and data
 195  * connections are separate, the indexes as well as the commands arrive from
 196  * the control connection and we have no control over the order so we could be
 197  * in a situation where too much data has been received on the data connection
 198  * before the rotation command on the control connection arrives.
 199  */
 200 static int rotate_truncate_stream(struct relay_stream *stream)
 201 {
 202         int ret;
 203         off_t lseek_ret, previous_stream_copy_origin;
 204         uint64_t copy_bytes_left, misplaced_data_size;
 205         bool acquired_reference;
 206         struct fs_handle *previous_stream_file = nullptr;
 207         struct lttng_trace_chunk *previous_chunk = nullptr;
 208
 209         if (!LTTNG_OPTIONAL_GET(stream->ongoing_rotation).next_trace_chunk) {
 210                 ERR("Protocol error encoutered in %s(): stream rotation "
 211                     "sequence number is before the current sequence number "
 212                     "and the next trace chunk is unset. Honoring this "
 213                     "rotation command would result in data loss",
 214                     __FUNCTION__);
 215                 ret = -1;
 216                 goto end;
 217         }
 218
 219         ASSERT_LOCKED(stream->lock);
 220         /*
 221          * Acquire a reference to the current trace chunk to ensure
 222          * it is not reclaimed when `stream_rotate_data_file` is called.
 223          * Failing to do so would violate the contract of the trace
 224          * chunk API as an active file descriptor would outlive the
 225          * trace chunk.
 226          */
 227         acquired_reference = lttng_trace_chunk_get(stream->trace_chunk);
 228         LTTNG_ASSERT(acquired_reference);
 229         previous_chunk = stream->trace_chunk;
 230
 231         /*
 232          * Steal the stream's reference to its stream_fd. A new
 233          * stream_fd will be created when the rotation completes and
 234          * the orinal stream_fd will be used to copy the "extra" data
 235          * to the new file.
 236          */
 237         LTTNG_ASSERT(stream->file);
 238         previous_stream_file = stream->file;
 239         stream->file = nullptr;
 240
 241         LTTNG_ASSERT(!stream->is_metadata);
 242         LTTNG_ASSERT(stream->tracefile_size_current > stream->pos_after_last_complete_data_index);
 243         misplaced_data_size =
 244                 stream->tracefile_size_current - stream->pos_after_last_complete_data_index;
 245         copy_bytes_left = misplaced_data_size;
 246         previous_stream_copy_origin = stream->pos_after_last_complete_data_index;
 247
 248         ret = stream_rotate_data_file(stream);
 249         if (ret) {
 250                 goto end;
 251         }
 252
 253         LTTNG_ASSERT(stream->file);
 254         /*
 255          * Seek the current tracefile to the position at which the rotation
 256          * should have occurred.
 257          */
 258         lseek_ret = fs_handle_seek(previous_stream_file, previous_stream_copy_origin, SEEK_SET);
 259         if (lseek_ret < 0) {
 260                 PERROR("Failed to seek to offset %" PRIu64
 261                        " while copying extra data received before a stream rotation",
 262                        (uint64_t) previous_stream_copy_origin);
 263                 ret = -1;
 264                 goto end;
 265         }
 266
 267         /* Move data from the old file to the new file. */
 268         while (copy_bytes_left) {
 269                 ssize_t io_ret;
 270                 char copy_buffer[FILE_IO_STACK_BUFFER_SIZE];
 271                 const off_t copy_size_this_pass =
 272                         std::min<uint64_t>(copy_bytes_left, sizeof(copy_buffer));
 273
 274                 io_ret = fs_handle_read(previous_stream_file, copy_buffer, copy_size_this_pass);
 275                 if (io_ret < (ssize_t) copy_size_this_pass) {
 276                         if (io_ret == -1) {
 277                                 PERROR("Failed to read %" PRIu64
 278                                        " bytes from previous stream file in %s(), returned %zi: stream id = %" PRIu64,
 279                                        copy_size_this_pass,
 280                                        __FUNCTION__,
 281                                        io_ret,
 282                                        stream->stream_handle);
 283                         } else {
 284                                 ERR("Failed to read %" PRIu64
 285                                     " bytes from previous stream file in %s(), returned %zi: stream id = %" PRIu64,
 286                                     copy_size_this_pass,
 287                                     __FUNCTION__,
 288                                     io_ret,
 289                                     stream->stream_handle);
 290                         }
 291                         ret = -1;
 292                         goto end;
 293                 }
 294
 295                 io_ret = fs_handle_write(stream->file, copy_buffer, copy_size_this_pass);
 296                 if (io_ret < (ssize_t) copy_size_this_pass) {
 297                         if (io_ret == -1) {
 298                                 PERROR("Failed to write %" PRIu64
 299                                        " bytes from previous stream file in %s(), returned %zi: stream id = %" PRIu64,
 300                                        copy_size_this_pass,
 301                                        __FUNCTION__,
 302                                        io_ret,
 303                                        stream->stream_handle);
 304                         } else {
 305                                 ERR("Failed to write %" PRIu64
 306                                     " bytes from previous stream file in %s(), returned %zi: stream id = %" PRIu64,
 307                                     copy_size_this_pass,
 308                                     __FUNCTION__,
 309                                     io_ret,
 310                                     stream->stream_handle);
 311                         }
 312                         ret = -1;
 313                         goto end;
 314                 }
 315                 copy_bytes_left -= copy_size_this_pass;
 316         }
 317
 318         /* Truncate the file to get rid of the excess data. */
 319         ret = fs_handle_truncate(previous_stream_file, previous_stream_copy_origin);
 320         if (ret) {
 321                 PERROR("Failed to truncate current stream file to offset %" PRIu64,
 322                        previous_stream_copy_origin);
 323                 goto end;
 324         }
 325
 326         /*
 327          * Update the offset and FD of all the eventual indexes created by the
 328          * data connection before the rotation command arrived.
