| From 355840e7a7e56bb2834fd3b0da64da5465f8aeaa Mon Sep 17 00:00:00 2001 |
| From: NeilBrown <neilb@suse.de> |
| Date: Wed, 26 Oct 2011 10:31:04 +1100 |
| Subject: md/raid5: fix bug that could result in reads from a failed device. |
| |
| From: NeilBrown <neilb@suse.de> |
| |
| commit 355840e7a7e56bb2834fd3b0da64da5465f8aeaa upstream. |
| |
| This bug was introduced in 415e72d034c50520ddb7ff79e7d1792c1306f0c9 |
| which was in 2.6.36. |
| |
| There is a small window of time between when a device fails and when |
| it is removed from the array. During this time we might still read |
| from it, but we won't write to it - so it is possible that we could |
| read stale data. |
| |
| We didn't need the test of 'Faulty' before because the test on |
| In_sync is sufficient. Since we started allowing reads from the early |
| part of non-In_sync devices we need a test on Faulty too. |
| |
| This is suitable for any kernel from 2.6.36 onwards, though the patch |
| might need a bit of tweaking in 3.0 and earlier. |
| |
| Signed-off-by: NeilBrown <neilb@suse.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/md/raid5.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/md/raid5.c |
| +++ b/drivers/md/raid5.c |
| @@ -3069,7 +3069,7 @@ static void analyse_stripe(struct stripe |
| } |
| } else if (test_bit(In_sync, &rdev->flags)) |
| set_bit(R5_Insync, &dev->flags); |
| - else { |
| + else if (!test_bit(Faulty, &rdev->flags)) { |
| /* in sync if before recovery_offset */ |
| if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) |
| set_bit(R5_Insync, &dev->flags); |
