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>
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index fa36d76..b98e4c1 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -105,6 +105,8 @@
int ret;
struct timespec now = current_kernel_time();
+ *cbh = NULL;
+
if (is_journal_aborted(journal))
return 0;
@@ -806,7 +808,7 @@
if (err)
__jbd2_journal_abort_hard(journal);
}
- if (!err && !is_journal_aborted(journal))
+ if (cbh)
err = journal_wait_on_commit_record(journal, cbh);
if (JBD2_HAS_INCOMPAT_FEATURE(journal,
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
