Re: [PATCH 0/5] export __clear_page_buffers to cleanup code

[Guoqing Jiang <guoqing.jiang@cloud.ionos.com>]

On 19.04.20 05:14, Matthew Wilcox wrote:
> On Sun, Apr 19, 2020 at 12:51:18AM +0200, Guoqing Jiang wrote:
>> When reading md code, I find md-bitmap.c copies __clear_page_buffers from
>> buffer.c, and after more search, seems there are some places in fs could
>> use this function directly. So this patchset tries to export the function
>> and use it to cleanup code.
> OK, I see why you did this, but there are a couple of problems with it.
>
> One is just a sequencing problem; between exporting __clear_page_buffers()
> and removing it from the md code, the md code won't build.

Thank for reminder, I missed that.

> More seriously, most of this code has nothing to do with buffers.  It
> uses page->private for its own purposes.
>
> What I would do instead is add:
>
> clear_page_private(struct page *page)
> {
> 	ClearPagePrivate(page);
> 	set_page_private(page, 0);
> 	put_page(page);
> }
>
> to include/linux/mm.h, then convert all callers of __clear_page_buffers()
> to call that instead.
>

Thanks for your suggestion!

Thanks,
Guoqing