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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 B56A5C636C8 for ; Thu, 15 Jul 2021 17:27:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89491613D7 for ; Thu, 15 Jul 2021 17:27:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229553AbhGORaO (ORCPT ); Thu, 15 Jul 2021 13:30:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229506AbhGORaN (ORCPT ); Thu, 15 Jul 2021 13:30:13 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71DC5C06175F; Thu, 15 Jul 2021 10:27:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=A/iOWH/eq2vDhfxyVOdH70jsjaoCTAYD+XN2BGv/PRg=; b=a8tBS7GQNc7/QxHn26QkbWu1LJ oF//nu8vv7GY7MZKmx17DZ1MD7SC81IBUpbTVoTfPdv5YGjHA96QLvp0bXYNYNHt4GjDzeW+5bYNd qqJr6939/NH5eT4uXvHtur9iFrH8mdUEtkYUEO+fs1nGlCVKLeJmUGAwAp2gHUj9iuBSfVz3G5r2e NX42m7HRiIJmgk3u7baJqppizWoLU3fHkkeDTKLm49i9XdC6RD0gVJuvJI1K7ydpntrk4jjifvSuv 6UU5ht9aFS97snKG1FD189wiAZs7sTMViCj2R/oXRpTKTud7iroRh2LvWpsgOvCHCxy0MH4s0PJwX aX0F++mA==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m4569-003ZP2-8Q; Thu, 15 Jul 2021 17:24:51 +0000 Date: Thu, 15 Jul 2021 18:24:33 +0100 From: Christoph Hellwig To: Josef Bacik Cc: Christoph Hellwig , NeilBrown , "J. Bruce Fields" , Chuck Lever , Chris Mason , David Sterba , linux-nfs@vger.kernel.org, Wang Yugui , Ulli Horlacher , linux-btrfs@vger.kernel.org Subject: Re: [PATCH/RFC] NFSD: handle BTRFS subvolumes better. Message-ID: References: <20210613115313.BC59.409509F4@e16-tech.com> <20210310074620.GA2158@tik.uni-stuttgart.de> <162632387205.13764.6196748476850020429@noble.neil.brown.name> <28bb883d-8d14-f11a-b37f-d8e71118f87f@toxicpanda.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <28bb883d-8d14-f11a-b37f-d8e71118f87f@toxicpanda.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Thu, Jul 15, 2021 at 01:11:29PM -0400, Josef Bacik wrote: > Because there's no alternative. We need a way to tell userspace they've > wandered into a different inode namespace. There's no argument that what > we're doing is ugly, but there's never been a clear "do X instead". Just a > lot of whinging that btrfs is broken. This makes userspace happy and is > simple and straightforward. I'm open to alternatives, but there have been 0 > workable alternatives proposed in the last decade of complaining about it. Make sure we cross a vfsmount when crossing the "st_dev" domain so that it is properly reported. Suggested many times and ignored all the time beause it requires a bit of work.