 329          */
 330         ret = relay_index_switch_all_files(stream);
 331         if (ret < 0) {
 332                 ERR("Failed to rotate index file");
 333                 goto end;
 334         }
 335
 336         stream->tracefile_size_current = misplaced_data_size;
 337         /* Index and data contents are back in sync. */
 338         stream->pos_after_last_complete_data_index = 0;
 339         ret = 0;
 340 end:
 341         lttng_trace_chunk_put(previous_chunk);
 342         return ret;
 343 }
 344
 345 /*
 346  * Check if a stream's data file (as opposed to index) should be rotated
 347  * (for session rotation).
 348  * Must be called with the stream lock held.
 349  *
 350  * Return 0 on success, a negative value on error.
 351  */
 352 static int try_rotate_stream_data(struct relay_stream *stream)
 353 {
 354         int ret = 0;
 355
 356         if (caa_likely(!stream->ongoing_rotation.is_set)) {
 357                 /* No rotation expected. */
 358                 goto end;
 359         }
 360
 361         if (stream->ongoing_rotation.value.data_rotated) {
 362                 /* Rotation of the data file has already occurred. */
 363                 goto end;
 364         }
 365
 366         DBG("%s: Stream %" PRIu64 " (rotate_at_index_packet_seq_num = %" PRIu64
 367             ", rotate_at_prev_data_net_seq = %" PRIu64 ", prev_data_seq = %" PRIu64 ")",
 368             __func__,
 369             stream->stream_handle,
 370             stream->ongoing_rotation.value.packet_seq_num,
 371             stream->ongoing_rotation.value.prev_data_net_seq,
 372             stream->prev_data_seq);
 373
 374         if (stream->prev_data_seq == -1ULL ||
 375             stream->ongoing_rotation.value.prev_data_net_seq == -1ULL ||
 376             stream->prev_data_seq < stream->ongoing_rotation.value.prev_data_net_seq) {
 377                 /*
 378                  * The next packet that will be written is not part of the next
 379                  * chunk yet.
 380                  */
 381                 DBG("Stream %" PRIu64 " data not yet ready for rotation "
 382                     "(rotate_at_index_packet_seq_num = %" PRIu64
 383                     ", rotate_at_prev_data_net_seq = %" PRIu64 ", prev_data_seq = %" PRIu64 ")",
 384                     stream->stream_handle,
 385                     stream->ongoing_rotation.value.packet_seq_num,
 386                     stream->ongoing_rotation.value.prev_data_net_seq,
 387                     stream->prev_data_seq);
 388                 goto end;
 389         } else if (stream->prev_data_seq > stream->ongoing_rotation.value.prev_data_net_seq) {
 390                 /*
 391                  * prev_data_seq is checked here since indexes and rotation
 392                  * commands are serialized with respect to each other.
 393                  */
 394                 DBG("Rotation after too much data has been written in tracefile "
 395                     "for stream %" PRIu64 ", need to truncate before "
 396                     "rotating",
 397                     stream->stream_handle);
 398                 ret = rotate_truncate_stream(stream);
 399                 if (ret) {
 400                         ERR("Failed to truncate stream");
 401                         goto end;
 402                 }
 403         } else {
 404                 ret = stream_rotate_data_file(stream);
 405         }
 406
 407 end:
 408         return ret;
 409 }
 410
 411 /*
 412  * Close the current index file if it is open, and create a new one.
 413  *
 414  * Return 0 on success, -1 on error.
 415  */
 416 static int create_index_file(struct relay_stream *stream, struct lttng_trace_chunk *chunk)
 417 {
 418         int ret;
 419         uint32_t major, minor;
 420         char *index_subpath = nullptr;
 421         enum lttng_trace_chunk_status status;
 422
 423         ASSERT_LOCKED(stream->lock);
 424
 425         /* Put ref on previous index_file. */
 426         if (stream->index_file) {
 427                 lttng_index_file_put(stream->index_file);
 428                 stream->index_file = nullptr;
 429         }
 430         major = stream->trace->session->major;
 431         minor = stream->trace->session->minor;
 432
 433         if (!chunk) {
 434                 ret = 0;
 435                 goto end;
 436         }
 437         ret = asprintf(&index_subpath, "%s/%s", stream->path_name, DEFAULT_INDEX_DIR);
 438         if (ret < 0) {
 439                 goto end;
 440         }
 441
 442         status = lttng_trace_chunk_create_subdirectory(chunk, index_subpath);
 443         free(index_subpath);
 444         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 445                 ret = -1;
 446                 goto end;
 447         }
 448         status = lttng_index_file_create_from_trace_chunk(chunk,
 449                                                           stream->path_name,
 450                                                           stream->channel_name,
 451                                                           stream->tracefile_size,
 452                                                           stream->tracefile_current_index,
 453                                                           lttng_to_index_major(major, minor),
 454                                                           lttng_to_index_minor(major, minor),
 455                                                           true,
 456                                                           &stream->index_file);
 457         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 458                 ret = -1;
 459                 goto end;
 460         }
 461
 462         ret = 0;
 463
 464 end:
 465         return ret;
 466 }
 467
 468 /*
 469  * Check if a stream's index file should be rotated (for session rotation).
 470  * Must be called with the stream lock held.
 471  *
 472  * Return 0 on success, a negative value on error.
