Re: Fix potential data loss and corruption due to Incorrect BIO Chain Handling

Stephen Zhang
2025-11-28T01:30:36Z

Christoph Hellwig <hch@infradead.org> 于2025年11月27日周四 15:17写道：
>
> On Thu, Nov 27, 2025 at 03:05:29PM +0800, Stephen Zhang wrote:
> > No, they are not using bcache.
>
> Then please figure out how bio_chain_endio even gets called in this
> setup. I think for mainline the approach should be to fix bcache
> and eorfs to not call into ->bi_end_io and add a BUG_ON() to
> bio_chain_endio to ensure no new callers appear. I
>

Okay, thanks for the suggestion.

> > If there are no further objections or other insights regarding this issue,
> > I will proceed with creating a v2 of this series.
>
> Not sure how that is helpful. You have a problem on a kernel from stone
> age, can't explain what actually happens and propose something that is
> mostly a no-op in mainline, with the callers that could even reach the
> area being clear API misuse.
>

Analysis of the 4.19 kernel bug confirmed it was not caused by the
->bi_end_io call. Instead, this investigation led us to discover a different bug
in the upstream kernel. The v2 patch series is dedicated to fixing this newly
found upstream issue.

Thanks,
shida
>