Re: [PATCH v2 1/5] iomap, xfs: lift zero range hole mapping flush into xfs

[Christoph Hellwig <hch@infradead.org>]

On Mon, Mar 02, 2026 at 02:02:10PM -0500, Brian Foster wrote:
> I got a chance to look into this. Note that I don't reproduce a
> generic/127 failure (even after running a few iters), so I don't know if
> that might be related to something on your end. I reproduce the other
> two and those looked like straight failures to zero. From that I think
> the issue is just that xfs_zoned_buffered_write_iomap_begin() minimally
> needs the flush treatment from patch 1. I.e., something like the
> appended diff allows these tests to pass with -rzoned=1.
> 
> Technically this could use the folio batch helper, but given that we
> don't use that for the unwritten case (and thus already rely on the
> iomap flush), and that this is currently experimental, I think this is
> probably fine for now. Perhaps if we lift zeroing off into its own set
> of callbacks, that might be a good opportunity to clean this up in both
> places.

Note that unwritten extents aren't supported for zoned rt inodes, so
that case doesn't actually exist.

The changes themselves look good.  I kinda hate the very deep
indentation, but I can't really see a good way to fix that easily.