src/bin/lttng-sessiond/rotate.c

   1 /*
   2  * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License, version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 51
  16  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _LGPL_SOURCE
  20 #include <lttng/trigger/trigger.h>
  21 #include <common/error.h>
  22 #include <common/config/session-config.h>
  23 #include <common/defaults.h>
  24 #include <common/utils.h>
  25 #include <common/futex.h>
  26 #include <common/align.h>
  27 #include <common/time.h>
  28 #include <common/hashtable/utils.h>
  29 #include <common/kernel-ctl/kernel-ctl.h>
  30 #include <sys/eventfd.h>
  31 #include <sys/stat.h>
  32 #include <time.h>
  33 #include <signal.h>
  34 #include <inttypes.h>
  35
  36 #include <lttng/notification/channel-internal.h>
  37 #include <lttng/rotate-internal.h>
  38
  39 #include "session.h"
  40 #include "rotate.h"
  41 #include "rotation-thread.h"
  42 #include "lttng-sessiond.h"
  43 #include "health-sessiond.h"
  44 #include "cmd.h"
  45 #include "utils.h"
  46 #include "notification-thread-commands.h"
  47
  48 #include <urcu.h>
  49 #include <urcu/list.h>
  50 #include <urcu/rculfhash.h>
  51
  52 /* The session's lock must be held by the caller. */
  53 static
  54 int session_rename_chunk(struct ltt_session *session, char *current_path,
  55                 char *new_path)
  56 {
  57         int ret;
  58         struct consumer_socket *socket;
  59         struct consumer_output *output;
  60         struct lttng_ht_iter iter;
  61         uid_t uid;
  62         gid_t gid;
  63
  64         DBG("Renaming session chunk path of session \"%s\" from %s to %s",
  65                         session->name, current_path, new_path);
  66
  67         /*
  68          * Either one of the sessions is enough to find the consumer_output
  69          * and uid/gid.
  70          */
  71         if (session->kernel_session) {
  72                 output = session->kernel_session->consumer;
  73                 uid = session->kernel_session->uid;
  74                 gid = session->kernel_session->gid;
  75         } else if (session->ust_session) {
  76                 output = session->ust_session->consumer;
  77                 uid = session->ust_session->uid;
  78                 gid = session->ust_session->gid;
  79         } else {
  80                 assert(0);
  81         }
  82
  83         if (!output || !output->socks) {
  84                 ERR("No consumer output found for session \"%s\"",
  85                                 session->name);
  86                 ret = -1;
  87                 goto end;
  88         }
  89
  90         rcu_read_lock();
  91         /*
  92          * We have to iterate to find a socket, but we only need to send the
  93          * rename command to one consumer, so we break after the first one.
  94          */
  95         cds_lfht_for_each_entry(output->socks->ht, &iter.iter, socket, node.node) {
  96                 pthread_mutex_lock(socket->lock);
  97                 ret = consumer_rotate_rename(socket, session->id, output,
  98                                 current_path, new_path, uid, gid);
  99                 pthread_mutex_unlock(socket->lock);
 100                 if (ret) {
 101                         ret = -1;
 102                         goto end_unlock;
 103                 }
 104                 break;
 105         }
 106
 107         ret = 0;
 108
 109 end_unlock:
 110         rcu_read_unlock();
 111 end:
 112         return ret;
 113 }
 114
 115 /* The session's lock must be held by the caller. */
 116 static
 117 int rename_first_chunk(struct ltt_session *session,
 118                 struct consumer_output *consumer, char *new_path)
 119 {
 120         int ret;
 121         char current_full_path[LTTNG_PATH_MAX], new_full_path[LTTNG_PATH_MAX];
 122
 123         if (session->net_handle > 0) {
 124                 /*
 125                  * Current domain path:
 126                  *   HOSTNAME/{SESSION-[TIMESTAMP], USER_DIRECTORY}/DOMAIN
 127                  */
 128                 ret = snprintf(current_full_path, sizeof(current_full_path),
 129                                 "%s%s",
 130                                 consumer->dst.net.base_dir,
 131                                 consumer->domain_subdir);
 132                 if (ret < 0 || ret >= sizeof(current_full_path)) {
 133                         ERR("Failed to initialize current full path while renaming first rotation chunk of session \"%s\"",
 134                                         session->name);
