/*
* 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
};