 473  */
 474 static int try_rotate_stream_index(struct relay_stream *stream)
 475 {
 476         int ret = 0;
 477
 478         if (!stream->ongoing_rotation.is_set) {
 479                 /* No rotation expected. */
 480                 goto end;
 481         }
 482
 483         if (stream->ongoing_rotation.value.index_rotated) {
 484                 /* Rotation of the index has already occurred. */
 485                 goto end;
 486         }
 487
 488         DBG("%s: Stream %" PRIu64 " (rotate_at_packet_seq_num = %" PRIu64
 489             ", received_packet_seq_num = "
 490             "(value = %" PRIu64 ", is_set = %" PRIu8 "))",
 491             __func__,
 492             stream->stream_handle,
 493             stream->ongoing_rotation.value.packet_seq_num,
 494             stream->received_packet_seq_num.value,
 495             stream->received_packet_seq_num.is_set);
 496
 497         if (!stream->received_packet_seq_num.is_set ||
 498             LTTNG_OPTIONAL_GET(stream->received_packet_seq_num) + 1 <
 499                     stream->ongoing_rotation.value.packet_seq_num) {
 500                 DBG("Stream %" PRIu64 " index not yet ready for rotation "
 501                     "(rotate_at_packet_seq_num = %" PRIu64 ", received_packet_seq_num = "
 502                     "(value = %" PRIu64 ", is_set = %" PRIu8 "))",
 503                     stream->stream_handle,
 504                     stream->ongoing_rotation.value.packet_seq_num,
 505                     stream->received_packet_seq_num.value,
 506                     stream->received_packet_seq_num.is_set);
 507                 goto end;
 508         } else {
 509                 /*
 510                  * The next index belongs to the new trace chunk; rotate.
 511                  * In overwrite mode, the packet seq num may jump over the
 512                  * rotation position.
 513                  */
 514                 LTTNG_ASSERT(LTTNG_OPTIONAL_GET(stream->received_packet_seq_num) + 1 >=
 515                              stream->ongoing_rotation.value.packet_seq_num);
 516                 DBG("Rotating stream %" PRIu64 " index file", stream->stream_handle);
 517                 if (stream->index_file) {
 518                         lttng_index_file_put(stream->index_file);
 519                         stream->index_file = nullptr;
 520                 }
 521                 stream->ongoing_rotation.value.index_rotated = true;
 522
 523                 /*
 524                  * Set the rotation pivot position for the data, now that we have the
 525                  * net_seq_num matching the packet_seq_num index pivot position.
 526                  */
 527                 stream->ongoing_rotation.value.prev_data_net_seq = stream->prev_index_seq;
 528                 if (stream->ongoing_rotation.value.data_rotated &&
 529                     stream->ongoing_rotation.value.index_rotated) {
 530                         /* Rotation completed; reset its state. */
 531                         DBG("Rotation completed for stream %" PRIu64, stream->stream_handle);
 532                         stream_complete_rotation(stream);
 533                 }
 534         }
 535
 536 end:
 537         return ret;
 538 }
 539
 540 static int stream_set_trace_chunk(struct relay_stream *stream, struct lttng_trace_chunk *chunk)
 541 {
 542         int ret = 0;
 543         enum lttng_trace_chunk_status status;
 544         bool acquired_reference;
 545
 546         status = lttng_trace_chunk_create_subdirectory(chunk, stream->path_name);
 547         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 548                 ret = -1;
 549                 goto end;
 550         }
 551
 552         lttng_trace_chunk_put(stream->trace_chunk);
 553         acquired_reference = lttng_trace_chunk_get(chunk);
 554         LTTNG_ASSERT(acquired_reference);
 555         stream->trace_chunk = chunk;
 556
 557         if (stream->file) {
 558                 fs_handle_close(stream->file);
 559                 stream->file = nullptr;
 560         }
 561         ret = stream_create_data_output_file_from_trace_chunk(stream, chunk, false, &stream->file);
 562 end:
 563         return ret;
 564 }
 565
 566 /*
 567  * We keep ownership of path_name and channel_name.
 568  */
 569 struct relay_stream *stream_create(struct ctf_trace *trace,
 570                                    uint64_t stream_handle,
 571                                    char *path_name,
 572                                    char *channel_name,
 573                                    uint64_t tracefile_size,
 574                                    uint64_t tracefile_count)
 575 {
 576         int ret;
 577         struct relay_stream *stream = nullptr;
 578         struct relay_session *session = trace->session;
 579         bool acquired_reference = false;
 580         struct lttng_trace_chunk *current_trace_chunk;
 581
 582         stream = zmalloc<relay_stream>();
 583         if (stream == nullptr) {
 584                 PERROR("relay stream zmalloc");
 585                 goto error_no_alloc;
 586         }
 587
 588         stream->stream_handle = stream_handle;
 589         stream->prev_data_seq = -1ULL;
 590         stream->prev_index_seq = -1ULL;
 591         stream->last_net_seq_num = -1ULL;
 592         stream->ctf_stream_id = -1ULL;
 593         stream->tracefile_size = tracefile_size;
 594         stream->tracefile_count = tracefile_count;
 595         stream->path_name = path_name;
 596         stream->channel_name = channel_name;
 597         stream->beacon_ts_end = -1ULL;
 598         lttng_ht_node_init_u64(&stream->node, stream->stream_handle);
 599         pthread_mutex_init(&stream->lock, nullptr);
 600         urcu_ref_init(&stream->ref);
 601         ctf_trace_get(trace);
 602         stream->trace = trace;
 603
 604         pthread_mutex_lock(&trace->session->lock);
 605         current_trace_chunk = trace->session->current_trace_chunk;
 606         if (current_trace_chunk) {
 607                 acquired_reference = lttng_trace_chunk_get(current_trace_chunk);
 608         }
 609         pthread_mutex_unlock(&trace->session->lock);
 610         if (!acquired_reference) {
 611                 ERR("Cannot create stream for channel \"%s\" as a reference to the session's current trace chunk could not be acquired",
 612                     channel_name);
 613                 ret = -1;
 614                 goto end;
 615         }
 616
 617         stream->indexes_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 618         if (!stream->indexes_ht) {
 619                 ERR("Cannot created indexes_ht");
 620                 ret = -1;
 621                 goto end;
 622         }
 623
 624         pthread_mutex_lock(&stream->lock);
 625         ret = stream_set_trace_chunk(stream, current_trace_chunk);
 626         pthread_mutex_unlock(&stream->lock);
 627         if (ret) {
 628                 ERR("Failed to set the current trace chunk of session \"%s\" on newly created stream of channel \"%s\"",
 629                     trace->session->session_name,
 630                     stream->channel_name);
 631                 ret = -1;
 632                 goto end;
 633         }
 634         stream->tfa = tracefile_array_create(stream->tracefile_count);
 635         if (!stream->tfa) {
 636                 ret = -1;
 637                 goto end;
 638         }
 639
 640         stream->is_metadata = !strcmp(stream->channel_name, DEFAULT_METADATA_NAME);
 641         stream->in_recv_list = true;
 642
 643         /*
 644          * Add the stream in the recv list of the session. Once the end stream
 645          * message is received, all session streams are published.
