On Wed, Sep 14, 2022 at 11:37 AM zhaoyang.huang
<zhaoyang.huang@xxxxxxxxxx> wrote:
>
> From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
>
> The page with special page type will be deemed as bad page wrongly since
> type share the same address with mapcount.
>
> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
> ---
> include/linux/page-flags.h | 4 ++--
> mm/page_alloc.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
> index e66f7aa..5d3274b 100644
> --- a/include/linux/page-flags.h
> +++ b/include/linux/page-flags.h
> @@ -946,9 +946,9 @@ static inline bool is_page_hwpoison(struct page *page)
> #define PageType(page, flag) \
> ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
>
> -static inline int page_has_type(struct page *page)
> +static inline bool page_has_type(struct page *page)
> {
> - return (int)page->page_type < PAGE_MAPCOUNT_RESERVE;
> + return (int)page->page_type < PAGE_MAPCOUNT_RESERVE;
amend the type conversion
> }
>
> #define PAGE_TYPE_OPS(uname, lname) \
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e008a3d..3714680 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1164,7 +1164,7 @@ int split_free_page(struct page *free_page,
> static inline bool page_expected_state(struct page *page,
> unsigned long check_flags)
> {
> - if (unlikely(atomic_read(&page->_mapcount) != -1))
> + if (unlikely(!page_has_type(page) && atomic_read(&page->_mapcount) != -1))
> return false;
>
> if (unlikely((unsigned long)page->mapping |
> --
> 1.9.1
>
