Re: [PATCH] mm: zswap: fix zswap_never_enabled() for CONFIG_ZSWAP==N

[Nhat Pham <nphamcs@gmail.com>]

On Sat, Jun 29, 2024 at 4:22 PM Barry Song <21cnbao@gmail.com> wrote:
>
> From: Barry Song <v-songbaohua@oppo.com>
>
> If CONFIG_ZSWAP is set to N, it means zswap cannot be enabled.
> zswap_never_enabled() should return true.
>
> Fixes: 0300e17d67c3 ("mm: zswap: add zswap_never_enabled()")
> Signed-off-by: Barry Song <v-songbaohua@oppo.com>
> Cc: Yosry Ahmed <yosryahmed@google.com>
> Cc: Nhat Pham <nphamcs@gmail.com>
> Cc: Chengming Zhou <chengming.zhou@linux.dev>
> Cc: Chris Li <chrisl@kernel.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  include/linux/zswap.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/zswap.h b/include/linux/zswap.h
> index bf83ae5e285d..6cecb4a4f68b 100644
> --- a/include/linux/zswap.h
> +++ b/include/linux/zswap.h
> @@ -68,7 +68,7 @@ static inline bool zswap_is_enabled(void)
>
>  static inline bool zswap_never_enabled(void)
>  {
> -       return false;
> +       return true;
>  }
>
>  #endif
> --
> 2.34.1
>

That's some pretty yikesy bug :) Thankfully this seems unused thus far
(which is probably why it is not caught until now).
Thanks for fixing this, Barry!

Reviewed-by: Nhat Pham <nphamcs@gmail.com>