src/bin/lttng-sessiond/manage-consumer.c

   1 /*
   2  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-only
   7  *
   8  */
   9
  10 #include <signal.h>
  11
  12 #include <common/pipe.h>
  13 #include <common/utils.h>
  14
  15 #include "manage-consumer.h"
  16 #include "testpoint.h"
  17 #include "health-sessiond.h"
  18 #include "utils.h"
  19 #include "thread.h"
  20 #include "ust-consumer.h"
  21
  22 struct thread_notifiers {
  23         struct lttng_pipe *quit_pipe;
  24         struct consumer_data *consumer_data;
  25         sem_t ready;
  26         int initialization_result;
  27 };
  28
  29 static void mark_thread_as_ready(struct thread_notifiers *notifiers)
  30 {
  31         DBG("Marking consumer management thread as ready");
  32         notifiers->initialization_result = 0;
  33         sem_post(&notifiers->ready);
  34 }
  35
  36 static void mark_thread_intialization_as_failed(
  37                 struct thread_notifiers *notifiers)
  38 {
  39         ERR("Consumer management thread entering error state");
  40         notifiers->initialization_result = -1;
  41         sem_post(&notifiers->ready);
  42 }
  43
  44 static void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
  45 {
  46         DBG("Waiting for consumer management thread to be ready");
  47         sem_wait(&notifiers->ready);
  48         DBG("Consumer management thread is ready");
  49 }
  50
  51 /*
  52  * This thread manage the consumer error sent back to the session daemon.
  53  */
  54 static void *thread_consumer_management(void *data)
  55 {
  56         int sock = -1, i, ret, pollfd, err = -1, should_quit = 0;
  57         uint32_t revents, nb_fd;
  58         enum lttcomm_return_code code;
  59         struct lttng_poll_event events;
  60         struct thread_notifiers *notifiers = data;
  61         struct consumer_data *consumer_data = notifiers->consumer_data;
  62         const int quit_pipe_read_fd = lttng_pipe_get_readfd(notifiers->quit_pipe);
  63         struct consumer_socket *cmd_socket_wrapper = NULL;
  64
  65         DBG("[thread] Manage consumer started");
  66
  67         rcu_register_thread();
  68         rcu_thread_online();
  69
  70         health_register(health_sessiond, HEALTH_SESSIOND_TYPE_CONSUMER);
  71
  72         health_code_update();
  73
  74         /*
  75          * Pass 3 as size here for the thread quit pipe, consumerd_err_sock and the
  76          * metadata_sock. Nothing more will be added to this poll set.
  77          */
  78         ret = lttng_poll_create(&events, 3, LTTNG_CLOEXEC);
  79         if (ret < 0) {
  80                 mark_thread_intialization_as_failed(notifiers);
  81                 goto error_poll;
  82         }
  83
  84         ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLERR);
  85         if (ret < 0) {
  86                 mark_thread_intialization_as_failed(notifiers);
  87                 goto error;
  88         }
  89
  90         /*
  91          * The error socket here is already in a listening state which was done
  92          * just before spawning this thread to avoid a race between the consumer
  93          * daemon exec trying to connect and the listen() call.
  94          */
  95         ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
  96         if (ret < 0) {
  97                 mark_thread_intialization_as_failed(notifiers);
  98                 goto error;
  99         }
 100
 101         health_code_update();
 102
 103         /* Infinite blocking call, waiting for transmission */
 104         health_poll_entry();
 105
 106         if (testpoint(sessiond_thread_manage_consumer)) {
 107                 mark_thread_intialization_as_failed(notifiers);
 108                 goto error;
 109         }
 110
 111         ret = lttng_poll_wait(&events, -1);
 112         health_poll_exit();
 113         if (ret < 0) {
 114                 mark_thread_intialization_as_failed(notifiers);
 115                 goto error;
 116         }
 117
 118         nb_fd = ret;
 119
 120         for (i = 0; i < nb_fd; i++) {
 121                 /* Fetch once the poll data */
 122                 revents = LTTNG_POLL_GETEV(&events, i);
 123                 pollfd = LTTNG_POLL_GETFD(&events, i);
 124
 125                 health_code_update();
 126
 127                 /* Thread quit pipe has been closed. Killing thread. */
 128                 if (pollfd == quit_pipe_read_fd) {
 129                         err = 0;
 130                         mark_thread_intialization_as_failed(notifiers);
 131                         goto exit;
 132                 } else if (pollfd == consumer_data->err_sock) {
 133                         /* Event on the registration socket */
 134                         if (revents & LPOLLIN) {
 135                                 continue;
 136                         } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 137                                 ERR("consumer err socket poll error");
 138                                 mark_thread_intialization_as_failed(notifiers);
 139                                 goto error;
 140                         } else {
 141                                 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
 142                                 mark_thread_intialization_as_failed(notifiers);
 143                                 goto error;
 144                         }
 145                 }
 146         }
 147
 148         sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
 149         if (sock < 0) {
 150                 mark_thread_intialization_as_failed(notifiers);
 151                 goto error;
 152         }
 153
 154         /*
 155          * Set the CLOEXEC flag. Return code is useless because either way, the
 156          * show must go on.
