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=-2.7 required=3.0 tests=BAYES_00,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 22A35C432BE for ; Fri, 6 Aug 2021 08:08:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04B7060E52 for ; Fri, 6 Aug 2021 08:08:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242851AbhHFIIx (ORCPT ); Fri, 6 Aug 2021 04:08:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236751AbhHFIIw (ORCPT ); Fri, 6 Aug 2021 04:08:52 -0400 Received: from mail-il1-x136.google.com (mail-il1-x136.google.com [IPv6:2607:f8b0:4864:20::136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07729C061798; Fri, 6 Aug 2021 01:08:36 -0700 (PDT) Received: by mail-il1-x136.google.com with SMTP id c3so7961632ilh.3; Fri, 06 Aug 2021 01:08:36 -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; bh=u2iJjJFlry6ovGIgHXp8jdUKenmn9J5pRKg6h9IJBLE=; b=QppjZKuw1aICGs/ZKOPmXanV4OJyMgg6oZLmrMF5DHQMbge1xiVbFCfktXZddUZV/N UCxGvWkL+cEVux4C4+jPiyB5jvHCNoOmOSOBlHZO3u8pcGDHLH3g/6kZbGboouH1o7/I kqd/49zQexQmjrAzZG4VBgYNjJAw8yDoAMcTskZwYA+LQsmDnmMQ1zWhXjce5HTtvL4M 1sjsnwp/rWwZPa3hnAXVU9REf5VZ92laZ5yjesP+8FwK+Gbejl49dhAYGl6zkwOBIspG tUp+szq/hMUsPq4D3iyZmH9Z5eO7LJHYxNTAi9ATdGVYeXHnzn0UULeY1xfA6aFZFDid C4Bg== 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; bh=u2iJjJFlry6ovGIgHXp8jdUKenmn9J5pRKg6h9IJBLE=; b=gMz/1ggry7smRb2uLeXvKrroY/soEx9XsHUxnYZ7WII+MP5otNkJP0z/gj8MScfdrL Qm0MO5uEDIm3fkweQgnKaazEI/7xXoT4cKbsw/gK3WMDo/75OulS51cM4cQQkf7GdZmg vgACAZER+ZEv5TUEyUOdHoW8jzGy6QUnxu5WoMN78NgJzKR3nKwzwPikQcQMwcNcVugi EtDKnIlLwuKhvxkYtdqBqqbIH9UTPxiRT2rIjvg1ZL3/eD9lI+PnPlITJponS9ICBnaZ uaDPMpMhPcY59jrQrQGcrltH5vcZBFbY69vzv50Dr2LjBwvfmVsSNBqzJ/XtpmUEWXyJ c+aQ== X-Gm-Message-State: AOAM532umVd+Pz5EobUCeCRmVerWaet3xZjydMtGwvDF8pRSdkU1aEBQ pcbFyJnDGI9nYJanrS88oMCce8LkiS0fysuM1c8= X-Google-Smtp-Source: ABdhPJzHyXbHZoWrAqDqGnDAlixxnNs6YfY//vUKy+VouysXVfonSE5WTUmijueoWBlEVcU9fTr14Si/Wox+e69rSeY= X-Received: by 2002:a92:c94f:: with SMTP id i15mr21326ilq.72.1628237315091; Fri, 06 Aug 2021 01:08:35 -0700 (PDT) MIME-Version: 1.0 References: <162742539595.32498.13687924366155737575.stgit@noble.brown> <162742546554.32498.9309110546560807513.stgit@noble.brown> <162751852209.21659.13294658501847453542@noble.neil.brown.name> In-Reply-To: From: Amir Goldstein Date: Fri, 6 Aug 2021 11:08:23 +0300 Message-ID: Subject: Re: [PATCH 07/11] exportfs: Allow filehandle lookup to cross internal mount points. To: Miklos Szeredi Cc: NeilBrown , Christoph Hellwig , Josef Bacik , "J. Bruce Fields" , Chuck Lever , Chris Mason , David Sterba , Alexander Viro , linux-fsdevel , Linux NFS Mailing List , Linux Btrfs Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Fri, Aug 6, 2021 at 10:52 AM Miklos Szeredi wrote: > > On Thu, 29 Jul 2021 at 07:27, Amir Goldstein wrote: > > > Given that today, subvolume mounts (or any mounts) on the lower layer > > are not followed by overlayfs, I don't really see the difference > > if mounts are created manually or automatically. > > Miklos? > > Never tried overlay on btrfs. Subvolumes AFAIK do not use submounts > currently, they are a sort of hack where the st_dev changes when > crossing the subvolume boundary, but there's no sign of them in > /proc/mounts (there's no d_automount in btrfs). That's what Niel's patch 11/11 is proposing to add and that's the reason he was asking if this is going to break overlayfs over btrfs. My question was, regardless of btrfs, can ovl_lookup() treat automount dentries gracefully as empty dirs or just read them as is, instead of returning EREMOTE on lookup? The rationale is that we use a private mount and we are not following across mounts from layers anyway, so what do we care about auto or manual mounts? Thanks, Amir.