From: Jakub Kicinski <kuba@kernel.org>
To: Stanislav Fomichev <sdf.kernel@gmail.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com,
pabeni@redhat.com
Subject: Re: [PATCH net-next 6/6] net: document NETDEV_UNREGISTER unlocked rationale
Date: Tue, 30 Jun 2026 16:43:36 -0700 [thread overview]
Message-ID: <20260630164336.1350403f@kernel.org> (raw)
In-Reply-To: <20260630182129.1601784-7-sdf@fomichev.me>
On Tue, 30 Jun 2026 11:21:29 -0700 Stanislav Fomichev wrote:
> +Many ``NETDEV_UNREGISTER`` handlers release their lowers with
> +``dev_close()``, which takes the instance lock itself. Holding
> +the lock across UNREGISTER would deadlock.
> +
> +Moving UNREGISTER under the lock is mechanical: switch those
> +callers to the ``netif_*()`` lock-held variants. Deferred to
> +limit churn.
Not following TBH. Let's say there's a UNREGISTER ntf for eth0.
Are you saying that eg. vlan which closes their own vlan0 devices
on top of eth0 needs to be switched to netif_ ? That wouldn't make
sense since the notification is holding netdev_lock(eth0) and
we're talking about netif_close(vlan0)?
Doing anything with the device that is sending the UNREGISTER
sounds odd, since it's going away..
next prev parent reply other threads:[~2026-06-30 23:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-30 18:21 [PATCH net-next 0/6] net: hold instance lock around NETDEV_DOWN and NETDEV_GOING_DOWN Stanislav Fomichev
2026-06-30 18:21 ` [PATCH net-next 1/6] net: hold instance lock around NETDEV_DOWN/GOING_DOWN Stanislav Fomichev
2026-06-30 18:21 ` [PATCH net-next 2/6] net: dsa: hold instance lock on close-on-shutdown paths Stanislav Fomichev
2026-06-30 18:21 ` [PATCH net-next 3/6] net: mtk_eth_soc: hold instance lock around DMA-device-swap close Stanislav Fomichev
2026-06-30 18:21 ` [PATCH net-next 4/6] net: rtnetlink: take instance lock inside rtnl_configure_link Stanislav Fomichev
2026-06-30 18:21 ` [PATCH net-next 5/6] net: require instance lock for NETDEV_DOWN/GOING_DOWN notifiers Stanislav Fomichev
2026-06-30 18:21 ` [PATCH net-next 6/6] net: document NETDEV_UNREGISTER unlocked rationale Stanislav Fomichev
2026-06-30 23:43 ` Jakub Kicinski [this message]
2026-07-01 16:02 ` Stanislav Fomichev
2026-07-01 16:52 ` Jakub Kicinski
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