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  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include <lttng/trigger/trigger.h>
  11 #include <common/error.h>
  12 #include <common/config/session-config.h>
  13 #include <common/defaults.h>
  14 #include <common/utils.h>
  15 #include <common/futex.h>
  16 #include <common/align.h>
  17 #include <common/time.h>
  18 #include <common/hashtable/utils.h>
  19 #include <common/kernel-ctl/kernel-ctl.h>
  20 #include <common/credentials.h>
  21 #include <sys/stat.h>
  22 #include <time.h>
  23 #include <signal.h>
  24 #include <inttypes.h>
  25
  26 #include <lttng/notification/channel-internal.h>
  27 #include <lttng/rotate-internal.h>
  28 #include <lttng/condition/condition-internal.h>
  29 #include <lttng/action/action-internal.h>
  30
  31 #include "session.h"
  32 #include "rotate.h"
  33 #include "rotation-thread.h"
  34 #include "lttng-sessiond.h"
  35 #include "health-sessiond.h"
  36 #include "cmd.h"
  37 #include "utils.h"
  38 #include "notification-thread-commands.h"
  39
  40 #include <urcu.h>
  41 #include <urcu/list.h>
  42 #include <urcu/rculfhash.h>
  43
  44 int subscribe_session_consumed_size_rotation(struct ltt_session *session, uint64_t size,
  45                 struct notification_thread_handle *notification_thread_handle)
  46 {
  47         int ret;
  48         enum lttng_condition_status condition_status;
  49         enum lttng_notification_channel_status nc_status;
  50         const uint64_t eventfd_increment_value = 1;
  51         const struct lttng_credentials session_creds = {
  52                 .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid),
  53                 .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid),
  54         };
  55         struct lttng_condition *rotate_condition;
  56         struct lttng_action *notify_action = NULL;
  57
  58         rotate_condition = lttng_condition_session_consumed_size_create();
  59         if (!rotate_condition) {
  60                 ERR("Failed to create session consumed size condition object");
  61                 ret = -1;
  62                 goto end;
  63         }
  64
  65         condition_status = lttng_condition_session_consumed_size_set_threshold(
  66                         rotate_condition, size);
  67         if (condition_status != LTTNG_CONDITION_STATUS_OK) {
  68                 ERR("Could not set session consumed size condition threshold (size = %" PRIu64 ")",
  69                                 size);
  70                 ret = -1;
  71                 goto end;
  72         }
  73
  74         condition_status =
  75                         lttng_condition_session_consumed_size_set_session_name(
  76                                 rotate_condition, 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         assert(!session->rotate_trigger);
  92         session->rotate_trigger = lttng_trigger_create(rotate_condition,
  93                         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(
 103                         session->rotate_trigger, &session_creds);
 104
 105         nc_status = lttng_notification_channel_subscribe(
 106                         rotate_notification_channel, rotate_condition);
 107         if (nc_status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 108                 ERR("Could not subscribe to session consumed size notification");
 109                 ret = -1;
 110                 goto end;
 111         }
 112
 113         ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
 114                           &eventfd_increment_value,
 115                           sizeof(eventfd_increment_value));
 116         if (ret != sizeof(eventfd_increment_value)) {
 117                 PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
 118                 ret = -1;
 119                 goto end;
 120         }
 121
 122         ret = notification_thread_command_register_trigger(
 123                         notification_thread_handle, session->rotate_trigger,
 124                         true);
 125         if (ret < 0 && ret != -LTTNG_ERR_TRIGGER_EXISTS) {
 126                 ERR("Register trigger, %s", lttng_strerror(ret));
 127                 ret = -1;
 128                 goto end;
 129         }
 130
 131         ret = 0;
 132
 133 end:
 134         lttng_condition_put(rotate_condition);
 135         lttng_action_put(notify_action);
 136         if (ret) {
 137                 lttng_trigger_put(session->rotate_trigger);
 138         }
 139         return ret;
 140 }
 141
 142 int unsubscribe_session_consumed_size_rotation(struct ltt_session *session,
 143                 struct notification_thread_handle *notification_thread_handle)
 144 {
 145         int ret = 0;
 146         enum lttng_notification_channel_status status;
 147         const uint64_t eventfd_increment_value = 1;
 148
 149         assert(session->rotate_trigger);
 150         status = lttng_notification_channel_unsubscribe(
 151                         rotate_notification_channel,
 152                         lttng_trigger_get_const_condition(session->rotate_trigger));
 153         if (status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
 154                 ERR("Session unsubscribe error: %d", (int) status);
 155                 ret = -1;
 156                 goto end;
 157         }
 158
 159         ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
 160                           &eventfd_increment_value,
 161                           sizeof(eventfd_increment_value));
 162         if (ret != sizeof(eventfd_increment_value)) {
 163                 PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
 164                 ret = -1;
 165                 goto end;
 166         }
 167
 168         ret = notification_thread_command_unregister_trigger(notification_thread_handle,
 169                                                              session->rotate_trigger);
 170         if (ret != LTTNG_OK) {
 171                 ERR("Session unregister trigger error: %d", ret);
 172                 goto end;
 173         }
 174
 175         lttng_trigger_put(session->rotate_trigger);
 176         session->rotate_trigger = NULL;
 177
 178         ret = 0;
 179 end:
 180         return ret;
 181 }