From fc2af28bd91561a30067c26a85776d1e457b4ad7 Mon Sep 17 00:00:00 2001 From: Yang Zhang Date: Wed, 31 Jan 2018 16:14:33 -0800 Subject: [PATCH] ocfs2/cluster: close a race that fence can't be triggered When some nodes of cluster face with TCP connection fault, ocfs2 will pick up a quorum to continue to work and other nodes will be fenced by resetting host. In order to decide which node should be fenced, ocfs2 leverages o2quo_state::qs_holds. If that variable is reduced to zero, then a try to decide if fence local node is performed. However, under a specific scenario that local node is not disconnected from others at the same time, above method has a problem to reduce ::qs_holds to zero. Because, o2net 90s idle timer corresponding to different nodes is triggered one after another. node 2 node 3 90s idle timer elapses clear ::qs_conn_bm set hold 40s is passed 90 idle timer elapses clear ::qs_conn_bm set hold still up timer elapses clear hold (NOT to zero ) 90s idle timer elapses AGAIN still up timer elapses. clear hold still up timer elapses To solve this issue, a node which has already be evicted from ::qs_conn_bm can't set hold again and again invoked from idle timer. Link: http://lkml.kernel.org/r/63ADC13FD55D6546B7DECE290D39E373F1F3F93B@H3CMLB12-EX.srv.huawei-3com.com Signed-off-by: Yang Zhang Signed-off-by: Changwei Ge Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Joseph Qi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/cluster/quorum.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/ocfs2/cluster/quorum.c b/fs/ocfs2/cluster/quorum.c index 62e8ec619b4c..af2e7473956e 100644 --- a/fs/ocfs2/cluster/quorum.c +++ b/fs/ocfs2/cluster/quorum.c @@ -314,12 +314,13 @@ void o2quo_conn_err(u8 node) node, qs->qs_connected); clear_bit(node, qs->qs_conn_bm); + + if (test_bit(node, qs->qs_hb_bm)) + o2quo_set_hold(qs, node); } mlog(0, "node %u, %d total\n", node, qs->qs_connected); - if (test_bit(node, qs->qs_hb_bm)) - o2quo_set_hold(qs, node); spin_unlock(&qs->qs_lock); }