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@xxxxxxxxxxxxx>
---
fs/nilfs2/recovery.c | 114 +++++++++++++++++++++++++++++++-------------------
1 files changed, 71 insertions(+), 43 deletions(-)
diff --git a/fs/nilfs2/recovery.c b/fs/nilfs2/recovery.c
index fd7fb41..cee9fa3 100644
--- a/fs/nilfs2/recovery.c
+++ b/fs/nilfs2/recovery.c
@@ -202,58 +202,63 @@ int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block,
}
/**
- * load_segment_summary - read segment summary of the specified partial segment
+ * nilfs_read_log_header - read summary header of the specified log
* @nilfs: nilfs object
- * @pseg_start: start disk block number of partial segment
- * @seg_seq: sequence number requested
- * @ssi: pointer to nilfs_segsum_info struct to store information
+ * @start_blocknr: start block number of the log
+ * @sum: pointer to return segment summary structure
*/
-static int
-load_segment_summary(struct the_nilfs *nilfs, sector_t pseg_start,
- u64 seg_seq, struct nilfs_segsum_info *ssi)
+static struct buffer_head *
+nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr,
+ struct nilfs_segment_summary **sum)
{
struct buffer_head *bh_sum;
- struct nilfs_segment_summary *sum;
- unsigned long nblock;
- u32 crc;
- int ret = NILFS_SEG_FAIL_IO;
- bh_sum = __bread(nilfs->ns_bdev, pseg_start, nilfs->ns_blocksize);
- if (!bh_sum)
- goto out;
+ bh_sum = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize);
+ if (bh_sum)
+ *sum = (struct nilfs_segment_summary *)bh_sum->b_data;
+ return bh_sum;
+}
- sum = (struct nilfs_segment_summary *)bh_sum->b_data;
+/**
+ * nilfs_validate_log - verify consistency of log
+ * @nilfs: nilfs object
+ * @seg_seq: sequence number of segment
+ * @bh_sum: buffer head of summary block
+ * @sum: segment summary struct
+ */
+static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq,
+ struct buffer_head *bh_sum,
+ struct nilfs_segment_summary *sum)
+{
+ unsigned long nblock;
+ u32 crc;
+ int ret;
- /* Check consistency of segment summary */
- if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) {
- ret = NILFS_SEG_FAIL_MAGIC;
- goto failed;
- }
- store_segsum_info(ssi, sum, nilfs->ns_blocksize);
- if (seg_seq != ssi->seg_seq) {
- ret = NILFS_SEG_FAIL_SEQ;
- goto failed;
- }
+ ret = NILFS_SEG_FAIL_MAGIC;
+ if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC)
+ goto out;
- nblock = ssi->nblocks;
- if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment)) {
+ ret = NILFS_SEG_FAIL_SEQ;
+ if (le64_to_cpu(sum->ss_seq) != seg_seq)
+ goto out;
+
+ nblock = le32_to_cpu(sum->ss_nblocks);
+ ret = NILFS_SEG_FAIL_CONSISTENCY;
+ if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment))
/* This limits the number of blocks read in the CRC check */
- ret = NILFS_SEG_FAIL_CONSISTENCY;
- goto failed;
- }
+ goto out;
+
+ ret = NILFS_SEG_FAIL_IO;
if (nilfs_compute_checksum(nilfs, bh_sum, &crc, sizeof(sum->ss_datasum),
((u64)nblock << nilfs->ns_blocksize_bits),
- pseg_start, nblock)) {
- ret = NILFS_SEG_FAIL_IO;
- goto failed;
- }
- if (crc == le32_to_cpu(sum->ss_datasum))
- ret = 0;
- else
- ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
- failed:
- brelse(bh_sum);
- out:
+ bh_sum->b_blocknr, nblock))
+ goto out;
+
+ ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
+ if (crc != le32_to_cpu(sum->ss_datasum))
+ goto out;
+ ret = 0;
+out:
return ret;
}
@@ -589,6 +594,8 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
struct nilfs_recovery_info *ri)
{
struct nilfs_segsum_info ssi;
+ struct buffer_head *bh_sum = NULL;
+ struct nilfs_segment_summary *sum;
sector_t pseg_start;
sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */
unsigned long nsalvaged_blocks = 0;
@@ -610,8 +617,14 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
+ brelse(bh_sum);
+ bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
+ if (!bh_sum) {
+ err = -EIO;
+ goto failed;
+ }
- ret = load_segment_summary(nilfs, pseg_start, seg_seq, &ssi);
+ ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
if (ret) {
if (ret == NILFS_SEG_FAIL_IO) {
err = -EIO;
@@ -619,6 +632,8 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
}
goto strayed;
}
+
+ store_segsum_info(&ssi, sum, nilfs->ns_blocksize);
if (unlikely(NILFS_SEG_HAS_SR(&ssi)))
goto confused;
@@ -682,6 +697,7 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
}
out:
+ brelse(bh_sum);
dispose_recovery_list(&dsync_blocks);
nilfs_detach_writer(nilfs, sbi);
return err;
@@ -807,6 +823,8 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
struct nilfs_recovery_info *ri)
{
struct nilfs_segsum_info ssi;
+ struct buffer_head *bh_sum = NULL;
+ struct nilfs_segment_summary *sum;
sector_t pseg_start, pseg_end, sr_pseg_start = 0;
sector_t seg_start, seg_end; /* range of full segment (block number) */
sector_t b, end;
@@ -831,12 +849,20 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
__breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize);
for (;;) {
- ret = load_segment_summary(nilfs, pseg_start, seg_seq, &ssi);
+ brelse(bh_sum);
+ ret = NILFS_SEG_FAIL_IO;
+ bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
+ if (!bh_sum)
+ goto failed;
+
+ ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
if (ret) {
if (ret == NILFS_SEG_FAIL_IO)
goto failed;
goto strayed;
}
+
+ store_segsum_info(&ssi, sum, nilfs->ns_blocksize);
pseg_end = pseg_start + ssi.nblocks - 1;
if (unlikely(pseg_end > seg_end)) {
ret = NILFS_SEG_FAIL_CONSISTENCY;
@@ -936,6 +962,7 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
super_root_found:
/* Updating pointers relating to the latest checkpoint */
+ brelse(bh_sum);
list_splice_tail(&segments, &ri->ri_used_segments);
nilfs->ns_last_pseg = sr_pseg_start;
nilfs->ns_last_seq = nilfs->ns_seg_seq;
@@ -943,6 +970,7 @@ int nilfs_search_super_root(struct the_nilfs *nilfs,
return 0;
failed:
+ brelse(bh_sum);
nilfs_dispose_segment_list(&segments);
return (ret < 0) ? ret : nilfs_warn_segment_error(ret);
}
--
1.6.3.4
--
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