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Date: Fri, 23 May 2025 05:46:57 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Keith Busch <kbusch@meta.com>
Cc: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org,
	Keith Busch <kbusch@kernel.org>
Subject: Re: [PATCH 2/5] block: add support for copy offload
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On Wed, May 21, 2025 at 03:31:04PM -0700, Keith Busch wrote:
>  struct bio_vec {
> -	struct page	*bv_page;
> -	unsigned int	bv_len;
> -	unsigned int	bv_offset;
> +	union {
> +		struct {
> +			struct page	*bv_page;
> +			unsigned int	bv_len;
> +			unsigned int	bv_offset;
> +		};
> +		struct {
> +			sector_t	bv_sector;
> +			sector_t	bv_sectors;
> +		};
> +	};

Urrgg.  Please don't overload the bio_vec. We've been working hard to
generalize it and share the data structures with more users in the
block layer.  If having a bio for each source range is too much overhead
for your user case (but I'd like to numbers for that), we'll need to
find a way to do that without overloading the actual bio_vec structure.