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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDA04C433EF for ; Sun, 17 Jul 2022 17:58:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230273AbiGQR6U (ORCPT ); Sun, 17 Jul 2022 13:58:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229487AbiGQR6S (ORCPT ); Sun, 17 Jul 2022 13:58:18 -0400 Received: from libero.it (smtp-17.italiaonline.it [213.209.10.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E33013D5D for ; Sun, 17 Jul 2022 10:58:16 -0700 (PDT) Received: from [192.168.1.27] ([94.34.5.22]) by smtp-17.iol.local with ESMTPA id D8WyoG7CFX0RaD8Wzot21b; Sun, 17 Jul 2022 19:58:13 +0200 x-libjamoibt: 1601 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=inwind.it; s=s2014; t=1658080694; bh=BaVwJEHmRUeYDGnivJGDdxKVjyxJ1aGzfe9iPUOfsJI=; h=From; b=YiOjQdnDPMlp5B19qalqxyvleuhfpzqhiZeZX81CHkm5VUK3Edk9jjB0QejGZyzYq 9Iu468khlOlwN6/Qu027yQzntYjTlZNLmTugRrBofbi1aHBCXzDHAP95+bb+A6Yne6 Dk5tOexOuUfeKRyaXDTyKmWwKv53DdzBMa/xtEoGW8AXkleqdVAcRMjmRTaQnekSrN J0cYFj+F5yGtcfJwBQxsJiM4h9l63hm2MLOjdqOqB+E4FrWtXfOiKEgtfVbt5yinoK YRH0dA9S916iZLrxWeVmuFvk2QVf8Np/3CcyRsZM4pP5ZSlIl/Iu8Ehih8cXJaeQPg fZbnPPwxOir0A== X-CNFS-Analysis: v=2.4 cv=P7T/OgMu c=1 sm=1 tr=0 ts=62d44db6 cx=a_exe a=hwDnfLutCD/4BcDojJwT2A==:117 a=hwDnfLutCD/4BcDojJwT2A==:17 a=IkcTkHD0fZMA:10 a=MiViPHvKzwGMHcKa0VoA:9 a=QEXdDO2ut3YA:10 Message-ID: <7734292e-2ceb-cd4e-db54-2ab3629ff75e@inwind.it> Date: Sun, 17 Jul 2022 19:58:12 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.0.2 Reply-To: kreijack@inwind.it Subject: Re: RAID56 discussion related to RST. (Was "Re: [RFC ONLY 0/8] btrfs: introduce raid-stripe-tree") Content-Language: en-US From: Goffredo Baroncelli To: Thiago Ramon , Qu Wenruo Cc: Johannes Thumshirn , Qu Wenruo , "linux-btrfs@vger.kernel.org" References: <03630cb7-e637-3375-37c6-d0eb8546c958@gmx.com> <1cf403d4-46a7-b122-96cf-bd1307829e5b@gmx.com> <96da9455-f30d-b3fc-522b-7cbd08ad3358@suse.com> <61694368-30ea-30a0-df74-fd607c4b7456@gmx.com> <8b3cf3d0-4812-0e92-d850-09a8d08b8169@libero.it> <1dcfecba-92fc-6f49-bdea-705896ece036@gmx.com> <928e46e3-51d2-4d7a-583a-5440f415671e@gmx.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfMMPPwwGVbvadmrNt0+wv7ZcbtZNEUv9fkPelHRPONJ1CNM6SZFGO3bmsOmXhBiJPYneNRU/cmXsobOcBXUARA1brtfcKvpvlbS7CZN6AsesXVCr8fgS Q8vJwH9Du1aKtQtm/n09lMsdx6RntbUNSrJdqeYHtyyzT1oB+1fi5Yx1e6IxhaxjcdD+3IcwWXLITpCtM+1TbtTyxBL3LBELVlHAc9lFbuXmn0qt3NDYTRA5 Qa5NXfTsSR7WJ153e3uxKFUNe5/hZMJEH5cOSHd3tu2qMqm4VDqChaTlNWpdLhyKeHktTP6NC+8RLu5LgwfpJg== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 16/07/2022 16.26, Goffredo Baroncelli wrote: > On 16/07/2022 15.52, Thiago Ramon wrote: >>> Good luck implementing that feature just for RAID56 on non-zoned devices. >> DIO definitely would be a problem this way. As you mention, a separate >> zone for high;y modified data would make things a lot easier (maybe a >> RAID1Cx zone), but that definitely would be a huge change on the way >> things are handled. > > > When you talk about DIO, do you mean O_DIRECT ? Because this is full reliable > even without RAID56... ehmm... I forgot a "not". So my last sentence is Because this is NOT fully reliable even without RAID56... > See my email > > "BUG: BTRFS and O_DIRECT could lead to wrong checksum and wrong data", sent 15/09/2017 > > > -- gpg @keyserver.linux.it: Goffredo Baroncelli Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5