btrfs: add forward declarations and headers, part 2

Do a cleanup in more 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, 8 insertions, 2 deletions

diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 97fe3ebf11a2..4691a84ca838 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -7,10 +7,18 @@
 #define BTRFS_COMPRESSION_H
 
 #include <linux/sizes.h>
+#include <linux/mm.h>
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/wait.h>
 #include "bio.h"
 
+struct address_space;
+struct page;
+struct inode;
 struct btrfs_inode;
 struct btrfs_ordered_extent;
+struct btrfs_bio;
 
 /*
  * We want to make sure that amount of RAM required to uncompress an extent is
@@ -32,8 +40,6 @@ static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);
 
 #define	BTRFS_ZLIB_DEFAULT_LEVEL		3
 
-struct page;
-
 struct compressed_bio {
 	/* Number of compressed pages in the array */
 	unsigned int nr_pages;