 157          */
 158         (void) utils_set_fd_cloexec(sock);
 159
 160         health_code_update();
 161
 162         DBG2("Receiving code from consumer err_sock");
 163
 164         /* Getting status code from kconsumerd */
 165         ret = lttcomm_recv_unix_sock(sock, &code,
 166                         sizeof(enum lttcomm_return_code));
 167         if (ret <= 0) {
 168                 mark_thread_intialization_as_failed(notifiers);
 169                 goto error;
 170         }
 171
 172         health_code_update();
 173         if (code != LTTCOMM_CONSUMERD_COMMAND_SOCK_READY) {
 174                 ERR("consumer error when waiting for SOCK_READY : %s",
 175                                 lttcomm_get_readable_code(-code));
 176                 mark_thread_intialization_as_failed(notifiers);
 177                 goto error;
 178         }
 179
 180         /* Connect both command and metadata sockets. */
 181         consumer_data->cmd_sock =
 182                         lttcomm_connect_unix_sock(
 183                                 consumer_data->cmd_unix_sock_path);
 184         consumer_data->metadata_fd =
 185                         lttcomm_connect_unix_sock(
 186                                 consumer_data->cmd_unix_sock_path);
 187         if (consumer_data->cmd_sock < 0 || consumer_data->metadata_fd < 0) {
 188                 PERROR("consumer connect cmd socket");
 189                 mark_thread_intialization_as_failed(notifiers);
 190                 goto error;
 191         }
 192
 193         consumer_data->metadata_sock.fd_ptr = &consumer_data->metadata_fd;
 194
 195         /* Create metadata socket lock. */
 196         consumer_data->metadata_sock.lock = zmalloc(sizeof(pthread_mutex_t));
 197         if (consumer_data->metadata_sock.lock == NULL) {
 198                 PERROR("zmalloc pthread mutex");
 199                 mark_thread_intialization_as_failed(notifiers);
 200                 goto error;
 201         }
 202         pthread_mutex_init(consumer_data->metadata_sock.lock, NULL);
 203
 204         DBG("Consumer command socket ready (fd: %d)", consumer_data->cmd_sock);
 205         DBG("Consumer metadata socket ready (fd: %d)",
 206                         consumer_data->metadata_fd);
 207
 208         /*
 209          * Remove the consumerd error sock since we've established a connection.
 210          */
 211         ret = lttng_poll_del(&events, consumer_data->err_sock);
 212         if (ret < 0) {
 213                 mark_thread_intialization_as_failed(notifiers);
 214                 goto error;
 215         }
 216
 217         /* Add new accepted error socket. */
 218         ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
 219         if (ret < 0) {
 220                 mark_thread_intialization_as_failed(notifiers);
 221                 goto error;
 222         }
 223
 224         /* Add metadata socket that is successfully connected. */
 225         ret = lttng_poll_add(&events, consumer_data->metadata_fd,
 226                         LPOLLIN | LPOLLRDHUP);
 227         if (ret < 0) {
 228                 mark_thread_intialization_as_failed(notifiers);
 229                 goto error;
 230         }
 231
 232         health_code_update();
 233
 234         /*
 235          * Transfer the write-end of the channel monitoring pipe to the consumer
 236          * by issuing a SET_CHANNEL_MONITOR_PIPE command.
