diff mbox series

[2/5] dax: fix cache flush on PMD-mapped pages

Message ID 20220121075515.79311-2-songmuchun@bytedance.com (mailing list archive)
State New, archived
Headers show
Series [1/5] mm: rmap: fix cache flush on THP pages | expand

Commit Message

Muchun Song Jan. 21, 2022, 7:55 a.m. UTC
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@bytedance.com>
---
 fs/dax.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Christoph Hellwig Jan. 24, 2022, 7:34 a.m. UTC | #1
On Fri, Jan 21, 2022 at 03:55:12PM +0800, 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@bytedance.com>
> ---
>  fs/dax.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index 88be1c02a151..2955ec65eb65 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -857,7 +857,7 @@ 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);

Same comment as for the previous one.
diff mbox series

Patch

diff --git a/fs/dax.c b/fs/dax.c
index 88be1c02a151..2955ec65eb65 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -857,7 +857,7 @@  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);