diff --git a/libblkid/src/superblocks/nilfs.c b/libblkid/src/superblocks/nilfs.c
new file mode 100644
index 0000000..3f03901
--- /dev/null
+++ b/libblkid/src/superblocks/nilfs.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2010 by Jiro SEKIBA <jir@unicus.jp>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License
+ */
+#include <stddef.h>
+#include <string.h>
+
+#include "superblocks.h"
+#include "crc32.h"
+
+struct nilfs_super_block {
+	uint32_t	s_rev_level;
+	uint16_t	s_minor_rev_level;
+	uint16_t	s_magic;
+
+	uint16_t	s_bytes;
+
+	uint16_t	s_flags;
+	uint32_t	s_crc_seed;
+	uint32_t	s_sum;
+
+	uint32_t	s_log_block_size;
+
+	uint64_t	s_nsegments;
+	uint64_t	s_dev_size;
+	uint64_t	s_first_data_block;
+	uint32_t	s_blocks_per_segment;
+	uint32_t	s_r_segments_percentage;
+
+	uint64_t	s_last_cno;
+	uint64_t	s_last_pseg;
+	uint64_t	s_last_seq;
+	uint64_t	s_free_blocks_count;
+
+	uint64_t	s_ctime;
+
+	uint64_t	s_mtime;
+	uint64_t	s_wtime;
+	uint16_t	s_mnt_count;
+	uint16_t	s_max_mnt_count;
+	uint16_t	s_state;
+	uint16_t	s_errors;
+	uint64_t	s_lastcheck;
+
+	uint32_t	s_checkinterval;
+	uint32_t	s_creator_os;
+	uint16_t	s_def_resuid;
+	uint16_t	s_def_resgid;
+	uint32_t	s_first_ino;
+
+	uint16_t	s_inode_size;
+	uint16_t	s_dat_entry_size;
+	uint16_t	s_checkpoint_size;
+	uint16_t	s_segment_usage_size;
+
+	uint8_t		s_uuid[16];
+	char		s_volume_name[80];
+
+	uint32_t	s_c_interval;
+	uint32_t	s_c_block_max;
+	uint32_t	s_reserved[192];
+};
+
+#define NILFS_SB_MAGIC		0x3434
+#define NILFS_SB_OFFSET		0x400
+
+static int nilfs_valid_sb(blkid_probe pr, struct nilfs_super_block *sb)
+{
+	static unsigned char sum[4];
+	const int sumoff = offsetof(struct nilfs_super_block, s_sum);
+	size_t bytes;
+	uint32_t crc;
+
+	if (!sb || le16_to_cpu(sb->s_magic) != NILFS_SB_MAGIC)
+		return 0;
+
+	bytes = le16_to_cpu(sb->s_bytes);
+	crc = crc32(le32_to_cpu(sb->s_crc_seed), (unsigned char *)sb, sumoff);
+	crc = crc32(crc, sum, 4);
+	crc = crc32(crc, (unsigned char *)sb + sumoff + 4, bytes - sumoff - 4);
+
+	return blkid_probe_verify_csum(pr, crc, le32_to_cpu(sb->s_sum));
+}
+
+static int probe_nilfs2(blkid_probe pr, const struct blkid_idmag *mag)
+{
+	struct nilfs_super_block *sb, *sbp, *sbb;
+	int valid[2], swp = 0;
+
+	/* primary */
+	sbp = (struct nilfs_super_block *) blkid_probe_get_buffer(
+			pr, NILFS_SB_OFFSET, sizeof(struct nilfs_super_block));
+	if (!sbp)
+		return errno ? -errno : 1;
+	/* backup */
+	sbb = (struct nilfs_super_block *) blkid_probe_get_buffer(
+			pr, ((pr->size / 0x200) - 8) * 0x200, sizeof(struct nilfs_super_block));
+	if (!sbb)
+		return errno ? -errno : 1;
+
+	/*
+	 * Compare two super blocks and set 1 in swp if the secondary
+	 * super block is valid and newer.  Otherwise, set 0 in swp.
+	 */
+	valid[0] = nilfs_valid_sb(pr, sbp);
+	valid[1] = nilfs_valid_sb(pr, sbb);
+	if (!valid[0] && !valid[1])
+		return 1;
+
+	swp = valid[1] && (!valid[0] ||
+			   le64_to_cpu(sbp->s_last_cno) >
+			   le64_to_cpu(sbb->s_last_cno));
+	sb = swp ? sbb : sbp;
+
+	DBG(LOWPROBE, ul_debug("nilfs2: primary=%d, backup=%d, swap=%d",
+				valid[0], valid[1], swp));
+
+	if (strlen(sb->s_volume_name))
+		blkid_probe_set_label(pr, (unsigned char *) sb->s_volume_name,
+				      sizeof(sb->s_volume_name));
+
+	blkid_probe_set_uuid(pr, sb->s_uuid);
+	blkid_probe_sprintf_version(pr, "%u", le32_to_cpu(sb->s_rev_level));
+
+	return 0;
+}
+
+const struct blkid_idinfo nilfs2_idinfo =
+{
+	.name		= "nilfs2",
+	.usage		= BLKID_USAGE_FILESYSTEM,
+	.probefunc	= probe_nilfs2,
+	/* default min.size is 128MiB, but 1MiB for "mkfs.nilfs2 -b 1024 -B 16" */
+	.minsz		= (1024 * 1024),
+	.magics		= BLKID_NONE_MAGIC
+};