Re: [PATCH] wfx: use container_of() to get vif

From: Kalle Valo <kvalo@kernel.org>
To: Jaehee Park <jhpark1013@gmail.com>
Cc: "Jérôme Pouiller" <jerome.pouiller@silabs.com>,
	"David S. Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Paolo Abeni" <pabeni@redhat.com>,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev,
	outreachy@lists.linux.dev, "Stefano Brivio" <sbrivio@redhat.com>
Subject: Re: [PATCH] wfx: use container_of() to get vif
Date: Wed, 20 Apr 2022 14:57:57 +0300	[thread overview]
Message-ID: <87y200nf0a.fsf@kernel.org> (raw)
In-Reply-To: <20220418035110.GA937332@jaehee-ThinkPad-X1-Extreme> (Jaehee Park's message of "Sun, 17 Apr 2022 23:51:10 -0400")

Jaehee Park <jhpark1013@gmail.com> writes:

> Currently, upon virtual interface creation, wfx_add_interface() stores
> a reference to the corresponding struct ieee80211_vif in private data,
> for later usage. This is not needed when using the container_of
> construct. This construct already has all the info it needs to retrieve
> the reference to the corresponding struct from the offset that is
> already available, inherent in container_of(), between its type and
> member inputs (struct ieee80211_vif and drv_priv, respectively).
> Remove vif (which was previously storing the reference to the struct
> ieee80211_vif) from the struct wfx_vif, define a function
> wvif_to_vif(wvif) for container_of(), and replace all wvif->vif with
> the newly defined container_of construct.
>
> Signed-off-by: Jaehee Park <jhpark1013@gmail.com>

[...]

> +static inline struct ieee80211_vif *wvif_to_vif(struct wfx_vif *wvif)
> +{
> +	return container_of((void *)wvif, struct ieee80211_vif, drv_priv);
> +}

Why the void pointer cast? Avoid casts as much possible.

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