Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762113AbXH1UKa (ORCPT ); Tue, 28 Aug 2007 16:10:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753346AbXH1UKV (ORCPT ); Tue, 28 Aug 2007 16:10:21 -0400 Received: from mx1.redhat.com ([66.187.233.31]:47292 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752387AbXH1UKU (ORCPT ); Tue, 28 Aug 2007 16:10:20 -0400 Date: Tue, 28 Aug 2007 16:09:51 -0400 From: Jeff Layton To: Trond Myklebust Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org, nfs@lists.sourceforge.net, linux-cifs-client@lists.samba.org, linux-kernel@vger.kernel.org Subject: Re: [NFS] [PATCH 0/4] add killattr inode operation to allow filesystems to interpret ATTR_KILL_S*ID bits Message-Id: <20070828160951.1a7d84fa.jlayton@redhat.com> In-Reply-To: <1188330591.6701.202.camel@heimdal.trondhjem.org> References: <200708271727.l7RHR36m007248@dantu.rdu.redhat.com> <20070828191114.GA3419@infradead.org> <1188330591.6701.202.camel@heimdal.trondhjem.org> X-Mailer: Sylpheed 2.3.1 (GTK+ 2.10.14; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2238 Lines: 60 On Tue, 28 Aug 2007 15:49:51 -0400 Trond Myklebust wrote: > On Tue, 2007-08-28 at 20:11 +0100, Christoph Hellwig wrote: > > Sorry for not replying to the previsious revisions, but I've been out > > for on vacation. > > > > I can't say I like this version. Now we've got callouts at two rather close > > levels which is not very nice from the interface POV. > > Agreed. > > > Maybe preference is for the first scheme where we simply move interpreation > > of the ATTR_KILL_SUID/ATTR_KILL_SGID into the setattr routine and provide > > a nice helper for the normal filesystem to use. > > > > If people are really concerned about adding two lines of code to the > > handfull of setattr operation there's a variant of this scheme that can > > avoid it: > > > > - notify_change is modified to not clear the ATTR_KILL_SUID/ATTR_KILL_SGID > > but update ia_mode and the ia_valid flag to include ATTR_MODE. > > - disk filesystems stay unchanged and never look at > > ATTR_KILL_SUID/ATTR_KILL_SGID, but nfs can check for it and ignore > > the ATTR_MODE flags and ia_valid in this case and do the right thing > > on the server side. > > Hmm... There has to be an implicit promise here that nobody else will > ever try to set ATTR_KILL_SUID/ATTR_KILL_SGID and ATTR_MODE at the same > time. Currently, that assumption is not there: > That was my concern with this scheme as well... > > > if (ia_valid & ATTR_KILL_SGID) { > > attr->ia_valid &= ~ ATTR_KILL_SGID; > > if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { > > if (!(ia_valid & ATTR_MODE)) { > > ia_valid = attr->ia_valid |= ATTR_MODE; > > attr->ia_mode = inode->i_mode; > > } > > attr->ia_mode &= ~S_ISGID; > > } > > } > > Should we perhaps just convert the above 'if (!(ia_valid & ATTR_MODE))' > into a 'BUG_ON(ia_valid & ATTR_MODE)'? > Sounds reasonable. I'll also throw in a comment that explains this reasoning... -- Jeff Layton - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/