From 31097a1c490c409385e28a64284bde16a4bfe76b Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 24 Apr 2012 10:23:16 +1000 Subject: [PATCH] md: fix possible corruption of array metadata on shutdown. commit 30b8aa9172dfeaac6d77897c67ee9f9fc574cdbb upstream. commit c744a65c1e2d59acc54333ce8 md: don't set md arrays to readonly on shutdown. removed the possibility of a 'BUG' when data is written to an array that has just been switched to read-only, but also introduced the possibility that the array metadata could be corrupted. If, when md_notify_reboot gets the mddev lock, the array is in a state where it is assembled but hasn't been started (as can happen if the personality module is not available, or in other unusual situations), then incorrect metadata will be written out making it impossible to re-assemble the array. So only call __md_stop_writes() if the array has actually been activated. This patch is needed for any stable kernel which has had the above commit applied. Reported-by: Christoph Nelles Signed-off-by: NeilBrown Signed-off-by: Ben Hutchings --- drivers/md/md.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 6f37aa48c075..065ab4f46594 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8100,7 +8100,8 @@ static int md_notify_reboot(struct notifier_block *this, for_each_mddev(mddev, tmp) { if (mddev_trylock(mddev)) { - __md_stop_writes(mddev); + if (mddev->pers) + __md_stop_writes(mddev); mddev->safemode = 2; mddev_unlock(mddev); } -- 2.30.2