ch: fix ch_remove oops

The latest git and 2.6.26 needs this fix.

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From: FUJITA Tomonori <[email protected]>
Subject: [PATCH] ch: fix ch_remove oops

The following commit causes ch_remove oops:

commit 24b42566c3fcbb5a9011d1446783d0f5844ccd45

Author: Greg Kroah-Hartman <[email protected]>
Date:   Fri May 16 17:55:12 2008 -0700

SCSI: fix race in device_create

There is a race from when a device is created with device_create() and then the drvdata is set with a call to dev_set_drvdata() in which a sysfs file could be open, yet the drvdata will be NULL, causing all sorts of bad things to happen.

This patch fixes the problem by using the new function, device_create_drvdata(). It fixes the problem in all of the scsi drivers that need it.

The problem is ch_probe stores ch's private data at a wrong place.

We need to store it at scsi_device->sdev_gendev but the above patch stores it at device struct that device_create_drvdata returns. So we hit an oops when ch_remove accesses scsi_device->sdev_gendev->driver_data, which is NULL.

Actually, there wasn't a race because ch doesn't create sysfs files with device struct that device_create returns. This patch puts back dev_set_drvdata() to set ch's private data properly.

---
 drivers/scsi/ch.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

index aa2011b..3c257fe 100644
@@ -930,6 +930,7 @@ static int ch_probe(struct device *dev)
 	if (init)
 		ch_init_elem(ch);
 
+	dev_set_drvdata(dev, ch);
 	sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
 
 	return 0;

1.5.4.2