From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752645Ab0CYKsx (ORCPT ); Thu, 25 Mar 2010 06:48:53 -0400 Received: from mail-fx0-f223.google.com ([209.85.220.223]:54190 "EHLO mail-fx0-f223.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750906Ab0CYKsv (ORCPT ); Thu, 25 Mar 2010 06:48:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:cc:content-type; b=XbEmH8EFRxbmXBHaZ7bRMm7Z0MtopQ0hGAykzkkJvC0BjKtErGrA5DXmREZ24QvQE/ FUvk7FLnTib7jdxTo0dXwkC7Ya9A1KAO/IcwewQz6woMlccsTKvTlabLcVEjzPjn8LHk N/K/RrjMJUiAyI1H/sh58eEGKJJBkd6BwGHOY= MIME-Version: 1.0 Date: Thu, 25 Mar 2010 11:48:49 +0100 Message-ID: Subject: INFO: suspicious rcu_dereference_check() From: Zdenek Kabelac To: Linux Kernel Mailing List Cc: linux-nfs@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi I've enabled rcu correctness for my todays 2.6.34-rc2 kernel. I'm getting this INFO: from my kvm guest (which uses host's nfs exported directory.) This =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- fs/nfs/delegation.c:348 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by rm/1820: #0: (&sb->s_type->i_mutex_key#13/1){+.+.+.}, at: [] do_unlinkat+0x9b/0x1c0 #1: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: [] vfs_unlink+0x56/0xf0 stack backtrace: Pid: 1820, comm: rm Not tainted 2.6.34-rc2-00186-ge79a302 #60 Call Trace: [] lockdep_rcu_dereference+0xbb/0xc0 [] nfs_inode_return_delegation+0x101/0x110 [nfs] [] nfs_unlink+0xad/0x2a0 [nfs] [] vfs_unlink+0x9a/0xf0 [] ? mnt_want_write+0x65/0xb0 [] do_unlinkat+0x183/0x1c0 [] ? retint_swapgs+0xe/0x13 [] ? trace_hardirqs_on_caller+0x155/0x1a0 [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] sys_unlinkat+0x22/0x40 [] sysenter_dispatch+0x7/0x2c Zdenek