src/bin/lttng-sessiond/rotate.cpp

   1 /*
   2  * Copyright (C) 2017 Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include "cmd.hpp"
  11 #include "health-sessiond.hpp"
  12 #include "lttng-sessiond.hpp"
  13 #include "notification-thread-commands.hpp"
  14 #include "rotate.hpp"
  15 #include "rotation-thread.hpp"
  16 #include "session.hpp"
  17 #include "utils.hpp"
  18
  19 #include <common/align.hpp>
  20 #include <common/config/session-config.hpp>
  21 #include <common/credentials.hpp>
  22 #include <common/defaults.hpp>
  23 #include <common/error.hpp>
  24 #include <common/futex.hpp>
  25 #include <common/hashtable/utils.hpp>
  26 #include <common/kernel-ctl/kernel-ctl.hpp>
  27 #include <common/time.hpp>
  28 #include <common/utils.hpp>
  29
  30 #include <lttng/action/action-internal.hpp>
  31 #include <lttng/condition/condition-internal.hpp>
  32 #include <lttng/notification/channel-internal.hpp>
  33 #include <lttng/rotate-internal.hpp>
  34 #include <lttng/trigger/trigger.h>
  35
  36 #include <inttypes.h>
  37 #include <signal.h>
  38 #include <sys/stat.h>
  39 #include <time.h>
  40 #include <urcu.h>
  41 #include <urcu/list.h>
  42 #include <urcu/rculfhash.h>
  43
  44 int subscribe_session_consumed_size_rotation(
  45         struct ltt_session *session,
  46         uint64_t size,
  47         struct notification_thread_handle *notification_thread_handle)
  48 {
  49         int ret;
  50         enum lttng_condition_status condition_status;
  51         enum lttng_notification_channel_status nc_status;
  52         const uint64_t eventfd_increment_value = 1;
  53         struct lttng_condition *rotate_condition = nullptr;
  54         struct lttng_action *notify_action = nullptr;
  55         const struct lttng_credentials session_creds = {
  56                 .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid),
  57                 .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid),
  58         };
  59
  60         rotate_condition = lttng_condition_session_consumed_size_create();
  61         if (!rotate_condition) {
  62                 ERR("Failed to create session consumed size condition object");
  63                 ret = -1;
  64                 goto end;
  65         }
  66
  67         condition_status =
  68                 lttng_condition_session_consumed_size_set_threshold(rotate_condition, size);
  69         if (condition_status != LTTNG_CONDITION_STATUS_OK) {
  70                 ERR("Could not set session consumed size condition threshold (size = %" PRIu64 ")",
  71                     size);
  72                 ret = -1;
  73                 goto end;
  74         }
  75
  76         condition_status = lttng_condition_session_consumed_size_set_session_name(rotate_condition,
  77                                                                                   session->name);
  78         if (condition_status != LTTNG_CONDITION_STATUS_OK) {
  79                 ERR("Could not set session consumed size condition session name (name = %s)",
  80                     session->name);
  81                 ret = -1;
  82                 goto end;
  83         }
  84
  85         notify_action = lttng_action_notify_create();
  86         if (!notify_action) {
  87                 ERR("Could not create notify action");
  88                 ret = -1;
  89                 goto end;
  90         }
  91
  92         LTTNG_ASSERT(!session->rotate_trigger);
  93         session->rotate_trigger = lttng_trigger_create(rotate_condition, notify_action);
  94         if (!session->rotate_trigger) {
  95                 ERR("Could not create size-based rotation trigger");
  96                 ret = -1;
  97                 goto end;
  98         }
  99
 100         /* Ensure this trigger is not visible to external users. */
 101         lttng_trigger_set_hidden(session->rotate_trigger);
 102         lttng_trigger_set_credentials(session->rotate_trigger, &session_creds);
 103
 104         nc_status =
 105                 lttng_notification_channel_subscribe(rotate_notification_channel, rotate_condition);
 106         if (nc_status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 107                 ERR("Could not subscribe to session consumed size notification");
 108                 ret = -1;
 109                 goto end;
 110         }
 111
 112         ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
 113                           &eventfd_increment_value,
 114                           sizeof(eventfd_increment_value));
 115         if (ret != sizeof(eventfd_increment_value)) {
 116                 PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
 117                 ret = -1;
 118                 goto end;
 119         }
 120
 121         ret = notification_thread_command_register_trigger(
 122                 notification_thread_handle, session->rotate_trigger, true);
 123         if (ret < 0 && ret != -LTTNG_ERR_TRIGGER_EXISTS) {
 124                 ERR("Register trigger, %s", lttng_strerror(ret));
 125                 ret = -1;
 126                 goto end;
 127         }
 128
 129         ret = 0;
 130
 131 end:
 132         lttng_condition_put(rotate_condition);
 133         lttng_action_put(notify_action);
 134         if (ret) {
 135                 lttng_trigger_put(session->rotate_trigger);
 136         }
 137         return ret;
 138 }
 139
 140 int unsubscribe_session_consumed_size_rotation(
 141         struct ltt_session *session, struct notification_thread_handle *notification_thread_handle)
 142 {
 143         int ret = 0;
 144         enum lttng_notification_channel_status status;
 145         const uint64_t eventfd_increment_value = 1;
 146
 147         LTTNG_ASSERT(session->rotate_trigger);
 148         status = lttng_notification_channel_unsubscribe(
 149                 rotate_notification_channel,
 150                 lttng_trigger_get_const_condition(session->rotate_trigger));
 151         if (status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 152                 ERR("Session unsubscribe error: %d", (int) status);
 153                 ret = -1;
 154                 goto end;
 155         }
 156
 157         ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
 158                           &eventfd_increment_value,
 159                           sizeof(eventfd_increment_value));
 160         if (ret != sizeof(eventfd_increment_value)) {
 161                 PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
 162                 ret = -1;
 163                 goto end;
 164         }
 165
 166         ret = notification_thread_command_unregister_trigger(notification_thread_handle,
 167                                                              session->rotate_trigger);
 168         if (ret != LTTNG_OK) {
 169                 ERR("Session unregister trigger error: %d", ret);
 170                 goto end;
 171         }
 172
 173         lttng_trigger_put(session->rotate_trigger);
 174         session->rotate_trigger = nullptr;
 175
 176         ret = 0;
 177 end:
 178         return ret;
 179 }