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