 646          */
 647         pthread_mutex_lock(&session->recv_list_lock);
 648         cds_list_add_rcu(&stream->recv_node, &session->recv_list);
 649         session->stream_count++;
 650         pthread_mutex_unlock(&session->recv_list_lock);
 651
 652         /*
 653          * Both in the ctf_trace object and the global stream ht since the data
 654          * side of the relayd does not have the concept of session.
 655          */
 656         lttng_ht_add_unique_u64(relay_streams_ht, &stream->node);
 657         stream->in_stream_ht = true;
 658
 659         DBG("Relay new stream added %s with ID %" PRIu64,
 660             stream->channel_name,
 661             stream->stream_handle);
 662         ret = 0;
 663
 664 end:
 665         if (ret) {
 666                 if (stream->file) {
 667                         fs_handle_close(stream->file);
 668                         stream->file = nullptr;
 669                 }
 670                 stream_put(stream);
 671                 stream = nullptr;
 672         }
 673         if (acquired_reference) {
 674                 lttng_trace_chunk_put(current_trace_chunk);
 675         }
 676         return stream;
 677
 678 error_no_alloc:
 679         /*
 680          * path_name and channel_name need to be freed explicitly here
 681          * because we cannot rely on stream_put().
 682          */
 683         free(path_name);
 684         free(channel_name);
 685         return nullptr;
 686 }
 687
 688 /*
 689  * Called with the session lock held.
 690  */
 691 void stream_publish(struct relay_stream *stream)
 692 {
 693         struct relay_session *session;
 694
 695         pthread_mutex_lock(&stream->lock);
 696         if (stream->published) {
 697                 goto unlock;
 698         }
 699
 700         session = stream->trace->session;
 701
 702         pthread_mutex_lock(&session->recv_list_lock);
 703         if (stream->in_recv_list) {
 704                 cds_list_del_rcu(&stream->recv_node);
 705                 stream->in_recv_list = false;
 706         }
 707         pthread_mutex_unlock(&session->recv_list_lock);
 708
 709         pthread_mutex_lock(&stream->trace->stream_list_lock);
 710         cds_list_add_rcu(&stream->stream_node, &stream->trace->stream_list);
 711         pthread_mutex_unlock(&stream->trace->stream_list_lock);
 712
 713         stream->published = true;
 714 unlock:
 715         pthread_mutex_unlock(&stream->lock);
 716 }
 717
 718 /*
 719  * Stream must be protected by holding the stream lock or by virtue of being
 720  * called from stream_destroy.
 721  */
 722 static void stream_unpublish(struct relay_stream *stream)
 723 {
 724         if (stream->in_stream_ht) {
 725                 struct lttng_ht_iter iter;
 726                 int ret;
 727
 728                 iter.iter.node = &stream->node.node;
 729                 ret = lttng_ht_del(relay_streams_ht, &iter);
 730                 LTTNG_ASSERT(!ret);
 731                 stream->in_stream_ht = false;
 732         }
 733         if (stream->published) {
 734                 pthread_mutex_lock(&stream->trace->stream_list_lock);
 735                 cds_list_del_rcu(&stream->stream_node);
 736                 pthread_mutex_unlock(&stream->trace->stream_list_lock);
 737                 stream->published = false;
 738         }
 739 }
 740
 741 static void stream_destroy(struct relay_stream *stream)
 742 {
 743         if (stream->indexes_ht) {
 744                 /*
 745                  * Calling lttng_ht_destroy in call_rcu worker thread so
 746                  * we don't hold the RCU read-side lock while calling
 747                  * it.
 748                  */
 749                 lttng_ht_destroy(stream->indexes_ht);
 750         }
 751         if (stream->tfa) {
 752                 tracefile_array_destroy(stream->tfa);
 753         }
 754         free(stream->path_name);
 755         free(stream->channel_name);
 756         free(stream);
 757 }
 758
 759 static void stream_destroy_rcu(struct rcu_head *rcu_head)
 760 {
 761         struct relay_stream *stream = lttng::utils::container_of(rcu_head, &relay_stream::rcu_node);
 762
 763         stream_destroy(stream);
 764 }
 765
 766 /*
 767  * No need to take stream->lock since this is only called on the final
 768  * stream_put which ensures that a single thread may act on the stream.
