Re: [PATCH v4 2/3] block: prohibit calls to bio_chain_endio

On Mon, Dec 1, 2025 at 10:05 AM zhangshida <[email protected]> wrote:
> From: Shida Zhang <[email protected]>
>
> Now that all potential callers of bio_chain_endio have been
> eliminated, completely prohibit any future calls to this function.
>
> Suggested-by: Ming Lei <[email protected]>
> Suggested-by: Andreas Gruenbacher <[email protected]>
> Suggested-by: Christoph Hellwig <[email protected]>
> Reviewed-by: Christoph Hellwig <[email protected]>
> Signed-off-by: Shida Zhang <[email protected]>
> ---
>  block/bio.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/block/bio.c b/block/bio.c
> index b3a79285c27..1b5e4577f4c 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -320,9 +320,13 @@ static struct bio *__bio_chain_endio(struct bio *bio)
>         return parent;
>  }
>
> +/**
> + * This function should only be used as a flag and must never be called.
> + * If execution reaches here, it indicates a serious programming error.
> + */
>  static void bio_chain_endio(struct bio *bio)
>  {
> -       bio_endio(__bio_chain_endio(bio));
> +       BUG_ON(1);

Just 'BUG()'.

>  }
>
>  /**

> --
> 2.34.1
>

Andreas