linux-kernel - [PATCH 3.16 097/212] jbd2: don't leak modified metadata buffers on an aborted journal

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Date:   Thu, 01 Jun 2017 16:43:16 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Theodore Ts'o" <tytso@....edu>
Subject: [PATCH 3.16 097/212] jbd2: don't leak modified metadata buffers
 on an aborted journal

3.16.44-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Theodore Ts'o <tytso@....edu>

commit e112666b4959b25a8552d63bc564e1059be703e8 upstream.

If the journal has been aborted, we shouldn't mark the underlying
buffer head as dirty, since that will cause the metadata block to get
modified.  And if the journal has been aborted, we shouldn't allow
this since it will almost certainly lead to a corrupted file system.

Signed-off-by: Theodore Ts'o <tytso@....edu>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 fs/jbd2/transaction.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1784,7 +1784,9 @@ static void __jbd2_journal_temp_unlink_b
 
 	__blist_del_buffer(list, jh);
 	jh->b_jlist = BJ_None;
-	if (test_clear_buffer_jbddirty(bh))
+	if (transaction && is_journal_aborted(transaction->t_journal))
+		clear_buffer_jbddirty(bh);
+	else if (test_clear_buffer_jbddirty(bh))
 		mark_buffer_dirty(bh);	/* Expose it to the VM */
 }