Btrfs: more block allocator work

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 4199172..c432222 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -250,6 +250,8 @@
 struct btrfs_block_group_cache {
 	struct btrfs_key key;
 	struct btrfs_block_group_item item;
+	u64 first_free;
+	u64 last_alloc;
 };
 
 struct crypto_hash;
@@ -257,7 +259,7 @@
 	struct btrfs_root *extent_root;
 	struct btrfs_root *tree_root;
 	struct btrfs_root *dev_root;
-	struct btrfs_key last_insert;
+	struct btrfs_block_group_cache *block_group_cache;
 	struct radix_tree_root fs_roots_radix;
 	struct radix_tree_root pending_del_radix;
 	struct radix_tree_root pinned_radix;