 135                         ret = -LTTNG_ERR_UNK;
 136                         goto error;
 137                 }
 138         } else {
 139                 /*
 140                  * Current domain path:
 141                  *   SESSION_OUTPUT_PATH/DOMAIN
 142                  */
 143                 ret = snprintf(current_full_path, sizeof(current_full_path),
 144                                 "%s/%s",
 145                                 consumer->dst.session_root_path,
 146                                 consumer->domain_subdir);
 147                 if (ret < 0 || ret >= sizeof(current_full_path)) {
 148                         ERR("Failed to initialize current full path while renaming first rotation chunk of session \"%s\"",
 149                                         session->name);
 150                         ret = -LTTNG_ERR_UNK;
 151                         goto error;
 152                 }
 153         }
 154         /*
 155          * New domain path:
 156          *   SESSION_BASE_PATH/<START_TS>_<END_TS>-INDEX/DOMAIN
 157          */
 158         ret = snprintf(new_full_path, sizeof(new_full_path), "%s/%s",
 159                         new_path, consumer->domain_subdir);
 160         if (ret < 0 || ret >= sizeof(new_full_path)) {
 161                 ERR("Failed to initialize new full path while renaming first rotation chunk of session \"%s\"",
 162                                 session->name);
 163                 ret = -LTTNG_ERR_UNK;
 164                 goto error;
 165         }
 166         /* Move the per-domain inside the first rotation chunk path. */
 167         ret = session_rename_chunk(session, current_full_path, new_full_path);
 168         if (ret < 0) {
 169                 ret = -LTTNG_ERR_UNK;
 170                 goto error;
 171         }
 172
 173         ret = 0;
 174
 175 error:
 176         return ret;
 177 }
 178
 179 /*
 180  * Rename a chunk folder after a rotation is complete.
 181  * session_lock_list and session lock must be held.
 182  *
 183  * Returns 0 on success, a negative value on error.
 184  */
 185 int rename_completed_chunk(struct ltt_session *session, time_t end_ts)
 186 {
 187         int ret;
 188         size_t strf_ret;
 189         struct tm *timeinfo;
 190         char new_path[LTTNG_PATH_MAX];
 191         char start_datetime[21], end_datetime[21];
 192
 193         DBG("Renaming completed chunk for session %s", session->name);
 194
 195         /* Format chunk start time. */
 196         timeinfo = localtime(&session->last_chunk_start_ts);
 197         if (!timeinfo) {
 198                 ERR("Failed to separate local time while renaming completed chunk");
 199                 ret = -1;
 200                 goto end;
 201         }
 202         strf_ret = strftime(start_datetime, sizeof(start_datetime),
 203                             "%Y%m%dT%H%M%S%z", timeinfo);
 204         if (strf_ret == 0) {
 205                 ERR("Failed to format timestamp while renaming completed session chunk");
 206                 ret = -1;
 207                 goto end;
 208         }
 209
 210         /* Format chunk end time. */
 211         timeinfo = localtime(&end_ts);
 212         if (!timeinfo) {
 213                 ERR("Failed to parse time while renaming completed chunk");
 214                 ret = -1;
 215                 goto end;
 216         }
 217         strf_ret = strftime(end_datetime, sizeof(end_datetime),
 218                         "%Y%m%dT%H%M%S%z", timeinfo);
 219         if (strf_ret == 0) {
 220                 ERR("Failed to format timestamp while renaming completed session chunk");
 221                 ret = -1;
 222                 goto end;
 223         }
 224
 225         /* Format completed chunk's path. */
 226         ret = snprintf(new_path, sizeof(new_path), "%s/archives/%s-%s-%" PRIu64,
 227                         session_get_base_path(session),
 228                         start_datetime, end_datetime,
 229                         session->current_archive_id);
 230         if (ret < 0 || ret >= sizeof(new_path)) {
 231                 ERR("Failed to format new chunk path while renaming chunk of session \"%s\"",
 232                                 session->name);
 233                 ret = -1;
 234                 goto error;
 235         }
 236
 237         if (session->current_archive_id == 1) {
 238                 /*
 239                  * On the first rotation, the current_rotate_path is the
 240                  * session_root_path, so we need to create the chunk folder
 241                  * and move the domain-specific folders inside it.
