Date: Tue, 4 Nov 2014 22:29:43 -0500
From: Tejun Heo <tj@kernel.org>
To: Yijing Wang <wangyijing@huawei.com>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>,
        Greg KH <gregkh@linuxfoundation.org>,
        Frans Klaver <fransklaver@gmail.com>, Jens Axboe <axboe@kernel.dk>,
        akpm@linux-foundation.org, adilger.kernel@dilger.ca,
        Jan Kara <jack@suse.cz>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Xiang Rui <rui.xiang@huawei.com>, Li Zefan <lizefan@huawei.com>,
        Huang Qiang <h.huangqiang@huawei.com>,
        Zhao Hongjiang <zhaohongjiang@huawei.com>
Subject: Re: Subject: [PATCH] kobject: fix the race between kobject_del and
 get_device_parent
Message-ID: <20141105032943.GB29392@htj.dyndns.org>
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 <543F7289.8010807@huawei.com>
 <20141016091328.GB24374@kroah.com>
 <544765D0.70302@huawei.com>
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Hello,

On Wed, Nov 05, 2014 at 11:27:39AM +0800, Yijing Wang wrote:
> Keep the parent directory looks good to me,  we could only add kobject_get(&parent)
> after the parent dir be created.
> 
> ....
> 		/* or create a new class-directory at the parent device */
> 		k = class_dir_create_and_add(dev->class, parent_kobj);
> 		/* do not emit an uevent for this simple "glue" directory */
> 		kobject_get(k);  <--------add parent ref count for first child device.

The created directory would already have the base ref.  I don't think
you need the above.  Just never put the parent once created.

Greg, how does this sound to you?

Thanks.

-- 
tejun
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