Re: [PATCH] device-dax: don't set kobj parent during cdev init

From: Dan Williams
Date: Sat Feb 11 2017 - 13:55:42 EST

On Sat, Feb 11, 2017 at 10:43 AM, Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote:
> On 11/02/17 11:27 AM, Dan Williams wrote:
>> Why, when the lifetime of the cdev is already correct?
> Well, it's only correct if you use the kobj parent trick which Greg is
> arguing against. As someone reviewing/copying code that trick is
> unclear, undocumented and it looks rather odd messing with internal
> kobjects. Taking the explicit reference would be very clear, very
> standard and only net one additional line.
>> See commit ba09c01d2fa8 "dax: convert to the cdev api". I used to take
>> explicit references like you suggest, but cdev made it cleaner.
> I agree that, on the whole, that patch makes things a good deal cleaner.
> I'm not so sure that this one small aspect is an improvement.
> In any case, it's up to you. If you'd like I can certainly submit a v2
> patch that adds the get/put.

Can we meet in the middle and just add some comments about what is going on?

It's a shame to add reference counts for something that is already
properly reference counted.