[RFC v9 PATCH 18/21] memory-hotplug: add node_device_release

[wency at cn.fujitsu.com]

From: Yasuaki Ishimatsu <isimatu.yasuaki at jp.fujitsu.com>

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>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki at jp.fujitsu.com>
Signed-off-by: Wen Congyang <wency at cn.fujitsu.com>
---
 drivers/base/node.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index af1a177..07523fb 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -252,6 +252,16 @@ static inline void hugetlb_register_node(struct node *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);
+
+#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS)
+	flush_work(&node_dev->node_work);
+#endif
+
+	memset(node_dev, 0, sizeof(struct node));
+}
 
 /*
  * register_node - Setup a sysfs device for a node.
@@ -265,6 +275,7 @@ int register_node(struct node *node, int num, struct node *parent)
 
 	node->dev.id = num;
 	node->dev.bus = &node_subsys;
+	node->dev.release = node_device_release;
 	error = device_register(&node->dev);
 
 	if (!error){
-- 
1.7.1