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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 904B9CA9ECF for ; Fri, 1 Nov 2019 14:55:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 609AB20650 for ; Fri, 1 Nov 2019 14:55:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lwR8MenV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727798AbfKAOzW (ORCPT ); Fri, 1 Nov 2019 10:55:22 -0400 Received: from mail-qt1-f194.google.com ([209.85.160.194]:39329 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727527AbfKAOzW (ORCPT ); Fri, 1 Nov 2019 10:55:22 -0400 Received: by mail-qt1-f194.google.com with SMTP id t8so13247004qtc.6 for ; Fri, 01 Nov 2019 07:55:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=NiI6f9HM5k9LcFeeBX6Tv9+K1BTlG6yQirpfWcV6V5g=; b=lwR8MenVgI9cOuxrEXooco2/mlJoCnWwAK3dvpWuLfqmI0sbx8xrVGixnxjjJObmYr P8JKwY+uQ+Bv98cjqNw99yzQykdCUvqScphvryKKok9cV9TKd7PXZl5lBsx+dhAWZsvk eK0487lJFs/DzOn28R9wUajn+dPt9AsCJgrO87ALVQIGngpW0uS/NfehGhbE9UOfQnNq ufJ0IseWkGnDBkq/WPTmlBOOr3oHbGHRPzXWmLnxRPuK3WxBA83ts0bnmE6mVRytONAK KNeqzhOgzy6YDTyeESas64KXZHoQDvEGrvYqLQcLjdBpxFeW9WFKMIQ6ZrPivTnLLsSk Mhig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=NiI6f9HM5k9LcFeeBX6Tv9+K1BTlG6yQirpfWcV6V5g=; b=E2CZM68AGZwRApQkxoLH3VQjQPgX1x+EXU9a1xi/ZlOSKoYGtU4oGr2+8iiadb2H0j /Wv4sO6X7IVcfiNH5qmXUFa4Iirq8TQ93ykX/sLSmqP0khvg+RZJ9tNPaWpxFmdDy8jj I/ulybGoFi3UitknQXeo36bP4sa7B/WyJi9d6j7u2VVxTxyd7yspkbMLGh12LFOgqijg fw0L1MW5S5MyWg7jDJ7Yyo2NQETs14s5Ak2bIY+humGNnlLm3qeK8Npz9thYv9kb5/4C 2tiplqozkmbPF3iN9r3KNivX6o2r6QBF5Fw248K4GsWEyOzp/egUMpaPa2f35eFNo7aO q2fg== X-Gm-Message-State: APjAAAX+Nzo3MmUassiUQnAQ4lSMpX1H2ssSjVoiZMdYfIuiUQ07UEzr NE2zKqo4bKmdvtWPapbu4NQv/ozeQnTeO9IgyB6WCMm6 X-Google-Smtp-Source: APXvYqySSvWdxO7V5R6dRxw9KYJnoP336fR8cnjUtjjYzAt5xUqYiFpUkllzjYbB1d2Wfx1xVD5pCYYhUcu+PKgkHnM= X-Received: by 2002:ac8:720f:: with SMTP id a15mr503524qtp.112.1572620121126; Fri, 01 Nov 2019 07:55:21 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Neal Gompa Date: Fri, 1 Nov 2019 10:54:45 -0400 Message-ID: Subject: Re: [PATCH v3 0/4] RAID1 with 3- and 4- copies To: David Sterba Cc: Btrfs BTRFS Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Oct 31, 2019 at 11:17 AM David Sterba wrote: > > Here it goes again, RAID1 with 3- and 4- copies. I found the bug that sto= pped > it from inclusion last time, it was in the test itself, so the kernel cod= e is > effectively unchanged. > > So, with 1 or 2 missing devices, replace by device id works. There's one > annoying thing but not new: regarding replace of a missing device, some > extra single/dup block groups are created during the replace process. > Example below. This can happen on plain raid1 with degraded read-write > mount as well. > > Now what's the merge target. > > The patches almost made it to 5.3, the changes build on existing code so = the > actual addition of new profiles is namely in the definitions and addition= al > cases. So it should be safe. > > I'm for adding it to 5.5 queue, though we're at rc5 and this can be seen = as a > late time for a feature. The user benefits are noticeable, raid1c3 can re= place > raid6 of metadata which is the most problematic part and much more compli= cated > to fix (write ahead journal or something like that). The feedback regardi= ng the > plain 3-copy as a replacement was positive, on IRC and there are mails ab= out > that too. > What's the reasoning for not submitting this for 5.4? I think the improvements here are definitely worth pulling into the 5.4 kernel release... --=20 =E7=9C=9F=E5=AE=9F=E3=81=AF=E3=81=84=E3=81=A4=E3=82=82=E4=B8=80=E3=81=A4=EF= =BC=81/ Always, there's only one truth!