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Date: Wed, 22 Sep 2010 12:02:30 +0200
From: Boaz Harrosh <bharrosh@panasas.com>
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To: Kay Sievers <kay.sievers@vrfy.org>
CC: Greg KH <greg@kroah.com>, Andrew Morton <akpm@linux-foundation.org>,
        Vasiliy Kulikov <segooon@gmail.com>, kernel-janitors@vger.kernel.org,
        Tejun Heo <tj@kernel.org>, Jiri Slaby <jirislaby@gmail.com>,
        linux-kernel@vger.kernel.org,
        James Bottomley <James.Bottomley@suse.de>,
        Dan Carpenter <error27@gmail.com>
Subject: Re: [PATCH 04/14] memstick: core: fix device_register() error handling
References: <1284900889-24369-1-git-send-email-segooon@gmail.com> <20100921152031.30365b3f.akpm@linux-foundation.org> <20100921224947.GA20183@kroah.com> <AANLkTimQWtQTBe3RBSbYd7vM4Y+SckkoBDbO8E+SwtJj@mail.gmail.com>
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On 09/22/2010 10:53 AM, 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.
> 
> I never liked this pretty useless "convenience API", which just wraps
> two simple functions and the first one can never fail anyway.
> 
> 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.
> 

That would be fine, and ping me when you do it, I'll help with my
driver. But don't forget to let us have a way to embed a device inside
a bigger structure.

For meanwhile Please check the patch James sent to add_device that cleans
up the allocation of the kobj.name member. (And the comment made there)

> Kay

Thanks
Boaz