From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752046AbeBHPLK (ORCPT ); Thu, 8 Feb 2018 10:11:10 -0500 Received: from mga09.intel.com ([134.134.136.24]:15652 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750847AbeBHPLJ (ORCPT ); Thu, 8 Feb 2018 10:11:09 -0500 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,479,1511856000"; d="scan'208";a="33143685" Date: Thu, 8 Feb 2018 08:15:08 -0700 From: Keith Busch To: "jianchao.wang" Cc: axboe@fb.com, sagi@grimberg.me, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, hch@lst.de Subject: Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case Message-ID: <20180208151508.GA4797@localhost.localdomain> References: <20180202182413.GH24417@localhost.localdomain> <20180205151314.GP24417@localhost.localdomain> <20180206151335.GE31110@localhost.localdomain> <20180207161345.GB1337@localhost.localdomain> <1826ebc1-d419-23da-12d4-dd7b1b3fe598@oracle.com> <958cae59-1a01-d60f-822b-cf81cfa31b8f@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <958cae59-1a01-d60f-822b-cf81cfa31b8f@oracle.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 08, 2018 at 10:17:00PM +0800, jianchao.wang wrote: > There is a dangerous scenario which caused by nvme_wait_freeze in nvme_reset_work. > please consider it. > > nvme_reset_work > -> nvme_start_queues > -> nvme_wait_freeze > > if the controller no response, we have to rely on the timeout path. > there are issues below: > nvme_dev_disable need to be invoked. > nvme_dev_disable will quiesce queues, cancel and requeue and outstanding requests. > nvme_reset_work will hang at nvme_wait_freeze We used to not requeue timed out commands, so that wasn't a problem before. Oh well, I'll take a look.