nilfs2: divide load_segment_summary function
load_segment_summary function has two distinct roles: getting summary header of a log, and verifying consistencies of the log. This divide it into two corresponding functions, nilfs_read_log_header and nilfs_validate_log to clarify the meaning. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
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@ -202,58 +202,63 @@ int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block,
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}
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/**
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* load_segment_summary - read segment summary of the specified partial segment
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* nilfs_read_log_header - read summary header of the specified log
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* @nilfs: nilfs object
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* @pseg_start: start disk block number of partial segment
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* @seg_seq: sequence number requested
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* @ssi: pointer to nilfs_segsum_info struct to store information
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* @start_blocknr: start block number of the log
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* @sum: pointer to return segment summary structure
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*/
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static int
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load_segment_summary(struct the_nilfs *nilfs, sector_t pseg_start,
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u64 seg_seq, struct nilfs_segsum_info *ssi)
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static struct buffer_head *
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nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr,
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struct nilfs_segment_summary **sum)
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{
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struct buffer_head *bh_sum;
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struct nilfs_segment_summary *sum;
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bh_sum = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize);
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if (bh_sum)
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*sum = (struct nilfs_segment_summary *)bh_sum->b_data;
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return bh_sum;
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}
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/**
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* nilfs_validate_log - verify consistency of log
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* @nilfs: nilfs object
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* @seg_seq: sequence number of segment
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* @bh_sum: buffer head of summary block
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* @sum: segment summary struct
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*/
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static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq,
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struct buffer_head *bh_sum,
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struct nilfs_segment_summary *sum)
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{
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unsigned long nblock;
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u32 crc;
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int ret = NILFS_SEG_FAIL_IO;
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int ret;
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bh_sum = __bread(nilfs->ns_bdev, pseg_start, nilfs->ns_blocksize);
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if (!bh_sum)
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ret = NILFS_SEG_FAIL_MAGIC;
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if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC)
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goto out;
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sum = (struct nilfs_segment_summary *)bh_sum->b_data;
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ret = NILFS_SEG_FAIL_SEQ;
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if (le64_to_cpu(sum->ss_seq) != seg_seq)
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goto out;
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/* Check consistency of segment summary */
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if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) {
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ret = NILFS_SEG_FAIL_MAGIC;
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goto failed;
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}
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store_segsum_info(ssi, sum, nilfs->ns_blocksize);
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if (seg_seq != ssi->seg_seq) {
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ret = NILFS_SEG_FAIL_SEQ;
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goto failed;
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}
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nblock = ssi->nblocks;
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if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment)) {
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nblock = le32_to_cpu(sum->ss_nblocks);
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ret = NILFS_SEG_FAIL_CONSISTENCY;
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if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment))
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/* This limits the number of blocks read in the CRC check */
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ret = NILFS_SEG_FAIL_CONSISTENCY;
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goto failed;
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}
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goto out;
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ret = NILFS_SEG_FAIL_IO;
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if (nilfs_compute_checksum(nilfs, bh_sum, &crc, sizeof(sum->ss_datasum),
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((u64)nblock << nilfs->ns_blocksize_bits),
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pseg_start, nblock)) {
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ret = NILFS_SEG_FAIL_IO;
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goto failed;
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}
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if (crc == le32_to_cpu(sum->ss_datasum))
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ret = 0;
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else
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ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
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failed:
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brelse(bh_sum);
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out:
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bh_sum->b_blocknr, nblock))
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goto out;
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ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
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if (crc != le32_to_cpu(sum->ss_datasum))
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goto out;
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ret = 0;
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out:
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return ret;
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}
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@ -589,6 +594,8 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
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struct nilfs_recovery_info *ri)
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{
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struct nilfs_segsum_info ssi;
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struct buffer_head *bh_sum = NULL;
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struct nilfs_segment_summary *sum;
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sector_t pseg_start;
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sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */
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unsigned long nsalvaged_blocks = 0;
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@ -610,8 +617,14 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
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nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
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while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
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brelse(bh_sum);
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bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
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if (!bh_sum) {
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err = -EIO;
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goto failed;
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}
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ret = load_segment_summary(nilfs, pseg_start, seg_seq, &ssi);
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ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
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if (ret) {
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if (ret == NILFS_SEG_FAIL_IO) {
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err = -EIO;
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@ -619,6 +632,8 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
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}
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goto strayed;
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}
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store_segsum_info(&ssi, sum, nilfs->ns_blocksize);
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if (unlikely(NILFS_SEG_HAS_SR(&ssi)))
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goto confused;
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@ -682,6 +697,7 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
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ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
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}
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out:
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brelse(bh_sum);
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dispose_recovery_list(&dsync_blocks);
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nilfs_detach_writer(nilfs, sbi);
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return err;
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@ -807,6 +823,8 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
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struct nilfs_recovery_info *ri)
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{
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struct nilfs_segsum_info ssi;
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struct buffer_head *bh_sum = NULL;
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struct nilfs_segment_summary *sum;
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sector_t pseg_start, pseg_end, sr_pseg_start = 0;
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sector_t seg_start, seg_end; /* range of full segment (block number) */
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sector_t b, end;
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@ -831,12 +849,20 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
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__breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize);
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for (;;) {
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ret = load_segment_summary(nilfs, pseg_start, seg_seq, &ssi);
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brelse(bh_sum);
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ret = NILFS_SEG_FAIL_IO;
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bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
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if (!bh_sum)
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goto failed;
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ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
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if (ret) {
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if (ret == NILFS_SEG_FAIL_IO)
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goto failed;
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goto strayed;
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}
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store_segsum_info(&ssi, sum, nilfs->ns_blocksize);
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pseg_end = pseg_start + ssi.nblocks - 1;
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if (unlikely(pseg_end > seg_end)) {
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ret = NILFS_SEG_FAIL_CONSISTENCY;
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@ -936,6 +962,7 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
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super_root_found:
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/* Updating pointers relating to the latest checkpoint */
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brelse(bh_sum);
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list_splice_tail(&segments, &ri->ri_used_segments);
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nilfs->ns_last_pseg = sr_pseg_start;
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nilfs->ns_last_seq = nilfs->ns_seg_seq;
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@ -943,6 +970,7 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
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return 0;
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failed:
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brelse(bh_sum);
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nilfs_dispose_segment_list(&segments);
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return (ret < 0) ? ret : nilfs_warn_segment_error(ret);
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}
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