ocfs2: Read from an unwritten extent returns zeros

Return an optional extent flags field from our lookup functions and wire up
callers to treat unwritten regions as holes for the purpose of returning
zeros to the user.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 78c99b5..310049b 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -1105,7 +1105,8 @@
 		return NULL;
 	}
 
-	tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL);
+	tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
+					     NULL);
 	if (tmperr < 0) {
 		mlog_errno(tmperr);
 		goto fail;