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Date:   Tue, 17 Oct 2023 08:12:15 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Mark O'Donovan <shiftee@posteo.net>
Cc:     linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
        sagi@grimberg.me, hch@lst.de, axboe@kernel.dk, kbusch@kernel.org,
        hare@suse.de, Akash Appaiah <Akash.Appaiah@dell.com>
Subject: Re: [PATCH v3 2/3] nvme-auth: use transformed key size to create
 resp
Message-ID: <20231017061215.GB8454@lst.de>
References: <20231016225857.3085234-1-shiftee@posteo.net> <20231016225857.3085234-3-shiftee@posteo.net>
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> +struct nvme_dhchap_key *nvme_auth_transform_key(struct nvme_dhchap_key *key, char *nqn)

Please avoid the overly long line.

> +		key_len = sizeof(*key) + key->len;

struct_size again.  And maybe add a helper to calculate the size for
a key instea dof duplicating it.

> +		transformed_key = kmemdup(key, key_len, GFP_KERNEL);
>  		return transformed_key ? transformed_key : ERR_PTR(-ENOMEM);

Nit, but I find the ? : syntax very confusing when not used in things
like macros or argument lines.  A 

		if (!transformed_key)
			return ERR_PTR(-ENOMEM);
 		return transformed_key;

is a bit longer, but much easier to read.

>  	}
>  	hmac_name = nvme_auth_hmac_name(key->hash);
> @@ -257,7 +258,7 @@ u8 *nvme_auth_transform_key(struct nvme_dhchap_key *key, char *nqn)
>  
>  	key_tfm = crypto_alloc_shash(hmac_name, 0, 0);
>  	if (IS_ERR(key_tfm))
> -		return (u8 *)key_tfm;
> +		return (void *)key_tfm;

This should (already in the original code) use ERR_CAST instead.

> +	transformed_key = nvme_auth_transform_key(ctrl->host_key, ctrl->hostnqn);

Please avoid the overly long line here as well.

> +struct nvme_dhchap_key *nvme_auth_transform_key(struct nvme_dhchap_key *key, char *nqn);

... and here.