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Date: Mon, 28 Apr 2025 12:07:06 -0600
From: Keith Busch <kbusch@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>, Yu Kuai <yukuai1@huaweicloud.com>,
	linux-block@vger.kernel.org, Hannes Reinecke <hare@suse.de>,
	Yu Kuai <yukuai3@huawei.com>
Subject: Re: [PATCH 4/5] brd: split I/O at page boundaries
Message-ID: <aA_Dyp97AIAqJ70G@kbusch-mbp.dhcp.thefacebook.com>
References: <20250428141014.2360063-1-hch@lst.de>
 <20250428141014.2360063-5-hch@lst.de>
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In-Reply-To: <20250428141014.2360063-5-hch@lst.de>

On Mon, Apr 28, 2025 at 07:09:50AM -0700, Christoph Hellwig wrote:
> A lot of complexity in brd stems from the fact that it tries to handle
> I/O spanning two backing pages.  Instead limit the size of a single
> bvec iteration so that it never crosses a page boundary and remove all
> the now unneeded code.

Doesn't bio_for_each_segment() already limit bvecs on page boundaries?
You'd need to use bio_for_each_bvec() to get multi-page bvecs.