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 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 DC1AAC4361B for ; Thu, 17 Dec 2020 19:47:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A303F22D72 for ; Thu, 17 Dec 2020 19:47:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727857AbgLQTrd (ORCPT ); Thu, 17 Dec 2020 14:47:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727368AbgLQTrd (ORCPT ); Thu, 17 Dec 2020 14:47:33 -0500 Received: from mail-ot1-x330.google.com (mail-ot1-x330.google.com [IPv6:2607:f8b0:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3475C061794 for ; Thu, 17 Dec 2020 11:46:52 -0800 (PST) Received: by mail-ot1-x330.google.com with SMTP id d20so10589412otl.3 for ; Thu, 17 Dec 2020 11:46:52 -0800 (PST) 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=JSHBznY61nzbcvETgxTC+sNW3vNQ48NZaRcwJrg1O5k=; b=q+sTALB90lys+NnVwsPsY582qJIKPuiiHXXVXeRVg+lW3QY0NMaiYdBw82tNXTp/O0 U46+0Ve3DcxXbGDnjIkFiSiTebDz0xZujRxzpEZjHaDAWjxeR+Nagre5p4UOwBMutHLE KA2t2rdrKBsNPluoAqoL/5hhY6uXREeWumb9kU8SnQNou6APWqDR5uGuaO68ykzReYnd Asu7A0+PLz45ULPkPILqJvPm3BfVcz77qIXbrluv1tkPYEh207E4BGG91wJAurmdAn5a gQ4DMqfrJ2jX6EdxzyoAeB2GsSA5XiLEs5NvX+N4hfkYu/obml8YJU1/UCPPif6upAY8 IvAQ== 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=JSHBznY61nzbcvETgxTC+sNW3vNQ48NZaRcwJrg1O5k=; b=VzUlk2EwAagVkqO+stRVihFvEJ3aUAw6hi+HpnDjcaqNzyKAmV+0mULwVAi1oZqG+Q qSiljjF1rjxU2EW3LnX79TmTZeSWuN7asWtFYPhYkAvXbYcQFAvwBF1Ulzaz3+lccu3V HehQlSYQPyx/RLYnaapCqB09qsH3xIa1pzNemNwCG6VOTt0uTH2MOIjxF/KW7IORfCcg KyilLNW0vEoNn4OXY58xcvw/D1WHBaGa8w3gGKgokVG2bqs7OdQUeU+NwIhUUifrVK8T KHRJQUP9e6l4DBajjKyVjoaUPFRpwH5YY5EIekJ5wNZnfDiqlNEZ0601Hv7f/urpfbd2 Z3VQ== X-Gm-Message-State: AOAM5325lYdpPgGU4uOSW9jv1kEcH/ME2balA8Ao9MTvOo4+F9RFdglg dREu0yDuV20oVzGFnws4chq1sq8oWTo52c+RrCZgF4sEkFEKWA== X-Google-Smtp-Source: ABdhPJwxXJ1CZml5Qctz9ZTszUb8FjP0VISlafAHCJXqosKvVhCmexzXx1rNJ07HzKiOZ3a2qFHgzJkG6WWSAlW9MYQ= X-Received: by 2002:a05:6830:23bb:: with SMTP id m27mr416530ots.198.1608234411909; Thu, 17 Dec 2020 11:46:51 -0800 (PST) MIME-Version: 1.0 References: <2nv9d47zt7.fsf@aldarion.sourceruckus.org> <2n1rfrf5l0.fsf@aldarion.sourceruckus.org> In-Reply-To: From: Michael Labriola Date: Thu, 17 Dec 2020 14:46:38 -0500 Message-ID: Subject: Re: failed open: No data available To: Amir Goldstein Cc: overlayfs , Miklos Szeredi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Thu, Dec 17, 2020 at 1:07 PM Amir Goldstein wrote: > > On Thu, Dec 17, 2020 at 6:22 PM Michael Labriola *snip* > > On Thu, Dec 17, 2020 at 7:00 AM Amir Goldstein wrote: > > Thanks, Amir. I didn't have CONFIG_DYNAMIC_DEBUG enabled, so > > I honestly don't expect to find much in the existing overlay debug prints > but you never know.. > I suspect you will have to add debug prints to find the problem. Ok, here goes. I had to setup a new virtual machine that doesn't use overlayfs for its root filesystem because turning on dynamic debug gave way too much output for a nice controlled test. It's exhibiting the same behavior as my previous tests (5.8 good, 5.9 bad). The is with a freshly compiled 5.9.15 w/ CONFIG_OVERLAY_FS_XINO_AUTO turned off and CONFIG_DYNAMIC_DEBUG turned on. Here's what we get: echo "file fs/overlayfs/* +p" > /sys/kernel/debug/dynamic_debug/control mount borky2.sqsh t mount -t tmpfs tmp tt mkdir -p tt/upper/{upper,work} mount -t overlay -o \ lowerdir=t,upperdir=tt/upper/upper,workdir=tt/upper/work blarg ttt [ 164.505193] overlayfs: mkdir(work/work, 040000) = 0 [ 164.505204] overlayfs: tmpfile(work/work, 0100000) = 0 [ 164.505209] overlayfs: create(work/#3, 0100000) = 0 [ 164.505210] overlayfs: rename(work/#3, work/#4, 0x4) [ 164.505216] overlayfs: unlink(work/#3) = 0 [ 164.505217] overlayfs: unlink(work/#4) = 0 [ 164.505221] overlayfs: setxattr(work/work, "trusted.overlay.opaque", "0", 1, 0x0) = 0 touch ttt/FOO touch: cannot touch 'ttt/FOO': No data available [ 191.919498] overlayfs: setxattr(upper/upper, "trusted.overlay.impure", "y", 1, 0x0) = 0 [ 191.919523] overlayfs: tmpfile(work/work, 0100644) = 0 [ 191.919788] overlayfs: tmpfile(work/work, 0100644) = 0 That give you any hints? I'll start reading through the overlayfs code. I've never actually looked at it, so I'll be planting printk calls at random. ;-) -- Michael D Labriola 21 Rip Van Winkle Cir Warwick, RI 02886 401-316-9844 (cell)