From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: [PATCH] md/raid5: STRIPE_ACTIVE has lock semantics, add barriers Date: Wed, 03 Aug 2011 17:31:23 -0700 Message-ID: <20110804003016.30281.26038.stgit@localhost6.localdomain6> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: neilb@suse.de Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids 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. Signed-off-by: Dan Williams --- This at least was the guarantee we had with sh->lock... drivers/md/raid5.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index dbae459..bd95123 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3116,7 +3116,7 @@ static void handle_stripe(struct stripe_head *sh) 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); @@ -3377,7 +3377,7 @@ 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)