Merge remote-tracking branches 'spi/topic/adi-v3', 'spi/topic/atmel', 'spi/topic...

[sfrench/cifs-2.6.git] / include / linux / pagemap.h

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 0a97b583ee8d12ae696cd3d33a13ee17c62b518f..e1474ae18c8847cba4a2f17c396c6e7b59167fed 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -398,6 +398,18 @@ static inline struct page *read_mapping_page(struct address_space *mapping,
        return read_cache_page(mapping, index, filler, data);
 }
 
+/*
+ * Get the offset in PAGE_SIZE.
+ * (TODO: hugepage should have ->index in PAGE_SIZE)
+ */
+static inline pgoff_t page_to_pgoff(struct page *page)
+{
+       if (unlikely(PageHeadHuge(page)))
+               return page->index << compound_order(page);
+       else
+               return page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+}
+
 /*
  * Return byte-offset into filesystem object for page.
  */