btrfs: export block group accounting helpers

Want to move these functions into block-group.c, so export them.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 749d340..886bfa8 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -192,6 +192,12 @@ void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
+int btrfs_update_block_group(struct btrfs_trans_handle *trans,
+			     u64 bytenr, u64 num_bytes, int alloc);
+int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
+			     u64 ram_bytes, u64 num_bytes, int delalloc);
+void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
+			       u64 num_bytes, int delalloc);
 
 static inline int btrfs_block_group_cache_done(
 		struct btrfs_block_group_cache *cache)