From: Joseph Qi <joseph.qi@huawei.com>
Date: Fri, 4 Sep 2015 22:43:57 +0000 (-0700)
Subject: ocfs2: fix BUG when o2hb_register_callback fails
X-Git-Tag: v4.3-rc1~73^2~89
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=cdd09f49cb271d95cbe69ef886459e0490040e98;p=linux-2.6-block.git

ocfs2: fix BUG when o2hb_register_callback fails

In dlm_register_domain_handlers, if o2hb_register_callback fails, it
will call dlm_unregister_domain_handlers to unregister.  This will
trigger the BUG_ON in o2hb_unregister_callback because hc_magic is 0.
So we should call o2hb_setup_callback to initialize hc first.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 7df88a6dd626..4f750701bd9a 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -1725,12 +1725,13 @@ static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
 
 	o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
 			    dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
+	o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
+			    dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
+
 	status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_down);
 	if (status)
 		goto bail;
 
-	o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
-			    dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
 	status = o2hb_register_callback(dlm->name, &dlm->dlm_hb_up);
 	if (status)
 		goto bail;