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Date: Thu, 14 Nov 2024 13:33:24 +0100
From: Christoph Hellwig <hch@lst.de>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Christoph Hellwig <hch@lst.de>, linux-block@vger.kernel.org
Subject: Re: [bug report] block: remove the write_hint field from struct
 request
Message-ID: <20241114123324.GA5936@lst.de>
References: <fff0e493-fc11-4ea1-a75e-454d052d23e5@stanley.mountain>
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On Thu, Nov 14, 2024 at 12:04:03PM +0300, Dan Carpenter wrote:
>    994		if (!blk_cgroup_mergeable(rq, bio))
>                                           ^^
> This dereferences rq->bio->
> 
>    995			return false;
>    996	
>    997		/* only merge integrity protected bio into ditto rq */
>    998		if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
>    999			return false;
>   1000	
>   1001		/* Only merge if the crypt contexts are compatible */
>   1002		if (!bio_crypt_rq_ctx_compatible(rq, bio))
>   1003			return false;
>   1004	
>   1005		if (rq->bio) {
>                     ^^^^^^^
> So this check shouldn't be required.

Hmm.  The only requests without bios are flush and passthrough
requests.  I guess we make sure they never end up here even if
it is not entirely obvious from the code.