From: Andi Kleen <andi@firstfloor.org>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, Trond.Myklebust@netapp.com
Subject: Re: NFS lockdep lock misordering mmap_sem<->i_mutex_key with 2.6.32-git1
Date: Mon, 7 Dec 2009 14:20:09 +0100 [thread overview]
Message-ID: <20091207132009.GI18989@one.firstfloor.org> (raw)
In-Reply-To: <20091207211216.E95E.A69D9226@jp.fujitsu.com>
On Mon, Dec 07, 2009 at 09:19:28PM +0900, KOSAKI Motohiro wrote:
> >
> > While booting 2.6.32-git1 on a NFS root box I got the following
> > lockdep warning early at boot. I haven't looked at details.
>
> It seems typical ABBA deadlock.
>
> vfs_readdir [grab i_mutex]
> nfs_readdir
> nfs_do_filldir
> filldir
> copy_to_user
> [page_fault] [grab mmap_sem]
>
> sys_mmap [grab mmap_sem]
> do_mmap_pgoff
> mmap_region
> nfs_file_mmap
> nfs_revalidate_mapping
> nfs_invalidate_mapping [grab i_mutex]
>
> I guess recent lockdep improvement find old bug.
Thanks for the analysis.
I guess should never do copy_*_user while holding i_mutex? There might
be lots of cases like that.
-Andi
next prev parent reply other threads:[~2009-12-07 13:20 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-07 11:59 NFS lockdep lock misordering mmap_sem<->i_mutex_key with 2.6.32-git1 Andi Kleen
2009-12-07 12:19 ` KOSAKI Motohiro
2009-12-07 13:20 ` Andi Kleen [this message]
2009-12-07 17:38 ` KOSAKI Motohiro
2009-12-15 22:21 ` Al Viro
2009-12-15 23:38 ` Andi Kleen
2009-12-15 23:54 ` Trond Myklebust
2009-12-16 0:09 ` Al Viro
2009-12-16 13:16 ` Trond Myklebust
2009-12-23 16:32 ` Andi Kleen
2009-12-16 0:53 ` Andi Kleen
2009-12-16 13:09 ` Trond Myklebust
2009-12-16 15:57 ` Andi Kleen
2009-12-16 0:06 ` KOSAKI Motohiro
2009-12-16 0:48 ` Andi Kleen
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