From a80ca1ae81fc52e304e753f6de4ef248df364f9e Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Fri, 27 Dec 2013 17:17:25 +0100 Subject: [PATCH] drbd: fix a race stopping the worker thread We may implicitly call drbd_send() from inside wait_for_work(), via maybe_send_barrier(). If the "stop" signal was send just before that, drbd_send() would call flush_signals(), and we would run an unbounded schedule() afterwards. Fix: check for thread_state == RUNNING before we schedule() Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_worker.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 59158858b17a..47bc84017b5b 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -1930,6 +1930,9 @@ static void wait_for_work(struct drbd_connection *connection, struct list_head * if (send_barrier) maybe_send_barrier(connection, connection->send.current_epoch_nr + 1); + /* drbd_send() may have called flush_signals() */ + if (get_t_state(&connection->worker) != RUNNING) + break; schedule(); /* may be woken up for other things but new work, too, * e.g. if the current epoch got closed. -- 2.20.1