From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f41.google.com ([74.125.82.41]:55073 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727338AbeGTLOH (ORCPT ); Fri, 20 Jul 2018 07:14:07 -0400 Received: by mail-wm0-f41.google.com with SMTP id c14-v6so9010966wmb.4 for ; Fri, 20 Jul 2018 03:26:31 -0700 (PDT) Date: Fri, 20 Jul 2018 11:26:19 +0100 From: Sudip Mukherjee To: Alan Jenkins Cc: Greg Kroah-Hartman , Bart Van Assche , stable@vger.kernel.org, Jens Axboe Subject: Re: request for 4.14-stable: 1dc3039bc87a ("block: do not use interruptible wait anywhere") Message-ID: <20180720102619.6ek7cntouhotgd33@debian> References: <20180719220936.wala6fa7st6q3xok@debian> <5f24dbd5-3c1d-9cab-eeca-467a4dd38a2d@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5f24dbd5-3c1d-9cab-eeca-467a4dd38a2d@gmail.com> Sender: stable-owner@vger.kernel.org List-ID: Hi Alan, On Fri, Jul 20, 2018 at 09:37:29AM +0100, Alan Jenkins wrote: > On 19/07/18 23:09, Sudip Mukherjee wrote: > > Hi Greg, > > > > This was missing in 4.14-stable. Please apply to your queue. > > > > -- > > Regards > > Sudip > > Hi Sudip, > > This is correct, seems low-risk, and I don't mind it going ahead. But I'm > curious� why you're interested in it for v4.14.� Mostly, I wonder if the > same reason would apply to older kernels as well? Well, since I have to use v4.14.y for my dayjob I will like to see all possible fixes landing in 4.14-stable. That makes my dayjob a little easier. :) > > While the bugfix is applicable to v4.14, the nasty X crash on suspend is > only on v4.15 and v4.16.� I think I left it to other's judgement, as to > whether the bugfix would be wanted outside that case. My thought was that since you said "or" in your commit message: "When blk_queue_enter() waits for a queue to unfreeze, or unset the PREEMPT_ONLY flag, do not allow it to be interrupted by a signal", so the fault condition can be when it is waiting on the queue and is interrupted. So even though 'PREEMPT_ONLY' is not there in v4.14.y, we can see the problem just because of getting interrupted while on queue. Plesase correct me if I was wrong. > > IIUC, the bugfix could be applied to *three* of the "longterm" kernel lines: > 4.14.56, 4.9.113, 4.4.142.� Since the commit says this bug was introduced to > the single-queue block layer in v4.4, commit 3ef28e8 ("block: generic > request_queue reference counting"). I will send the backport for v4.9.y and v4.4.y also. -- Regards Sudip