From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752142AbbCTQyE (ORCPT ); Fri, 20 Mar 2015 12:54:04 -0400 Received: from mail-wi0-f181.google.com ([209.85.212.181]:36842 "EHLO mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751637AbbCTQx7 (ORCPT ); Fri, 20 Mar 2015 12:53:59 -0400 Date: Fri, 20 Mar 2015 17:53:52 +0100 From: Miklos Szeredi To: Al Viro Cc: Josh Boyer , Karel Zak , dhowells@redhat.com, linux-kernel@vger.kernel.org, linux-unionfs@vger.kernel.org Subject: Re: d_path() and overlay fs Message-ID: <20150320165352.GF20913@tucsk> References: <20150320132914.GA1749@ws.net.home> <20150320160123.GE20913@tucsk> <20150320162558.GA29656@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150320162558.GA29656@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 20, 2015 at 04:25:58PM +0000, Al Viro wrote: > On Fri, Mar 20, 2015 at 05:01:23PM +0100, Miklos Szeredi wrote: > > > But it does take care of the majority of f_path users that actually want the > > covering path. > > Bloody bad idea, IMO. I have no objections against adding _helpers_ from > that patch (seq_file_path(), etc.), but I really don't like adding that > second struct path there. And it still doesn't fix the issue with > LSM, etc., so we'll _still_ need to fix it sane way. Obviously getting rid of the extra path would be good. But we still have lots of f_path.dentry in filesystems and we need to start with that. struct dentry *file_dentry(struct file *) ? Implemented how? Rename f_inode to f_dentry and reimplement file_inode() based on that. BTW, since nobody is accessing ->f_covering_path directly except the single f_covering_path() helper, it would be extremely easy to get rid of it later. That's why I posted this patch, I think it's simple enough to get it into v4.0 which would fix the majority of cases that people complain about. The thing could even be made dependent on CONFIG_OVERLAY_FS if the addition actually increases the footprint of struct file (I haven't checked). Thanks, Miklos