From d8091fda7895ed0624d1641089f4080164e75a35 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 15 Dec 2011 10:54:39 +1100 Subject: [PATCH] md/raid5: fix bug that could result in reads from a failed device. commit 355840e7a7e56bb2834fd3b0da64da5465f8aeaa upstream. commit a847627709b3402163d99f7c6fda4a77bcd6b51b in linux-3.0.9 attempted to backport this to 3.0 but only made one change were two were necessary. This add the second change. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid5.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index cbb50d3883a..1f6c68df6f3 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3078,7 +3078,7 @@ static void handle_stripe5(struct stripe_head *sh) /* Not in-sync */; else if (test_bit(In_sync, &rdev->flags)) set_bit(R5_Insync, &dev->flags); - else { + else if (!test_bit(Faulty, &rdev->flags)) { /* could be in-sync depending on recovery/reshape status */ if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset) set_bit(R5_Insync, &dev->flags); -- 2.11.4.GIT