Re: [PATCH RFC 06/14] fs/f2fs: stop using PG_private

[Usama Arif]

On Fri, 31 Jul 2026 22:13:29 -0400 Zi Yan <ziy@xxxxxxxxxx> wrote:

> f2fs sets its PAGE_PRIVATE_* flags in page->private and checking
> page->private != NULL is equivalent to checking PG_private. Change
> PagePrivate() to page_private(). Meanwhile, in set_page_private_##name(),
> page->private is first set to 0/NULL before an PAGE_PRIVATE_* flag is set,
> but it can cause confusion when PG_private is removed and
> page->private != NULL is used instead. Change it to initialize
> page->private to PAGE_PRIVATE_NOT_POINTER instead and retain the original
> semantics.
> 
> It prepares for a future commit that removes PG_private.
> 
> No funtional change intended.
> 
> Assisted-by: Claude:claude-opus-4-8
> Assisted-by: Codex:gpt-5
> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
> To: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> To: Chao Yu <chao@xxxxxxxxxx>
> Cc: linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
>  fs/f2fs/f2fs.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

Acked-by: Usama Arif <usama.arif@xxxxxxxxx>

> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 8f3e632f315cc..edf01eb4b3b30 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -2643,7 +2643,7 @@ static inline bool folio_test_f2fs_##name(const struct folio *folio)	\
>  }									\
>  static inline bool page_private_##name(struct page *page) \
>  { \
> -	return PagePrivate(page) && \
> +	return page_private(page) && \
>  		test_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)) && \
>  		test_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \
>  }
> @@ -2662,9 +2662,9 @@ static inline void folio_set_f2fs_##name(struct folio *folio)		\
>  }									\
>  static inline void set_page_private_##name(struct page *page) \
>  { \
> -	if (!PagePrivate(page)) \
> -		attach_page_private(page, (void *)0); \
> -	set_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)); \
> +	if (!page_private(page)) \
> +		attach_page_private(page, \
> +				(void *)BIT(PAGE_PRIVATE_NOT_POINTER)); \
>  	set_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \
>  }
>  
> 
> -- 
> 2.53.0
> 
>