@@ -1557,8 +1557,21 @@ static int journal_reset(journal_t *journal)
journal->j_first = first;
journal->j_last = last;
- journal->j_head = journal->j_first;
- journal->j_tail = journal->j_first;
+ if (journal->j_flags & JBD2_CYCLE_RECORD) {
+ /*
+ * Disable the cycled recording mode if the journal head block
+ * number is not correct.
+ */
+ if (journal->j_head < first || journal->j_head >= last) {
+ printk(KERN_WARNING "JBD2: Incorrect Journal head block %lu, "
+ "disable journal_cycle_record\n",
+ journal->j_head);
+ journal->j_head = journal->j_first;
+ }
+ } else {
+ journal->j_head = journal->j_first;
+ }
+ journal->j_tail = journal->j_head;
journal->j_free = journal->j_last - journal->j_first;
journal->j_tail_sequence = journal->j_transaction_sequence;
@@ -1730,6 +1743,7 @@ static void jbd2_mark_journal_empty(journal_t *journal, blk_opf_t write_flags)
sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
sb->s_start = cpu_to_be32(0);
+ sb->s_head = cpu_to_be32(journal->j_head);
if (jbd2_has_feature_fast_commit(journal)) {
/*
* When journal is clean, no need to commit fast commit flag and
@@ -29,6 +29,7 @@ struct recovery_info
{
tid_t start_transaction;
tid_t end_transaction;
+ unsigned long head_block;
int nr_replays;
int nr_revokes;
@@ -301,11 +302,11 @@ int jbd2_journal_recover(journal_t *journal)
* is always zero if, and only if, the journal was cleanly
* unmounted.
*/
-
if (!sb->s_start) {
- jbd2_debug(1, "No recovery required, last transaction %d\n",
- be32_to_cpu(sb->s_sequence));
+ jbd2_debug(1, "No recovery required, last transaction %d, head block %u\n",
+ be32_to_cpu(sb->s_sequence), be32_to_cpu(sb->s_head));
journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
+ journal->j_head = be32_to_cpu(sb->s_head);
return 0;
}
@@ -324,6 +325,9 @@ int jbd2_journal_recover(journal_t *journal)
/* Restart the log at the next transaction ID, thus invalidating
* any existing commit records in the log. */
journal->j_transaction_sequence = ++info.end_transaction;
+ journal->j_head = info.head_block;
+ jbd2_debug(1, "JBD2: last transaction %d, head block %lu\n",
+ journal->j_transaction_sequence, journal->j_head);
jbd2_journal_clear_revoke(journal);
err2 = sync_blockdev(journal->j_fs_dev);
@@ -364,6 +368,7 @@ int jbd2_journal_skip_recovery(journal_t *journal)
if (err) {
printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
++journal->j_transaction_sequence;
+ journal->j_head = journal->j_first;
} else {
#ifdef CONFIG_JBD2_DEBUG
int dropped = info.end_transaction -
@@ -373,6 +378,7 @@ int jbd2_journal_skip_recovery(journal_t *journal)
dropped, (dropped == 1) ? "" : "s");
#endif
journal->j_transaction_sequence = ++info.end_transaction;
+ journal->j_head = info.head_block;
}
journal->j_tail = 0;
@@ -462,7 +468,7 @@ static int do_one_pass(journal_t *journal,
struct recovery_info *info, enum passtype pass)
{
unsigned int first_commit_ID, next_commit_ID;
- unsigned long next_log_block;
+ unsigned long next_log_block, head_block;
int err, success = 0;
journal_superblock_t * sb;
journal_header_t * tmp;
@@ -485,6 +491,7 @@ static int do_one_pass(journal_t *journal,
sb = journal->j_superblock;
next_commit_ID = be32_to_cpu(sb->s_sequence);
next_log_block = be32_to_cpu(sb->s_start);
+ head_block = next_log_block;
first_commit_ID = next_commit_ID;
if (pass == PASS_SCAN)
@@ -809,6 +816,7 @@ static int do_one_pass(journal_t *journal,
if (commit_time < last_trans_commit_time)
goto ignore_crc_mismatch;
info->end_transaction = next_commit_ID;
+ info->head_block = head_block;
if (!jbd2_has_feature_async_commit(journal)) {
journal->j_failed_commit =
@@ -817,8 +825,10 @@ static int do_one_pass(journal_t *journal,
break;
}
}
- if (pass == PASS_SCAN)
+ if (pass == PASS_SCAN) {
last_trans_commit_time = commit_time;
+ head_block = next_log_block;
+ }
brelse(bh);
next_commit_ID++;
continue;
@@ -868,6 +878,8 @@ static int do_one_pass(journal_t *journal,
if (pass == PASS_SCAN) {
if (!info->end_transaction)
info->end_transaction = next_commit_ID;
+ if (!info->head_block)
+ info->head_block = head_block;
} else {
/* It's really bad news if different passes end up at
* different places (but possible due to IO errors). */
@@ -265,8 +265,10 @@ typedef struct journal_superblock_s
__u8 s_padding2[3];
/* 0x0054 */
__be32 s_num_fc_blks; /* Number of fast commit blocks */
-/* 0x0058 */
- __u32 s_padding[41];
+ __be32 s_head; /* blocknr of head of log, only uptodate
+ * while the filesystem is clean */
+/* 0x005C */
+ __u32 s_padding[40];
__be32 s_checksum; /* crc32c(superblock) */
/* 0x0100 */
@@ -1392,6 +1394,9 @@ JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT)
#define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
* data write error in ordered
* mode */
+#define JBD2_CYCLE_RECORD 0x080 /* Journal cycled record log on
+ * clean and empty filesystem
+ * logging area */
#define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */
#define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */
#define JBD2_JOURNAL_FLUSH_DISCARD 0x0001
For a newly mounted file system, the journal committing thread always record log from the beginning of the journal area, no matter whether the journal is clean or it has just been recovered. It is disadvantageous to analysis corrupted file system image and locate the file system inconsistency bugs. When we get a corrupted file system image and want to find out what has happened, besides lookup the system log, one effective may is to backtrack the journal log. But we may not always run e2fsck before each mount and the default fsck -a mode also cannot always find all inconsistencies, so it could left over some inconsistencies into the next mount until we detect it. Finally, the transactions in the journal may probably discontinuous and some relatively new transactions has been covered, it becomes hard to analyse. So if we could records transactions continuously between each mounts, we could acquire more useful info from the journal. |Previous mount checkpointed/recovered logs|Current mount logs | |{------}{---}{--------} ... {------}| ... |{======}{========}...000000| This patch save the head blocknr in the superblock after flushing the journal or unmounting the file system, let the next mount could continue to record new transaction behind it. This change is backward compatible because the old kernel does not care about the head blocknr of the journal. It is also fine if we mount a clean old image without valid head blocknr, we fail back to set it to s_first just like before. Finally, for the case of mount an unclean file system, we could also get the journal head easily after scanning the journal, it will continue to record new transaction after the recovered transactions. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> --- fs/jbd2/journal.c | 18 ++++++++++++++++-- fs/jbd2/recovery.c | 22 +++++++++++++++++----- include/linux/jbd2.h | 9 +++++++-- 3 files changed, 40 insertions(+), 9 deletions(-)