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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 815E1C1975A for ; Fri, 13 Mar 2020 01:01:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AE9A20637 for ; Fri, 13 Mar 2020 01:01:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chrisdown.name header.i=@chrisdown.name header.b="fbJPeQvI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727150AbgCMBBE (ORCPT ); Thu, 12 Mar 2020 21:01:04 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:52253 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727077AbgCMBBC (ORCPT ); Thu, 12 Mar 2020 21:01:02 -0400 Received: by mail-wm1-f68.google.com with SMTP id 11so8189881wmo.2 for ; Thu, 12 Mar 2020 18:00:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=2U6tAzdLF1x4vnU8NvQtzG93LtZx8bGoRnFmPfqzr44=; b=fbJPeQvIkVYKb9c1z7XgxRxx4/zfKwEcy6ajBhwUYxVUorFsSnvoInvgs6/KSmWLvz LdXzEIc4+V3XoENOHwR/e8OLYs4uvwpyncqQCDonDb+Oeak8teYTgUW57sGK8xMgpEBK P5bPncy48nsYk/HrlB2rCtcGyUogOalJxiMwQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=2U6tAzdLF1x4vnU8NvQtzG93LtZx8bGoRnFmPfqzr44=; b=ebHBf1S29uPk3t4rSxLniAK0McqnhRDVln2BVSY+T0Xe2f43GJLCU0PhMohkrm0vac hwPPrwPt3r9csOHnr/3qrCzzyn97iuOCuviM7HbRxkdVdXzpD0c/bLqx8vDDwLJs3m7u dGyrGFZX4gkdtHktckFTxlU79Xb2CjDDiXDApQWi5Ws5U5gRCcFLTas1j6BeDF6T4rJX zYKLGgSJwIm34AO7oYSoeCZOZtluoSe0XCoRC11idmvuoiIcN5dZdPWbzm/CihZsWiMq Fi8SA0qiYLsX6BQ6Le6LGMloZxX4NRsJM4RnvxCujym+U423jRciL64ub9NXXili5KAn Sf4Q== X-Gm-Message-State: ANhLgQ3NQawdNY9D1LkfWe3fQDR/afWHqJYMKoc8B0ol0iN7GewmKD4W RS7urFSLN8SdIDeB5Efop9PJZg== X-Google-Smtp-Source: ADFU+vu3vr8f21ZL3B+XWi8+py7H/hfbmXTl27EUZLH/IAxHz0tps0u94v2tYSJjBvt8bj2pSUpGow== X-Received: by 2002:a1c:a384:: with SMTP id m126mr7548567wme.84.1584061258757; Thu, 12 Mar 2020 18:00:58 -0700 (PDT) Received: from localhost ([2a01:4b00:8432:8a00:fa59:71ff:fe7e:8d21]) by smtp.gmail.com with ESMTPSA id b16sm75473908wrq.14.2020.03.12.18.00.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Mar 2020 18:00:58 -0700 (PDT) Date: Fri, 13 Mar 2020 01:00:57 +0000 From: Chris Down To: Daniel Xu Cc: cgroups@vger.kernel.org, tj@kernel.org, lizefan@huawei.com, hannes@cmpxchg.org, viro@zeniv.linux.org.uk, shakeelb@google.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, kernel-team@fb.com Subject: Re: [PATCH v3 0/4] Support user xattrs in cgroupfs Message-ID: <20200313010057.GB24320@chrisdown.name> References: <20200312200317.31736-1-dxu@dxuuu.xyz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20200312200317.31736-1-dxu@dxuuu.xyz> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Daniel Xu writes: >User extended attributes are useful as metadata storage for kernfs >consumers like cgroups. Especially in the case of cgroups, it is useful >to have a central metadata store that multiple processes/services can >use to coordinate actions. > >A concrete example is for userspace out of memory killers. We want to >let delegated cgroup subtree owners (running as non-root) to be able to >say "please avoid killing this cgroup". This is especially important for >desktop linux as delegated subtrees owners are less likely to run as >root. > >The first two commits set up some stuff for the third commit which >intro introduce a new flag, KERNFS_ROOT_SUPPORT_USER_XATTR, >that lets kernfs consumers enable user xattr support. The final commit >turns on user xattr support for cgroupfs. The whole series looks good to me, thanks. For the whole series: Acked-by: Chris Down