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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 25B22C433DB for ; Sun, 31 Jan 2021 23:00:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFCD464E2A for ; Sun, 31 Jan 2021 23:00:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229645AbhAaW7m (ORCPT ); Sun, 31 Jan 2021 17:59:42 -0500 Received: from bee.birch.relay.mailchannels.net ([23.83.209.14]:41096 "EHLO bee.birch.relay.mailchannels.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229535AbhAaW7g (ORCPT ); Sun, 31 Jan 2021 17:59:36 -0500 X-Sender-Id: instrampxe0y3a|x-authsender|calestyo@scientia.net Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 323EA2262E for ; Sun, 31 Jan 2021 22:50:26 +0000 (UTC) Received: from mailgw-02.dd24.net (100-96-18-11.trex.outbound.svc.cluster.local [100.96.18.11]) (Authenticated sender: instrampxe0y3a) by relay.mailchannels.net (Postfix) with ESMTPA id 5046B226CA for ; Sun, 31 Jan 2021 22:50:25 +0000 (UTC) X-Sender-Id: instrampxe0y3a|x-authsender|calestyo@scientia.net Received: from mailgw-02.dd24.net (mailgw-02.dd24.net [193.46.215.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384) by 100.96.18.11 (trex/6.0.2); Sun, 31 Jan 2021 22:50:26 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: instrampxe0y3a|x-authsender|calestyo@scientia.net X-MailChannels-Auth-Id: instrampxe0y3a X-Arithmetic-Cooing: 18838bdd04e7f78e_1612133425861_2622138207 X-MC-Loop-Signature: 1612133425861:3759016569 X-MC-Ingress-Time: 1612133425861 Received: from heisenberg.scientia.net (p57b044d2.dip0.t-ipconnect.de [87.176.68.210]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: calestyo@scientia.net) by smtp.dd24.net (Postfix) with ESMTPSA id 517455FC4B for ; Sun, 31 Jan 2021 22:50:23 +0000 (UTC) Message-ID: <956e08b1aed7805f7ee387cc4994702c02b61560.camel@scientia.net> Subject: Re: is back and forth incremental send/receive supported/stable? From: Christoph Anton Mitterer To: linux-btrfs@vger.kernel.org Date: Sun, 31 Jan 2021 23:50:22 +0100 In-Reply-To: <20210129192058.GN4090@savella.carfax.org.uk> References: <157ed91bb66820d1fef89eb05d00e65c25607938.camel@scientia.net> <20210129192058.GN4090@savella.carfax.org.uk> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.3-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hey Hugo. Thanks for your explanation. I assume such a swapped send/receive would fail at least gracefully? On Fri, 2021-01-29 at 19:20 +0000, Hugo Mills wrote: >    In your scenario with MASTER and COPY-1 swapped, you'd have to > match the received_uuid from the sending side (on old COPY-1) to the > actual UUID on old MASTER. The code doesn't do this, so you'd have to > patch send/receive to do this. Well from the mailing list thread you've referenced it seems that the whole thing is rather quite non-trivial... so I guess it's nothing for someone who has basically no insight into btrfs code ^^ It's a pity though, that this doesn't work. Especially the use case of sending back (backup)snapshots would seem pretty useful. Given that this thread is nearly 6 years, I'd guess the whole idea has been abandoned upstream?! Cheers, Chris.