src/bin/lttng-relayd/stream.c

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *               2015 - Mathieu Desnoyers <mathieu.desnoyers@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 <common/common.h>
  22 #include <common/utils.h>
  23 #include <common/defaults.h>
  24 #include <urcu/rculist.h>
  25 #include <sys/stat.h>
  26
  27 #include "lttng-relayd.h"
  28 #include "index.h"
  29 #include "stream.h"
  30 #include "viewer-stream.h"
  31
  32 /* Should be called with RCU read-side lock held. */
  33 bool stream_get(struct relay_stream *stream)
  34 {
  35         return urcu_ref_get_unless_zero(&stream->ref);
  36 }
  37
  38 /*
  39  * Get stream from stream id from the streams hash table. Return stream
  40  * if found else NULL. A stream reference is taken when a stream is
  41  * returned. stream_put() must be called on that stream.
  42  */
  43 struct relay_stream *stream_get_by_id(uint64_t stream_id)
  44 {
  45         struct lttng_ht_node_u64 *node;
  46         struct lttng_ht_iter iter;
  47         struct relay_stream *stream = NULL;
  48
  49         rcu_read_lock();
  50         lttng_ht_lookup(relay_streams_ht, &stream_id, &iter);
  51         node = lttng_ht_iter_get_node_u64(&iter);
  52         if (!node) {
  53                 DBG("Relay stream %" PRIu64 " not found", stream_id);
  54                 goto end;
  55         }
  56         stream = caa_container_of(node, struct relay_stream, node);
  57         if (!stream_get(stream)) {
  58                 stream = NULL;
  59         }
  60 end:
  61         rcu_read_unlock();
  62         return stream;
  63 }
  64
  65 /*
  66  * We keep ownership of path_name and channel_name.
  67  */
  68 struct relay_stream *stream_create(struct ctf_trace *trace,
  69         uint64_t stream_handle, char *path_name,
  70         char *channel_name, uint64_t tracefile_size,
  71         uint64_t tracefile_count,
  72         const struct relay_stream_chunk_id *chunk_id)
  73 {
  74         int ret;
  75         struct relay_stream *stream = NULL;
  76         struct relay_session *session = trace->session;
  77
  78         stream = zmalloc(sizeof(struct relay_stream));
  79         if (stream == NULL) {
  80                 PERROR("relay stream zmalloc");
  81                 goto error_no_alloc;
  82         }
  83
  84         stream->stream_handle = stream_handle;
  85         stream->prev_data_seq = -1ULL;
  86         stream->prev_index_seq = -1ULL;
  87         stream->last_net_seq_num = -1ULL;
  88         stream->ctf_stream_id = -1ULL;
  89         stream->tracefile_size = tracefile_size;
  90         stream->tracefile_count = tracefile_count;
  91         stream->path_name = path_name;
  92         stream->prev_path_name = NULL;
  93         stream->channel_name = channel_name;
  94         stream->rotate_at_seq_num = -1ULL;
  95         stream->beacon_ts_end = -1ULL;
  96         lttng_ht_node_init_u64(&stream->node, stream->stream_handle);
  97         pthread_mutex_init(&stream->lock, NULL);
  98         urcu_ref_init(&stream->ref);
  99         ctf_trace_get(trace);
 100         stream->trace = trace;
 101         stream->current_chunk_id = *chunk_id;
 102
 103         stream->indexes_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 104         if (!stream->indexes_ht) {
 105                 ERR("Cannot created indexes_ht");
 106                 ret = -1;
 107                 goto end;
 108         }
 109
 110         ret = utils_mkdir_recursive(stream->path_name, S_IRWXU | S_IRWXG,
 111                         -1, -1);
 112         if (ret < 0) {
 113                 ERR("relay creating output directory");
 114                 goto end;
 115         }
 116
 117         /*
 118          * No need to use run_as API here because whatever we receive,
 119          * the relayd uses its own credentials for the stream files.
