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=-2.2 required=3.0 tests=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 10168C2D0DB for ; Wed, 29 Jan 2020 18:08:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E91F320720 for ; Wed, 29 Jan 2020 18:08:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727119AbgA2SIP (ORCPT ); Wed, 29 Jan 2020 13:08:15 -0500 Received: from mx2.suse.de ([195.135.220.15]:40648 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726245AbgA2SIO (ORCPT ); Wed, 29 Jan 2020 13:08:14 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id DCB4BAD86; Wed, 29 Jan 2020 18:08:12 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 72695DA730; Wed, 29 Jan 2020 19:07:53 +0100 (CET) Date: Wed, 29 Jan 2020 19:07:53 +0100 From: David Sterba To: Anand Jain Cc: linux-btrfs@vger.kernel.org, josef@toxicpanda.com, btrfs-list@steev.me.uk Subject: Re: [PATCH v4 0/2] readmirror feature (sysfs and in-memory only approach) Message-ID: <20200129180752.GK3929@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Anand Jain , linux-btrfs@vger.kernel.org, josef@toxicpanda.com, btrfs-list@steev.me.uk References: <20200105151402.1440-1-anand.jain@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200105151402.1440-1-anand.jain@oracle.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Sun, Jan 05, 2020 at 11:14:00PM +0800, Anand Jain wrote: > There were few RFCs [1] before, mainly to figure out storage > (or in memory only) for the readmirror policy and the interface needed. The persistent storage of the policy is not settled but adding the sysfs value that's both read and write is safe enough so this patchset is in the list of features for 5.7. With the new raid1c34 profiles we'll need a better mirror selection to utilize all the copies more effectively. Besides the default PID policy we should have at least one more so it's not just the bare interface without any real use.