Re: [f2fs-dev] [PATCH 1/3] f2fs: call flush_dcache_page when the page was updated

[Jaegeuk Kim]

On Thu, Nov 20, 2014 at 03:04:10PM +0900, Changman Lee wrote:
> Hi Jaegeuk,
> 
> We should call flush_dcache_page before kunmap because the purpose of the cache flush is to address aliasing problem related to virtual address.

Oh, I just followed zero_user_segments below.

static inline void zero_user_segments(struct page *page,
	unsigned start1, unsigned end1,
	unsigned start2, unsigned end2)
{
	void *kaddr = kmap_atomic(page);

	BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);

	if (end1 > start1)
		memset(kaddr + start1, 0, end1 - start1);

	if (end2 > start2)
		memset(kaddr + start2, 0, end2 - start2);

	kunmap_atomic(kaddr);
	flush_dcache_page(page);
}

Is this a wrong reference? Or, a bug?

Anyway I modified as below.

Thanks,