1 files changed, 14 insertions, 1 deletions

diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index e91a2e9619ee..0eae6c420acb 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -6,12 +6,19 @@
 #define EXTENT_MAP_INLINE (u64)-2
 #define EXTENT_MAP_DELALLOC (u64)-1
 
+struct extent_map_ops {
+        int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
+        int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
+        int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
+        int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end);
+};
+
 struct extent_map_tree {
         struct rb_root map;
         struct rb_root state;
         struct address_space *mapping;
         rwlock_t lock;
-        int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
+        struct extent_map_ops *ops;
 };
 
 /* note, this must start with the same fields as fs/extent_map.c:tree_entry */
@@ -36,6 +43,10 @@ struct extent_state {
         wait_queue_head_t wq;
         atomic_t refs;
         unsigned long state;
+
+        /* for use by the FS */
+        u64 private;
+
         struct list_head list;
 };
 
@@ -89,4 +100,6 @@ int extent_commit_write(struct extent_map_tree *tree,
                         struct inode *inode, struct page *page,
                         unsigned from, unsigned to);
 int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end);
+int set_state_private(struct extent_map_tree *tree, u64 start, u64 private);
+int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private);
 #endif