Commit a1470c7b authored Nov 15, 2013 by James Bottomley

[SCSI] enclosure: fix WARN_ON in dual path device removing



Bug report from: wenxiong@linux.vnet.ibm.com

The issue is happened in dual controller configuration. We got the
sysfs warnings when rmmod the ipr module.

enclosure_unregister() in drivers/msic/enclosure.c, call device_unregister()
for each componment deivce, device_unregister() ->device_del()->kobject_del()
->sysfs_remove_dir(). In sysfs_remove_dir(), set kobj->sd = NULL.

For each componment device,
enclosure_component_release()->enclosure_remove_links()->sysfs_remove_link()
in which checking kobj->sd again, it has been set as NULL when doing
device_unregister. So we saw all these sysfs WARNING.

Tested-by:  <wenxiong@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

parent 6cd60b37

drivers/misc/enclosure.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -198,6 +198,13 @@ static void enclosure_remove_links(struct enclosure_component *cdev)
		{
		char name[ENCLOSURE_NAME_SIZE];

		/*
		* In odd circumstances, like multipath devices, something else may
		* already have removed the links, so check for this condition first.
		*/
		if (!cdev->dev->kobj.sd)
		return;

		enclosure_link_name(cdev, name);
		sysfs_remove_link(&cdev->dev->kobj, name);
		sysfs_remove_link(&cdev->cdev.kobj, "device");

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