From e678a4f0f50d4fa4f7aaa6de8eb3f071513356a0 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 27 Mar 2013 17:30:59 +0100 Subject: jbd: don't wait (forever) for stale tid caused by wraparound In the case where an inode has a very stale transaction id (tid) in i_datasync_tid or i_sync_tid, it's possible that after a very large (2**31) number of transactions, that the tid number space might wrap, causing tid_geq()'s calculations to fail. Commit d9b0193 "jbd: fix fsync() tid wraparound bug" attempted to fix this problem, but it only avoided kjournald spinning forever by fixing the logic in jbd_log_start_commit(). Signed-off-by: Jan Kara --- fs/jbd/journal.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'fs/jbd') diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c index 81cc7eaff86..81880c6d6b5 100644 --- a/fs/jbd/journal.c +++ b/fs/jbd/journal.c @@ -564,6 +564,16 @@ int log_wait_commit(journal_t *journal, tid_t tid) spin_unlock(&journal->j_state_lock); #endif spin_lock(&journal->j_state_lock); + /* + * Not running or committing trans? Must be already committed. This + * saves us from waiting for a *long* time when tid overflows. + */ + if (!((journal->j_running_transaction && + journal->j_running_transaction->t_tid == tid) || + (journal->j_committing_transaction && + journal->j_committing_transaction->t_tid == tid))) + goto out_unlock; + if (!tid_geq(journal->j_commit_waited, tid)) journal->j_commit_waited = tid; while (tid_gt(tid, journal->j_commit_sequence)) { @@ -575,6 +585,7 @@ int log_wait_commit(journal_t *journal, tid_t tid) !tid_gt(tid, journal->j_commit_sequence)); spin_lock(&journal->j_state_lock); } +out_unlock: spin_unlock(&journal->j_state_lock); if (unlikely(is_journal_aborted(journal))) { -- cgit v1.2.3-70-g09d2