btrfs: add forward declarations and headers, part 3

Do a cleanup in the rest of the headers:

- add forward declarations for types referenced by pointers
- add includes when types need them

This fixes potential compilation problems if the headers are reordered
or the missing includes are not provided indirectly.

Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.h b/fs/btrfs/extent-tree.h
index 3fbcb7776a03..af9f8800d5ac 100644
--- a/fs/btrfs/extent-tree.h
+++ b/fs/btrfs/extent-tree.h
@@ -13,6 +13,7 @@ struct btrfs_free_cluster;
 struct btrfs_fs_info;
 struct btrfs_root;
 struct btrfs_path;
+struct btrfs_ref;
 struct btrfs_disk_key;
 struct btrfs_delayed_ref_head;
 struct btrfs_delayed_ref_root;