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, 7 insertions, 0 deletions

diff --git a/fs/ocfs2/cluster/nodemanager.h b/fs/ocfs2/cluster/nodemanager.h
index c992ea0da4ad..09ea2d388bbb 100644
--- a/fs/ocfs2/cluster/nodemanager.h
+++ b/fs/ocfs2/cluster/nodemanager.h
@@ -33,6 +33,12 @@
 #include <linux/configfs.h>
 #include <linux/rbtree.h>
 
+enum o2nm_fence_method {
+        O2NM_FENCE_RESET        = 0,
+        O2NM_FENCE_PANIC,
+        O2NM_FENCE_METHODS,     /* Number of fence methods */
+};
+
 struct o2nm_node {
         spinlock_t              nd_lock;
         struct config_item      nd_item;
@@ -58,6 +64,7 @@ struct o2nm_cluster {
         unsigned int            cl_idle_timeout_ms;
         unsigned int            cl_keepalive_delay_ms;
         unsigned int            cl_reconnect_delay_ms;
+        enum o2nm_fence_method  cl_fence_method;
 
         /* this bitmap is part of a hack for disk bitmap.. will go eventually. - zab */
         unsigned long   cl_nodes_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];