 769  */
 770 static void stream_release(struct urcu_ref *ref)
 771 {
 772         struct relay_stream *stream = lttng::utils::container_of(ref, &relay_stream::ref);
 773         struct relay_session *session;
 774
 775         session = stream->trace->session;
 776
 777         DBG("Releasing stream id %" PRIu64, stream->stream_handle);
 778
 779         pthread_mutex_lock(&session->recv_list_lock);
 780         session->stream_count--;
 781         if (stream->in_recv_list) {
 782                 cds_list_del_rcu(&stream->recv_node);
 783                 stream->in_recv_list = false;
 784         }
 785         pthread_mutex_unlock(&session->recv_list_lock);
 786
 787         stream_unpublish(stream);
 788
 789         if (stream->file) {
 790                 fs_handle_close(stream->file);
 791                 stream->file = nullptr;
 792         }
 793         if (stream->index_file) {
 794                 lttng_index_file_put(stream->index_file);
 795                 stream->index_file = nullptr;
 796         }
 797         if (stream->trace) {
 798                 ctf_trace_put(stream->trace);
 799                 stream->trace = nullptr;
 800         }
 801         stream_complete_rotation(stream);
 802         lttng_trace_chunk_put(stream->trace_chunk);
 803         stream->trace_chunk = nullptr;
 804
 805         call_rcu(&stream->rcu_node, stream_destroy_rcu);
 806 }
 807
 808 void stream_put(struct relay_stream *stream)
 809 {
 810         lttng::urcu::read_lock_guard read_lock;
 811         LTTNG_ASSERT(stream->ref.refcount != 0);
 812         /*
 813          * Wait until we have processed all the stream packets before
 814          * actually putting our last stream reference.
 815          */
 816         urcu_ref_put(&stream->ref, stream_release);
 817 }
 818
 819 int stream_set_pending_rotation(struct relay_stream *stream,
 820                                 struct lttng_trace_chunk *next_trace_chunk,
 821                                 uint64_t rotation_sequence_number)
 822 {
 823         int ret = 0;
 824         const struct relay_stream_rotation rotation = {
 825                 .data_rotated = false,
 826                 .index_rotated = false,
 827                 .packet_seq_num = rotation_sequence_number,
 828                 .prev_data_net_seq = -1ULL,
 829                 .next_trace_chunk = next_trace_chunk,
 830         };
 831
 832         if (stream->ongoing_rotation.is_set) {
 833                 ERR("Attempted to set a pending rotation on a stream already being rotated (protocol error)");
 834                 ret = -1;
 835                 goto end;
 836         }
 837
 838         if (next_trace_chunk) {
 839                 const bool reference_acquired = lttng_trace_chunk_get(next_trace_chunk);
 840
 841                 LTTNG_ASSERT(reference_acquired);
 842         }
 843         LTTNG_OPTIONAL_SET(&stream->ongoing_rotation, rotation);
 844
 845         DBG("Setting pending rotation: stream_id = %" PRIu64
 846             ", rotate_at_packet_seq_num = %" PRIu64,
 847             stream->stream_handle,
 848             rotation_sequence_number);
 849         if (stream->is_metadata) {
 850                 /*
 851                  * A metadata stream has no index; consider it already rotated.
 852                  */
 853                 stream->ongoing_rotation.value.index_rotated = true;
 854                 if (next_trace_chunk) {
 855                         /*
 856                          * The metadata will be received again in the new chunk.
 857                          */
 858                         stream->metadata_received = 0;
 859                 }
 860                 ret = stream_rotate_data_file(stream);
 861         } else {
 862                 ret = try_rotate_stream_index(stream);
 863                 if (ret < 0) {
 864                         goto end;
 865                 }
 866
 867                 ret = try_rotate_stream_data(stream);
 868                 if (ret < 0) {
 869                         goto end;
 870                 }
 871         }
 872 end:
 873         return ret;
 874 }
 875
 876 void try_stream_close(struct relay_stream *stream)
 877 {
 878         bool session_aborted;
 879         struct relay_session *session = stream->trace->session;
 880
 881         DBG("Trying to close stream %" PRIu64, stream->stream_handle);
 882
 883         pthread_mutex_lock(&session->lock);
 884         session_aborted = session->aborted;
 885         pthread_mutex_unlock(&session->lock);
 886
 887         pthread_mutex_lock(&stream->lock);
 888         /*
 889          * Can be called concurently by connection close and reception of last
 890          * pending data.
 891          */
 892         if (stream->closed) {
 893                 pthread_mutex_unlock(&stream->lock);
 894                 DBG("closing stream %" PRIu64 " aborted since it is already marked as closed",
 895                     stream->stream_handle);
 896                 return;
 897         }
 898
 899         stream->close_requested = true;
 900
 901         if (stream->last_net_seq_num == -1ULL) {
 902                 /*
 903                  * Handle connection close without explicit stream close
 904                  * command.
 905                  *
 906                  * We can be clever about indexes partially received in
 907                  * cases where we received the data socket part, but not
 908                  * the control socket part: since we're currently closing
 909                  * the stream on behalf of the control socket, we *know*
 910                  * there won't be any more control information for this
 911                  * socket. Therefore, we can destroy all indexes for
 912                  * which we have received only the file descriptor (from
 913                  * data socket). This takes care of consumerd crashes
 914                  * between sending the data and control information for
 915                  * a packet. Since those are sent in that order, we take
 916                  * care of consumerd crashes.
 917                  */
 918                 DBG("relay_index_close_partial_fd");
 919                 relay_index_close_partial_fd(stream);
 920                 /*
 921                  * Use the highest net_seq_num we currently have pending
 922                  * As end of stream indicator.  Leave last_net_seq_num
 923                  * at -1ULL if we cannot find any index.
