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Date: Fri, 16 May 2025 08:22:43 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: <andrew+netdev@lunn.ch>, <davem@davemloft.net>, <edumazet@google.com>,
 <horms@kernel.org>, <netdev@vger.kernel.org>, <pabeni@redhat.com>,
 <sdf@fomichev.me>
Subject: Re: [PATCH net-next] net: let lockdep compare instance locks
Message-ID: <20250516082243.1befa6f4@kernel.org>
In-Reply-To: <20250516030000.48858-1-kuniyu@amazon.com>
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On Thu, 15 May 2025 19:59:41 -0700 Kuniyuki Iwashima wrote:
> > Is the thinking that once the big rtnl lock disappears in cleanup_net
> > the devices are safe to destroy without any locking because there can't
> > be any live users trying to access them?  
> 
> I hope yes, but removing VF via sysfs and removing netns might
> race and need some locking ?

I think we should take the small lock around default_device_exit_net()
and then we'd be safe? Either a given VF gets moved to init_net first
or the sysfs gets to it and unregisters it safely in the old netns.