From b41b554c1ee75070a14c02a88496b1f231c7eacc Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Thu, 7 Jan 2021 18:24:41 +0100 Subject: s390/qeth: fix locking for discipline setup / removal Due to insufficient locking, qeth_core_set_online() and qeth_dev_layer2_store() can run in parallel, both attempting to load & setup the discipline (and stepping on each other toes along the way). A similar race can also occur between qeth_core_remove_device() and qeth_dev_layer2_store(). Access to .discipline is meant to be protected by the discipline_mutex, so add/expand the locking in qeth_core_remove_device() and qeth_core_set_online(). Adjust the locking in qeth_l*_remove_device() accordingly, as it's now handled by the callers in a consistent manner. Based on an initial patch by Ursula Braun. Fixes: 9dc48ccc68b9 ("qeth: serialize sysfs-triggered device configurations") Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter Signed-off-by: Jakub Kicinski --- drivers/s390/net/qeth_l2_main.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/s390/net/qeth_l2_main.c') diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 37279b1e29f6..4254caf1d9b6 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -2207,11 +2207,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *gdev) qeth_set_allowed_threads(card, 0, 1); wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0); - if (gdev->state == CCWGROUP_ONLINE) { - mutex_lock(&card->discipline_mutex); + if (gdev->state == CCWGROUP_ONLINE) qeth_set_offline(card, card->discipline, false); - mutex_unlock(&card->discipline_mutex); - } cancel_work_sync(&card->close_dev_work); if (card->dev->reg_state == NETREG_REGISTERED) -- cgit v1.2.3-59-g8ed1b