From b7219ccb33aa0df9949a60c68b5e9f712615e56f Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Jul 2012 10:05:34 +1000 Subject: [PATCH] md/raid1: don't abort a resync on the first badblock. 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. Cc: stable@vger.kernel.org Reported-by: Alexander Lyakas Signed-off-by: NeilBrown --- 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 7aa958ed2847..d2361b162de5 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; -- 2.20.1