jbd2: Use tracepoints for history file
The /proc/fs/jbd2/<dev>/history was maintained manually; by using
tracepoints, we can get all of the existing functionality of the /proc
file plus extra capabilities thanks to the ftrace infrastructure. We
save memory as a bonus.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 5d70b3e..ca0f5eb 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -643,6 +643,7 @@
int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
{
+ struct transaction_chp_stats_s *stats;
transaction_t *transaction;
journal_t *journal;
int ret = 0;
@@ -679,6 +680,12 @@
/* OK, that was the last buffer for the transaction: we can now
safely remove this transaction from the log */
+ stats = &transaction->t_chp_stats;
+ if (stats->cs_chp_time)
+ stats->cs_chp_time = jbd2_time_diff(stats->cs_chp_time,
+ jiffies);
+ trace_jbd2_checkpoint_stats(journal->j_fs_dev->bd_dev,
+ transaction->t_tid, stats);
__jbd2_journal_drop_transaction(journal, transaction);
kfree(transaction);