1 files changed, 38 insertions, 4 deletions

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 6f4dff182c91..135f0a10f557 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1597,9 +1597,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
                         __jbd2_journal_unfile_buffer(jh);
                         if (!buffer_jbd(bh)) {
                                 spin_unlock(&journal->j_list_lock);
-                                jbd_unlock_bh_state(bh);
-                                __bforget(bh);
-                                goto drop;
+                                goto not_jbd;
                         }
                 }
                 spin_unlock(&journal->j_list_lock);
@@ -1632,9 +1630,40 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
                         if (was_modified)
                                 drop_reserve = 1;
                 }
+        } else {
+                /*
+                 * Finally, if the buffer is not belongs to any
+                 * transaction, we can just drop it now if it has no
+                 * checkpoint.
+                 */
+                spin_lock(&journal->j_list_lock);
+                if (!jh->b_cp_transaction) {
+                        JBUFFER_TRACE(jh, "belongs to none transaction");
+                        spin_unlock(&journal->j_list_lock);
+                        goto not_jbd;
+                }
+
+                /*
+                 * Otherwise, if the buffer has been written to disk,
+                 * it is safe to remove the checkpoint and drop it.
+                 */
+                if (!buffer_dirty(bh)) {
+                        __jbd2_journal_remove_checkpoint(jh);
+                        spin_unlock(&journal->j_list_lock);
+                        goto not_jbd;
+                }
+
+                /*
+                 * The buffer is still not written to disk, we should
+                 * attach this buffer to current transaction so that the
+                 * buffer can be checkpointed only after the current
+                 * transaction commits.
+                 */
+                clear_buffer_dirty(bh);
+                __jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
+                spin_unlock(&journal->j_list_lock);
         }
 
-not_jbd:
         jbd_unlock_bh_state(bh);
         __brelse(bh);
 drop:
@@ -1643,6 +1672,11 @@ drop:
                 handle->h_buffer_credits++;
         }
         return err;
+
+not_jbd:
+        jbd_unlock_bh_state(bh);
+        __bforget(bh);
+        goto drop;
 }
 
 /**