Re: [RFC PATCH 8/9] orangefs: use set/clear_fs_page_private

Guoqing Jiang
2020-04-27T08:18:38Z

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