JBD2_UNMOUNT
journal->j_flags & JBD2_UNMOUNT)
if (unlikely(journal->j_flags & JBD2_UNMOUNT))
if (journal->j_flags & JBD2_UNMOUNT)
journal->j_flags |= JBD2_UNMOUNT;
BUG_ON(journal->j_flags & JBD2_UNMOUNT);