 924                  */
 925                 stream->last_net_seq_num = relay_index_find_last(stream);
 926                 DBG("Updating stream->last_net_seq_num to %" PRIu64, stream->last_net_seq_num);
 927                 /* Fall-through into the next check. */
 928         }
 929
 930         if (stream->last_net_seq_num != -1ULL &&
 931             ((int64_t) (stream->prev_data_seq - stream->last_net_seq_num)) < 0 &&
 932             !session_aborted) {
 933                 /*
 934                  * Don't close since we still have data pending. This
 935                  * handles cases where an explicit close command has
 936                  * been received for this stream, and cases where the
 937                  * connection has been closed, and we are awaiting for
 938                  * index information from the data socket. It is
 939                  * therefore expected that all the index fd information
 940                  * we need has already been received on the control
 941                  * socket. Matching index information from data socket
 942                  * should be Expected Soon(TM).
 943                  *
 944                  * TODO: We should implement a timer to garbage collect
 945                  * streams after a timeout to be resilient against a
 946                  * consumerd implementation that would not match this
 947                  * expected behavior.
 948                  */
 949                 pthread_mutex_unlock(&stream->lock);
 950                 DBG("closing stream %" PRIu64 " aborted since it still has data pending",
 951                     stream->stream_handle);
 952                 return;
 953         }
 954         /*
 955          * We received all the indexes we can expect.
 956          */
 957         stream_unpublish(stream);
 958         stream->closed = true;
 959         /* Relay indexes are only used by the "consumer/sessiond" end. */
 960         relay_index_close_all(stream);
 961
 962         /*
 963          * If we are closed by an application exiting (per-pid buffers),
 964          * we need to put our reference on the stream trace chunk right
 965          * away, because otherwise still holding the reference on the
 966          * trace chunk could allow a viewer stream (which holds a reference
 967          * to the stream) to postpone destroy waiting for the chunk to cease
 968          * to exist endlessly until the viewer is detached.
 969          */
 970
 971         /* Put stream fd before put chunk. */
 972         if (stream->file) {
 973                 fs_handle_close(stream->file);
 974                 stream->file = nullptr;
 975         }
 976         if (stream->index_file) {
 977                 lttng_index_file_put(stream->index_file);
 978                 stream->index_file = nullptr;
 979         }
 980         lttng_trace_chunk_put(stream->trace_chunk);
 981         stream->trace_chunk = nullptr;
 982         pthread_mutex_unlock(&stream->lock);
 983         DBG("Succeeded in closing stream %" PRIu64, stream->stream_handle);
 984         stream_put(stream);
 985 }
 986
 987 int stream_init_packet(struct relay_stream *stream, size_t packet_size, bool *file_rotated)
 988 {
 989         int ret = 0;
 990
 991         ASSERT_LOCKED(stream->lock);
 992
 993         if (!stream->file || !stream->trace_chunk) {
 994                 ERR("Protocol error: received a packet for a stream that doesn't have a current trace chunk: stream_id = %" PRIu64
 995                     ", channel_name = %s",
 996                     stream->stream_handle,
 997                     stream->channel_name);
 998                 ret = -1;
 999                 goto end;
1000         }
1001
1002         if (caa_likely(stream->tracefile_size == 0)) {
1003                 /* No size limit set; nothing to check. */
1004                 goto end;
1005         }
1006
1007         /*
1008          * Check if writing the new packet would exceed the maximal file size.
1009          */
1010         if (caa_unlikely((stream->tracefile_size_current + packet_size) > stream->tracefile_size)) {
1011                 const uint64_t new_file_index =
1012                         (stream->tracefile_current_index + 1) % stream->tracefile_count;
1013
1014                 if (new_file_index < stream->tracefile_current_index) {
1015                         stream->tracefile_wrapped_around = true;
1016                 }
1017                 DBG("New stream packet causes stream file rotation: stream_id = %" PRIu64
1018                     ", current_file_size = %" PRIu64
1019                     ", packet_size = %zu, current_file_index = %" PRIu64
1020                     " new_file_index = %" PRIu64,
1021                     stream->stream_handle,
1022                     stream->tracefile_size_current,
1023                     packet_size,
1024                     stream->tracefile_current_index,
1025                     new_file_index);
1026                 tracefile_array_file_rotate(stream->tfa, TRACEFILE_ROTATE_WRITE);
1027                 stream->tracefile_current_index = new_file_index;
1028
1029                 if (stream->file) {
1030                         fs_handle_close(stream->file);
1031                         stream->file = nullptr;
1032                 }
1033                 ret = stream_create_data_output_file_from_trace_chunk(
1034                         stream, stream->trace_chunk, false, &stream->file);
1035                 if (ret) {
1036                         ERR("Failed to perform trace file rotation of stream %" PRIu64,
1037                             stream->stream_handle);
1038                         goto end;
1039                 }
1040
1041                 /*
1042                  * Reset current size because we just performed a stream
1043                  * rotation.
