[PATCH 2/2]suppress "Device nodeX does not have a release() function"warning

From: Yasuaki Ishimatsu
Date: Thu Oct 11 2012 - 01:27:01 EST


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."

The reason is node's device struct does not have a release() function.

So the patch registers node_device_release() to the device's release()
function for suppressing the warning message. Additionally, the patch adds
memset() to initialize a node struct into register_node(). Because the node
struct is part of node_devices[] array and it cannot be freed by
node_device_release(). So if system reuses the node struct, it has a garbage.

CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
drivers/base/node.c | 11 +++++++++++
1 file changed, 11 insertions(+)

Index: linux-3.6/drivers/base/node.c
===================================================================
--- linux-3.6.orig/drivers/base/node.c 2012-10-11 10:04:02.149758748 +0900
+++ linux-3.6/drivers/base/node.c 2012-10-11 10:20:34.111806931 +0900
@@ -252,6 +252,14 @@ static inline void hugetlb_register_node
static inline void hugetlb_unregister_node(struct node *node) {}
#endif

+static void node_device_release(struct device *dev)
+{
+#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS)
+ struct node *node_dev = to_node(dev);
+
+ flush_work(&node_dev->node_work);
+#endif
+}

/*
* register_node - Setup a sysfs device for a node.
@@ -263,8 +271,11 @@ int register_node(struct node *node, int
{
int error;

+ memset(node, 0, sizeof(*node));
+
node->dev.id = num;
node->dev.bus = &node_subsys;
+ node->dev.release = node_device_release;
error = device_register(&node->dev);

if (!error){

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