 120          */
 121         ret = utils_create_stream_file(stream->path_name, stream->channel_name,
 122                         stream->tracefile_size, 0, -1, -1, NULL);
 123         if (ret < 0) {
 124                 ERR("Create output file");
 125                 goto end;
 126         }
 127         stream->stream_fd = stream_fd_create(ret);
 128         if (!stream->stream_fd) {
 129                 if (close(ret)) {
 130                         PERROR("Error closing file %d", ret);
 131                 }
 132                 ret = -1;
 133                 goto end;
 134         }
 135         stream->tfa = tracefile_array_create(stream->tracefile_count);
 136         if (!stream->tfa) {
 137                 ret = -1;
 138                 goto end;
 139         }
 140         if (stream->tracefile_size) {
 141                 DBG("Tracefile %s/%s_0 created", stream->path_name, stream->channel_name);
 142         } else {
 143                 DBG("Tracefile %s/%s created", stream->path_name, stream->channel_name);
 144         }
 145
 146         if (!strncmp(stream->channel_name, DEFAULT_METADATA_NAME, LTTNG_NAME_MAX)) {
 147                 stream->is_metadata = 1;
 148         }
 149
 150         stream->in_recv_list = true;
 151
 152         /*
 153          * Add the stream in the recv list of the session. Once the end stream
 154          * message is received, all session streams are published.
 155          */
 156         pthread_mutex_lock(&session->recv_list_lock);
 157         cds_list_add_rcu(&stream->recv_node, &session->recv_list);
 158         session->stream_count++;
 159         pthread_mutex_unlock(&session->recv_list_lock);
 160
 161         /*
 162          * Both in the ctf_trace object and the global stream ht since the data
 163          * side of the relayd does not have the concept of session.
 164          */
 165         lttng_ht_add_unique_u64(relay_streams_ht, &stream->node);
 166         stream->in_stream_ht = true;
 167
 168         DBG("Relay new stream added %s with ID %" PRIu64, stream->channel_name,
 169                         stream->stream_handle);
 170         ret = 0;
 171
 172 end:
 173         if (ret) {
 174                 if (stream->stream_fd) {
 175                         stream_fd_put(stream->stream_fd);
 176                         stream->stream_fd = NULL;
 177                 }
 178                 stream_put(stream);
 179                 stream = NULL;
 180         }
 181         return stream;
 182
 183 error_no_alloc:
 184         /*
 185          * path_name and channel_name need to be freed explicitly here
 186          * because we cannot rely on stream_put().
 187          */
 188         free(path_name);
 189         free(channel_name);
 190         return NULL;
 191 }
 192
 193 /*
 194  * Called with the session lock held.
 195  */
 196 void stream_publish(struct relay_stream *stream)
 197 {
 198         struct relay_session *session;
 199
 200         pthread_mutex_lock(&stream->lock);
 201         if (stream->published) {
 202                 goto unlock;
 203         }
 204
 205         session = stream->trace->session;
 206
 207         pthread_mutex_lock(&session->recv_list_lock);
 208         if (stream->in_recv_list) {
 209                 cds_list_del_rcu(&stream->recv_node);
 210                 stream->in_recv_list = false;
 211         }
 212         pthread_mutex_unlock(&session->recv_list_lock);
 213
 214         pthread_mutex_lock(&stream->trace->stream_list_lock);
 215         cds_list_add_rcu(&stream->stream_node, &stream->trace->stream_list);
 216         pthread_mutex_unlock(&stream->trace->stream_list_lock);
 217
 218         stream->published = true;
 219 unlock:
 220         pthread_mutex_unlock(&stream->lock);
 221 }
 222
 223 /*
 224  * Stream must be protected by holding the stream lock or by virtue of being
 225  * called from stream_destroy.
 226  */
 227 static void stream_unpublish(struct relay_stream *stream)
 228 {
 229         if (stream->in_stream_ht) {
 230                 struct lttng_ht_iter iter;
 231                 int ret;
 232
 233                 iter.iter.node = &stream->node.node;
 234                 ret = lttng_ht_del(relay_streams_ht, &iter);
 235                 assert(!ret);
 236                 stream->in_stream_ht = false;
 237         }
 238         if (stream->published) {
 239                 pthread_mutex_lock(&stream->trace->stream_list_lock);
 240                 cds_list_del_rcu(&stream->stream_node);
 241                 pthread_mutex_unlock(&stream->trace->stream_list_lock);
 242                 stream->published = false;
 243         }
 244 }
 245
 246 static void stream_destroy(struct relay_stream *stream)
 247 {
 248         if (stream->indexes_ht) {
 249                 /*
 250                  * Calling lttng_ht_destroy in call_rcu worker thread so
 251                  * we don't hold the RCU read-side lock while calling
 252                  * it.
