1 files changed, 22 insertions, 5 deletions

diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c
index 5d1a00a5041b..05f0754f2b46 100644
--- a/fs/jbd/checkpoint.c
+++ b/fs/jbd/checkpoint.c
@@ -453,8 +453,6 @@ out:
  *
  * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
  *
- * Called with the journal lock held.
- *
  * This is the only part of the journaling code which really needs to be
  * aware of transaction aborts.  Checkpointing involves writing to the
  * main filesystem area rather than to the journal, so it can proceed
@@ -472,13 +470,14 @@ int cleanup_journal_tail(journal_t *journal)
         if (is_journal_aborted(journal))
                 return 1;
 
-        /* OK, work out the oldest transaction remaining in the log, and
+        /*
+         * OK, work out the oldest transaction remaining in the log, and
          * the log block it starts at.
          *
          * If the log is now empty, we need to work out which is the
          * next transaction ID we will write, and where it will
-         * start. */
-
+         * start.
+         */
         spin_lock(&journal->j_state_lock);
         spin_lock(&journal->j_list_lock);
         transaction = journal->j_checkpoint_transactions;
@@ -504,7 +503,25 @@ int cleanup_journal_tail(journal_t *journal)
                 spin_unlock(&journal->j_state_lock);
                 return 1;
         }
+        spin_unlock(&journal->j_state_lock);
+
+        /*
+         * We need to make sure that any blocks that were recently written out
+         * --- perhaps by log_do_checkpoint() --- are flushed out before we
+         * drop the transactions from the journal. It's unlikely this will be
+         * necessary, especially with an appropriately sized journal, but we
+         * need this to guarantee correctness.  Fortunately
+         * cleanup_journal_tail() doesn't get called all that often.
+         */
+        if (journal->j_flags & JFS_BARRIER)
+                blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
 
+        spin_lock(&journal->j_state_lock);
+        if (!tid_gt(first_tid, journal->j_tail_sequence)) {
+                spin_unlock(&journal->j_state_lock);
+                /* Someone else cleaned up journal so return 0 */
+                return 0;
+        }
         /* OK, update the superblock to recover the freed space.
          * Physical blocks come first: have we wrapped beyond the end of
          * the log?  */