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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 19A3DC433E7 for ; Tue, 1 Sep 2020 06:07:45 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C35E2208DB for ; Tue, 1 Sep 2020 06:07:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C35E2208DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=hallyn.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=containers-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 8C30D86EA6; Tue, 1 Sep 2020 06:07:44 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KwRiTozlADmx; Tue, 1 Sep 2020 06:07:41 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id ADE4586EAA; Tue, 1 Sep 2020 06:07:41 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 8B1DBC088B; Tue, 1 Sep 2020 06:07:41 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id BA495C0052 for ; Tue, 1 Sep 2020 06:07:39 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id A15E2203BB for ; Tue, 1 Sep 2020 06:07:39 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id iVB1Apewa5PL for ; Tue, 1 Sep 2020 06:07:33 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail.hallyn.com (mail.hallyn.com [178.63.66.53]) by silver.osuosl.org (Postfix) with ESMTPS id 99D8520345 for ; Tue, 1 Sep 2020 06:06:33 +0000 (UTC) Received: by mail.hallyn.com (Postfix, from userid 1001) id C2E9A82A; Tue, 1 Sep 2020 01:06:31 -0500 (CDT) Date: Tue, 1 Sep 2020 01:06:31 -0500 From: "Serge E. Hallyn" To: "Eric W. Biederman" Subject: Re: Use cases for multiple uid mapping? Message-ID: <20200901060631.GA5193@mail.hallyn.com> References: <87zh6eiyv7.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <87zh6eiyv7.fsf@x220.int.ebiederm.org> User-Agent: Mutt/1.9.4 (2018-02-28) Cc: Linux Containers , Christian Brauner X-BeenThere: containers@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux Containers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: containers-bounces@lists.linux-foundation.org Sender: "Containers" On Fri, Aug 28, 2020 at 10:17:16AM -0500, Eric W. Biederman wrote: > > We had a discussion in the hackroom at LPC talking about use cases for > a shiftfs style setup where there are different mappings of uids to > disk. > > In the discussion we had a couple of ideas of kernel developments > we should look at that address some of these. > > - Fix rlimits in user namespaces (This potentially allows multiple > containers to run with the same userids simplifying the mapping > problem). > > - Look at extending kuid_t to 64bits and using the highbits to > implement uids that are private to user namespaces and don't > map out. > > - Look at ways for allowing setgroups unprivileged. > > > Together this has the potential that the existing uid & gid mappings > will be able to function the same as the proposed fusid mappings. Fingers crossed. > > > I had some problems with audio and a lot of people were talking > quickly. So I did not manage to capture everyone's use cases. And I > definitely was not able to see how everyone's use cases interacted with > the changes we are looking at. > > I know for certain I missed Serge's usecase (apologies). > > Can people follow up to this and report their use cases? Sorry - I'll do so later this week. > There are some real challenges and I would like to see if we > can solve them, while avoiding scary problems like changing > uids on write. > > Eric > > > > > > > > > _______________________________________________ Containers mailing list Containers@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/containers