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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 282FFC433E0 for ; Wed, 10 Feb 2021 12:51:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6EEB64E38 for ; Wed, 10 Feb 2021 12:51:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229649AbhBJMvD (ORCPT ); Wed, 10 Feb 2021 07:51:03 -0500 Received: from mx2.suse.de ([195.135.220.15]:52184 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229503AbhBJMu5 (ORCPT ); Wed, 10 Feb 2021 07:50:57 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7BA9EAEBE; Wed, 10 Feb 2021 12:50:15 +0000 (UTC) Date: Wed, 10 Feb 2021 12:50:14 +0000 From: Michal Rostecki To: =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= Cc: Chris Mason , Josef Bacik , David Sterba , "open list:BTRFS FILE SYSTEM" , open list , Michal Rostecki Subject: Re: [PATCH RFC 4/6] btrfs: Check if the filesystem is has mixed type of devices Message-ID: <20210210125014.GC23499@wotan.suse.de> References: <20210209203041.21493-1-mrostecki@suse.de> <20210209203041.21493-5-mrostecki@suse.de> <20210210040805.GB12086@qmqm.qmqm.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210210040805.GB12086@qmqm.qmqm.pl> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Wed, Feb 10, 2021 at 05:08:05AM +0100, Michał Mirosław wrote: > On Tue, Feb 09, 2021 at 09:30:38PM +0100, Michal Rostecki wrote: > > From: Michal Rostecki > > > > Add the btrfs_check_mixed() function which checks if the filesystem has > > the mixed type of devices (non-rotational and rotational). This > > information is going to be used in roundrobin raid1 read policy.a > [...] > > @@ -669,8 +699,12 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices, > > } > > > > q = bdev_get_queue(bdev); > > - if (!blk_queue_nonrot(q)) > > + rotating = !blk_queue_nonrot(q); > > + device->rotating = rotating; > > + if (rotating) > > fs_devices->rotating = true; > > + if (!fs_devices->mixed) > > + fs_devices->mixed = btrfs_check_mixed(fs_devices, rotating); > [...] > > Since this is adding to a set, a faster way is: > > if (fs_devices->rotating != rotating) > fs_devices->mixed = true; > Good idea. > The scan might be necessary on device removal, though. > And good point. I didn't address the case of device removal at all. > > - if (!blk_queue_nonrot(q)) > > + rotating = !blk_queue_nonrot(q); > > + device->rotating = rotating; > > + if (rotating) > > fs_devices->rotating = true; > > + if (!fs_devices->mixed) > > + fs_devices->mixed = btrfs_check_mixed(fs_devices, rotating); > > Duplication. Maybe pull all this into a function? > Will do that as well. > Best Regards, > Michał Mirosław Regards, Michal