/**
* nilfs_read_super_root_block - read super root block
* @nilfs: nilfs object
* @sr_block: disk block number of the super root block
* @pbh: address of a buffer_head pointer to return super root buffer
* @check: CRC check flag
*/
int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block,
struct buffer_head **pbh, int check)
{
struct buffer_head *bh_sr;
struct nilfs_super_root *sr;
u32 crc;
int ret;
*pbh = NULL;
bh_sr = __bread(nilfs->ns_bdev, sr_block, nilfs->ns_blocksize);
if (unlikely(!bh_sr)) {
ret = NILFS_SEG_FAIL_IO;
goto failed;
}
sr = (struct nilfs_super_root *)bh_sr->b_data;
if (check) {
unsigned int bytes = le16_to_cpu(sr->sr_bytes);
if (bytes == 0 || bytes > nilfs->ns_blocksize) {
ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
goto failed_bh;
}
if (nilfs_compute_checksum(
nilfs, bh_sr, &crc, sizeof(sr->sr_sum), bytes,
sr_block, 1)) {
ret = NILFS_SEG_FAIL_IO;
goto failed_bh;
}
if (crc != le32_to_cpu(sr->sr_sum)) {
ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
goto failed_bh;
}
}
*pbh = bh_sr;
return 0;
failed_bh:
brelse(bh_sr);
failed:
return nilfs_warn_segment_error(nilfs->ns_sb, ret);
}
/**
* nilfs_read_super_root_block - read super root block
* @sb: super_block
* @sr_block: disk block number of the super root block
* @pbh: address of a buffer_head pointer to return super root buffer
* @check: CRC check flag
*/
int nilfs_read_super_root_block(struct super_block *sb, sector_t sr_block,
struct buffer_head **pbh, int check)
{
struct buffer_head *bh_sr;
struct nilfs_super_root *sr;
u32 crc;
int ret;
*pbh = NULL;
bh_sr = sb_bread(sb, sr_block);
if (unlikely(!bh_sr)) {
ret = NILFS_SEG_FAIL_IO;
goto failed;
}
sr = (struct nilfs_super_root *)bh_sr->b_data;
if (check) {
unsigned bytes = le16_to_cpu(sr->sr_bytes);
if (bytes == 0 || bytes > sb->s_blocksize) {
ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
goto failed_bh;
}
if (calc_crc_cont(NILFS_SB(sb), bh_sr, &crc,
sizeof(sr->sr_sum), bytes, sr_block, 1)) {
ret = NILFS_SEG_FAIL_IO;
goto failed_bh;
}
if (crc != le32_to_cpu(sr->sr_sum)) {
ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
goto failed_bh;
}
}
*pbh = bh_sr;
return 0;
failed_bh:
brelse(bh_sr);
failed:
return nilfs_warn_segment_error(ret);
}
