From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758226AbcG0APd (ORCPT ); Tue, 26 Jul 2016 20:15:33 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:44269 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757385AbcG0AP1 convert rfc822-to-8bit (ORCPT ); Tue, 26 Jul 2016 20:15:27 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: =?utf-8?Q?Micha=C5=82?= Zegan Cc: Linus Torvalds , Linux Containers , linux-fsdevel@vger.kernel.org, Seth Forshee , linux-kernel@vger.kernel.org References: <87bn1kwjad.fsf@x220.int.ebiederm.org> <6ec55309-209d-7b90-9289-19e6fd180af9@poczta.onet.pl> Date: Tue, 26 Jul 2016 19:02:24 -0500 In-Reply-To: <6ec55309-209d-7b90-9289-19e6fd180af9@poczta.onet.pl> (=?utf-8?Q?=22Micha=C5=82?= Zegan"'s message of "Wed, 27 Jul 2016 01:18:01 +0200") Message-ID: <8737mwne27.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-XM-SPF: eid=1bSCVQ-0007fd-Jo;;;mid=<8737mwne27.fsf@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=67.3.204.119;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+onHSaq8QRQRuhvGvvHfK6dJs8gTXojzA= X-SA-Exim-Connect-IP: 67.3.204.119 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 X-Spam-DCC: ; X-Spam-Combo: =?ISO-8859-1?Q?;Micha=c5=82 Zegan ?= X-Spam-Relay-Country: X-Spam-Timing: total 60 ms - load_scoreonly_sql: 0.04 (0.1%), signal_user_changed: 3.9 (6.4%), b_tie_ro: 2.9 (4.7%), parse: 1.01 (1.7%), extract_message_metadata: 7 (11.6%), get_uri_detail_list: 0.99 (1.6%), tests_pri_-1000: 15 (24.5%), tests_pri_-950: 1.17 (1.9%), tests_pri_-900: 0.96 (1.6%), tests_pri_-400: 17 (27.3%), check_bayes: 15 (25.6%), b_tokenize: 4.0 (6.7%), b_tok_get_all: 4.8 (8.0%), b_comp_prob: 1.46 (2.4%), b_tok_touch_all: 3.0 (5.0%), b_finish: 0.75 (1.2%), tests_pri_0: 11 (18.5%), rewrite_mail: 0.00 (0.0%) Subject: Re: [GIT PULL] userns related vfs enhancements for v4.8 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 in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michał Zegan writes: > I have one question: what uids are written in the filesystem inodes? > those that the kernel sees, or those mapped by user namespaces? and so, > is it true that the filesystem will still require shifting uids, > directly or indirectly, to be usable from inside user namespace? can't > uids be mapped dynamically from what is in the inode to kernel uids > based on the user namespace they are used from? Maybe because the fs can > be mounted from outside before starting the container? Feel free to read the code. As best I can understand your question the best answer is in reading and understanding the code yourself. Eric