1 files changed, 31 insertions, 0 deletions

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 8b220f1ab54f..f6c5ba027f4f 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -708,6 +708,37 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
 }
 
 /*
+ * When this function returns the transaction corresponding to tid
+ * will be completed.  If the transaction has currently running, start
+ * committing that transaction before waiting for it to complete.  If
+ * the transaction id is stale, it is by definition already completed,
+ * so just return SUCCESS.
+ */
+int jbd2_complete_transaction(journal_t *journal, tid_t tid)
+{
+        int     need_to_wait = 1;
+
+        read_lock(&journal->j_state_lock);
+        if (journal->j_running_transaction &&
+            journal->j_running_transaction->t_tid == tid) {
+                if (journal->j_commit_request != tid) {
+                        /* transaction not yet started, so request it */
+                        read_unlock(&journal->j_state_lock);
+                        jbd2_log_start_commit(journal, tid);
+                        goto wait_commit;
+                }
+        } else if (!(journal->j_committing_transaction &&
+                     journal->j_committing_transaction->t_tid == tid))
+                need_to_wait = 0;
+        read_unlock(&journal->j_state_lock);
+        if (!need_to_wait)
+                return 0;
+wait_commit:
+        return jbd2_log_wait_commit(journal, tid);
+}
+EXPORT_SYMBOL(jbd2_complete_transaction);
+
+/*
  * Log buffer allocation routines:
  */