Commit 6cba611e authored Apr 05, 2011 by Zhang Huan Committed by Theodore Ts'o Apr 05, 2011

jbd2: fix potential memory leak on transaction commit



There is potential memory leak of journal head in function
jbd2_journal_commit_transaction. The problem is that JBD2 will not
reclaim the journal head of commit record if error occurs or journal
is abotred.

I use the following script to reproduce this issue, on a RHEL6
system. I found it very easy to reproduce with async commit enabled.

mount /dev/sdb /mnt -o journal_checksum,journal_async_commit
touch /mnt/xxx
echo offline > /sys/block/sdb/device/state
sync
umount /mnt
rmmod ext4
rmmod jbd2

Removal of the jbd2 module will make slab complaining that
"cache `jbd2_journal_head': can't free all objects".

Signed-off-by: Zhang Huan <zhhuan@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

parent 46e4690b

fs/jbd2/commit.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -105,6 +105,8 @@ static int journal_submit_commit_record(journal_t *journal,
	int ret;		int ret;
	struct timespec now = current_kernel_time();		struct timespec now = current_kernel_time();

			*cbh = NULL;

	if (is_journal_aborted(journal))		if (is_journal_aborted(journal))
	return 0;		return 0;

	@@ -806,7 +808,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
	if (err)		if (err)
	__jbd2_journal_abort_hard(journal);		__jbd2_journal_abort_hard(journal);
	}		}
	if (!err && !is_journal_aborted(journal))		if (cbh)
	err = journal_wait_on_commit_record(journal, cbh);		err = journal_wait_on_commit_record(journal, cbh);
	if (JBD2_HAS_INCOMPAT_FEATURE(journal,		if (JBD2_HAS_INCOMPAT_FEATURE(journal,
	JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&		JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&