ocfs2/cluster: Make fence method configurable - v2

By default, o2cb fences the box by calling emergency_restart(). While this
scheme works well in production, it comes in the way during testing as it
does not let the tester take stack/core dumps for analysis.

This patch allows user to dynamically change the fence method to panic() by:
# echo "panic" > /sys/kernel/config/cluster/<clustername>/fence_method

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/fs/ocfs2/cluster/quorum.c b/fs/ocfs2/cluster/quorum.c
index bbacf7da48a4..639024033fce 100644
--- a/fs/ocfs2/cluster/quorum.c
+++ b/fs/ocfs2/cluster/quorum.c
@@ -74,8 +74,20 @@ static void o2quo_fence_self(void)
 	 * threads can still schedule, etc, etc */
 	o2hb_stop_all_regions();
 
-	printk("ocfs2 is very sorry to be fencing this system by restarting\n");
-	emergency_restart();
+	switch (o2nm_single_cluster->cl_fence_method) {
+	case O2NM_FENCE_PANIC:
+		panic("*** ocfs2 is very sorry to be fencing this system by "
+		      "panicing ***\n");
+		break;
+	default:
+		WARN_ON(o2nm_single_cluster->cl_fence_method >=
+			O2NM_FENCE_METHODS);
+	case O2NM_FENCE_RESET:
+		printk(KERN_ERR "*** ocfs2 is very sorry to be fencing this "
+		       "system by restarting ***\n");
+		emergency_restart();
+		break;
+	};
 }
 
 /* Indicate that a timeout occured on a hearbeat region write. The