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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=dVMuVeYu; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CA06D606A31A for ; Fri, 30 Oct 2026 12:56:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=dVMuVeYu Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74F391F000C1; Fri, 30 Oct 2026 12:56:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793365010; bh=hlxYCNH4xX2W+jA2Jsv3FHD2vBPtuxYtgLUT6lp5I+c=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=dVMuVeYupsinQkQhlpfMG1pm6IsRP5W0BU8H1KaVMFeRdc1ja39wpsOypbbcODD81 OVq/jrXuc4TsRmlkB2Q5hZQt/CYib23G3VTC4TbF9BPGMkm8XEcTwjPqiI07LzuIy4 a6bbM5A0iO3f0PdQcsdf8V+0BiFNuhU6P/GDkbSEQoTdIqLeao3JKijgHfxaOh+qrY lw9M2RpmXF/fWRNAIgpGaH2kdhMIrVk20pc1WyNHuO6JE7oLXFl+OmzIMUpvkC/Qo3 Gat7W4yxKbSb7nk/xDIgFtp8seWdCe8/6lyMUQSTna/rUgqigk147y/fiyY5yBlY5a QM1pRmt+2t4WA== Message-ID: <22d6d605-cb50-4c73-97b9-8b1602f59fc1@kernel.org> Date: Fri, 30 Oct 2026 13:56:46 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/9] w1: remove the master's files before taking its locks To: Greg Kroah-Hartman Cc: Josef Bacik , linux-kernel@vger.kernel.org, stable References: <20261027-llm-char-misc-w1-v1-0-d2e6bfafb6a4@linuxfoundation.org> <20261027-llm-char-misc-w1-v1-2-d2e6bfafb6a4@linuxfoundation.org> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 27/10/2026 17:04, Greg Kroah-Hartman wrote: > From: Josef Bacik > > __w1_remove_master_device() calls w1_destroy_master_attributes() with > both the mutex of the master and list_mutex held. Removing the files > waits for the callbacks which are running, and nearly all of them take > one of these two locks: > > __w1_remove_master_device() read() of .../w1_master_slaves > mutex_lock(&dev->mutex) kernfs active reference > mutex_lock(&dev->list_mutex) w1_master_attribute_show_slaves() > w1_destroy_master_attributes() mutex_lock(&md->list_mutex) > sysfs_remove_group() waits > waits for the reference Reviewed-by: Krzysztof Kozlowski Best regards, Krzysztof