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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 7D5D5C54FCC for ; Mon, 20 Apr 2020 07:35:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DCF72078C for ; Mon, 20 Apr 2020 07:35:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ULkgTSO7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726412AbgDTHfz (ORCPT ); Mon, 20 Apr 2020 03:35:55 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:46427 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726055AbgDTHfv (ORCPT ); Mon, 20 Apr 2020 03:35:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587368150; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ddEryRA8fru8sR3cTZfHtReHkDM3BB1oRAtqx9hNvis=; b=ULkgTSO7Zit4YIa/TepJ8PX8CtxFbCCWSCexscJs8ppY40n50f9CH+PFBgkxZcozymRr30 CB6Pg4m5nZgEuAHtSG7xD3j65+nwq40llotAIXrFsXBgnTs4hIyRY1IOJbArPW8kPF3XSK rp/a0lL2e2cet3Jg6YCSpvqJkMo7We0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-77-0FRc6vd3N_eWC6A3SdG2Nw-1; Mon, 20 Apr 2020 03:35:47 -0400 X-MC-Unique: 0FRc6vd3N_eWC6A3SdG2Nw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 27C56149C5; Mon, 20 Apr 2020 07:35:46 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.194.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8F8D760C63; Mon, 20 Apr 2020 07:35:39 +0000 (UTC) Subject: Re: [dm-devel] [PATCH 0/3] dm raid/raid1: enable discard support when any devices support discard To: dm-devel@redhat.com Cc: Paul Wise , Mike Snitzer , linux-kernel@vger.kernel.org, Alasdair Kergon References: <20200419073026.197967-1-pabs3@bonedaddy.net> <20200419131908.GA22398@redhat.com> <9cb6a39a43178be29af2f47a92c2e84754b62b69.camel@bonedaddy.net> From: Ondrej Kozina Message-ID: <6bbf9d94-2fbb-f96f-ea85-a480ba109c55@redhat.com> Date: Mon, 20 Apr 2020 09:35:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <9cb6a39a43178be29af2f47a92c2e84754b62b69.camel@bonedaddy.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/19/20 4:48 PM, Paul Wise wrote: > On Sun, 2020-04-19 at 09:19 -0400, Mike Snitzer wrote: > >> You went overboard with implementation before checking to see if your >> work would be well received. Your 2/3 patch header shows you're >> capable of analyzing past commits to explain the evolution of code, >> etc. But yet you make no mention of this commit header which explicitly >> speaks to why what you're proposing is _not_ acceptable: >> >> commit 8a74d29d541cd86569139c6f3f44b2d210458071 >> Author: Mike Snitzer >> Date: Tue Nov 14 15:40:52 2017 -0500 >> >> dm: discard support requires all targets in a table support discards > > I do remember seeing this commit while working on this, I guess I > ignored it in my attempts to get fstrim working on my rootfs, woops. > >> I haven't looked closely at MD raid in this area but if you trully think >> underlying MD raid can cope with issuing discards to devices that don't >> support them (or that it avoids issuing them?) then please update >> dm-raid.c to conditionally set ti->discard_supported (if not all devices >> support discard). That is how to inform DM core that the target knows >> better and it will manage discards issued to it. It keeps the change >> local to dm-raid.c without the flag-day you're proposing. > > On my system I have a HDD and an SSD, with /boot on MD RAID and / on > ext4 on DM RAID on 2 DM crypt volumes. In this setup fstrim works on > /boot but does not work on / and with my patches it works on / again. > In addition I don't see any messages in dmesg or other issues when > doing fstrim / with my patches. Did you have discard allowed on both dm-crypt devices? dm-crypt (kernel) does not allow discards by default. Regards O.