diff --git a/[refs] b/[refs]
index dd9c4bee021e..447fc4bfb8ab 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a7fdffbd3ea4b3cc2993af006bde38a423b38b72
+refs/heads/master: 9af45ef5ab8ce4a13c553200dc15509441fbd68f
diff --git a/trunk/fs/f2fs/gc.c b/trunk/fs/f2fs/gc.c
index 809cfec6683c..c386910dacc5 100644
--- a/trunk/fs/f2fs/gc.c
+++ b/trunk/fs/f2fs/gc.c
@@ -424,7 +424,11 @@ static int gc_node_segment(struct f2fs_sb_info *sbi,
 }
 
 /*
- * Calculate start block index that this node page contains
+ * Calculate start block index indicating the given node offset.
+ * Be careful, caller should give this node offset only indicating direct node
+ * blocks. If any node offsets, which point the other types of node blocks such
+ * as indirect or double indirect node blocks, are given, it must be a caller's
+ * bug.
  */
 block_t start_bidx_of_node(unsigned int node_ofs)
 {