2 files changed, 21 insertions, 3 deletions

diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index d2f652e6e22e..cd931ef1f000 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -472,6 +472,9 @@ void journal_commit_transaction(journal_t *journal)
          */
         commit_transaction->t_state = T_COMMIT;
 
+        J_ASSERT(commit_transaction->t_nr_buffers <=
+                 commit_transaction->t_outstanding_credits);
+
         descriptor = NULL;
         bufs = 0;
         while (commit_transaction->t_buffers) {
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index 2e9670e2237e..d8dd3d915fd9 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -1235,6 +1235,7 @@ int journal_forget (handle_t *handle, struct buffer_head *bh)
         struct journal_head *jh;
         int drop_reserve = 0;
         int err = 0;
+        int was_modified = 0;
 
         BUFFER_TRACE(bh, "entry");
 
@@ -1253,6 +1254,9 @@ int journal_forget (handle_t *handle, struct buffer_head *bh)
                 goto not_jbd;
         }
 
+        /* keep track of wether or not this transaction modified us */
+        was_modified = jh->b_modified;
+
         /*
          * The buffer's going from the transaction, we must drop
          * all references -bzzz
@@ -1270,7 +1274,12 @@ int journal_forget (handle_t *handle, struct buffer_head *bh)
 
                 JBUFFER_TRACE(jh, "belongs to current transaction: unfile");
 
-                drop_reserve = 1;
+                /*
+                 * we only want to drop a reference if this transaction
+                 * modified the buffer
+                 */
+                if (was_modified)
+                        drop_reserve = 1;
 
                 /*
                  * We are no longer going to journal this buffer.
@@ -1310,7 +1319,13 @@ int journal_forget (handle_t *handle, struct buffer_head *bh)
                 if (jh->b_next_transaction) {
                         J_ASSERT(jh->b_next_transaction == transaction);
                         jh->b_next_transaction = NULL;
-                        drop_reserve = 1;
+
+                        /*
+                         * only drop a reference if this transaction modified
+                         * the buffer
+                         */
+                        if (was_modified)
+                                drop_reserve = 1;
                 }
         }
 
@@ -2082,7 +2097,7 @@ void __journal_refile_buffer(struct journal_head *jh)
         jh->b_transaction = jh->b_next_transaction;
         jh->b_next_transaction = NULL;
         __journal_file_buffer(jh, jh->b_transaction,
-                                was_dirty ? BJ_Metadata : BJ_Reserved);
+                                jh->b_modified ? BJ_Metadata : BJ_Reserved);
         J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING);
 
         if (was_dirty)