Re: [PATCH v3 1/8] xfs: fix iomap hole map reporting for zoned zero range

[Christoph Hellwig <hch@infradead.org>]

On Mon, Mar 09, 2026 at 09:44:59AM -0400, Brian Foster wrote:
> The hole mapping logic for zero range in zoned mode is not quite
> correct. It currently reports a hole whenever one exists in the data
> fork. If the first write to a sparse range has completed and not yet
> written back, the blocks exist in the COW fork as delalloc until
> writeback completes, at which point they are allocated and mapped
> into the data fork. If a zero range occurs on a range that has not
> yet populated the data fork, we will incorrectly report it as a
> hole.
> 
> Note that this currently functions correctly because we are bailed
> out by the pagecache flush in iomap_zero_range(). If a hole or
> unwritten mapping is reported with dirty pagecache, it assumes there
> is pending data, flushes to induce any pending block
> allocations/remaps, and retries the lookup. We want to remove this
> hack from iomap, however, so update iomap_begin() to only report a
> hole for zeroing when one exists in both forks.
> 
> Signed-off-by: Brian Foster <bfoster@redhat.com>

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>