don't merge bios over iomap boundaries, was: Re: [PATCH] erofs: prevent buffered read bio merges across device chunks

[Christoph Hellwig]

On Fri, Jun 12, 2026 at 11:42:38AM +0800, Gao Xiang wrote:
> > Reported-by: Kelu Ye <yekelu1@xxxxxxxxxx>
> > Assisted-by: Codex:GPT-5.5
> > Signed-off-by: Yifan Zhao <zhaoyifan28@xxxxxxxxxx>
> 
> I think it's an iomap bug instead, see:
> 
> iomap_bio_read_folio_range(), we should fix iomap instead.

Yes.  iomap should not try to build bios over iomap boundaries.
caused various issues.  Ritesh ran into that with the ext2 port
back in the day, and I actually ran into it again with an under
development xfs feature.

Can you try this patch?

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