struct file *lower_file);
int ecryptfs_do_readpage(struct file *file, struct page *page,
pgoff_t lower_page_index);
-int ecryptfs_grab_and_map_lower_page(struct page **lower_page,
- char **lower_virt,
- struct inode *lower_inode,
- unsigned long lower_page_index);
int ecryptfs_writepage_and_release_lower_page(struct page *lower_page,
struct inode *lower_inode,
struct writeback_control *wbc);