1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index c7552459a15f..37a4d9e32cd3 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -333,6 +333,16 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
                         mapping_gfp_mask(mapping));
 }
 
+static inline struct page *find_subpage(struct page *page, pgoff_t offset)
+{
+        if (PageHuge(page))
+                return page;
+
+        VM_BUG_ON_PAGE(PageTail(page), page);
+
+        return page + (offset & (compound_nr(page) - 1));
+}
+
 struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
 struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
 unsigned find_get_entries(struct address_space *mapping, pgoff_t start,