 237          */
 238         cmd_socket_wrapper = consumer_allocate_socket(&consumer_data->cmd_sock);
 239         if (!cmd_socket_wrapper) {
 240                 mark_thread_intialization_as_failed(notifiers);
 241                 goto error;
 242         }
 243         cmd_socket_wrapper->lock = &consumer_data->lock;
 244
 245         pthread_mutex_lock(cmd_socket_wrapper->lock);
 246         ret = consumer_init(cmd_socket_wrapper, sessiond_uuid);
 247         if (ret) {
 248                 ERR("Failed to send sessiond uuid to consumer daemon");
 249                 mark_thread_intialization_as_failed(notifiers);
 250                 pthread_mutex_unlock(cmd_socket_wrapper->lock);
 251                 goto error;
 252         }
 253         pthread_mutex_unlock(cmd_socket_wrapper->lock);
 254
 255         ret = consumer_send_channel_monitor_pipe(cmd_socket_wrapper,
 256                         consumer_data->channel_monitor_pipe);
 257         if (ret) {
 258                 mark_thread_intialization_as_failed(notifiers);
 259                 goto error;
 260         }
 261
 262         /* Discard the socket wrapper as it is no longer needed. */
 263         consumer_destroy_socket(cmd_socket_wrapper);
 264         cmd_socket_wrapper = NULL;
 265
 266         /* The thread is completely initialized, signal that it is ready. */
 267         mark_thread_as_ready(notifiers);
 268
 269         /* Infinite blocking call, waiting for transmission */
 270         while (1) {
 271                 health_code_update();
 272
 273                 /* Exit the thread because the thread quit pipe has been triggered. */
 274                 if (should_quit) {
 275                         /* Not a health error. */
 276                         err = 0;
 277                         goto exit;
 278                 }
 279
 280                 health_poll_entry();
 281                 ret = lttng_poll_wait(&events, -1);
 282                 health_poll_exit();
 283                 if (ret < 0) {
 284                         goto error;
 285                 }
 286
 287                 nb_fd = ret;
 288
 289                 for (i = 0; i < nb_fd; i++) {
 290                         /* Fetch once the poll data */
 291                         revents = LTTNG_POLL_GETEV(&events, i);
 292                         pollfd = LTTNG_POLL_GETFD(&events, i);
 293
 294                         health_code_update();
 295
 296                         /*
 297                          * Thread quit pipe has been triggered, flag that we should stop
 298                          * but continue the current loop to handle potential data from
 299                          * consumer.
 300                          */
 301                         if (pollfd == quit_pipe_read_fd) {
 302                                 should_quit = 1;
 303                         } else if (pollfd == sock) {
 304                                 /* Event on the consumerd socket */
 305                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)
 306                                                 && !(revents & LPOLLIN)) {
 307                                         ERR("consumer err socket second poll error");
 308                                         goto error;
 309                                 }
 310                                 health_code_update();
 311                                 /* Wait for any kconsumerd error */
 312                                 ret = lttcomm_recv_unix_sock(sock, &code,
 313                                                 sizeof(enum lttcomm_return_code));
 314                                 if (ret <= 0) {
 315                                         ERR("consumer closed the command socket");
 316                                         goto error;
 317                                 }
 318
 319                                 ERR("consumer return code : %s",
 320                                                 lttcomm_get_readable_code(-code));
 321
 322                                 goto exit;
 323                         } else if (pollfd == consumer_data->metadata_fd) {
 324                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)
 325                                                 && !(revents & LPOLLIN)) {
 326                                         ERR("consumer err metadata socket second poll error");
 327                                         goto error;
 328                                 }
 329                                 /* UST metadata requests */
 330                                 ret = ust_consumer_metadata_request(
 331                                                 &consumer_data->metadata_sock);
 332                                 if (ret < 0) {
 333                                         ERR("Handling metadata request");
 334                                         goto error;
 335                                 }
 336                         }
 337                         /* No need for an else branch all FDs are tested prior. */
 338                 }
 339                 health_code_update();
 340         }
 341
 342 exit:
 343 error:
 344         /*
 345          * We lock here because we are about to close the sockets and some other
 346          * thread might be using them so get exclusive access which will abort all
 347          * other consumer command by other threads.