 253                  */
 254                 lttng_ht_destroy(stream->indexes_ht);
 255         }
 256         if (stream->tfa) {
 257                 tracefile_array_destroy(stream->tfa);
 258         }
 259         free(stream->path_name);
 260         free(stream->prev_path_name);
 261         free(stream->channel_name);
 262         free(stream);
 263 }
 264
 265 static void stream_destroy_rcu(struct rcu_head *rcu_head)
 266 {
 267         struct relay_stream *stream =
 268                 caa_container_of(rcu_head, struct relay_stream, rcu_node);
 269
 270         stream_destroy(stream);
 271 }
 272
 273 /*
 274  * No need to take stream->lock since this is only called on the final
 275  * stream_put which ensures that a single thread may act on the stream.
 276  */
 277 static void stream_release(struct urcu_ref *ref)
 278 {
 279         struct relay_stream *stream =
 280                 caa_container_of(ref, struct relay_stream, ref);
 281         struct relay_session *session;
 282
 283         session = stream->trace->session;
 284
 285         DBG("Releasing stream id %" PRIu64, stream->stream_handle);
 286
 287         pthread_mutex_lock(&session->recv_list_lock);
 288         session->stream_count--;
 289         if (stream->in_recv_list) {
 290                 cds_list_del_rcu(&stream->recv_node);
 291                 stream->in_recv_list = false;
 292         }
 293         pthread_mutex_unlock(&session->recv_list_lock);
 294
 295         stream_unpublish(stream);
 296
 297         if (stream->stream_fd) {
 298                 stream_fd_put(stream->stream_fd);
 299                 stream->stream_fd = NULL;
 300         }
 301         if (stream->index_file) {
 302                 lttng_index_file_put(stream->index_file);
 303                 stream->index_file = NULL;
 304         }
 305         if (stream->trace) {
 306                 ctf_trace_put(stream->trace);
 307                 stream->trace = NULL;
 308         }
 309
 310         call_rcu(&stream->rcu_node, stream_destroy_rcu);
 311 }
 312
 313 void stream_put(struct relay_stream *stream)
 314 {
 315         DBG("stream put for stream id %" PRIu64, stream->stream_handle);
 316         rcu_read_lock();
 317         assert(stream->ref.refcount != 0);
 318         /*
 319          * Wait until we have processed all the stream packets before
 320          * actually putting our last stream reference.
 321          */
 322         DBG("stream put stream id %" PRIu64 " refcount %d",
 323                         stream->stream_handle,
 324                         (int) stream->ref.refcount);
 325         urcu_ref_put(&stream->ref, stream_release);
 326         rcu_read_unlock();
 327 }
 328
 329 void try_stream_close(struct relay_stream *stream)
 330 {
 331         bool session_aborted;
 332         struct relay_session *session = stream->trace->session;
 333
 334         DBG("Trying to close stream %" PRIu64, stream->stream_handle);
 335
 336         pthread_mutex_lock(&session->lock);
 337         session_aborted = session->aborted;
 338         pthread_mutex_unlock(&session->lock);
 339
 340         pthread_mutex_lock(&stream->lock);
 341         /*
 342          * Can be called concurently by connection close and reception of last
 343          * pending data.
 344          */
 345         if (stream->closed) {
 346                 pthread_mutex_unlock(&stream->lock);
 347                 DBG("closing stream %" PRIu64 " aborted since it is already marked as closed", stream->stream_handle);
 348                 return;
 349         }
 350
 351         stream->close_requested = true;
 352
 353         if (stream->last_net_seq_num == -1ULL) {
 354                 /*
 355                  * Handle connection close without explicit stream close
 356                  * command.
