diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index d391a5913c79..06dda733f958 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -517,7 +517,7 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 
 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
 	for (i = 0; i < entries; i++)
-		dmap[i] = (cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
+		dmap[i] = ~(cur_map[i] | ckpt_map[i]);
 
 	while (force || SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);