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Date: Thu, 12 Sep 2024 15:18:03 +0200
From: Christoph Hellwig <hch@lst.de>
To: John Garry <john.g.garry@oracle.com>
Cc: axboe@kernel.dk, song@kernel.org, yukuai3@huawei.com, kbusch@kernel.org,
	hch@lst.de, sagi@grimberg.me, James.Bottomley@HansenPartnership.com,
	martin.petersen@oracle.com, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
	linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org
Subject: Re: [PATCH RFC 4/4] md/raid0: Atomic write support
Message-ID: <20240912131803.GD29641@lst.de>
References: <20240903150748.2179966-1-john.g.garry@oracle.com> <20240903150748.2179966-5-john.g.garry@oracle.com>
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On Tue, Sep 03, 2024 at 03:07:48PM +0000, John Garry wrote:
>  	if (sectors < bio_sectors(bio)) {
> -		struct bio *split = bio_split(bio, sectors, GFP_NOIO,
> +		struct bio *split;
> +
> +		if (bio->bi_opf & REQ_ATOMIC)
> +			return false;

I guess this is the erroring out when attempting to split the request.
Can you add a comment to explain that and why it can't happen for the
normal I/O patterns?