From 509c317d092a551f5c26de05445fc8d5b81cc23d Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 4 Jul 2013 16:41:53 +1000 Subject: [PATCH] md/raid10: fix bug which causes all RAID10 reshapes to move no data. commit 1376512065b23f39d5f9a160948f313397dde972 upstream. The recent comment: commit 7e83ccbecd608b971f340e951c9e84cd0343002f md/raid10: Allow skipping recovery when clean arrays are assembled Causes raid10 to skip a recovery in certain cases where it is safe to do so. Unfortunately it also causes a reshape to be skipped which is never safe. The result is that an attempt to reshape a RAID10 will appear to complete instantly, but no data will have been moves so the array will now contain garbage. (If nothing is written, you can recovery by simple performing the reverse reshape which will also complete instantly). Bug was introduced in 3.10, so this is suitable for 3.10-stable. Signed-off-by: NeilBrown Cc: Martin Wilck Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid10.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 6ddae2501b9a..f2f4a6e4f4f4 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -2909,14 +2909,13 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, */ if (mddev->bitmap == NULL && mddev->recovery_cp == MaxSector && + mddev->reshape_position == MaxSector && + !test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && + !test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && conf->fullsync == 0) { *skipped = 1; - max_sector = mddev->dev_sectors; - if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) || - test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) - max_sector = mddev->resync_max_sectors; - return max_sector - sector_nr; + return mddev->dev_sectors - sector_nr; } skipped: -- 2.34.1