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Date: Wed, 4 Oct 2023 10:09:55 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Lorenzo Bianconi <lorenzo@kernel.org>
Cc: linux-nfs@vger.kernel.org, lorenzo.bianconi@redhat.com,
 jlayton@kernel.org, neilb@suse.de, chuck.lever@oracle.com,
 netdev@vger.kernel.org
Subject: Re: [PATCH v3] NFSD: convert write_threads, write_maxblksize and
 write_maxconn to netlink commands
Message-ID: <20231004100955.32417c33@kernel.org>
In-Reply-To: <27646a34a3ddac3e0b0ad9b49aaf66b3cee5844f.1695766257.git.lorenzo@kernel.org>
References: <27646a34a3ddac3e0b0ad9b49aaf66b3cee5844f.1695766257.git.lorenzo@kernel.org>
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On Wed, 27 Sep 2023 00:13:15 +0200 Lorenzo Bianconi wrote:
> +int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info)
> +{
> +	u32 nthreads;
> +	int ret;
> +
> +	if (!info->attrs[NFSD_A_CONTROL_PLANE_THREADS])
> +		return -EINVAL;

Consider using GENL_REQ_ATTR_CHECK(), it will auto-add nice error
message to the reply on error.

> +	nthreads = nla_get_u32(info->attrs[NFSD_A_CONTROL_PLANE_THREADS]);
> +
> +	ret = nfsd_svc(nthreads, genl_info_net(info), get_current_cred());
> +	return ret == nthreads ? 0 : ret;
> +}
> +
> +static int nfsd_nl_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
> +			    int cmd, int attr, u32 val)

YNL will dutifully return a list for every dump. If you're only getting
a single reply 'do' will be much better.