 242                  */
 243                 if (session->kernel_session) {
 244                         ret = rename_first_chunk(session,
 245                                         session->kernel_session->consumer,
 246                                         new_path);
 247                         if (ret) {
 248                                 ERR("Failed to rename kernel session trace folder to \"%s\"", new_path);
 249                                 /*
 250                                  * This is not a fatal error for the rotation
 251                                  * thread, we just need to inform the client
 252                                  * that a problem occurred with the rotation.
 253                                  * Returning 0, same for the other errors
 254                                  * below.
 255                                  */
 256                                 ret = 0;
 257                                 goto error;
 258                         }
 259                 }
 260                 if (session->ust_session) {
 261                         ret = rename_first_chunk(session,
 262                                         session->ust_session->consumer,
 263                                         new_path);
 264                         if (ret) {
 265                                 ERR("Failed to rename userspace session trace folder to \"%s\"", new_path);
 266                                 ret = 0;
 267                                 goto error;
 268                         }
 269                 }
 270         } else {
 271                 /*
 272                  * After the first rotation, all the trace data is already in
 273                  * its own chunk folder, we just need to append the suffix.
 274                  */
 275                 ret = session_rename_chunk(session,
 276                                 session->rotation_chunk.current_rotate_path,
 277                                 new_path);
 278                 if (ret) {
 279                         ERR("Failed to rename session trace folder from \"%s\" to \"%s\"",
 280                                         session->rotation_chunk.current_rotate_path,
 281                                         new_path);
 282                         ret = 0;
 283                         goto error;
 284                 }
 285         }
 286
 287         /*
 288          * Store the path where the readable chunk is. This path is valid
 289          * and can be queried by the client with rotate_pending until the next
 290          * rotation is started.
 291          */
 292         ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
 293                         new_path,
 294                         sizeof(session->rotation_chunk.current_rotate_path));
 295         if (ret) {
 296                 ERR("Failed the current chunk's path of session \"%s\"",
 297                                 session->name);
 298                 ret = -1;
 299                 goto error;
 300         }
 301
 302         goto end;
 303
 304 error:
 305         session->rotation_state = LTTNG_ROTATION_STATE_ERROR;
 306 end:
 307         return ret;
 308 }
 309
 310 int rename_active_chunk(struct ltt_session *session)
 311 {
 312         int ret;
 313
 314         session->current_archive_id++;
 315
 316         /*
 317          * The currently active tracing path is now the folder we
 318          * want to rename.
 319          */
 320         ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
 321                         session->rotation_chunk.active_tracing_path,
 322                         sizeof(session->rotation_chunk.current_rotate_path));
 323         if (ret) {
 324                 ERR("Failed to copy active tracing path");
 325                 goto end;
 326         }
 327
 328         ret = rename_completed_chunk(session, time(NULL));
 329         if (ret < 0) {
 330                 ERR("Failed to rename current rotation's path");
 331                 goto end;
 332         }
 333
 334         /*
 335          * We just renamed, the folder, we didn't do an actual rotation, so
 336          * the active tracing path is now the renamed folder and we have to
 337          * restore the rotate count.
