[PATCH 7/9] jbd2: make the whole kjournald2 kthread NOFS safe
From: Michal Hocko
Date: Thu Dec 15 2016 - 09:11:14 EST
From: Michal Hocko <mhocko@xxxxxxxx>
kjournald2 is central to the transaction commit processing. As such any
potential allocation from this kernel thread has to be GFP_NOFS. Make
sure to mark the whole kernel thread GFP_NOFS by the memalloc_nofs_save.
Suggested-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
fs/jbd2/journal.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 8ed971eeab44..6dad8c5d6ddf 100644
@@ -206,6 +206,13 @@ static int kjournald2(void *arg)
+ * Make sure that no allocations from this kernel thread will ever recurse
+ * to the fs layer because we are responsible for the transaction commit
+ * and any fs involvement might get stuck waiting for the trasn. commit.
* And now, wait forever for commit wakeup events.