1 files changed, 12 insertions, 2 deletions

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 7aeb31087f88..711d12b80028 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -282,8 +282,18 @@ void free_extent_buffer_stale(struct extent_buffer *eb);
 int read_extent_buffer_pages(struct extent_io_tree *tree,
                              struct extent_buffer *eb, u64 start, int wait,
                              get_extent_t *get_extent, int mirror_num);
-unsigned long num_extent_pages(u64 start, u64 len);
-struct page *extent_buffer_page(struct extent_buffer *eb, unsigned long i);
+
+static inline unsigned long num_extent_pages(u64 start, u64 len)
+{
+        return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
+                (start >> PAGE_CACHE_SHIFT);
+}
+
+static inline struct page *extent_buffer_page(struct extent_buffer *eb,
+                                              unsigned long i)
+{
+        return eb->pages[i];
+}
 
 static inline void extent_buffer_get(struct extent_buffer *eb)
 {