From mboxrd@z Thu Jan  1 00:00:00 1970
From: swhiteho@redhat.com <swhiteho@redhat.com>
Date: Mon,  9 Jul 2007 17:02:54 +0100
Subject: [Cluster-devel] [PATCH] [DLM] Telnet to port 21064 can stop all
	lockspaces
In-Reply-To: <11839970832750-git-send-email-swhiteho@redhat.com>
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From: Patrick Caulfield <pcaulfie@redhat.com>

This patch fixes Red Hat bz#245892

Opening a tcp connection from a cluster member to another cluster member
targeting the dlm port it is enough to stop every dlm operation in the cluster.
This means that GFS and rgmanager will hang.

Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index fc0bff7..73d44f5 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -720,11 +720,17 @@ static int tcp_accept_from_sock(struct connection *con)
 			INIT_WORK(&othercon->rwork, process_recv_sockets);
 			set_bit(CF_IS_OTHERCON, &othercon->flags);
 			newcon->othercon = othercon;
+			othercon->sock = newsock;
+			newsock->sk->sk_user_data = othercon;
+			add_sock(newsock, othercon);
+			addcon = othercon;
+		}
+		else {
+			printk("Extra connection from node %d attempted\n", nodeid);
+			result = -EAGAIN;
+			up_write(&newcon->sock_sem);
+			goto accept_err;
 		}
-		othercon->sock = newsock;
-		newsock->sk->sk_user_data = othercon;
-		add_sock(newsock, othercon);
-		addcon = othercon;
 	}
 	else {
 		newsock->sk->sk_user_data = newcon;
-- 
1.5.1.2