 338          */
 339         ret = lttng_strncpy(session->rotation_chunk.active_tracing_path,
 340                         session->rotation_chunk.current_rotate_path,
 341                         sizeof(session->rotation_chunk.active_tracing_path));
 342         if (ret) {
 343                 ERR("Failed to rename active session chunk tracing path");
 344                 goto end;
 345         }
 346 end:
 347         session->current_archive_id--;
 348         return ret;
 349 }
 350
 351 int subscribe_session_consumed_size_rotation(struct ltt_session *session, uint64_t size,
 352                 struct notification_thread_handle *notification_thread_handle)
 353 {
 354         int ret;
 355         enum lttng_condition_status condition_status;
 356         enum lttng_notification_channel_status nc_status;
 357         struct lttng_action *action;
 358
 359         session->rotate_condition = lttng_condition_session_consumed_size_create();
 360         if (!session->rotate_condition) {
 361                 ERR("Failed to create session consumed size condition object");
 362                 ret = -1;
 363                 goto end;
 364         }
 365
 366         condition_status = lttng_condition_session_consumed_size_set_threshold(
 367                         session->rotate_condition, size);
 368         if (condition_status != LTTNG_CONDITION_STATUS_OK) {
 369                 ERR("Could not set session consumed size condition threshold (size = %" PRIu64 ")",
 370                                 size);
 371                 ret = -1;
 372                 goto end;
 373         }
 374
 375         condition_status =
 376                         lttng_condition_session_consumed_size_set_session_name(
 377                                 session->rotate_condition, session->name);
 378         if (condition_status != LTTNG_CONDITION_STATUS_OK) {
 379                 ERR("Could not set session consumed size condition session name (name = %s)",
 380                                 session->name);
 381                 ret = -1;
 382                 goto end;
 383         }
 384
 385         action = lttng_action_notify_create();
 386         if (!action) {
 387                 ERR("Could not create notify action");
 388                 ret = -1;
 389                 goto end;
 390         }
 391
 392         session->rotate_trigger = lttng_trigger_create(session->rotate_condition,
 393                         action);
 394         if (!session->rotate_trigger) {
 395                 ERR("Could not create size-based rotation trigger");
 396                 ret = -1;
 397                 goto end;
 398         }
 399
 400         nc_status = lttng_notification_channel_subscribe(
 401                         rotate_notification_channel, session->rotate_condition);
 402         if (nc_status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 403                 ERR("Could not subscribe to session consumed size notification");
 404                 ret = -1;
 405                 goto end;
 406         }
 407
 408         ret = notification_thread_command_register_trigger(
 409                         notification_thread_handle, session->rotate_trigger);
 410         if (ret < 0 && ret != -LTTNG_ERR_TRIGGER_EXISTS) {
 411                 ERR("Register trigger, %s", lttng_strerror(ret));
 412                 ret = -1;
 413                 goto end;
 414         }
 415
 416         ret = 0;
 417
 418 end:
 419         return ret;
 420 }
 421
 422 int unsubscribe_session_consumed_size_rotation(struct ltt_session *session,
 423                 struct notification_thread_handle *notification_thread_handle)
 424 {
 425         int ret = 0;
 426         enum lttng_notification_channel_status status;
 427
 428         status = lttng_notification_channel_unsubscribe(
 429                         rotate_notification_channel,
 430                         session->rotate_condition);
 431         if (status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 432                 ERR("Session unsubscribe error: %d", (int) status);
 433                 ret = -1;
 434                 goto end;
 435         }
 436
 437         ret = notification_thread_command_unregister_trigger(
 438                         notification_thread_handle, session->rotate_trigger);
 439         if (ret != LTTNG_OK) {
 440                 ERR("Session unregister trigger error: %d", ret);
 441                 goto end;
 442         }
 443
 444         ret = 0;
 445 end:
 446         return ret;
 447 }