src/bin/lttng-sessiond/rotation-thread.c

   1 /*
   2  * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <lttng/trigger/trigger.h>
  20 #include <common/error.h>
  21 #include <common/config/session-config.h>
  22 #include <common/defaults.h>
  23 #include <common/utils.h>
  24 #include <common/futex.h>
  25 #include <common/align.h>
  26 #include <common/time.h>
  27 #include <common/hashtable/utils.h>
  28 #include <sys/eventfd.h>
  29 #include <sys/stat.h>
  30 #include <time.h>
  31 #include <signal.h>
  32 #include <inttypes.h>
  33
  34 #include <common/kernel-ctl/kernel-ctl.h>
  35 #include "rotation-thread.h"
  36 #include "lttng-sessiond.h"
  37 #include "health-sessiond.h"
  38 #include "rotate.h"
  39 #include "cmd.h"
  40
  41 #include <urcu.h>
  42 #include <urcu/list.h>
  43 #include <urcu/rculfhash.h>
  44
  45 struct cds_lfht *channel_pending_rotate_ht;
  46
  47 static
  48 void channel_rotation_info_destroy(struct rotation_channel_info *channel_info)
  49 {
  50         assert(channel_info);
  51         free(channel_info);
  52 }
  53
  54 static
  55 int match_channel_info(struct cds_lfht_node *node, const void *key)
  56 {
  57         struct rotation_channel_key *channel_key = (struct rotation_channel_key *) key;
  58         struct rotation_channel_info *channel_info;
  59
  60         channel_info = caa_container_of(node, struct rotation_channel_info,
  61                         rotate_channels_ht_node);
  62
  63         return !!((channel_key->key == channel_info->channel_key.key) &&
  64                         (channel_key->domain == channel_info->channel_key.domain));
  65 }
  66
  67 static
  68 struct rotation_channel_info *lookup_channel_pending(uint64_t key,
  69                 enum lttng_domain_type domain)
  70 {
  71         struct cds_lfht_iter iter;
  72         struct cds_lfht_node *node;
  73         struct rotation_channel_info *channel_info = NULL;
  74         struct rotation_channel_key channel_key = { .key = key,
  75                 .domain = domain };
  76
  77         cds_lfht_lookup(channel_pending_rotate_ht,
  78                         hash_channel_key(&channel_key),
  79                         match_channel_info,
  80                         &channel_key, &iter);
  81         node = cds_lfht_iter_get_node(&iter);
  82         if (!node) {
  83                 goto end;
  84         }
  85
  86         channel_info = caa_container_of(node, struct rotation_channel_info,
  87                         rotate_channels_ht_node);
  88         cds_lfht_del(channel_pending_rotate_ht, node);
  89 end:
  90         return channel_info;
  91 }
  92
  93 /*
  94  * Destroy the thread data previously created by the init function.
  95  */
  96 void rotation_thread_handle_destroy(
  97                 struct rotation_thread_handle *handle)
  98 {
  99         int ret;
 100
 101         if (!handle) {
 102                 goto end;
 103         }
 104
 105         if (handle->ust32_consumer >= 0) {
 106                 ret = close(handle->ust32_consumer);
 107                 if (ret) {
 108                         PERROR("close 32-bit consumer channel rotation pipe");
 109                 }
 110         }
 111         if (handle->ust64_consumer >= 0) {
 112                 ret = close(handle->ust64_consumer);
 113                 if (ret) {
 114                         PERROR("close 64-bit consumer channel rotation pipe");
 115                 }
 116         }
 117         if (handle->kernel_consumer >= 0) {
 118                 ret = close(handle->kernel_consumer);
 119                 if (ret) {
 120                         PERROR("close kernel consumer channel rotation pipe");
 121                 }
 122         }
 123
 124 end:
 125         free(handle);
 126 }
 127
 128 struct rotation_thread_handle *rotation_thread_handle_create(
 129                 struct lttng_pipe *ust32_channel_rotate_pipe,
 130                 struct lttng_pipe *ust64_channel_rotate_pipe,
 131                 struct lttng_pipe *kernel_channel_rotate_pipe,
 132                 int thread_quit_pipe)
 133 {
 134         struct rotation_thread_handle *handle;
 135
 136         handle = zmalloc(sizeof(*handle));
 137         if (!handle) {
 138                 goto end;
 139         }
 140
 141         if (ust32_channel_rotate_pipe) {
 142                 handle->ust32_consumer =
 143                                 lttng_pipe_release_readfd(
 144                                         ust32_channel_rotate_pipe);
 145                 if (handle->ust32_consumer < 0) {
 146                         goto error;
 147                 }
 148         } else {
 149                 handle->ust32_consumer = -1;
 150         }
 151         if (ust64_channel_rotate_pipe) {
 152                 handle->ust64_consumer =
 153                                 lttng_pipe_release_readfd(
