Re: [PATCH 4/4] xfs: fallback to buffered I/O for direct I/O when stable writes are required

Christoph Hellwig
2025-10-30T06:49:22Z

On Thu, Oct 30, 2025 at 05:07:44PM +1030, Qu Wenruo wrote:
> I mean some open flag like O_DIRECT_NO_FALLBACK, then we can directly
> reutrn -ENOBLK without falling back to buffered IO (and no need to bother
> the warning of falling back).
>
> This will provide the most accurate, true zero-copy for those programs that
> really require zero-copy.
>
> And we won't need to bother falling back to buffered IO, it will be
> something for the user space to bother.

So what is your application going to do if the open fails?

>
> Thanks,
> Qu
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