+ /*
+ * We cannot remove the buffer from checkpoint lists until the
+ * transaction adding inode to orphan list (let's call it T)
+ * is committed. Otherwise if the transaction changing the
+ * buffer would be cleaned from the journal before T is
+ * committed, a crash will cause that the correct contents of
+ * the buffer will be lost. On the other hand we have to
+ * clear the buffer dirty bit at latest at the moment when the
+ * transaction marking the buffer as freed in the filesystem
+ * structures is committed because from that moment on the
+ * buffer can be reallocated and used by a different page.
+ * Since the block hasn't been freed yet but the inode has
+ * already been added to orphan list, it is safe for us to add
+ * the buffer to BJ_Forget list of the newest transaction.
+ */