Re: sanlock events - events not received after releasing and acquiring host id

[David Teigland]

>  1. Why listening for events stop working after releasing host id and
>  acquiring it again on the same lockspace? 
events are tied directly into the lockspace.

>  2. Is this the right behavior? 
yes

>  3. Assuming this is the right behavior, why the listener does not
> fail? I think it is
>     expected that the event fds would close or fail so the listener can release
>     the resources.
>     For example, when I restart sanlock, the listener fails with:
>  
>         sanlock.SanlockException: (1, 'Unable to get events', 'Operation not
> permitted')
>  
>     So a similar failure is expected in this case.
>  
>  4. Do we have an event fd leak until the listener reg_end() the fd? 
Thanks, you found a bug there. I wasn't closing the event fds when the
lockspace was removed.  The listener will now get a poll error on its
registered fd if the lockspace is removed.  I'll push out this fix:

diff --git a/src/lockspace.c b/src/lockspace.c
index 352287ec5f65..8309d25a11f5 100644
--- a/src/lockspace.c
+++ b/src/lockspace.c
@@ -451,6 +451,20 @@ static int corrupt_result(int result)
        }
 }
 
+static void close_event_fds(struct space *sp)
+{
+       int i;
+
+       pthread_mutex_lock(&sp->mutex);
+       for (i = 0; i < MAX_EVENT_FDS; i++) {
+               if (sp->event_fds[i] == -1)
+                       continue;
+
+               close(sp->event_fds[i]);
+               sp->event_fds[i] = -1;
+       }
+}
+
 /*
  * This thread must not be stopped unless all pids that may be using any
  * resources in it are dead/gone.  (The USED flag in the lockspace represents
@@ -671,6 +685,8 @@ static void *lockspace_thread(void *arg_in)
 
        purge_resource_orphans(sp->space_name);
 
+       close_event_fds(sp);
+
        close_task_aio(&task);
        return NULL;
 }