Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754633AbXLHRPx (ORCPT ); Sat, 8 Dec 2007 12:15:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751744AbXLHRPq (ORCPT ); Sat, 8 Dec 2007 12:15:46 -0500 Received: from wa-out-1112.google.com ([209.85.146.183]:63568 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751291AbXLHRPo (ORCPT ); Sat, 8 Dec 2007 12:15:44 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=SvDzgwpm2dpLksx0FSykrQGVBmzmb2NSMunXQRjBbPAZBxw9nwA6CKk1AGU8YB/0wK2QnqLPwxZKqdSluJttWAnjPZI58mn1aPWOQ1n3OYhJhlOFCty+AJ8Gfr+mFvFaeJH1bjlo79mZcBiz9kNhw5y1BvFe+8lXR5VAvlUQDpY= Message-ID: Date: Sat, 8 Dec 2007 12:15:44 -0500 From: Shane To: "Eric W. Biederman" Subject: Re: [PATCH 2.6.24-rc4] proc: Remove/Fix proc generic d_revalidate Cc: "Andrew Morton" , "Alexey Dobriyan" , rjw@sisk.pl, trond.myklebust@fys.uio.no, linux-kernel@vger.kernel.org, bfields@fieldses.org, den@openvz.org, "Pavel Emelyanov" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1197067918.10831.13.camel@heimdal.trondhjem.org> <20071207151444.af5d8e11.akpm@linux-foundation.org> <200712080043.29292.rjw@sisk.pl> <20071208000043.GC1951@martell.zuzino.mipt.ru> <20071207161508.afe8fdf1.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2429 Lines: 66 On Dec 7, 2007 11:25 PM, Eric W. Biederman wrote: > > Ultimately to implement /proc perfectly we need an implementation > of d_revalidate because files and directories can be removed behind > the back of the VFS, and d_revalidate is the only way we can let > the VFS know that this has happened. > > Unfortunately the linux VFS can not cope with anything in the path > to a mount point going away. So a proper d_revalidate method that > calls d_drop also needs to call have_submounts which is moderately > expensive, so you really don't want a d_revalidate method that > unconditionally calls it, but instead only calls it when the > backing object has really gone away. > > proc generic entries only disappear on module_unload (when > not counting the fledgling network namespace) so it is quite rare > that we actually encounter that case and has not actually caused > us real world trouble yet. > > So until we get a proper test for keeping dentries in the dcache > fix the current d_revalidate method by completely removing it. This > returns us to the current status quo. > > So with CONFIG_NETNS=n things should look as they have always looked. > > For CONFIG_NETNS=y things work most of the time but there are a few > rare corner cases that don't behave properly. As the network namespace > is barely present in 2.6.24 this should not be a problem. > > Signed-off-by: Eric W. Biederman > --- > fs/proc/generic.c | 7 ------- > 1 files changed, 0 insertions(+), 7 deletions(-) > > diff --git a/fs/proc/generic.c b/fs/proc/generic.c > index 8d49838..6a2fe51 100644 > --- a/fs/proc/generic.c > +++ b/fs/proc/generic.c > @@ -374,16 +374,9 @@ static int proc_delete_dentry(struct dentry * dentry) > return 1; > } > > -static int proc_revalidate_dentry(struct dentry *dentry, struct nameidata *nd) > -{ > - d_drop(dentry); > - return 0; > -} > - > static struct dentry_operations proc_dentry_operations = > { > .d_delete = proc_delete_dentry, > - .d_revalidate = proc_revalidate_dentry, > }; > > /* > -- > 1.5.3.rc6.17.g1911 Confirmed. This patch fixes the problem for me. Shane -- 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/