 357                  *
 358                  * We can be clever about indexes partially received in
 359                  * cases where we received the data socket part, but not
 360                  * the control socket part: since we're currently closing
 361                  * the stream on behalf of the control socket, we *know*
 362                  * there won't be any more control information for this
 363                  * socket. Therefore, we can destroy all indexes for
 364                  * which we have received only the file descriptor (from
 365                  * data socket). This takes care of consumerd crashes
 366                  * between sending the data and control information for
 367                  * a packet. Since those are sent in that order, we take
 368                  * care of consumerd crashes.
 369                  */
 370                 DBG("relay_index_close_partial_fd");
 371                 relay_index_close_partial_fd(stream);
 372                 /*
 373                  * Use the highest net_seq_num we currently have pending
 374                  * As end of stream indicator.  Leave last_net_seq_num
 375                  * at -1ULL if we cannot find any index.
 376                  */
 377                 stream->last_net_seq_num = relay_index_find_last(stream);
 378                 DBG("Updating stream->last_net_seq_num to %" PRIu64, stream->last_net_seq_num);
 379                 /* Fall-through into the next check. */
 380         }
 381
 382         if (stream->last_net_seq_num != -1ULL &&
 383                         ((int64_t) (stream->prev_data_seq - stream->last_net_seq_num)) < 0
 384                         && !session_aborted) {
 385                 /*
 386                  * Don't close since we still have data pending. This
 387                  * handles cases where an explicit close command has
 388                  * been received for this stream, and cases where the
 389                  * connection has been closed, and we are awaiting for
 390                  * index information from the data socket. It is
 391                  * therefore expected that all the index fd information
 392                  * we need has already been received on the control
 393                  * socket. Matching index information from data socket
 394                  * should be Expected Soon(TM).
 395                  *
 396                  * TODO: We should implement a timer to garbage collect
 397                  * streams after a timeout to be resilient against a
 398                  * consumerd implementation that would not match this
 399                  * expected behavior.
 400                  */
 401                 pthread_mutex_unlock(&stream->lock);
 402                 DBG("closing stream %" PRIu64 " aborted since it still has data pending", stream->stream_handle);
 403                 return;
 404         }
 405         /*
 406          * We received all the indexes we can expect.
 407          */
 408         stream_unpublish(stream);
 409         stream->closed = true;
 410         /* Relay indexes are only used by the "consumer/sessiond" end. */
 411         relay_index_close_all(stream);
 412         pthread_mutex_unlock(&stream->lock);
 413         DBG("Succeeded in closing stream %" PRIu64, stream->stream_handle);
 414         stream_put(stream);
 415 }
 416
 417 static void print_stream_indexes(struct relay_stream *stream)
 418 {
 419         struct lttng_ht_iter iter;
 420         struct relay_index *index;
 421
 422         rcu_read_lock();
 423         cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter, index,
 424                         index_n.node) {
 425                 DBG("index %p net_seq_num %" PRIu64 " refcount %ld"
 426                                 " stream %" PRIu64 " trace %" PRIu64
 427                                 " session %" PRIu64,
 428                                 index,
 429                                 index->index_n.key,
 430                                 stream->ref.refcount,
 431                                 index->stream->stream_handle,
 432                                 index->stream->trace->id,
 433                                 index->stream->trace->session->id);
 434         }
 435         rcu_read_unlock();
 436 }
 437
 438 void print_relay_streams(void)
 439 {
 440         struct lttng_ht_iter iter;
 441         struct relay_stream *stream;
 442
 443         if (!relay_streams_ht) {
 444                 return;
 445         }
 446
 447         rcu_read_lock();
 448         cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, stream,
 449                         node.node) {
 450                 if (!stream_get(stream)) {
 451                         continue;
 452                 }
 453                 DBG("stream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
 454                                 " session %" PRIu64,
 455                                 stream,
 456                                 stream->ref.refcount,
 457                                 stream->stream_handle,
 458                                 stream->trace->id,
 459                                 stream->trace->session->id);
 460                 print_stream_indexes(stream);
 461                 stream_put(stream);
 462         }
 463         rcu_read_unlock();
 464 }