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Date: Wed, 22 Sep 2010 08:50:04 -0700
From: Greg KH <greg@kroah.com>
To: Kay Sievers <kay.sievers@vrfy.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Vasiliy Kulikov <segooon@gmail.com>, kernel-janitors@vger.kernel.org,
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        linux-kernel@vger.kernel.org,
        James Bottomley <James.Bottomley@suse.de>,
        Dan Carpenter <error27@gmail.com>, Boaz Harrosh <bharrosh@panasas.com>
Subject: Re: [PATCH 04/14] memstick: core: fix device_register() error
 handling
Message-ID: <20100922155004.GC26178@kroah.com>
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On Wed, Sep 22, 2010 at 10:53:21AM +0200, Kay Sievers wrote:
> On Wed, Sep 22, 2010 at 00:49, Greg KH <greg@kroah.com> wrote:
> 
> >  int device_register(struct device *dev)
> >  {
> > +       int retval;
> > +
> >        device_initialize(dev);
> > -       return device_add(dev);
> > +       retval = device_add(dev);
> > +       if (retval)
> > +               put_device(dev);
> > +       return retval;
> >  }
> 
> > Kay, what am I missing here, why can't we just do this?  Hm, the
> > side-affect might be that if device_register() fails, NO ONE had better
> > touch that device again, as it might have just been freed from the
> > system.  I wonder if that will cause problems...
> 
> That looks right, besides that there might be callers already doing
> this. Which needs to be checked.

Yes, it would be.  I'll go through the tree.

> I never liked this pretty useless "convenience API", which just wraps
> two simple functions and the first one can never fail anyway.

Agreed.

> We better remove that device_register() stuff entirely in the long
> run, it's not doing any good. At the kobject level we killed the same
> stuff already long ago.

It's one of the things on my "to change" list.

thanks,

greg k-h