Re: [PATCH v2 2/6] dax: fix cache flush on PMD-mapped pages

[Jan Kara]

On Wed 02-02-22 22:33:03, Muchun Song wrote:
> The flush_cache_page() only remove a PAGE_SIZE sized range from the cache.
> However, it does not cover the full pages in a THP except a head page.
> Replace it with flush_cache_range() to fix this issue.
> 
> Fixes: f729c8c9b24f ("dax: wrprotect pmd_t in dax_mapping_entry_mkclean")
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/dax.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index 88be1c02a151..e031e4b6c13c 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -857,7 +857,8 @@ static void dax_entry_mkclean(struct address_space *mapping, pgoff_t index,
>  			if (!pmd_dirty(*pmdp) && !pmd_write(*pmdp))
>  				goto unlock_pmd;
>  
> -			flush_cache_page(vma, address, pfn);
> +			flush_cache_range(vma, address,
> +					  address + HPAGE_PMD_SIZE);
>  			pmd = pmdp_invalidate(vma, address, pmdp);
>  			pmd = pmd_wrprotect(pmd);
>  			pmd = pmd_mkclean(pmd);
> -- 
> 2.11.0
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR