Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/jbd2/journal.c    |    2 +-
 include/linux/jbd2.h |    3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff -puN fs/jbd2/journal.c~ext4-jbd-stats-through-procfs_fix fs/jbd2/journal.c
--- a/fs/jbd2/journal.c~ext4-jbd-stats-through-procfs_fix
+++ a/fs/jbd2/journal.c
@@ -751,7 +751,7 @@ static int jbd2_seq_history_open(struct 
 		return -EIO;
 	size = sizeof(struct transaction_stats_s) * journal->j_history_max;
 	s->stats = kmalloc(size, GFP_KERNEL);
-	if (s == NULL) {
+	if (s->stats == NULL) {
 		kfree(s);
 		return -EIO;
 	}
diff -puN include/linux/jbd2.h~ext4-jbd-stats-through-procfs_fix include/linux/jbd2.h
--- a/include/linux/jbd2.h~ext4-jbd-stats-through-procfs_fix
+++ a/include/linux/jbd2.h
@@ -927,6 +927,9 @@ struct journal_s
 	struct transaction_stats_s *j_history;
 	int			j_history_max;
 	int			j_history_cur;
+	/*
+	 * Protect the transactions statistics history
+	 */
 	spinlock_t		j_history_lock;
 	struct proc_dir_entry	*j_proc_entry;
 	struct transaction_stats_s j_stats;
_