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=-6.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 1ED0DC43441 for ; Thu, 15 Nov 2018 17:45:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7801223CB for ; Thu, 15 Nov 2018 17:45:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="K0c1be03" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C7801223CB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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 S2388509AbeKPDx4 (ORCPT ); Thu, 15 Nov 2018 22:53:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:47756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726910AbeKPDx4 (ORCPT ); Thu, 15 Nov 2018 22:53:56 -0500 Received: from localhost (unknown [64.114.255.97]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A3CC821780; Thu, 15 Nov 2018 17:45:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542303909; bh=RDzebsoglcjSA6jz06hC6i8s2tVLCMsDKrMeNBhlFt8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=K0c1be03yFqYR8qB/e5E9TmHh4Ig+/PE/x/mcKqMuIat+vNlJrfX215rqnZkM2wL7 I5BwtqaDv6Ke2pbhNLi78slDPDASAz+AqmQQpx1D+KPS4h2CKILLwASV+4p+/602lU mfN2orLjyMo62qlz/LG7UTHcO94KdwMkYOHJcHRU= Date: Thu, 15 Nov 2018 12:45:04 -0500 From: Sasha Levin To: Minchan Kim Cc: stable@vger.kernel.org, LKML , Andrew Morton , Sergey Senozhatsky , Hannes Reinecke , Howard Chen Subject: Re: [PATCH] zram: close udev startup race condition as default groups Message-ID: <20181115174504.GJ95254@sasha-vm> References: <20181114055223.66476-1-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20181114055223.66476-1-minchan@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 14, 2018 at 02:52:23PM +0900, 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 I've queued this for 4.19 and 4.18, but it doesn't apply to anything older than that. -- Thanks, Sasha