From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+w=401wt.eu-S1755833AbZDOT3T@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1755833AbZDOT3T (ORCPT <rfc822;w@1wt.eu>);
	Wed, 15 Apr 2009 15:29:19 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752838AbZDOT3F
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Wed, 15 Apr 2009 15:29:05 -0400
Received: from smtp1.linux-foundation.org ([140.211.169.13]:42429 "EHLO
	smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK)
	by vger.kernel.org with ESMTP id S1752097AbZDOT3E convert rfc822-to-8bit
	(ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Wed, 15 Apr 2009 15:29:04 -0400
Date: Wed, 15 Apr 2009 12:25:32 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Luca Tettamanti <kronos.it@gmail.com>
Cc: linux-kernel@vger.kernel.org, john@johnmccutchan.com, rlove@rlove.org,
       eparis@redhat.com
Subject: Re: [PATCH] Fix inconsistent lock state in inotify
Message-Id: <20090415122532.0a0c5f24.akpm@linux-foundation.org>
In-Reply-To: <68676e00904150459q6cc34f9fjb9475937a4e73c71@mail.gmail.com>
References: <20090410192533.GA24345@dreamland.darkstar.lan>
	<20090414161329.094b977c.akpm@linux-foundation.org>
	<68676e00904150459q6cc34f9fjb9475937a4e73c71@mail.gmail.com>
X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu)
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, 15 Apr 2009 13:59:29 +0200
Luca Tettamanti <kronos.it@gmail.com> wrote:

> >> +++ b/fs/notify/inotify/inotify_user.c
> >> @@ -220,7 +220,7 @@ static struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie,
> >>                               rem = 0;
> >>               }
> >>
> >> -             kevent->name = kmalloc(len + rem, GFP_KERNEL);
> >> +             kevent->name = kmalloc(len + rem, GFP_NOFS);
> >>               if (unlikely(!kevent->name)) {
> >>                       kmem_cache_free(event_cachep, kevent);
> >>                       return NULL;
> >
> > Thanks.
> >
> > This is in fact a false positive and we plan to fix it via lockdep
> > annotation.
> 
> Well, I trust you on the "false positive", but a few line before there this:
> 
>   kevent = kmem_cache_alloc(event_cachep, GFP_NOFS);
> 
> so can kmem_cache_alloc also use GFP_KERNEL?

Yes, it looks that way.

umm, I think I'll merge your original patch as a reminder-to-self.
If the problem doesn't get fixed in a better way for 2.6.30 then I
might end up going with the GFP_NOFS approach.

But it's bad to weaken the memory allocation mode just to plug a lockdep
warning.