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Subject: Re: [RFC PATCH 8/9] orangefs: use set/clear_fs_page_private
To:     Dave Chinner <david@fromorbit.com>,
        Matthew Wilcox <willy@infradead.org>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        hch@infradead.org, Mike Marshall <hubcap@omnibond.com>,
        Martin Brandenburg <martin@omnibond.com>,
        devel@lists.orangefs.org
References: <20200426214925.10970-1-guoqing.jiang@cloud.ionos.com>
 <20200426214925.10970-9-guoqing.jiang@cloud.ionos.com>
 <20200426222455.GB2005@dread.disaster.area>
 <20200427001234.GB29705@bombadil.infradead.org>
 <20200427022709.GC2005@dread.disaster.area>
From:   Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Message-ID: <ac7728a0-c184-214a-70a9-ae219db72331@cloud.ionos.com>
Date:   Mon, 27 Apr 2020 10:18:30 +0200
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Hi Mattew and Dave,

On 4/27/20 4:27 AM, Dave Chinner wrote:
> On Sun, Apr 26, 2020 at 05:12:34PM -0700, Matthew Wilcox wrote:
>> On Mon, Apr 27, 2020 at 08:24:55AM +1000, Dave Chinner wrote:
>>>> @@ -460,17 +456,13 @@ static void orangefs_invalidatepage(struct page *page,
>>>>   
>>>>   	if (offset == 0 && length == PAGE_SIZE) {
>>>>   		kfree((struct orangefs_write_range *)page_private(page));
>>>> -		set_page_private(page, 0);
>>>> -		ClearPagePrivate(page);
>>>> -		put_page(page);
>>>> +		clear_fs_page_private(page);
>>> Ditto:
>>> 		wr = clear_fs_page_private(page);
>>> 		kfree(wr);
>> You don't want to be as succinct as the btrfs change you suggested?
>>
>> 		kfree(clear_fs_page_private(page));
> That could be done, yes. I was really just trying to point out the
> use after free that was occurring here rather than write compact
> code...

Really appreciate for your review, thanks.

Best Regards,
Guoqing