From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964874Ab2HGDjG (ORCPT ); Mon, 6 Aug 2012 23:39:06 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:59830 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964804Ab2HGDix (ORCPT ); Mon, 6 Aug 2012 23:38:53 -0400 Message-Id: <20120807032802.080640518@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Tue, 07 Aug 2012 04:28:36 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, NeilBrown , Alexander Lyakas Subject: [ 41/70] md/raid1: dont abort a resync on the first badblock. In-Reply-To: <20120807032755.803571133@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit b7219ccb33aa0df9949a60c68b5e9f712615e56f upstream. If a resync of a RAID1 array with 2 devices finds a known bad block one device it will neither read from, or write to, that device for this block offset. So there will be one read_target (The other device) and zero write targets. This condition causes md/raid1 to abort the resync assuming that it has finished - without known bad blocks this would be true. When there are no write targets because of the presence of bad blocks we should only skip over the area covered by the bad block. RAID10 already gets this right, raid1 doesn't. Or didn't. As this can cause a 'sync' to abort early and appear to have succeeded it could lead to some data corruption, so it suitable for -stable. Reported-by: Alexander Lyakas Signed-off-by: NeilBrown Signed-off-by: Ben Hutchings --- drivers/md/raid1.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 7aa958e..d2361b1 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -2502,7 +2502,10 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp /* There is nowhere to write, so all non-sync * drives must be failed - so we are finished */ - sector_t rv = max_sector - sector_nr; + sector_t rv; + if (min_bad > 0) + max_sector = sector_nr + min_bad; + rv = max_sector - sector_nr; *skipped = 1; put_buf(r1_bio); return rv;