ocfs2: live heartbeat depends on the local node configuration

Removing the local node configuration out from underneath a running
heartbeat is "bad".  Provide an API in the ocfs2 nodemanager to request
a configfs dependancy on the local node, then use it in heartbeat.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

3 files changed, 46 insertions, 3 deletions

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index e331f4cb2c81..2877d468f115 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -1693,9 +1693,18 @@ static int o2hb_region_get(const char *region_uuid)
                 ret = -ENOENT;
         spin_unlock(&o2hb_live_lock);
 
-        if (!ret)
-                ret = o2nm_depend_item(&reg->hr_item);
+        if (ret)
+                goto out;
+
+        ret = o2nm_depend_this_node();
+        if (ret)
+                goto out;
 
+        ret = o2nm_depend_item(&reg->hr_item);
+        if (ret)
+                o2nm_undepend_this_node();
+
+out:
         return ret;
 }
 
@@ -1709,8 +1718,10 @@ static void o2hb_region_put(const char *region_uuid)
 
         spin_unlock(&o2hb_live_lock);
 
-        if (reg)
+        if (reg) {
                 o2nm_undepend_item(&reg->hr_item);
+                o2nm_undepend_this_node();
+        }
 }
 
 int o2hb_register_callback(const char *region_uuid,
diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index eab46d8a7c8c..af2070da308b 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -910,6 +910,36 @@ void o2nm_undepend_item(struct config_item *item)
         configfs_undepend_item(&o2nm_cluster_group.cs_subsys, item);
 }
 
+int o2nm_depend_this_node(void)
+{
+        int ret = 0;
+        struct o2nm_node *local_node;
+
+        local_node = o2nm_get_node_by_num(o2nm_this_node());
+        if (!local_node) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        ret = o2nm_depend_item(&local_node->nd_item);
+        o2nm_node_put(local_node);
+
+out:
+        return ret;
+}
+
+void o2nm_undepend_this_node(void)
+{
+        struct o2nm_node *local_node;
+
+        local_node = o2nm_get_node_by_num(o2nm_this_node());
+        BUG_ON(!local_node);
+
+        o2nm_undepend_item(&local_node->nd_item);
+        o2nm_node_put(local_node);
+}
+
+
 static void __exit exit_o2nm(void)
 {
         if (ocfs2_table_header)
diff --git a/fs/ocfs2/cluster/nodemanager.h b/fs/ocfs2/cluster/nodemanager.h
index 55ae1a00d735..7c860361b8dd 100644
--- a/fs/ocfs2/cluster/nodemanager.h
+++ b/fs/ocfs2/cluster/nodemanager.h
@@ -79,5 +79,7 @@ void o2nm_node_put(struct o2nm_node *node);
 
 int o2nm_depend_item(struct config_item *item);
 void o2nm_undepend_item(struct config_item *item);
+int o2nm_depend_this_node(void);
+void o2nm_undepend_this_node(void);
 
 #endif /* O2CLUSTER_NODEMANAGER_H */