Received: by 2002:a05:6a10:f3d0:0:0:0:0 with SMTP id a16csp2680557pxv; Sun, 11 Jul 2021 22:29:18 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyyw0Mebc3Ohv/VQCW/6o+YjL/JzwFvjPzM2c421qgVc9r9X0YtOfIDTS42m5iS2mKoer1n X-Received: by 2002:a5d:8511:: with SMTP id q17mr39208920ion.98.1626067758391; Sun, 11 Jul 2021 22:29:18 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1626067758; cv=none; d=google.com; s=arc-20160816; b=JmCxJWGdrH+h8R9eewiacqg4WySQ4oeflXyWCbtA19n1zqKzdyI7iwGEjgdgr1xlMw /ezCqyFcCjERp4o0UYaqsIroyyGLQmvFR/3E7sNWm4wryyefxLLo0p3RnA5U0yECTrQs UZOeDxkMzA896E3vdsoO5TXfXPVe4j6x+rVB7PaaS+IVzLGTeS+G6t3/d8JVFPtYGXJ/ SFrhLHVkhtRIFl552aYMJO59nMHr9MPnxryx8MpwO3QRViSHXzKKJw2StXdsFmvDjQVI GAJ7WCecxhOjJwhMBCgyonFHuCRyJG512vld+uTCrC98vU9Nhe4j2giom9nBq9Uv1W2M il6g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=twLrcmKXSPiuISHChJ9chOMvUmchtB727hdFpVXlUeo=; b=lrQq2096tpqF92Zw/+h49GL+g1WyQLWFj1RnxVuTWT3bk1EdRn4gRMQthmNmq+yRA9 /VnKvlz7o3IXr7DXu/wKVj7HszFAgMEptylt9gQRqtMAG5tcs9xslGaamVy2Q8ho0cuJ CTS/wRLeLm4xPOWhoCTj/J1hwCCC4lOpel6W9ldE3LRFgEK/jAQqrScsEnn+O2zLEKgG h1sfZwCVvtv7YoTsK+DO6VILo7xfUzaypiu0LvJmjBh4rpv8TZZAoSGU2peMelJuiYeH q8a7diVv2DLesVmzNsF0/vG7Ct4FTndn6/0qJwgI1Kf7rCUQG2QZ1dsiervEqznEpPuV da3Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id d2si15284849ilv.78.2021.07.11.22.29.04; Sun, 11 Jul 2021 22:29:18 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230215AbhGLFab (ORCPT + 99 others); Mon, 12 Jul 2021 01:30:31 -0400 Received: from verein.lst.de ([213.95.11.211]:51066 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230062AbhGLFab (ORCPT ); Mon, 12 Jul 2021 01:30:31 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 2341467373; Mon, 12 Jul 2021 07:27:40 +0200 (CEST) Date: Mon, 12 Jul 2021 07:27:40 +0200 From: Christoph Hellwig To: Hillf Danton Cc: syzbot , axboe@kernel.dk, hch@lst.de, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Desmond Cheong Zhi Xi Subject: Re: [syzbot] possible deadlock in loop_add Message-ID: <20210712052740.GA8599@lst.de> References: <000000000000ec01e405c6c2cee3@google.com> <20210710131638.605-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210710131638.605-1-hdanton@sina.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 10, 2021 at 09:16:38PM +0800, Hillf Danton wrote: > To break the lock chain, un/register blkdev without mtd_table_mutex held. Yes, Desmond Cheong Zhi Xi sent pretty much the same patch on June 18th (mtd: break circular locks in register_mtd_blktrans), but it did not get picked up.