 154                                         ust64_channel_rotate_pipe);
 155                 if (handle->ust64_consumer < 0) {
 156                         goto error;
 157                 }
 158         } else {
 159                 handle->ust64_consumer = -1;
 160         }
 161         if (kernel_channel_rotate_pipe) {
 162                 handle->kernel_consumer =
 163                                 lttng_pipe_release_readfd(
 164                                         kernel_channel_rotate_pipe);
 165                 if (handle->kernel_consumer < 0) {
 166                         goto error;
 167                 }
 168         } else {
 169                 handle->kernel_consumer = -1;
 170         }
 171         handle->thread_quit_pipe = thread_quit_pipe;
 172
 173 end:
 174         return handle;
 175 error:
 176         rotation_thread_handle_destroy(handle);
 177         return NULL;
 178 }
 179
 180 static
 181 int init_poll_set(struct lttng_poll_event *poll_set,
 182                 struct rotation_thread_handle *handle)
 183 {
 184         int ret;
 185
 186         /*
 187          * Create pollset with size 4:
 188          *      - sessiond quit pipe
 189          *      - consumerd (32-bit user space) channel rotate pipe,
 190          *      - consumerd (64-bit user space) channel rotate pipe,
 191          *      - consumerd (kernel) channel rotate pipe.
 192          */
 193         ret = lttng_poll_create(poll_set, 4, LTTNG_CLOEXEC);
 194         if (ret < 0) {
 195                 goto end;
 196         }
 197
 198         ret = lttng_poll_add(poll_set, handle->thread_quit_pipe,
 199                         LPOLLIN | LPOLLERR);
 200         if (ret < 0) {
 201                 ERR("[rotation-thread] Failed to add thread_quit_pipe fd to pollset");
 202                 goto error;
 203         }
 204         ret = lttng_poll_add(poll_set, handle->ust32_consumer,
 205                         LPOLLIN | LPOLLERR);
 206         if (ret < 0) {
 207                 ERR("[rotation-thread] Failed to add ust-32 channel rotation pipe fd to pollset");
 208                 goto error;
 209         }
 210         ret = lttng_poll_add(poll_set, handle->ust64_consumer,
 211                         LPOLLIN | LPOLLERR);
 212         if (ret < 0) {
 213                 ERR("[rotation-thread] Failed to add ust-64 channel rotation pipe fd to pollset");
 214                 goto error;
 215         }
 216         if (handle->kernel_consumer < 0) {
 217                 goto end;
 218         }
 219         ret = lttng_poll_add(poll_set, handle->kernel_consumer,
 220                         LPOLLIN | LPOLLERR);
 221         if (ret < 0) {
 222                 ERR("[rotation-thread] Failed to add kernel channel rotation pipe fd to pollset");
 223                 goto error;
 224         }
 225
 226 end:
 227         return ret;
 228 error:
 229         lttng_poll_clean(poll_set);
 230         return ret;
 231 }
 232
 233 static
 234 void fini_thread_state(struct rotation_thread_state *state)
 235 {
 236         lttng_poll_clean(&state->events);
 237 }
 238
 239 static
 240 int init_thread_state(struct rotation_thread_handle *handle,
 241                 struct rotation_thread_state *state)
 242 {
 243         int ret;
 244
 245         memset(state, 0, sizeof(*state));
 246         lttng_poll_init(&state->events);
 247
 248         ret = init_poll_set(&state->events, handle);
 249         if (ret) {
 250                 goto end;
 251         }
 252
 253         channel_pending_rotate_ht = cds_lfht_new(DEFAULT_HT_SIZE,
 254                         1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
 255         if (!channel_pending_rotate_ht) {
 256                 ret = -1;
 257         }
 258
 259 end:
 260         return 0;
 261 }
 262
 263 static
 264 int handle_channel_rotation_pipe(int fd, uint32_t revents,
 265                 struct rotation_thread_handle *handle,
 266                 struct rotation_thread_state *state)
 267 {
 268         int ret = 0;
 269         enum lttng_domain_type domain;
 270         struct rotation_channel_info *channel_info;
 271         uint64_t key;
 272
 273         if (fd == handle->ust32_consumer ||
 274                         fd == handle->ust64_consumer) {
 275                 domain = LTTNG_DOMAIN_UST;
 276         } else if (fd == handle->kernel_consumer) {
 277                 domain = LTTNG_DOMAIN_KERNEL;
 278         } else {
 279                 abort();
 280         }
 281
 282         if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 283                 ret = lttng_poll_del(&state->events, fd);
 284                 if (ret) {
 285                         ERR("[rotation-thread] Failed to remove consumer "
 286                                         "rotation pipe from poll set");
 287                 }
