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Date: Mon, 2 Nov 2026 15:41:03 +0100
From: Florian Westphal <fw@strlen.de>
To: Christian Brauner <brauner@kernel.org>
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Subject: Re: [PATCH RFC 03/38] netfilter: xt_recent: don't remove the proc
 entries under a spinlock
Message-ID: <auig_zhd3L0HEis3@strlen.de>
References: <20261102-work-procfs-bugfixes-v1-0-59422ed3e465@kernel.org>
 <20261102-work-procfs-bugfixes-v1-3-59422ed3e465@kernel.org>
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In-Reply-To: <20261102-work-procfs-bugfixes-v1-3-59422ed3e465@kernel.org>

Christian Brauner <brauner@kernel.org> wrote:
> recent_proc_net_exit() removes the proc entries of all tables with
> recent_lock held. remove_proc_entry() waits until nobody calls into the
> entry anymore, and reading one of them takes recent_lock in
> recent_seq_start() while procfs has the entry pinned. So when a reader
> gets there while the network namespace goes away, the exit path sleeps
> with a spinlock held and bh disabled, waiting for a reader that spins
> on that very lock:

Yes, but note that this change is already part of a pending nf -> net
merge request.