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Date: Thu, 9 Nov 2023 22:36:47 -0800
From: Christoph Hellwig <hch@infradead.org>
To: ed.tsai@mediatek.com
Cc: ming.lei@redhat.com, hch@lst.de, Jens Axboe <axboe@kernel.dk>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	wsd_upstream@mediatek.com, chun-hung.wu@mediatek.com,
	casper.li@mediatek.com, will.shiu@mediatek.com,
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	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org
Subject: Re: [PATCH v2] block: limit the extract size to align queue limit
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Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org

On Fri, Nov 10, 2023 at 01:19:49PM +0800, ed.tsai@mediatek.com wrote:
> +	if (bdev && blk_queue_pci_p2pdma(bdev->bd_disk->queue))
>  		extraction_flags |= ITER_ALLOW_P2PDMA;

As pointed out in reply to Ming, you really need to first figure out
if we can assume we have a valid bdev or not, and if not pass all the
relevant information separately.

> +	if (bdev && bio_op(bio) != REQ_OP_ZONE_APPEND) {
> +		unsigned int max = queue_max_bytes(bdev_get_queue(bdev));

The higher level code must not look at queue_max_bytes, that is only
used for splitting and might not even be initialized.