 288                 goto end;
 289         }
 290
 291         do {
 292                 ret = read(fd, &key, sizeof(key));
 293         } while (ret == -1 && errno == EINTR);
 294         if (ret != sizeof(key)) {
 295                 ERR("[rotation-thread] Failed to read from pipe (fd = %i)",
 296                                 fd);
 297                 ret = -1;
 298                 goto end;
 299         }
 300
 301         DBG("[rotation-thread] Received notification for chan %" PRIu64
 302                         ", domain %d\n", key, domain);
 303
 304         channel_info = lookup_channel_pending(key, domain);
 305         if (!channel_info) {
 306                 ERR("[rotation-thread] Failed to find channel_info (key = %"
 307                                 PRIu64 ")", key);
 308                 ret = -1;
 309                 goto end;
 310         }
 311
 312         if (--channel_info->session->nr_chan_rotate_pending == 0) {
 313                 time_t now = time(NULL);
 314
 315                 if (now == (time_t) -1) {
 316                         channel_info->session->rotate_status = LTTNG_ROTATE_ERROR;
 317                         ret = LTTNG_ERR_ROTATE_NOT_AVAILABLE;
 318                         goto end;
 319                 }
 320
 321                 ret = rename_complete_chunk(channel_info->session, now);
 322                 if (ret < 0) {
 323                         ERR("Failed to rename completed rotation chunk");
 324                         goto end;
 325                 }
 326         }
 327
 328         channel_rotation_info_destroy(channel_info);
 329
 330         ret = 0;
 331
 332 end:
 333         return ret;
 334 }
 335
 336 void *thread_rotation(void *data)
 337 {
 338         int ret;
 339         struct rotation_thread_handle *handle = data;
 340         struct rotation_thread_state state;
 341
 342         DBG("[rotation-thread] Started rotation thread");
 343
 344         if (!handle) {
 345                 ERR("[rotation-thread] Invalid thread context provided");
 346                 goto end;
 347         }
 348
 349         rcu_register_thread();
 350         rcu_thread_online();
 351
 352         health_register(health_sessiond, HEALTH_SESSIOND_TYPE_ROTATION);
 353         health_code_update();
 354
 355         ret = init_thread_state(handle, &state);
 356         if (ret) {
 357                 goto end;
 358         }
 359
 360         /* Ready to handle client connections. */
 361         sessiond_notify_ready();
 362
 363         while (true) {
 364                 int fd_count, i;
 365
 366                 health_poll_entry();
 367                 DBG("[rotation-thread] Entering poll wait");
 368                 ret = lttng_poll_wait(&state.events, -1);
 369                 DBG("[rotation-thread] Poll wait returned (%i)", ret);
 370                 health_poll_exit();
 371                 if (ret < 0) {
 372                         /*
 373                          * Restart interrupted system call.
 374                          */
 375                         if (errno == EINTR) {
 376                                 continue;
 377                         }
 378                         ERR("[rotation-thread] Error encountered during lttng_poll_wait (%i)", ret);
 379                         goto error;
 380                 }
 381
 382                 fd_count = ret;
 383                 for (i = 0; i < fd_count; i++) {
 384                         int fd = LTTNG_POLL_GETFD(&state.events, i);
 385                         uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
 386
 387                         DBG("[rotation-thread] Handling fd (%i) activity (%u)",
 388                                         fd, revents);
 389
 390                         if (fd == handle->thread_quit_pipe) {
 391                                 DBG("[rotation-thread] Quit pipe activity");
 392                                 goto exit;
 393                         } else if (fd == handle->ust32_consumer ||
 394                                         fd == handle->ust64_consumer ||
 395                                         fd == handle->kernel_consumer) {
 396                                 ret = handle_channel_rotation_pipe(fd,
 397                                                 revents, handle, &state);
 398                                 if (ret) {
 399                                         ERR("[rotation-thread] Exit main loop");
 400                                         goto error;
 401                                 }
 402                         }
 403                 }
 404         }
 405 exit:
 406 error:
 407         fini_thread_state(&state);
 408         health_unregister(health_sessiond);
 409         rcu_thread_offline();
 410         rcu_unregister_thread();
 411 end:
 412         return NULL;
 413 }