From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932328AbeBGBcl (ORCPT ); Tue, 6 Feb 2018 20:32:41 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:55950 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932184AbeBGBck (ORCPT ); Tue, 6 Feb 2018 20:32:40 -0500 Date: Wed, 7 Feb 2018 09:24:37 +0800 From: Ming Lei To: wenxiong Cc: Keith Busch , wenxiong@vmlinux.vnet.ibm.com, linux-nvme@lists.infradead.org, axboe@fb.com, linux-kernel@vger.kernel.org, wenxiong@us.ibm.com Subject: Re: [PATCH]nvme-pci: Fixes EEH failure on ppc Message-ID: <20180207012353.GD13470@ming.t460p> References: <1517867380-18790-1-git-send-email-wenxiong@vmlinux.vnet.ibm.com> <20180206163347.GG31110@localhost.localdomain> <787e4960b62a03b3888c67e73d7e1ee2@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <787e4960b62a03b3888c67e73d7e1ee2@linux.vnet.ibm.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 Tue, Feb 06, 2018 at 02:01:05PM -0600, wenxiong wrote: > On 2018-02-06 10:33, Keith Busch wrote: > > On Mon, Feb 05, 2018 at 03:49:40PM -0600, wenxiong@vmlinux.vnet.ibm.com > > wrote: > > > @@ -1189,6 +1183,12 @@ static enum blk_eh_timer_return > > > nvme_timeout(struct request *req, bool reserved) > > > struct nvme_command cmd; > > > u32 csts = readl(dev->bar + NVME_REG_CSTS); > > > > > > + /* If PCI error recovery process is happening, we cannot reset or > > > + * the recovery mechanism will surely fail. > > > + */ > > > + if (pci_channel_offline(to_pci_dev(dev->dev))) > > > + return BLK_EH_HANDLED; > > > + > > > > This patch will tell the block layer to complete the request and > > consider > > it a success, but it doesn't look like the command actually completed at > > all. You're going to get data corruption this way, right? Is returning > > BLK_EH_HANDLED immediately really the right thing to do here? > > Hi Ming, > > Can you help checking if it is ok if returning BLK_EH_HANDLEDED in this > case? Hi Wenxiong, Looks Keith is correct, and this timed out request will be completed by block layer and NVMe driver if BLK_EH_HANDLED is returned, but this IO isn't completed actually, so either data loss(write) or read failure is caused. Maybe BLK_EH_RESET_TIMER is fine under this situation. Thanks, Ming