1 files changed, 13 insertions, 3 deletions

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index b3713afaaa9e..e2d4285fbe90 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -437,9 +437,12 @@ int __log_space_left(journal_t *journal)
 int __log_start_commit(journal_t *journal, tid_t target)
 {
         /*
-         * Are we already doing a recent enough commit?
+         * The only transaction we can possibly wait upon is the
+         * currently running transaction (if it exists).  Otherwise,
+         * the target tid must be an old one.
          */
-        if (!tid_geq(journal->j_commit_request, target)) {
+        if (journal->j_running_transaction &&
+            journal->j_running_transaction->t_tid == target) {
                 /*
                  * We want a new commit: OK, mark the request and wakeup the
                  * commit thread.  We do _not_ do the commit ourselves.
@@ -451,7 +454,14 @@ int __log_start_commit(journal_t *journal, tid_t target)
                           journal->j_commit_sequence);
                 wake_up(&journal->j_wait_commit);
                 return 1;
-        }
+        } else if (!tid_geq(journal->j_commit_request, target))
+                /* This should never happen, but if it does, preserve
+                   the evidence before kjournald goes into a loop and
+                   increments j_commit_sequence beyond all recognition. */
+                WARN_ONCE(1, "jbd: bad log_start_commit: %u %u %u %u\n",
+                    journal->j_commit_request, journal->j_commit_sequence,
+                    target, journal->j_running_transaction ?
+                    journal->j_running_transaction->t_tid : 0);
         return 0;
 }