From 9fd0132a29b4e40e5cf5ff82a02227b7f603bba7 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 19 Sep 2012 12:52:30 +1000 Subject: md/raid5: fix calculate of 'degraded' when a replacement becomes active. commit e5c86471f933608db5d43679f84cb4346c32033e upstream. When a replacement device becomes active, we mark the device that it replaces as 'faulty' so that it can subsequently get removed. However 'calc_degraded' only pays attention to the primary device, not the replacement, so the array appears to become degraded, which is wrong. So teach 'calc_degraded' to consider any replacement if a primary device is faulty. This is suitable for -stable as an incorrect 'degraded' value can confuse md and could lead to data corruption. This is only relevant for 3.3 and later. Reported-by: Robin Hill Reported-by: John Drescher Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid5.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/md') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 73a58007eb9..0240576564d 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -380,6 +380,8 @@ static int calc_degraded(struct r5conf *conf) degraded = 0; for (i = 0; i < conf->previous_raid_disks; i++) { struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); + if (rdev && test_bit(Faulty, &rdev->flags)) + rdev = rcu_dereference(conf->disks[i].replacement); if (!rdev || test_bit(Faulty, &rdev->flags)) degraded++; else if (test_bit(In_sync, &rdev->flags)) @@ -404,6 +406,8 @@ static int calc_degraded(struct r5conf *conf) degraded2 = 0; for (i = 0; i < conf->raid_disks; i++) { struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); + if (rdev && test_bit(Faulty, &rdev->flags)) + rdev = rcu_dereference(conf->disks[i].replacement); if (!rdev || test_bit(Faulty, &rdev->flags)) degraded2++; else if (test_bit(In_sync, &rdev->flags)) -- cgit v1.2.3