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

zhangshida posted 3 patches 2 months, 1 week ago
There is a newer version of this series
[PATCH v4 2/3] block: prohibit calls to bio_chain_endio
Posted by zhangshida 2 months, 1 week ago
From: Shida Zhang <zhangshida@kylinos.cn>

Now that all potential callers of bio_chain_endio have been
eliminated, completely prohibit any future calls to this function.

Suggested-by: Ming Lei <ming.lei@redhat.com>
Suggested-by: Andreas Gruenbacher <agruenba@redhat.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
---
 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);
 }
 
 /**
-- 
2.34.1
Re: [PATCH v4 2/3] block: prohibit calls to bio_chain_endio
Posted by Andreas Gruenbacher 2 months, 1 week ago
On Mon, Dec 1, 2025 at 10:05 AM zhangshida <starzhangzsd@gmail.com> wrote:
> From: Shida Zhang <zhangshida@kylinos.cn>
>
> Now that all potential callers of bio_chain_endio have been
> eliminated, completely prohibit any future calls to this function.
>
> Suggested-by: Ming Lei <ming.lei@redhat.com>
> Suggested-by: Andreas Gruenbacher <agruenba@redhat.com>
> Suggested-by: Christoph Hellwig <hch@infradead.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
> ---
>  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
Re: [PATCH v4 2/3] block: prohibit calls to bio_chain_endio
Posted by Stephen Zhang 2 months, 1 week ago
Andreas Gruenbacher <agruenba@redhat.com> 于2025年12月1日周一 17:34写道:
>
> On Mon, Dec 1, 2025 at 10:05 AM zhangshida <starzhangzsd@gmail.com> wrote:
> > From: Shida Zhang <zhangshida@kylinos.cn>
> >
> > Now that all potential callers of bio_chain_endio have been
> > eliminated, completely prohibit any future calls to this function.
> >
> > Suggested-by: Ming Lei <ming.lei@redhat.com>
> > Suggested-by: Andreas Gruenbacher <agruenba@redhat.com>
> > Suggested-by: Christoph Hellwig <hch@infradead.org>
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
> > ---
> >  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()'.
>

Yeah, that’s much clearer now. I'll resend the updated version.

Thanks,
Shida

> >  }
> >
> >  /**
>
> > --
> > 2.34.1
> >
>
> Andreas
>