Btrfs: Add a per-inode csum mutex to avoid races creating csum items

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 0c53ff7..8e909cb9 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -477,7 +477,7 @@
 			if (err)
 				ret = err;
 			nr = trans->blocks_used;
-			ret = btrfs_end_transaction(trans, tree_root);
+			ret = btrfs_end_transaction_throttle(trans, tree_root);
 			BUG_ON(ret);
 
 			mutex_unlock(&root->fs_info->drop_mutex);