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         struct lttng_condition *rotate_condition = nullptr;
  53         struct lttng_action *notify_action = nullptr;
  54         const struct lttng_credentials session_creds = {
  55                 .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid),
  56                 .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid),
  57         };
  58
  59         rotate_condition = lttng_condition_session_consumed_size_create();
  60         if (!rotate_condition) {
  61                 ERR("Failed to create session consumed size condition object");
  62                 ret = -1;
  63                 goto end;
  64         }
  65
  66         condition_status =
  67                 lttng_condition_session_consumed_size_set_threshold(rotate_condition, size);
  68         if (condition_status != LTTNG_CONDITION_STATUS_OK) {
  69                 ERR("Could not set session consumed size condition threshold (size = %" PRIu64 ")",
  70                     size);
  71                 ret = -1;
  72                 goto end;
  73         }
  74
  75         condition_status = lttng_condition_session_consumed_size_set_session_name(rotate_condition,
  76                                                                                   session->name);
  77         if (condition_status != LTTNG_CONDITION_STATUS_OK) {
  78                 ERR("Could not set session consumed size condition session name (name = %s)",
  79                     session->name);
  80                 ret = -1;
  81                 goto end;
  82         }
  83
  84         notify_action = lttng_action_notify_create();
  85         if (!notify_action) {
  86                 ERR("Could not create notify action");
  87                 ret = -1;
  88                 goto end;
  89         }
  90
  91         LTTNG_ASSERT(!session->rotate_trigger);
  92         session->rotate_trigger = lttng_trigger_create(rotate_condition, notify_action);
  93         if (!session->rotate_trigger) {
  94                 ERR("Could not create size-based rotation trigger");
  95                 ret = -1;
  96                 goto end;
  97         }
  98
  99         /* Ensure this trigger is not visible to external users. */
 100         lttng_trigger_set_hidden(session->rotate_trigger);
 101         lttng_trigger_set_credentials(session->rotate_trigger, &session_creds);
 102
 103         nc_status =
 104                 lttng_notification_channel_subscribe(rotate_notification_channel, rotate_condition);
 105         if (nc_status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 106                 ERR("Could not subscribe to session consumed size notification");
 107                 ret = -1;
 108                 goto end;
 109         }
 110
 111         ret = notification_thread_command_register_trigger(
 112                 notification_thread_handle, session->rotate_trigger, true);
 113         if (ret < 0 && ret != -LTTNG_ERR_TRIGGER_EXISTS) {
 114                 ERR("Register trigger, %s", lttng_strerror(ret));
 115                 ret = -1;
 116                 goto end;
 117         }
 118
 119         ret = 0;
 120
 121 end:
 122         lttng_condition_put(rotate_condition);
 123         lttng_action_put(notify_action);
 124         if (ret) {
 125                 lttng_trigger_put(session->rotate_trigger);
 126         }
 127         return ret;
 128 }
 129
 130 int unsubscribe_session_consumed_size_rotation(
 131         struct ltt_session *session, struct notification_thread_handle *notification_thread_handle)
 132 {
 133         int ret = 0;
 134         enum lttng_notification_channel_status status;
 135
 136         LTTNG_ASSERT(session->rotate_trigger);
 137         status = lttng_notification_channel_unsubscribe(
 138                 rotate_notification_channel,
 139                 lttng_trigger_get_const_condition(session->rotate_trigger));
 140         if (status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 141                 ERR("Session unsubscribe error: %d", (int) status);
 142                 ret = -1;
 143                 goto end;
 144         }
 145
 146         ret = notification_thread_command_unregister_trigger(notification_thread_handle,
 147                                                              session->rotate_trigger);
 148         if (ret != LTTNG_OK) {
 149                 ERR("Session unregister trigger error: %d", ret);
 150                 goto end;
 151         }
 152
 153         lttng_trigger_put(session->rotate_trigger);
 154         session->rotate_trigger = nullptr;
 155
 156         ret = 0;
 157 end:
 158         return ret;
 159 }