From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cyrill Gorcunov <gorcunov@gmail.com>
Subject: Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/
 directory v6
Date: Mon, 5 Sep 2011 23:20:09 +0400
Message-ID: <20110905192009.GJ761@sun>
References: <20110831075814.003575573@openvz.org>
 <20110831080229.100652529@openvz.org>
 <20110831090612.GA3253@albatros>
 <20110831112642.GI25465@sun>
 <20110831140416.GA17626@shutemov.name>
 <20110831142622.GB30615@sun>
 <20110831151023.5b7e12da.akpm@linux-foundation.org>
 <20110901080508.GF30615@sun>
 <20110902163711.GA3124@albatros>
 <20110905185358.GA2103@albatros>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: Andrew Morton <akpm@linux-foundation.org>,
	"Kirill A. Shutemov" <kirill@shutemov.name>,
	containers@lists.osdl.org, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, Nathan Lynch <ntl@pobox.com>,
	kernel-hardening@lists.openwall.com,
	Oren Laadan <orenl@cs.columbia.edu>,
	Daniel Lezcano <dlezcano@fr.ibm.com>,
	Glauber Costa <glommer@parallels.com>,
	James Bottomley <jbottomley@parallels.com>,
	Tejun Heo <tj@kernel.org>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Al Viro <viro@ZenIV.linux.org.uk>,
	Pavel Emelyanov <xemul@parallels.com>
To: Vasiliy Kulikov <segoon@openwall.com>
Return-path: <linux-fsdevel-owner@vger.kernel.org>
Received: from mail-bw0-f46.google.com ([209.85.214.46]:52806 "EHLO
	mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753276Ab1IETUQ (ORCPT
	<rfc822;linux-fsdevel@vger.kernel.org>);
	Mon, 5 Sep 2011 15:20:16 -0400
Content-Disposition: inline
In-Reply-To: <20110905185358.GA2103@albatros>
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <linux-fsdevel.vger.kernel.org>

On Mon, Sep 05, 2011 at 10:53:58PM +0400, Vasiliy Kulikov wrote:
...
>  
> +static int pid_no_revalidate(struct dentry *dentry, struct nameidata *nd)
> +{
> +	if (nd && nd->flags & LOOKUP_RCU)
> +		return -ECHILD;
> +
> +	d_drop(dentry);
> +	return 0;
> +}
> +

Thanks Vasiliy! So every lookup will cause dcache to drop previous cached
entry and alloc and hash new one instead, pretty dramatic, espec in case
of huge number of files mapped ;) Still since it's not time critical operation
(at least for now) I tend to agree.

	Cyrill