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Subject: Re: [RFC PATCH 6/9] iomap: use set/clear_fs_page_private
To:     Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        david@fromorbit.com, "Darrick J. Wong" <darrick.wong@oracle.com>,
        linux-xfs@vger.kernel.org
References: <20200426214925.10970-1-guoqing.jiang@cloud.ionos.com>
 <20200426214925.10970-7-guoqing.jiang@cloud.ionos.com>
 <20200427002631.GC29705@bombadil.infradead.org>
 <20200427055540.GC16709@infradead.org>
From:   Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Message-ID: <fac074af-02e3-d384-fae0-3219ef83ef76@cloud.ionos.com>
Date:   Mon, 27 Apr 2020 10:15:10 +0200
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On 4/27/20 7:55 AM, Christoph Hellwig wrote:
> On Sun, Apr 26, 2020 at 05:26:31PM -0700, Matthew Wilcox wrote:
>> On Sun, Apr 26, 2020 at 11:49:22PM +0200, Guoqing Jiang wrote:
>>> @@ -59,24 +59,18 @@ iomap_page_create(struct inode *inode, struct page *page)
>>>   	 * migrate_page_move_mapping() assumes that pages with private data have
>>>   	 * their count elevated by 1.
>>>   	 */
>>> -	get_page(page);
>>> -	set_page_private(page, (unsigned long)iop);
>>> -	SetPagePrivate(page);
>>> -	return iop;
>>> +	return (struct iomap_page *)set_fs_page_private(page, iop);
>>>   }
>> This cast is unnecessary.  void * will be automatically cast to the
>> appropriate pointer type.
> I also find the pattern eather strange.  A:
>
> 	attach_page_private(page, iop);
> 	return iop;
>
> explains the intent much better.

Thanks for the review, will do it.

Thanks,
Guoqing