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=-0.6 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 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 A385DC433DF for ; Thu, 4 Jun 2020 18:05:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 84D3D206C3 for ; Thu, 4 Jun 2020 18:05:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LxwDsfhG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730174AbgFDSFL (ORCPT ); Thu, 4 Jun 2020 14:05:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730008AbgFDSFK (ORCPT ); Thu, 4 Jun 2020 14:05:10 -0400 Received: from mail-il1-x142.google.com (mail-il1-x142.google.com [IPv6:2607:f8b0:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD1B0C08C5C0; Thu, 4 Jun 2020 11:05:10 -0700 (PDT) Received: by mail-il1-x142.google.com with SMTP id p5so6988453ile.6; Thu, 04 Jun 2020 11:05:10 -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=X1b4BEr/DHZQvQyvdQ9WJt5QLV82BJBnaAPWqeJ7CbY=; b=LxwDsfhGYIoloqCEYEN6havWe+hHDiiiSWB2lxrkhSlWYqlgCcvvGfQ1EO9CnzqRYI tbcjhekFwcQV4EBwzr7ciUqScRgSLunqVWtr1mPUV3+GN743iaG1qXVyedYo125GtheB R3U68HkD01CC64FEYjv4CjsXpvrOeeNnaSw87DL1Gu4REtV3Jx/Nw4I8bR4lt+MuFRl8 TbQgGqxR2cZZuWtK20hJjl9dRQYr9Mhug3Yp+lbxAGz0i94B22hNSRSqn2otStGbfgMI cTb/yQ9TUpRc74y1Af2O3TJGgGDed2kMkNCNdF1Dk3rxaXggM0i/Zj9lWoEyF6em/PRW eZGQ== 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=X1b4BEr/DHZQvQyvdQ9WJt5QLV82BJBnaAPWqeJ7CbY=; b=Y214IBXDtetwtXFDL2gYUTH9ydfTNxmcgX/wWMiWzPqH0veW0xcdtSGm1W2vzE5VsV bMhzzh0j99G0UVpk0dAIEW1fjpFNhTjBKdAonv3aIQ3zWor9NpxZgJJXEaIdqG6cojAA CPgpYjc+DLSydwguqfD2e5k5hJbEKIqSlnPbFEfvW0fBgBJwMkGVojf/uuH07qzV+L39 ZFckNeTiu3oBUgis8tkqO5wec0iECtgaC1+mdY2v1vAdMDWyuer/azytYVh3zoI57XBh f5D22njRBzeUJ1KoXN/Cr1uJAEXD1VtBdJy7QudD6lBvr8klxFfc7H/HwWTikQt56QBS ojOg== X-Gm-Message-State: AOAM531s8QDn5x0GcNUnEBndX+Sp133jA3gZV7IxSAPPuu9QyCbqENwx 8FIXMLJI8Cv2J6HFYvPui+8siLSrX3I+TX9D4ENLPA== X-Google-Smtp-Source: ABdhPJwTGNq+lts75fMK6GZCnI9DekzO33pOxX+DxEM9Hqbj/tJNJuBrTQOnBrFuXCIXjdDRGFoD+++N8JKDhvPn9PI= X-Received: by 2002:a92:c9ce:: with SMTP id k14mr5108937ilq.250.1591293910251; Thu, 04 Jun 2020 11:05:10 -0700 (PDT) MIME-Version: 1.0 References: <20200604161133.20949-1-alexander.mikhalitsyn@virtuozzo.com> In-Reply-To: <20200604161133.20949-1-alexander.mikhalitsyn@virtuozzo.com> From: Amir Goldstein Date: Thu, 4 Jun 2020 21:04:58 +0300 Message-ID: Subject: Re: [PATCH 0/2] overlayfs: C/R enhancements To: Alexander Mikhalitsyn Cc: Miklos Szeredi , Andrei Vagin , ptikhomirov@virtuozzo.com, khorenko@virtuozzo.com, vvs@virtuozzo.com, ktkhai@virtuozzo.com, overlayfs , linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-unionfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Thu, Jun 4, 2020 at 7:13 PM Alexander Mikhalitsyn wrote: > > This patchset aimed to make C/R of overlayfs mounts with CRIU possible. > We introduce two new overlayfs module options -- dyn_path_opts and > mnt_id_path_opts. If enabled this options allows to see real *full* paths > in lowerdir, workdir, upperdir options, and also mnt_ids for corresponding > paths. > > This changes should not break anything because for showing mnt_ids we simply > introduce new show-time mount options. And for paths we simply *always* > provide *full paths* instead of relative path on mountinfo. > > BEFORE > > overlay on /var/lib/docker/overlay2/XYZ/merged type overlay (rw,relatime, > lowerdir=/var/lib/docker/overlay2/XYZ-init/diff:/var/lib/docker/overlay2/ > ABC/diff,upperdir=/var/lib/docker/overlay2/XYZ/diff,workdir=/var/lib/docker > /overlay2/XYZ/work) > none on /sys type sysfs (rw,relatime) > > AFTER > > overlay on /var/lib/docker/overlay2/XYZ/merged type overlay (rw,relatime, > lowerdir=/var/lib/docker/overlay2/XYZ-init/diff:/var/lib/docker/overlay2/ > ABC/diff,upperdir=/var/lib/docker/overlay2/XYZ/diff,workdir=/var/lib/docker > /overlay2/XYZ/work,lowerdir_mnt_id=175:175,upperdir_mnt_id=175) > none on /sys type sysfs (rw,relatime) > But overlayfs won't accept these "output only" options as input args, which is a problem. Wouldn't it be better for C/R to implement mount options that overlayfs can parse and pass it mntid and fhandle instead of paths? I believe C/R is using a similar method to export inotify/fanotify marks. FWIW overlayfs already has utilities that encode filehandle to text and back, see ovl_get_index_name(). Thanks, Amir.