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=-7.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 EC16DC433EF for ; Fri, 17 Sep 2021 08:30:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6EEB61108 for ; Fri, 17 Sep 2021 08:30:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245383AbhIQIcI (ORCPT ); Fri, 17 Sep 2021 04:32:08 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:41546 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232295AbhIQIcH (ORCPT ); Fri, 17 Sep 2021 04:32:07 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 5AFCF22286; Fri, 17 Sep 2021 08:30:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1631867444; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5eb8TqjzrqfA6ERLZr5A6LRYLt6Dsy4QQOdugdSe97Q=; b=XdmkuscCNdsJbshxJludjY9UBBxnrbeeje9zR82u+BctBDXam0UMT8SP2fcDBYZ8aK/Smc KK/ENfXXqaYp1ZVw7dgw7fKlvNMDcINECnbmaTL/uw1vFM3xyY9gnITACUu6/fHxERD3Z9 M0t8mT0HGmh5SlFuY54Ma1mexoGe2VQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1631867444; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5eb8TqjzrqfA6ERLZr5A6LRYLt6Dsy4QQOdugdSe97Q=; b=E/Cq/YykbiDucpkCYq/JzAf9kaune18m05B2tIsNjSE0lmHWgW8/GBS+8vNCJeMe80D3SL 8yGpCLimjZj+SGBw== Received: from quack2.suse.cz (unknown [10.100.224.230]) by relay2.suse.de (Postfix) with ESMTP id 18851A3B84; Fri, 17 Sep 2021 08:30:44 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id EEBB21E0CA7; Fri, 17 Sep 2021 10:30:43 +0200 (CEST) Date: Fri, 17 Sep 2021 10:30:43 +0200 From: Jan Kara To: "Darrick J. Wong" Cc: xfs , linux-ext4 , linux-btrfs , linux-fsdevel Subject: Re: Shameless plug for the FS Track at LPC next week! Message-ID: <20210917083043.GA6547@quack2.suse.cz> References: <20210916013916.GD34899@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210916013916.GD34899@magnolia> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hi! We did a small update to the schedule: > Christian Brauner will run the second session, discussing what idmapped > filesystem mounts are for and the current status of supporting more > filesystems. We have extended this session as we'd like to discuss and get some feedback from users about project quotas and project ids: Project quotas were originally mostly a collaborative feature and later got used by some container runtimes to implement limitation of used space on a filesystem shared by multiple containers. As a result current semantics of project quotas are somewhat surprising and handling of project ids is not consistent among filesystems. The main two contending points are: 1) Currently the inode owner can set project id of the inode to any arbitrary number if he is in init_user_ns. It cannot change project id at all in other user namespaces. 2) Should project IDs be mapped in user namespaces or not? User namespace code does implement the mapping, VFS quota code maps project ids when using them. However e.g. XFS does not map project IDs in its calls setting them in the inode. Among other things this results in some funny errors if you set project ID to (unsigned)-1. In the session we'd like to get feedback how project quotas / ids get used / could be used so that we can define the common semantics and make the code consistently follow these rules. Honza -- Jan Kara SUSE Labs, CR