From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752803AbcBFSdt (ORCPT ); Sat, 6 Feb 2016 13:33:49 -0500 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:45156 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752286AbcBFSdr (ORCPT ); Sat, 6 Feb 2016 13:33:47 -0500 Message-ID: <1454783624.2809.6.camel@HansenPartnership.com> Subject: complete boot failure in 4.5-rc1 caused by nvme: make SG_IO support optional From: James Bottomley To: "linux-nvme@lists.infradead.org" , linux-block@vger.kernel.org, linux-scsi , linux-kernel Cc: Christoph Hellwig , Jens Axboe Date: Sat, 06 Feb 2016 10:33:44 -0800 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The reason is fairly obvious: the default for the new option BLK_DEV_NVME_SCSI is N and all the distribution kernels (and me when testing) take the default options (I checked in the OBS kernel builds and this is true). The net result is that scsi_id from udev no longer works on nvme disks and that means that the /dev/disk/by-id links are all gone in 4.5-rc1. If this happens to be how you name your disks in fstab or crypttab, you can't boot. If you're going to break an ABI in this way, you really have to plan for it in userspace. How are NVMe disk ids supposed to be exported now? Does udev need a nvme_id program to do this? Until there's an infrastructure ready to work in this way, we need to unconditionally enable BLK_DEV_NVME_SCSI. James