From 1cc03eb93245e63b0b7a7832165efdc52e25b4e6 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 6 Jan 2014 13:19:42 +1100 Subject: [PATCH] md/raid5: Fix possible confusion when multiple write errors occur. commit 5d8c71f9e5fbdd95650be00294d238e27a363b5c md: raid5 crash during degradation Fixed a crash in an overly simplistic way which could leave R5_WriteError or R5_MadeGood set in the stripe cache for devices for which it is no longer relevant. When those devices are removed and spares added the flags are still set and can cause incorrect behaviour. commit 14a75d3e07c784c004b4b44b34af996b8e4ac453 md/raid5: preferentially read from replacement device if possible. Fixed the same bug if a more effective way, so we can now revert the original commit. Reported-and-tested-by: Alexander Lyakas Cc: stable@vger.kernel.org (3.2+ - 3.2 will need a different fix though) Fixes: 5d8c71f9e5fbdd95650be00294d238e27a363b5c Signed-off-by: NeilBrown --- drivers/md/raid5.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index cc055da02e2a..9168173deaf3 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3608,7 +3608,7 @@ static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) */ set_bit(R5_Insync, &dev->flags); - if (rdev && test_bit(R5_WriteError, &dev->flags)) { + if (test_bit(R5_WriteError, &dev->flags)) { /* This flag does not apply to '.replacement' * only to .rdev, so make sure to check that*/ struct md_rdev *rdev2 = rcu_dereference( @@ -3621,7 +3621,7 @@ static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s) } else clear_bit(R5_WriteError, &dev->flags); } - if (rdev && test_bit(R5_MadeGood, &dev->flags)) { + if (test_bit(R5_MadeGood, &dev->flags)) { /* This flag does not apply to '.replacement' * only to .rdev, so make sure to check that*/ struct md_rdev *rdev2 = rcu_dereference( -- 2.20.1