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> Reviewed-by: Jan Kara <jack@xxxxxxx> --- fs/jbd2/journal.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index a097048ed1a3..3a449150f834 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -206,6 +206,13 @@ static int kjournald2(void *arg) wake_up(&journal->j_wait_done_commit); /* + * 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. + */ + memalloc_nofs_save(); + + /* * And now, wait forever for commit wakeup events. */ write_lock(&journal->j_state_lock); -- 2.11.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>