From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out3-smtp.messagingengine.com ([66.111.4.27]:58567 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752452AbcGATds convert rfc822-to-8bit (ORCPT ); Fri, 1 Jul 2016 15:33:48 -0400 From: Nikolaus Rath To: ebiederm@xmission.com (Eric W. Biederman) Cc: "Michael j Theall" , Seth Forshee , fuse-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, Miklos Szeredi Subject: Re: [fuse-devel] [RFC] fuse: Support posix ACLs References: <20160629190731.GF53123@ubuntu-hedt> <87vb0rhhpr.fsf@x220.int.ebiederm.org> Date: Fri, 01 Jul 2016 12:33:40 -0700 In-Reply-To: <87vb0rhhpr.fsf@x220.int.ebiederm.org> (Eric W. Biederman's message of "Wed, 29 Jun 2016 15:18:24 -0500") Message-ID: <87furt9mqz.fsf@thinkpad.rath.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Jun 29 2016, ebiederm@xmission.com (Eric W. Biederman) wrote: > "Michael j Theall" writes: > >> Going by the patch I posted a couple of years ago: >> https://sourceforge.net/p/fuse/mailman/message/33033653/ >> >> The only hole I see in your patch is that in setattr() you are not >> updating the cached acl if the ATTR_MODE is updated. The other major >> difference is that my version uses the get_acl/set_acl inode >> operations but you use that plus the xattr handlers. I'm not >> up-to-speed on the kernel so I'm not sure if you actually need to >> implement both. > > That makes an interesting question. Is it desirable to keep > inode->i_mode in sync with the posix acls in fuse or should a filesystem > that supports posix acls worry about that? A FUSE file system should be able to support ACLs without requiring the file system process to do more than support extended attributes. I believe this means that the kernel should keep i_mode and the ACLs in sync -- it would be a rather bug prone and redundant for each FUSE file system to implement its own parser for format in which the ACLs are stored in xattrs. Best, -Nikolaus -- GPG encrypted emails preferred. Key id: 0xD113FCAC3C4E599F Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F »Time flies like an arrow, fruit flies like a Banana.«