s390/qeth: cancel RX reclaim work earlier

When qeth's napi poll code fails to refill an entirely empty RX ring, it
kicks off buffer_reclaim_work to try again later.

Make sure that this worker is cancelled when setting the qeth device
offline. Otherwise a RX refill action can unexpectedly end up running
concurrently to bigger re-configurations (eg. resizing the buffer pool),
without any locking.

Fixes: b3332930 ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core_main.c

@@ -2392,7 +2392,6 @@ static void qeth_free_qdio_queues(struct qeth_card *card)
 		return;
 
 	qeth_free_cq(card);
-	cancel_delayed_work_sync(&card->buffer_reclaim_work);
 	for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; ++j) {
 		if (card->qdio.in_q->bufs[j].rx_skb)
 			dev_kfree_skb_any(card->qdio.in_q->bufs[j].rx_skb);

drivers/s390/net/qeth_l2_main.c

@@ -284,6 +284,7 @@ static void qeth_l2_stop_card(struct qeth_card *card)
 	if (card->state == CARD_STATE_SOFTSETUP) {
 		qeth_clear_ipacmd_list(card);
 		qeth_drain_output_queues(card);
+		cancel_delayed_work_sync(&card->buffer_reclaim_work);
 		card->state = CARD_STATE_DOWN;
 	}
 

drivers/s390/net/qeth_l3_main.c

@@ -1178,6 +1178,7 @@ static void qeth_l3_stop_card(struct qeth_card *card)
 		qeth_l3_clear_ip_htable(card, 1);
 		qeth_clear_ipacmd_list(card);
 		qeth_drain_output_queues(card);
+		cancel_delayed_work_sync(&card->buffer_reclaim_work);
 		card->state = CARD_STATE_DOWN;
 	}