btrfs: add forward declarations and headers, part 1

Do a cleanup in the short 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, 10 insertions, 0 deletions

diff --git a/fs/btrfs/defrag.h b/fs/btrfs/defrag.h
index 5a62763528d1..878528e086fb 100644
--- a/fs/btrfs/defrag.h
+++ b/fs/btrfs/defrag.h
@@ -3,6 +3,16 @@
 #ifndef BTRFS_DEFRAG_H
 #define BTRFS_DEFRAG_H
 
+#include <linux/types.h>
+#include <linux/compiler_types.h>
+
+struct inode;
+struct file_ra_state;
+struct btrfs_fs_info;
+struct btrfs_root;
+struct btrfs_trans_handle;
+struct btrfs_ioctl_defrag_range_args;
+
 int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra,
 		      struct btrfs_ioctl_defrag_range_args *range,
 		      u64 newer_than, unsigned long max_to_defrag);