md: Fix regression with raid1 arrays without persistent metadata.

A RAID1 which has no persistent metadata, whether internal or
external, will hang on the first write.
This is caused by commit  070dc6dd7103b6b3f7e4d46e754354a5c15f366e
In that case, MD_CHANGE_PENDING never gets cleared.

So during md_update_sb, is neither persistent or external,
clear MD_CHANGE_PENDING.

This is suitable for 2.6.36-stable.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 225815197a3d..64f97168cefa 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2108,6 +2108,8 @@ repeat:
         if (!mddev->persistent) {
                 clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
                 clear_bit(MD_CHANGE_DEVS, &mddev->flags);
+                if (!mddev->external)
+                        clear_bit(MD_CHANGE_PENDING, &mddev->flags);
                 wake_up(&mddev->sb_wait);
                 return;
         }