1044                  */
1045                 DBG("%s: reset tracefile_size_current for stream %" PRIu64 " was %" PRIu64,
1046                     __func__,
1047                     stream->stream_handle,
1048                     stream->tracefile_size_current);
1049                 stream->tracefile_size_current = 0;
1050                 *file_rotated = true;
1051         } else {
1052                 *file_rotated = false;
1053         }
1054 end:
1055         return ret;
1056 }
1057
1058 /* Note that the packet is not necessarily complete. */
1059 int stream_write(struct relay_stream *stream,
1060                  const struct lttng_buffer_view *packet,
1061                  size_t padding_len)
1062 {
1063         int ret = 0;
1064         ssize_t write_ret;
1065         size_t padding_to_write = padding_len;
1066         char padding_buffer[FILE_IO_STACK_BUFFER_SIZE];
1067
1068         ASSERT_LOCKED(stream->lock);
1069         memset(padding_buffer, 0, std::min(sizeof(padding_buffer), padding_to_write));
1070
1071         if (!stream->file || !stream->trace_chunk) {
1072                 ERR("Protocol error: received a packet for a stream that doesn't have a current trace chunk: stream_id = %" PRIu64
1073                     ", channel_name = %s",
1074                     stream->stream_handle,
1075                     stream->channel_name);
1076                 ret = -1;
1077                 goto end;
1078         }
1079         if (packet) {
1080                 write_ret = fs_handle_write(stream->file, packet->data, packet->size);
1081                 if (write_ret != packet->size) {
1082                         PERROR("Failed to write to stream file of %sstream %" PRIu64,
1083                                stream->is_metadata ? "metadata " : "",
1084                                stream->stream_handle);
1085                         ret = -1;
1086                         goto end;
1087                 }
1088         }
1089
1090         while (padding_to_write > 0) {
1091                 const size_t padding_to_write_this_pass =
1092                         std::min(padding_to_write, sizeof(padding_buffer));
1093
1094                 write_ret =
1095                         fs_handle_write(stream->file, padding_buffer, padding_to_write_this_pass);
1096                 if (write_ret != padding_to_write_this_pass) {
1097                         PERROR("Failed to write padding to file of %sstream %" PRIu64,
1098                                stream->is_metadata ? "metadata " : "",
1099                                stream->stream_handle);
1100                         ret = -1;
1101                         goto end;
1102                 }
1103                 padding_to_write -= padding_to_write_this_pass;
1104         }
1105
1106         if (stream->is_metadata) {
1107                 size_t recv_len;
1108
1109                 recv_len = packet ? packet->size : 0;
1110                 recv_len += padding_len;
1111                 stream->metadata_received += recv_len;
1112                 if (recv_len) {
1113                         stream->no_new_metadata_notified = false;
1114                 }
1115         }
1116
1117         DBG("Wrote to %sstream %" PRIu64 ": data_length = %zu, padding_length = %zu",
1118             stream->is_metadata ? "metadata " : "",
1119             stream->stream_handle,
1120             packet ? packet->size : (size_t) 0,
1121             padding_len);
1122 end:
1123         return ret;
1124 }
1125
1126 /*
1127  * Update index after receiving a packet for a data stream.
1128  *
1129  * Called with the stream lock held.
1130  *
1131  * Return 0 on success else a negative value.
1132  */
1133 int stream_update_index(struct relay_stream *stream,
1134                         uint64_t net_seq_num,
1135                         bool rotate_index,
1136                         bool *flushed,
1137                         uint64_t total_size)
1138 {
1139         int ret = 0;
1140         uint64_t data_offset;
1141         struct relay_index *index;
1142
1143         LTTNG_ASSERT(stream->trace_chunk);
1144         ASSERT_LOCKED(stream->lock);
1145         /* Get data offset because we are about to update the index. */
1146         data_offset = htobe64(stream->tracefile_size_current);
1147
1148         DBG("handle_index_data: stream %" PRIu64 " net_seq_num %" PRIu64 " data offset %" PRIu64,
1149             stream->stream_handle,
1150             net_seq_num,
1151             stream->tracefile_size_current);
1152
1153         /*
1154          * Lookup for an existing index for that stream id/sequence
1155          * number. If it exists, the control thread has already received the
1156          * data for it, thus we need to write it to disk.
1157          */
1158         index = relay_index_get_by_id_or_create(stream, net_seq_num);
1159         if (!index) {
1160                 ret = -1;
1161                 goto end;
1162         }
1163
1164         if (rotate_index || !stream->index_file) {
1165                 ret = create_index_file(stream, stream->trace_chunk);
1166                 if (ret) {
1167                         ERR("Failed to create index file for stream %" PRIu64,
1168                             stream->stream_handle);
1169                         /* Put self-ref for this index due to error. */
1170                         relay_index_put(index);
1171                         index = nullptr;
1172                         goto end;
1173                 }
1174         }
1175
1176         if (relay_index_set_file(index, stream->index_file, data_offset)) {
1177                 ret = -1;
1178                 /* Put self-ref for this index due to error. */
1179                 relay_index_put(index);
1180                 index = nullptr;
1181                 goto end;
1182         }
1183
1184         ret = relay_index_try_flush(index);
1185         if (ret == 0) {
1186                 tracefile_array_file_rotate(stream->tfa, TRACEFILE_ROTATE_READ);
1187                 tracefile_array_commit_seq(stream->tfa, stream->index_received_seqcount);
1188                 stream->index_received_seqcount++;
1189                 LTTNG_OPTIONAL_SET(&stream->received_packet_seq_num,
1190                                    be64toh(index->index_data.packet_seq_num));
1191                 *flushed = true;
1192         } else if (ret > 0) {
1193                 index->total_size = total_size;
1194                 /* No flush. */
1195                 ret = 0;
1196         } else {
1197                 /*
1198                  * ret < 0
1199                  *
1200                  * relay_index_try_flush is responsible for the self-reference
1201                  * put of the index object on error.
1202                  */
1203                 ERR("relay_index_try_flush error %d", ret);
1204                 ret = -1;
1205         }
1206 end:
1207         return ret;
1208 }
1209
1210 int stream_complete_packet(struct relay_stream *stream,
1211                            size_t packet_total_size,
1212                            uint64_t sequence_number,
1213                            bool index_flushed)
1214 {
1215         int ret = 0;
1216
1217         ASSERT_LOCKED(stream->lock);
1218
1219         stream->tracefile_size_current += packet_total_size;
1220         if (index_flushed) {
1221                 stream->pos_after_last_complete_data_index = stream->tracefile_size_current;
1222                 stream->prev_index_seq = sequence_number;
1223                 ret = try_rotate_stream_index(stream);
1224                 if (ret < 0) {
1225                         goto end;
1226                 }
1227         }
1228
1229         stream->prev_data_seq = sequence_number;
1230         ret = try_rotate_stream_data(stream);
1231
1232 end:
1233         return ret;
1234 }
1235
1236 int stream_add_index(struct relay_stream *stream, const struct lttcomm_relayd_index *index_info)
1237 {
1238         int ret = 0;
1239         struct relay_index *index;
1240
1241         ASSERT_LOCKED(stream->lock);
1242
1243         DBG("stream_add_index for stream %" PRIu64, stream->stream_handle);
1244
1245         /* Live beacon handling */
1246         if (index_info->packet_size == 0) {
1247                 DBG("Received live beacon for stream %" PRIu64, stream->stream_handle);
1248
1249                 /*
1250                  * Only flag a stream inactive when it has already
1251                  * received data and no indexes are in flight.
