Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760113AbaJCX22 (ORCPT ); Fri, 3 Oct 2014 19:28:28 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46327 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757402AbaJCWD6 (ORCPT ); Fri, 3 Oct 2014 18:03:58 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, NeilBrown Subject: [PATCH 3.16 332/357] md/raid1: Dont use next_resync to determine how far resync has progressed Date: Fri, 3 Oct 2014 14:31:58 -0700 Message-Id: <20141003212943.432448674@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141003212933.458851516@linuxfoundation.org> References: <20141003212933.458851516@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit 235549605eb7f1c5a37cef8b09d12e6d412c5cd6 upstream. next_resync is (approximately) the location for the next resync request. However it does *not* reliably determine the earliest location at which resync might be happening. This is because resync requests can complete out of order, and we only limit the number of current requests, not the distance from the earliest pending request to the latest. mddev->curr_resync_completed is a reliable indicator of the earliest position at which resync could be happening. It is updated less frequently, but is actually reliable which is more important. So use it to determine if a write request is before the region being resynced and so safe from conflict. This error can allow resync IO to interfere with normal IO which could lead to data corruption. Hence: stable. Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761 Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid1.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -875,12 +875,10 @@ static bool need_to_wait_for_sync(struct if (conf->array_frozen || !bio) wait = true; else if (conf->barrier && bio_data_dir(bio) == WRITE) { - if (conf->next_resync < RESYNC_WINDOW_SECTORS) - wait = true; - else if ((conf->next_resync - RESYNC_WINDOW_SECTORS - >= bio_end_sector(bio)) || - (conf->next_resync + NEXT_NORMALIO_DISTANCE - <= bio->bi_iter.bi_sector)) + if ((conf->mddev->curr_resync_completed + >= bio_end_sector(bio)) || + (conf->next_resync + NEXT_NORMALIO_DISTANCE + <= bio->bi_iter.bi_sector)) wait = false; else wait = true; @@ -918,7 +916,7 @@ static sector_t wait_barrier(struct r1co if (bio && bio_data_dir(bio) == WRITE) { if (bio->bi_iter.bi_sector >= - conf->next_resync) { + conf->mddev->curr_resync_completed) { if (conf->start_next_window == MaxSector) conf->start_next_window = conf->next_resync + -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/