Re: [PATCH] ch: add refcounting

[Christoph Hellwig <hch@infradead.org>]

On Thu, Apr 10, 2014 at 04:12:57PM +0200, Hannes Reinecke wrote:
> On 04/10/2014 01:51 PM, Christoph Hellwig wrote:
> >>  static int
> >>  ch_release(struct inode *inode, struct file *file)
> >>  {
> >>  	scsi_changer *ch = file->private_data;
> >>  
> >>  	scsi_device_put(ch->device);
> >> +	ch->device = NULL;
> >>  	file->private_data = NULL;
> >> +	kref_put(&ch->ref, ch_destroy);
> > 
> > Any reason you need to put the scsi_device here already?  Defering
> > this would give you much eaiser life time rules, and no need to
> > deal with a NULL ch->device ever.
> > 
> Sure. But this would require a far more in-depth analysis of the
> lifetime of the ch object, and most likely a far more intrusive
> patch. You're welcome to do so :-)
> 
> This patch is just a minimal fix; I didn't dare to change too much
> of the internals.

Oh well, let's go with your simpler version for now.

Reviewed-by: Christoph Hellwig <hch@lst.de>