From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91541C43610 for ; Wed, 14 Nov 2018 07:09:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48AEF223DD for ; Wed, 14 Nov 2018 07:09:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 48AEF223DD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731709AbeKNRLZ (ORCPT ); Wed, 14 Nov 2018 12:11:25 -0500 Received: from smtp.nue.novell.com ([195.135.221.5]:48820 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728686AbeKNRLY (ORCPT ); Wed, 14 Nov 2018 12:11:24 -0500 Received: from [10.160.4.48] (nat.nue.novell.com [195.135.221.2]) by smtp.nue.novell.com with ESMTP (TLS encrypted); Wed, 14 Nov 2018 08:09:24 +0100 Subject: Re: [PATCH] zram: close udev startup race condition as default groups To: Minchan Kim , stable@vger.kernel.org Cc: LKML , Andrew Morton , Sergey Senozhatsky , Howard Chen References: <20181114055223.66476-1-minchan@kernel.org> From: Hannes Reinecke Message-ID: <5e9e9db6-1373-484f-2461-096fbcb83414@suse.com> Date: Wed, 14 Nov 2018 08:09:23 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20181114055223.66476-1-minchan@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/14/18 6:52 AM, Minchan Kim wrote: > commit fef912bf860e upstream. > commit 98af4d4df889 upstream. > > I got a report from Howard Chen that he saw zram and sysfs race(ie, > zram block device file is created but sysfs for it isn't yet) > when he tried to create new zram devices via hotadd knob. > > v4.20 kernel fixes it by [1, 2] but it's too large size to merge > into -stable so this patch fixes the problem by registering defualt > group by Greg KH's approach[3]. > > This patch should be applied to every stable tree [3.16+] currently > existing from kernel.org because the problem was introduced at 2.6.37 > by [4]. > > [1] fef912bf860e, block: genhd: add 'groups' argument to device_add_disk > [2] 98af4d4df889, zram: register default groups with device_add_disk() > [3] http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/ > [4] 33863c21e69e9, Staging: zram: Replace ioctls with sysfs interface > > Cc: Sergey Senozhatsky > Cc: Hannes Reinecke > Tested-by: Howard Chen > Signed-off-by: Minchan Kim > --- > drivers/block/zram/zram_drv.c | 26 ++++++-------------------- > 1 file changed, 6 insertions(+), 20 deletions(-) > Actually, I have a similar patch for NVMe in older revisions, so maybe I should push it to -stable, too. Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.com +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)