| From | Greg Kroah-Hartman <> | Subject | [ 093/262] md/raid5: fix calculate of degraded when a replacement becomes active. | Date | Fri, 28 Sep 2012 11:50:22 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.5-stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown <neilb@suse.de>
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 <robin@robinhill.me.uk> Reported-by: John Drescher <drescherjm@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/raid5.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -380,6 +380,8 @@ static int calc_degraded(struct r5conf * 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 * 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))
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