1 files changed, 17 insertions, 4 deletions

diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index f2b9a571f4cf..52c15c776029 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -298,6 +298,7 @@ void journal_commit_transaction(journal_t *journal)
         int tag_flag;
         int i;
         struct blk_plug plug;
+        int write_op = WRITE;
 
         /*
          * First job: lock down the current transaction and wait for
@@ -307,7 +308,16 @@ void journal_commit_transaction(journal_t *journal)
         /* Do we need to erase the effects of a prior journal_flush? */
         if (journal->j_flags & JFS_FLUSHED) {
                 jbd_debug(3, "super block updated\n");
-                journal_update_superblock(journal, 1);
+                mutex_lock(&journal->j_checkpoint_mutex);
+                /*
+                 * We hold j_checkpoint_mutex so tail cannot change under us.
+                 * We don't need any special data guarantees for writing sb
+                 * since journal is empty and it is ok for write to be
+                 * flushed only with transaction commit.
+                 */
+                journal_update_sb_log_tail(journal, journal->j_tail_sequence,
+                                           journal->j_tail, WRITE_SYNC);
+                mutex_unlock(&journal->j_checkpoint_mutex);
         } else {
                 jbd_debug(3, "superblock not updated\n");
         }
@@ -413,13 +423,16 @@ void journal_commit_transaction(journal_t *journal)
 
         jbd_debug (3, "JBD: commit phase 2\n");
 
+        if (tid_geq(journal->j_commit_waited, commit_transaction->t_tid))
+                write_op = WRITE_SYNC;
+
         /*
          * Now start flushing things to disk, in the order they appear
          * on the transaction lists.  Data blocks go first.
          */
         blk_start_plug(&plug);
         err = journal_submit_data_buffers(journal, commit_transaction,
-                                          WRITE_SYNC);
+                                          write_op);
         blk_finish_plug(&plug);
 
         /*
@@ -478,7 +491,7 @@ void journal_commit_transaction(journal_t *journal)
 
         blk_start_plug(&plug);
 
-        journal_write_revoke_records(journal, commit_transaction, WRITE_SYNC);
+        journal_write_revoke_records(journal, commit_transaction, write_op);
 
         /*
          * If we found any dirty or locked buffers, then we should have
@@ -649,7 +662,7 @@ start_journal_io:
                                 clear_buffer_dirty(bh);
                                 set_buffer_uptodate(bh);
                                 bh->b_end_io = journal_end_buffer_io_sync;
-                                submit_bh(WRITE_SYNC, bh);
+                                submit_bh(write_op, bh);
                         }
                         cond_resched();