From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751327AbeBVTTE (ORCPT ); Thu, 22 Feb 2018 14:19:04 -0500 Received: from out03.mta.xmission.com ([166.70.13.233]:37192 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbeBVTTC (ORCPT ); Thu, 22 Feb 2018 14:19:02 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Miklos Szeredi Cc: lkml , Linux Containers , linux-fsdevel , Alban Crequy , Seth Forshee , Sargun Dhillon , Dongsu Park , "Serge E. Hallyn" References: <878tbmf5vl.fsf@xmission.com> <20180221202908.17258-4-ebiederm@xmission.com> Date: Thu, 22 Feb 2018 13:18:33 -0600 In-Reply-To: (Miklos Szeredi's message of "Thu, 22 Feb 2018 12:40:18 +0100") Message-ID: <87inao6dfa.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1eowOS-0001Y1-KQ;;;mid=<87inao6dfa.fsf@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=174.19.85.160;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+SFVSLBzenQTZACdnxye1HsPTEJHh/H5A= X-SA-Exim-Connect-IP: 174.19.85.160 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4945] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa06 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa06 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Miklos Szeredi X-Spam-Relay-Country: X-Spam-Timing: total 380 ms - load_scoreonly_sql: 0.03 (0.0%), signal_user_changed: 2.4 (0.6%), b_tie_ro: 1.59 (0.4%), parse: 0.72 (0.2%), extract_message_metadata: 9 (2.4%), get_uri_detail_list: 1.03 (0.3%), tests_pri_-1000: 6 (1.5%), tests_pri_-950: 1.17 (0.3%), tests_pri_-900: 1.01 (0.3%), tests_pri_-400: 18 (4.7%), check_bayes: 17 (4.4%), b_tokenize: 5 (1.4%), b_tok_get_all: 6 (1.5%), b_comp_prob: 1.77 (0.5%), b_tok_touch_all: 2.1 (0.6%), b_finish: 0.51 (0.1%), tests_pri_0: 335 (88.1%), check_dkim_signature: 0.45 (0.1%), check_dkim_adsp: 2.8 (0.7%), tests_pri_500: 4.8 (1.3%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH v6 4/5] fuse: Ensure posix acls are translated outside of init_user_ns X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Miklos Szeredi writes: > On Wed, Feb 21, 2018 at 9:29 PM, Eric W. Biederman > wrote: >> Ensure the translation happens by failing to read or write >> posix acls when the filesystem has not indicated it supports >> posix acls. > > For the first iteration this is fine, but we could convert the raw > xattrs as well, if we later want to, right? I will say maybe. This is tricky. The code would not be too hard, and the function to do the work posix_acl_fix_xattr_userns already exists in fs/posix_acl.c I don't actually expect that to work longterm. I expect the direction the kernel internals are moving is that all filesystems that implement posix acls will be expected to implement .get_acl and .set_acl. I would have to reread the old thread that got us to this point with posix acls before I could really understand the backwards compatible fuse use case, and I would have to reread the rest of the acl processing in the kernel before I could recall exactly what makes sense. If there was an obvious way to whitelist xattrs that fuse can support for user namespaces I think I would go for that. Just to avoid future problems with future xattrs. Eric