Btrfs: start of support for many FS volumes

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index e159841..3439ffb 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -3,6 +3,8 @@
 
 struct btrfs_inode {
 	u32 magic;
+	struct btrfs_root *root;
+	struct btrfs_key location;
 	struct inode vfs_inode;
 	u32 magic2;
 };