Re: [PATCH] Fix reference counting for failed SCSI devices

James Bottomley
2005-05-25T12:27:52Z

On Wed, 2005-05-25 at 08:50 +0200, Hannes Reinecke wrote:
> >>+ class_device_put(&sdev->sdev_classdev);
> >
> > This is unnecessary since the class device is simply occupying a private
> > area in the scsi_device. As long as its never made visible to the
> > system, its refcount is irrelevant
> >
> It's not. Whenever you try to rmmod the adapter it becomes highly
> relevant. If it doesn't crash you've at least generated a memleak as the
> class device is never freed.
> (And these are quite a few for Wide-SCSI Double-channel adapters ...)

? Look at the code; you're not doing a put on a pointer to the
sdev_classdev, you're doing a put on a reference to it.

It's defined in scsi_device.h:

struct scsi_device {
...
struct class_device sdev_classdev;
...
};

so it's contained within the scsi_device. Freeing the scsi_device frees
the classdev (and the gendev).

James