 348          */
 349         pthread_mutex_lock(&consumer_data->lock);
 350
 351         /* Immediately set the consumerd state to stopped */
 352         if (consumer_data->type == LTTNG_CONSUMER_KERNEL) {
 353                 uatomic_set(&kernel_consumerd_state, CONSUMER_ERROR);
 354         } else if (consumer_data->type == LTTNG_CONSUMER64_UST ||
 355                         consumer_data->type == LTTNG_CONSUMER32_UST) {
 356                 uatomic_set(&ust_consumerd_state, CONSUMER_ERROR);
 357         } else {
 358                 /* Code flow error... */
 359                 assert(0);
 360         }
 361
 362         if (consumer_data->err_sock >= 0) {
 363                 ret = close(consumer_data->err_sock);
 364                 if (ret) {
 365                         PERROR("close");
 366                 }
 367                 consumer_data->err_sock = -1;
 368         }
 369         if (consumer_data->cmd_sock >= 0) {
 370                 ret = close(consumer_data->cmd_sock);
 371                 if (ret) {
 372                         PERROR("close");
 373                 }
 374                 consumer_data->cmd_sock = -1;
 375         }
 376         if (consumer_data->metadata_sock.fd_ptr &&
 377             *consumer_data->metadata_sock.fd_ptr >= 0) {
 378                 ret = close(*consumer_data->metadata_sock.fd_ptr);
 379                 if (ret) {
 380                         PERROR("close");
 381                 }
 382         }
 383         if (sock >= 0) {
 384                 ret = close(sock);
 385                 if (ret) {
 386                         PERROR("close");
 387                 }
 388         }
 389
 390         unlink(consumer_data->err_unix_sock_path);
 391         unlink(consumer_data->cmd_unix_sock_path);
 392         pthread_mutex_unlock(&consumer_data->lock);
 393
 394         /* Cleanup metadata socket mutex. */
 395         if (consumer_data->metadata_sock.lock) {
 396                 pthread_mutex_destroy(consumer_data->metadata_sock.lock);
 397                 free(consumer_data->metadata_sock.lock);
 398         }
 399         lttng_poll_clean(&events);
 400
 401         if (cmd_socket_wrapper) {
 402                 consumer_destroy_socket(cmd_socket_wrapper);
 403         }
 404 error_poll:
 405         if (err) {
 406                 health_error();
 407                 ERR("Health error occurred in %s", __func__);
 408         }
 409         health_unregister(health_sessiond);
 410         DBG("consumer thread cleanup completed");
 411
 412         rcu_thread_offline();
 413         rcu_unregister_thread();
 414
 415         return NULL;
 416 }
 417
 418 static bool shutdown_consumer_management_thread(void *data)
 419 {
 420         struct thread_notifiers *notifiers = data;
 421         const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
 422
 423         return notify_thread_pipe(write_fd) == 1;
 424 }
 425
 426 static void cleanup_consumer_management_thread(void *data)
 427 {
 428         struct thread_notifiers *notifiers = data;
 429
 430         lttng_pipe_destroy(notifiers->quit_pipe);
 431         free(notifiers);
 432 }
 433
 434 bool launch_consumer_management_thread(struct consumer_data *consumer_data)
 435 {
 436         struct lttng_pipe *quit_pipe;
 437         struct thread_notifiers *notifiers = NULL;
 438         struct lttng_thread *thread;
 439
 440         notifiers = zmalloc(sizeof(*notifiers));
 441         if (!notifiers) {
 442                 goto error_alloc;
 443         }
 444
 445         quit_pipe = lttng_pipe_open(FD_CLOEXEC);
 446         if (!quit_pipe) {
 447                 goto error;
 448         }
 449         notifiers->quit_pipe = quit_pipe;
 450         notifiers->consumer_data = consumer_data;
 451         sem_init(&notifiers->ready, 0, 0);
 452
 453         thread = lttng_thread_create("Consumer management",
 454                         thread_consumer_management,
 455                         shutdown_consumer_management_thread,
 456                         cleanup_consumer_management_thread,
 457                         notifiers);
 458         if (!thread) {
 459                 goto error;
 460         }
 461         wait_until_thread_is_ready(notifiers);
 462         lttng_thread_put(thread);
 463         if (notifiers->initialization_result) {
 464                 return false;
 465         }
 466         return true;
 467 error:
 468         cleanup_consumer_management_thread(notifiers);
 469 error_alloc:
 470         return false;
 471 }