ocfs2: clear journal dirty flag after shutdown journal

Dirty flag of the journal should be cleared at the last stage of umount,
if do it before jbd2_journal_destroy(), then some metadata in uncommitted
transaction could be lost due to io error, but as dirty flag of journal
was already cleared, we can't find that until run a full fsck.  This may
cause system panic or other corruption.

Link: http://lkml.kernel.org/r/20181121020023.3034-3-junxiao.bi@oracle.comSigned-off-by: NJunxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: NYiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: NJoseph Qi <jiangqi903@gmail.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@versity.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/journal.c

@@ -1017,7 +1017,8 @@ void ocfs2_journal_shutdown(struct ocfs2_super *osb)
 			mlog_errno(status);
 	}
 
-	if (status == 0) {
+	/* Shutdown the kernel journal system */
+	if (!jbd2_journal_destroy(journal->j_journal) && !status) {
 		/*
 		 * Do not toggle if flush was unsuccessful otherwise
 		 * will leave dirty metadata in a "clean" journal
@@ -1026,9 +1027,6 @@ void ocfs2_journal_shutdown(struct ocfs2_super *osb)
 		if (status < 0)
 			mlog_errno(status);
 	}
-
-	/* Shutdown the kernel journal system */
-	jbd2_journal_destroy(journal->j_journal);
 	journal->j_journal = NULL;
 
 	OCFS2_I(inode)->ip_open_count--;