From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: complete boot failure in 4.5-rc1 caused by nvme: make SG_IO support optional Date: Mon, 8 Feb 2016 08:32:26 +0100 Message-ID: <56B8448A.3000106@suse.de> References: <1454783624.2809.6.camel@HansenPartnership.com> <20160207092241.GA15331@lst.de> <1454861040.2329.4.camel@HansenPartnership.com> <56B7C527.6050300@kernel.dk> <1454886441.2329.27.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1454886441.2329.27.camel@HansenPartnership.com> Sender: linux-kernel-owner@vger.kernel.org To: James Bottomley , Jens Axboe , Christoph Hellwig Cc: "linux-nvme@lists.infradead.org" , linux-block@vger.kernel.org, linux-scsi , linux-kernel List-Id: linux-scsi@vger.kernel.org On 02/08/2016 12:07 AM, James Bottomley wrote: > On Sun, 2016-02-07 at 15:28 -0700, Jens Axboe wrote: >> On 02/07/2016 09:04 AM, James Bottomley wrote: >>> On Sun, 2016-02-07 at 10:22 +0100, Christoph Hellwig wrote: >>>> Keith said it should be on by default, and I promised him to >>>> change >>>> it once we run into problems, which I guess this counts as. >>>> >>>> But just curious: what distro are you using? Upstream systemd >>>> explicitly rejected using scsi_id for NVMe here: >>>> >>>> https://github.com/systemd/systemd/issues/1453 >>>> >>>> and all my test systems don't do this either. >>> >>> This was SUSE (in my case, openSUSE Leap). I just checked the >>> source >>> package; they patch the by-id rules back in for NVME: >>> >>> # PATCH-FIX-SUSE 1101-rules-persistent-device-names-for-NVMe >>> -devices.patch (bsc#944132) >>> Patch1101: 1101-rules-persistent-device-names-for-NVMe >>> -devices.patch >>> >>> The bugzilla is giving access denied for bug id 944132, so it's >>> likely >>> some proprietary vendor problem. The patch has no preamble, so >>> it's >>> hard to tell what they were thinking. >> >> I run root-on-nvme on my laptop, and I haven't observed any problems= =2E >=20 > Me too apparently. It looks like this problem may be SUSE specific > unless another distro has enabled this. I can see why they would: yo= u > do need persistent names for devices, even NVMe ones. >=20 >> Generally I hate for options to default y unless absolutely=20 >> necessary, it's a sure fire way to feature creep your kernel without= =20 >> noticing. I don't think getting all hot about this issue is fair, if= =20 >> the only known case is suse. >=20 > Well, OK, I'm annoyed because it was a systemd system which means > debugging boot failures are excruciatingly difficult so it took me a > week and a half to find out what the problem was. Perhaps I was a bi= t > rash to label this as an easily foreseen problem. >=20 > I opened a bug against SUSE to tell them to turn it on: >=20 > https://bugzilla.opensuse.org/show_bug.cgi?id=3D965497 >=20 > The second problem is that there's currently no way to transition to > using the serial attribute the way the udev 60-persistent-storage.rul= es > are written, so if distros have some by-id hack, it will have to be > maintained for a while. I annotated the already closed bug on this i= n > systemd with the rules that work for me. >=20 Why, but you can. That's precisely what I did with the transition to sg_inq; I've added a new set of rules (55-sg_inq.rules and 59-sg-symlinks.rules) which will override the values from 60-persistent-storage.rules. Do we have defined sysfs attributes for NVMe devices nowadays? If so I'd be willing to create/send some sysfs rules for them. Cheers, Hannes --=20 Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg GF: F. Imend=C3=B6rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG N=C3=BCrnberg)