From 03f4d804a1b4748885dc4613a4afe10089a731c8 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 15 Apr 2010 22:16:24 +0200 Subject: [PATCH] jbd: Provide function to check whether transaction will issue data barrier Provide a function which returns whether a transaction with given tid will send a barrier to the filesystem device. The function will be used by ext3 to detect whether fsync needs to send a separate barrier or not. Signed-off-by: Jan Kara --- fs/jbd/commit.c | 8 +++++++- fs/jbd/journal.c | 33 +++++++++++++++++++++++++++++++++ include/linux/jbd.h | 3 ++- 3 files changed, 42 insertions(+), 2 deletions(-) diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index ecb44c94ba8d..28a9ddaa0c49 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -786,6 +786,12 @@ wait_for_iobuf: jbd_debug(3, "JBD: commit phase 6\n"); + /* All metadata is written, now write commit record and do cleanup */ + spin_lock(&journal->j_state_lock); + J_ASSERT(commit_transaction->t_state == T_COMMIT); + commit_transaction->t_state = T_COMMIT_RECORD; + spin_unlock(&journal->j_state_lock); + if (journal_write_commit_record(journal, commit_transaction)) err = -EIO; @@ -923,7 +929,7 @@ restart_loop: jbd_debug(3, "JBD: commit phase 8\n"); - J_ASSERT(commit_transaction->t_state == T_COMMIT); + J_ASSERT(commit_transaction->t_state == T_COMMIT_RECORD); commit_transaction->t_state = T_FINISHED; J_ASSERT(commit_transaction == journal->j_committing_transaction); diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c index bd224eec9b07..99c71940155a 100644 --- a/fs/jbd/journal.c +++ b/fs/jbd/journal.c @@ -564,6 +564,38 @@ int log_wait_commit(journal_t *journal, tid_t tid) return err; } +/* + * Return 1 if a given transaction has not yet sent barrier request + * connected with a transaction commit. If 0 is returned, transaction + * may or may not have sent the barrier. Used to avoid sending barrier + * twice in common cases. + */ +int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid) +{ + int ret = 0; + transaction_t *commit_trans; + + if (!(journal->j_flags & JFS_BARRIER)) + return 0; + spin_lock(&journal->j_state_lock); + /* Transaction already committed? */ + if (tid_geq(journal->j_commit_sequence, tid)) + goto out; + /* + * Transaction is being committed and we already proceeded to + * writing commit record? + */ + commit_trans = journal->j_committing_transaction; + if (commit_trans && commit_trans->t_tid == tid && + commit_trans->t_state >= T_COMMIT_RECORD) + goto out; + ret = 1; +out: + spin_unlock(&journal->j_state_lock); + return ret; +} +EXPORT_SYMBOL(journal_commit_will_send_barrier); + /* * Log buffer allocation routines: */ @@ -1157,6 +1189,7 @@ int journal_destroy(journal_t *journal) { int err = 0; + /* Wait for the commit thread to wake up and die. */ journal_kill_thread(journal); diff --git a/include/linux/jbd.h b/include/linux/jbd.h index 516a2a27e87a..e06965081ba5 100644 --- a/include/linux/jbd.h +++ b/include/linux/jbd.h @@ -427,9 +427,9 @@ struct transaction_s enum { T_RUNNING, T_LOCKED, - T_RUNDOWN, T_FLUSH, T_COMMIT, + T_COMMIT_RECORD, T_FINISHED } t_state; @@ -991,6 +991,7 @@ int journal_start_commit(journal_t *journal, tid_t *tid); int journal_force_commit_nested(journal_t *journal); int log_wait_commit(journal_t *journal, tid_t tid); int log_do_checkpoint(journal_t *journal); +int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid); void __log_wait_for_space(journal_t *journal); extern void __journal_drop_transaction(journal_t *, transaction_t *); -- 2.30.2