diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index ecabf00..a2b625e 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4123,7 +4123,7 @@
 	 */
 	map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
 	newex.ee_block = cpu_to_le32(map->m_lblk);
-	cluster_offset = EXT4_LBLK_CMASK(sbi, map->m_lblk);
+	cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
 
 	/*
 	 * If we are doing bigalloc, check to see if the extent returned