1252                  */
1253                 if (stream->index_received_seqcount > 0 && stream->indexes_in_flight == 0) {
1254                         stream->beacon_ts_end = index_info->timestamp_end;
1255                 }
1256                 ret = 0;
1257                 goto end;
1258         } else {
1259                 stream->beacon_ts_end = -1ULL;
1260         }
1261
1262         if (stream->ctf_stream_id == -1ULL) {
1263                 stream->ctf_stream_id = index_info->stream_id;
1264         }
1265
1266         index = relay_index_get_by_id_or_create(stream, index_info->net_seq_num);
1267         if (!index) {
1268                 ret = -1;
1269                 ERR("Failed to get or create index %" PRIu64, index_info->net_seq_num);
1270                 goto end;
1271         }
1272         if (relay_index_set_control_data(index, index_info, stream->trace->session->minor)) {
1273                 ERR("set_index_control_data error");
1274                 relay_index_put(index);
1275                 ret = -1;
1276                 goto end;
1277         }
1278         ret = relay_index_try_flush(index);
1279         if (ret == 0) {
1280                 tracefile_array_file_rotate(stream->tfa, TRACEFILE_ROTATE_READ);
1281                 tracefile_array_commit_seq(stream->tfa, stream->index_received_seqcount);
1282                 stream->index_received_seqcount++;
1283                 stream->pos_after_last_complete_data_index += index->total_size;
1284                 stream->prev_index_seq = index_info->net_seq_num;
1285                 LTTNG_OPTIONAL_SET(&stream->received_packet_seq_num, index_info->packet_seq_num);
1286
1287                 ret = try_rotate_stream_index(stream);
1288                 if (ret < 0) {
1289                         goto end;
1290                 }
1291                 ret = try_rotate_stream_data(stream);
1292                 if (ret < 0) {
1293                         goto end;
1294                 }
1295         } else if (ret > 0) {
1296                 /* no flush. */
1297                 ret = 0;
1298         } else {
1299                 /*
1300                  * ret < 0
1301                  *
1302                  * relay_index_try_flush is responsible for the self-reference
1303                  * put of the index object on error.
1304                  */
1305                 ERR("relay_index_try_flush error %d", ret);
1306                 ret = -1;
1307         }
1308 end:
1309         return ret;
1310 }
1311
1312 static void print_stream_indexes(struct relay_stream *stream)
1313 {
1314         struct lttng_ht_iter iter;
1315         struct relay_index *index;
1316
1317         {
1318                 lttng::urcu::read_lock_guard read_lock;
1319
1320                 cds_lfht_for_each_entry (stream->indexes_ht->ht, &iter.iter, index, index_n.node) {
1321                         DBG("index %p net_seq_num %" PRIu64 " refcount %ld"
1322                             " stream %" PRIu64 " trace %" PRIu64 " session %" PRIu64,
1323                             index,
1324                             index->index_n.key,
1325                             stream->ref.refcount,
1326                             index->stream->stream_handle,
1327                             index->stream->trace->id,
1328                             index->stream->trace->session->id);
1329                 }
1330         }
1331 }
1332
1333 int stream_reset_file(struct relay_stream *stream)
1334 {
1335         ASSERT_LOCKED(stream->lock);
1336
1337         if (stream->file) {
1338                 int ret;
1339
1340                 ret = fs_handle_close(stream->file);
1341                 if (ret) {
1342                         ERR("Failed to close stream file handle: channel name = \"%s\", id = %" PRIu64,
1343                             stream->channel_name,
1344                             stream->stream_handle);
1345                 }
1346                 stream->file = nullptr;
1347         }
1348
1349         DBG("%s: reset tracefile_size_current for stream %" PRIu64 " was %" PRIu64,
1350             __func__,
1351             stream->stream_handle,
1352             stream->tracefile_size_current);
1353         stream->tracefile_size_current = 0;
1354         stream->prev_data_seq = 0;
1355         stream->prev_index_seq = 0;
1356         /* Note that this does not reset the tracefile array. */
1357         stream->tracefile_current_index = 0;
1358         stream->pos_after_last_complete_data_index = 0;
1359
1360         return stream_create_data_output_file_from_trace_chunk(
1361                 stream, stream->trace_chunk, true, &stream->file);
1362 }
1363
1364 void print_relay_streams()
1365 {
1366         struct lttng_ht_iter iter;
1367         struct relay_stream *stream;
1368
1369         if (!relay_streams_ht) {
1370                 return;
1371         }
1372
1373         {
1374                 lttng::urcu::read_lock_guard read_lock;
1375
1376                 cds_lfht_for_each_entry (relay_streams_ht->ht, &iter.iter, stream, node.node) {
1377                         if (!stream_get(stream)) {
1378                                 continue;
1379                         }
1380
1381                         DBG("stream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
1382                             " session %" PRIu64,
1383                             stream,
1384                             stream->ref.refcount,
1385                             stream->stream_handle,
1386                             stream->trace->id,
1387                             stream->trace->session->id);
1388                         print_stream_indexes(stream);
1389                         stream_put(stream);
1390                 }
1391         }
1392 }