From: NeilBrown Date: Wed, 19 Sep 2012 02:52:30 +0000 (+1000) Subject: md/raid5: fix calculate of 'degraded' when a replacement becomes active. X-Git-Tag: v3.5.5~171 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0177d47e166d716789e3fb5b58cfddf451ab8998;p=karo-tx-linux.git 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 --- diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 04348d76bb30..bcd096b2c496 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))