Merge pull request #3149 from rpv-tomsk/libvirt-2

virt plugin: Do not fail if no connection on init()

diff --combined src/virt.c
index 4232911,cd82dca..18e951b
--- 1/src/virt.c
--- 2/src/virt.c
+++ b/src/virt.c
@@@ -635,6 -635,8 +635,8 @@@ static enum if_field interface_format 
  static time_t last_refresh = (time_t)0;
  
  static int refresh_lists(struct lv_read_instance *inst);
+ static int register_event_impl(void);
+ static int start_event_loop(virt_notif_thread_t *thread_data);
  
  struct lv_block_stats {
    virDomainBlockStatsStruct bi;
@@@ -916,10 -918,10 +918,10 @@@ static void memory_submit(virDomainPtr 
  
  static void memory_stats_submit(gauge_t value, virDomainPtr dom,
                                  int tag_index) {
 -  static const char *tags[] = {"swap_in",        "swap_out", "major_fault",
 -                               "minor_fault",    "unused",   "available",
 -                               "actual_balloon", "rss",      "usable",
 -                               "last_update"};
 +  static const char *tags[] = {"swap_in",        "swap_out",   "major_fault",
 +                               "minor_fault",    "unused",     "available",
 +                               "actual_balloon", "rss",        "usable",
 +                               "last_update",    "disk_caches"};
  
    if ((tag_index < 0) || (tag_index >= (int)STATIC_ARRAY_SIZE(tags))) {
      ERROR("virt plugin: Array index out of bounds: tag_index = %d", tag_index);
@@@ -1441,6 -1443,11 +1443,11 @@@ static int lv_config(oconfig_item_t *ci
  
  static int lv_connect(void) {
    if (conn == NULL) {
+     /* event implementation must be registered before connection is opened */
+     if (!persistent_notification)
+       if (register_event_impl() != 0)
+         return -1;
+ 
  /* `conn_string == NULL' is acceptable */
  #ifdef HAVE_FS_INFO
      /* virDomainGetFSInfo requires full read-write access connection */
@@@ -1458,8 -1465,17 +1465,17 @@@
      int status = virNodeGetInfo(conn, &nodeinfo);
      if (status != 0) {
        ERROR(PLUGIN_NAME " plugin: virNodeGetInfo failed");
+       virConnectClose(conn);
+       conn = NULL;
        return -1;
      }
+ 
+     if (!persistent_notification)
+       if (start_event_loop(&notif_thread) != 0) {
+         virConnectClose(conn);
+         conn = NULL;
+         return -1;
+       }
    }
    c_release(LOG_NOTICE, &conn_complain,
              PLUGIN_NAME " plugin: Connection established.");
@@@ -2091,10 -2107,9 +2107,9 @@@ static void *event_loop_worker(void *ar
  }
  
  static int virt_notif_thread_init(virt_notif_thread_t *thread_data) {
-   int ret;
- 
    assert(thread_data != NULL);
-   ret = pthread_mutex_init(&thread_data->active_mutex, NULL);
+ 
+   int ret = pthread_mutex_init(&thread_data->active_mutex, NULL);
    if (ret != 0) {
      ERROR(PLUGIN_NAME " plugin: Failed to initialize mutex, err %u", ret);
      return ret;
@@@ -2230,33 -2245,26 +2245,26 @@@ static int persistent_domains_state_not
  }
  
  static int lv_read(user_data_t *ud) {
-   time_t t;
-   struct lv_read_instance *inst = NULL;
-   struct lv_read_state *state = NULL;
- 
    if (ud->data == NULL) {
      ERROR(PLUGIN_NAME " plugin: NULL userdata");
      return -1;
    }
  
-   inst = ud->data;
-   state = &inst->read_state;
- 
-   bool reconnect = conn == NULL ? true : false;
-   /* event implementation must be registered before connection is opened */
-   if (inst->id == 0) {
-     if (!persistent_notification && reconnect)
-       if (register_event_impl() != 0)
-         return -1;
+   struct lv_read_instance *inst = ud->data;
+   struct lv_read_state *state = &inst->read_state;
  
+   if (inst->id == 0)
      if (lv_connect() < 0)
        return -1;
  
-     if (!persistent_notification && reconnect && conn != NULL)
-       if (start_event_loop(&notif_thread) != 0)
-         return -1;
+   /* Wait until inst#0 establish connection */
+   if (conn == NULL) {
+     DEBUG(PLUGIN_NAME " plugin#%s: Wait until inst#0 establish connection",
+           inst->tag);
+     return 0;
    }
  
+   time_t t;
    time(&t);
  
    /* Need to refresh domain or device lists? */
@@@ -2377,19 -2385,11 +2385,11 @@@ static int lv_init(void) 
    if (lv_init_ignorelists() != 0)
      return -1;
  
-   /* event implementation must be registered before connection is opened */
    if (!persistent_notification)
-     if (register_event_impl() != 0)
+     if (virt_notif_thread_init(&notif_thread) != 0)
        return -1;
  
-   if (lv_connect() != 0)
-     return -1;
- 
-   if (!persistent_notification) {
-     virt_notif_thread_init(&notif_thread);
-     if (start_event_loop(&notif_thread) != 0)
-       return -1;
-   }
+   lv_connect();
  
    DEBUG(PLUGIN_NAME " plugin: starting %i instances", nr_instances);