From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932543Ab2DXWfm (ORCPT ); Tue, 24 Apr 2012 18:35:42 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:38637 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932495Ab2DXWfg (ORCPT ); Tue, 24 Apr 2012 18:35:36 -0400 Message-Id: <20120424223244.786802919@linuxfoundation.org> User-Agent: quilt/0.60-19.1 Date: Tue, 24 Apr 2012 15:33:14 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Christoph Nelles , NeilBrown Subject: [ 33/62] md: fix possible corruption of array metadata on shutdown. In-Reply-To: <20120424223305.GA7748@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit 30b8aa9172dfeaac6d77897c67ee9f9fc574cdbb upstream. commit c744a65c1e2d59acc54333ce8 md: don't set md arrays to readonly on shutdown. removed the possibility of a 'BUG' when data is written to an array that has just been switched to read-only, but also introduced the possibility that the array metadata could be corrupted. If, when md_notify_reboot gets the mddev lock, the array is in a state where it is assembled but hasn't been started (as can happen if the personality module is not available, or in other unusual situations), then incorrect metadata will be written out making it impossible to re-assemble the array. So only call __md_stop_writes() if the array has actually been activated. This patch is needed for any stable kernel which has had the above commit applied. Reported-by: Christoph Nelles Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8160,7 +8160,8 @@ static int md_notify_reboot(struct notif for_each_mddev(mddev, tmp) { if (mddev_trylock(mddev)) { - __md_stop_writes(mddev); + if (mddev->pers) + __md_stop_writes(mddev); mddev->safemode = 2; mddev_unlock(mddev); }