From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id AF4941381F3 for ; Sun, 13 Oct 2013 23:50:21 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id DDD5DE0A60; Sun, 13 Oct 2013 23:50:10 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) (using TLSv1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 1907EE09C4 for ; Sun, 13 Oct 2013 23:50:10 +0000 (UTC) Received: from mail-ie0-x22e.google.com (mail-ie0-x22e.google.com [IPv6:2607:f8b0:4001:c03::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: floppym) by smtp.gentoo.org (Postfix) with ESMTPSA id 6455F33E182 for ; Sun, 13 Oct 2013 23:50:03 +0000 (UTC) Received: by mail-ie0-f174.google.com with SMTP id qd12so6833118ieb.19 for ; Sun, 13 Oct 2013 16:50:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=+9jnwgLr4X9gz61R70zq+mT2ozegvClW2ZGQ9GOnduU=; b=ZXHxt7Ta9jsppvDM6FFm9WUTCxH63l1kOOS8GTqsMs/hDFJmavBxYVtPA8o9/YYktq eEfUp95sVoEOYkRhSm5O1Q1OyX6iM/H0P+vHH5BqxS15c50l2rHhp35KzdDkUDSenygK Z0D6QL5iDn2iWH+rjq+lwzSNmX2sRiPZ5zopAo/BEH/i8w2YeCK2sKsVnD0/DL4OoFzr taYUGafY4rBs/SLNZLuB2I03Pn+8v3baeDV0Vc9SbxwuZd5J/rftTvy9RkRXjUL3OcFK JyoF+9NDXHgwrA+vKvuNo7UKWoSmcsQzsIg0LiLG8zb6qjiSiv5fYXF+noZDc1k0FXux 5PTw== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@lists.gentoo.org Reply-to: gentoo-dev@lists.gentoo.org MIME-Version: 1.0 X-Received: by 10.50.170.225 with SMTP id ap1mr5486563igc.47.1381708201250; Sun, 13 Oct 2013 16:50:01 -0700 (PDT) Received: by 10.64.139.5 with HTTP; Sun, 13 Oct 2013 16:50:01 -0700 (PDT) In-Reply-To: <525B2EEB.1080103@gentoo.org> References: <20131013193232.GA10488@linux1> <525B2B0B.8010404@gentoo.org> <525B2EEB.1080103@gentoo.org> Date: Sun, 13 Oct 2013 19:50:01 -0400 Message-ID: Subject: Re: [gentoo-dev] rfc: converting /etc/mtab to a symlink From: Mike Gilbert To: Gentoo Dev Content-Type: text/plain; charset=UTF-8 X-Archives-Salt: 0dbae912-081a-4bd5-a7aa-fa69990b4522 X-Archives-Hash: 7cd40e4df3c6225fb073f41737f9d653 On Sun, Oct 13, 2013 at 7:38 PM, Patrick Lauer wrote: > On 10/14/2013 07:29 AM, Mike Gilbert wrote: >> On Sun, Oct 13, 2013 at 7:21 PM, Patrick Lauer wrote: >>> On 10/14/2013 03:32 AM, William Hubbs wrote: >>>> All, >>>> >>>> from what I'm seeing, we should look into converting /etc/mtab to a >>>> symlink to /proc/self/mounts [1]. >>>> >>>> Are there any remaining concerns about doing this? >>> >>> Apart from breaking umount -a and some other things? >>> None at all ;) >>> >>> (The breakage is visible e.g. with umount -a tmpfs, which used to be >>> quite useful if you had a few chroots with /var/tmp/portage as tmpfs and >>> wanted to reset them. Now it'll also punt random things like /run if >>> you're lucky - and in the past it knocked out the OpenRC state directory >>> reliably) >>> >> >> I don't follow this: it seems like umount -a is supposed to unmount >> all filesystems. umount -a -t tmpfs would unmount all tmpfs >> filesystems. /run should be included in that set, even if mtab is a >> regular file. >> > > And the magic trick is to keep "system mounts" like /run out of > /etc/mtab (willful desynchronization) so that umount -a doesn't nuke > them by accident. > > ... why else would you keep such data in two non-synchronized locations?! :D > That's certainly a neat trick. However, it seems a bit weird to use a system-wide database for such a use case; what if multiple users are setting up mounts like this? I guess the key takeaway from this is that people do unconventional things. Probably best to just change the default, and throw up a big warning for existing users as you indicated in your original reply.