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