[RFC PATCH v4 12/13] memory-hotplug : add node_device_release

[Yasuaki Ishimatsu]

When calling unregister_node(), the function shows following message at
device_release().

Device 'node2' does not have a release() function, it is broken and must be
fixed.

So the patch implements node_device_release()

CC: David Rientjes <rientjes at google.com>
CC: Jiang Liu <liuj97 at gmail.com>
CC: Len Brown <len.brown at intel.com>
CC: Benjamin Herrenschmidt <benh at kernel.crashing.org>
CC: Paul Mackerras <paulus at samba.org> 
CC: Christoph Lameter <cl at linux.com>
Cc: Minchan Kim <minchan.kim at gmail.com>
CC: Andrew Morton <akpm at linux-foundation.org>
CC: KOSAKI Motohiro <kosaki.motohiro at jp.fujitsu.com> 
CC: Wen Congyang <wency at cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki at jp.fujitsu.com>

---
 drivers/base/node.c |    7 +++++++
 1 file changed, 7 insertions(+)

Index: linux-3.5-rc6/drivers/base/node.c
===================================================================
--- linux-3.5-rc6.orig/drivers/base/node.c	2012-07-18 18:24:29.191121066 +0900
+++ linux-3.5-rc6/drivers/base/node.c	2012-07-18 18:25:47.111146983 +0900
@@ -252,6 +252,12 @@ static inline void hugetlb_register_node
 static inline void hugetlb_unregister_node(struct node *node) {}
 #endif
 
+static void node_device_release(struct device *dev)
+{
+	struct node *node_dev = to_node(dev);
+
+	memset(node_dev, 0, sizeof(struct node));
+}
 
 /*
  * register_node - Setup a sysfs device for a node.
@@ -265,6 +271,7 @@ int register_node(struct node *node, int
 
 	node->dev.id = num;
 	node->dev.bus = &node_subsys;
+	node->dev.release = node_device_release;
 	error = device_register(&node->dev);
 
 	if (!error){