From 3339578f05787259917788f461f4196b7349c2a4 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 13 Mar 2012 22:45:38 -0400 Subject: jbd2: cleanup journal tail after transaction commit Normally, we have to issue a cache flush before we can update journal tail in journal superblock, effectively wiping out old transactions from the journal. So use the fact that during transaction commit we issue cache flush anyway and opportunistically push journal tail as far as we can. Since update of journal superblock is still costly (we have to use WRITE_FUA), we update log tail only if we can free significant amount of space. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" --- fs/jbd2/journal.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'fs/jbd2/journal.c') diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index c5ff177400ff..bda564f63864 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -821,6 +821,19 @@ void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) write_unlock(&journal->j_state_lock); } +/* + * This is a variaon of __jbd2_update_log_tail which checks for validity of + * provided log tail and locks j_checkpoint_mutex. So it is safe against races + * with other threads updating log tail. + */ +void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) +{ + mutex_lock(&journal->j_checkpoint_mutex); + if (tid_gt(tid, journal->j_tail_sequence)) + __jbd2_update_log_tail(journal, tid, block); + mutex_unlock(&journal->j_checkpoint_mutex); +} + struct jbd2_stats_proc_session { journal_t *journal; struct transaction_stats_s *stats; -- cgit v1.2.3