Re: [BUG] iomap/io_uring: O_APPEND async buffered write silently re-appends a data chunk (corruption) on XFS, 6.1.y/6.12.y

On Mon, Jun 8, 2026 at 12:03 PM Brian Foster <[email protected]> wrote:
> Another idea that came to mind is to try and just replace the -EAGAIN
> return sequence from the low level iterator with a flag that triggers
> -EAGAIN from the next iter advance. The idea here is to allow the write
> to return partial completion (i.e. so no iov_iter revert) without having
> to return an error from the lowest level in the stack. I had claude come
> up with a quick patch [1] for reference/experimentation.
>
> This is based on v6.12 stable and compile tested only. It needs more
> review and testing in general but might be worth throwing your
> reproducer at if you can..?

With that patch applied, the reproducer runs clean - no errors - and
gets roughly the same performance (maybe slightly better) as when run
against a 6.18 kernel on the same VM.

Thanks,
-Eric