From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965986Ab1KJDtu (ORCPT ); Wed, 9 Nov 2011 22:49:50 -0500 Received: from cantor2.suse.de ([195.135.220.15]:45306 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966155Ab1KJDtp (ORCPT ); Wed, 9 Nov 2011 22:49:45 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Nov 9 13:32:08 2011 Message-Id: <20111109213208.240820913@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 09 Nov 2011 13:35:02 -0800 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, Dan Williams , NeilBrown Subject: [255/264] md/raid5: STRIPE_ACTIVE has lock semantics, add barriers In-Reply-To: <20111109213508.GA3476@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams commit 257a4b42af7586fab4eaec7f04e6896b86551843 upstream. All updates that occur under STRIPE_ACTIVE should be globally visible when STRIPE_ACTIVE clears. test_and_set_bit() implies a barrier, but clear_bit() does not. This is suitable for 3.1-stable. Signed-off-by: Dan Williams Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid5.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3116,7 +3116,7 @@ static void handle_stripe(struct stripe_ struct r5dev *pdev, *qdev; clear_bit(STRIPE_HANDLE, &sh->state); - if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) { + if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) { /* already being handled, ensure it gets handled * again when current action finishes */ set_bit(STRIPE_HANDLE, &sh->state); @@ -3381,7 +3381,7 @@ finish: return_io(s.return_bi); - clear_bit(STRIPE_ACTIVE, &sh->state); + clear_bit_unlock(STRIPE_ACTIVE, &sh->state); } static void raid5_activate_delayed(raid5_conf_t *conf)