[PATCH 4.9 50/61] libceph: reschedule a tick in finish_hunting()
From: Greg Kroah-Hartman
Date: Mon Apr 30 2018 - 16:21:51 EST
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilya Dryomov <idryomov@xxxxxxxxx>
commit 7b4c443d139f1d2b5570da475f7a9cbcef86740c upstream.
If we go without an established session for a while, backoff delay will
climb to 30 seconds. The keepalive timeout is also 30 seconds, so it's
pretty easily hit after a prolonged hunting for a monitor: we don't get
a chance to send out a keepalive in time, which means we never get back
a keepalive ack in time, cutting an established session and attempting
to connect to a different monitor every 30 seconds:
[Sun Apr 1 23:37:05 2018] libceph: mon0 10.80.20.99:6789 session established
[Sun Apr 1 23:37:36 2018] libceph: mon0 10.80.20.99:6789 session lost, hunting for new mon
[Sun Apr 1 23:37:36 2018] libceph: mon2 10.80.20.103:6789 session established
[Sun Apr 1 23:38:07 2018] libceph: mon2 10.80.20.103:6789 session lost, hunting for new mon
[Sun Apr 1 23:38:07 2018] libceph: mon1 10.80.20.100:6789 session established
[Sun Apr 1 23:38:37 2018] libceph: mon1 10.80.20.100:6789 session lost, hunting for new mon
[Sun Apr 1 23:38:37 2018] libceph: mon2 10.80.20.103:6789 session established
[Sun Apr 1 23:39:08 2018] libceph: mon2 10.80.20.103:6789 session lost, hunting for new mon
The regular keepalive interval is 10 seconds. After ->hunting is
cleared in finish_hunting(), call __schedule_delayed() to ensure we
send out a keepalive after 10 seconds.
Cc: stable@xxxxxxxxxxxxxxx # 4.7+
Link: http://tracker.ceph.com/issues/23537
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Reviewed-by: Jason Dillaman <dillaman@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ceph/mon_client.c | 1 +
1 file changed, 1 insertion(+)
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -1124,6 +1124,7 @@ static void finish_hunting(struct ceph_m
monc->hunting = false;
monc->had_a_connection = true;
un_backoff(monc);
+ __schedule_delayed(monc);
}
}