Btrfs: Do delalloc accounting via hooks in the extent_state code

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index f1e8bf2..a96c5a1 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -33,6 +33,10 @@
 				    struct extent_state *state);
 	void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
 				      struct extent_state *state);
+	int (*set_bit_hook)(struct inode *inode, u64 start, u64 end,
+			    unsigned long bits);
+	int (*clear_bit_hook)(struct inode *inode, u64 start, u64 end,
+			    unsigned long bits);
 };
 
 struct extent_io_tree {