From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Gruenbacher Subject: Re: [PATCH] Fix d_path for lazy unmounts Date: Wed, 14 Feb 2007 18:43:49 -0800 Message-ID: <200702141843.49668.agruen@suse.de> References: <200702021923.02491.agruen@suse.de> <17862.30489.694079.138765@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Tony Jones To: Neil Brown Return-path: Received: from mx1.suse.de ([195.135.220.2]:60617 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964873AbXBOCnr (ORCPT ); Wed, 14 Feb 2007 21:43:47 -0500 In-Reply-To: <17862.30489.694079.138765@notabene.brown> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sunday 04 February 2007 16:15, Neil Brown wrote: > The behaviour in the face of a lazy unmount should be clarified in > this comment. Done. > If sys_getcwd is called on a directory that is no longer > connected to the root, it isn't clear to me that it should return > without an error. > Without your patch it can return garbage which is clearly wrong. > With you patch it will return a relative path name, which is also > wrong (it isn't a valid path that leads to the current working directory). Right, it should return -ENOENT instead in that case. Fixed as well. > I would suggest that 'fail_deleted' be (e.g.) changed to > 'fail_condition' where two conditions are defined > #define DPATH_FAIL_DELETED 1 > #define DPATH_FAIL_DISCONNECTED 2 The much cleaner interface is to check if the path returned starts with a slash. If it doesn't, we know the path is bad as far as sys_getcwd() is concerned. We will construct the partial path in __d_path before figuring out that the path is disconnected, so no performance penalty, either. > In reality, you are comparing "buflen < namelen+1" but spelling it as > "buflen <= namelen". I would prefer the full spelling with least room > for confusion. I'm fine either way. > Maybe: > > + buflen -= namelen + 1; > > + buffer -= namelen + 1; > > + memcpy(buffer+1, dentry->d_name.name, namelen); > > + *buffer = '/'; That's better, yes. Thanks, Andreas