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Commit ff883aeb authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'xen-netfront' 



David Vrabel says:

====================
xen-netfront: multi-queue related locking fixes

Two fixes to the per-queue locking bugs in xen-netfront that were
introduced in 3.16-rc1 with the multi-queue support.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 6e08d5e3 f9feb1e6

drivers/net/xen-netfront.c

+16 −11
Original line number Diff line number Diff line
@@ -1439,16 +1439,11 @@ static void xennet_disconnect_backend(struct netfront_info *info) 
	unsigned int i = 0;

	unsigned int num_queues = info->netdev->real_num_tx_queues;



	netif_carrier_off(info->netdev);



	for (i = 0; i < num_queues; ++i) {

		struct netfront_queue *queue = &info->queues[i];



		/* Stop old i/f to prevent errors whilst we rebuild the state. */

		spin_lock_bh(&queue->rx_lock);

		spin_lock_irq(&queue->tx_lock);

		netif_carrier_off(queue->info->netdev);

		spin_unlock_irq(&queue->tx_lock);

		spin_unlock_bh(&queue->rx_lock);



		if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))

			unbind_from_irqhandler(queue->tx_irq, queue);

		if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
@@ -1458,6 +1453,8 @@ static void xennet_disconnect_backend(struct netfront_info *info) 
		queue->tx_evtchn = queue->rx_evtchn = 0;

		queue->tx_irq = queue->rx_irq = 0;



		napi_synchronize(&queue->napi);



		/* End access and free the pages */

		xennet_end_access(queue->tx_ring_ref, queue->tx.sring);

		xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
@@ -2046,13 +2043,15 @@ static int xennet_connect(struct net_device *dev) 
	/* By now, the queue structures have been set up */

	for (j = 0; j < num_queues; ++j) {

		queue = &np->queues[j];

		spin_lock_bh(&queue->rx_lock);

		spin_lock_irq(&queue->tx_lock);



		/* Step 1: Discard all pending TX packet fragments. */

		spin_lock_irq(&queue->tx_lock);

		xennet_release_tx_bufs(queue);

		spin_unlock_irq(&queue->tx_lock);



		/* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */

		spin_lock_bh(&queue->rx_lock);



		for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {

			skb_frag_t *frag;

			const struct page *page;
@@ -2076,6 +2075,8 @@ static int xennet_connect(struct net_device *dev) 
		}



		queue->rx.req_prod_pvt = requeue_idx;



		spin_unlock_bh(&queue->rx_lock);

	}



	/*
@@ -2087,13 +2088,17 @@ static int xennet_connect(struct net_device *dev) 
	netif_carrier_on(np->netdev);

	for (j = 0; j < num_queues; ++j) {

		queue = &np->queues[j];



		notify_remote_via_irq(queue->tx_irq);

		if (queue->tx_irq != queue->rx_irq)

			notify_remote_via_irq(queue->rx_irq);

		xennet_tx_buf_gc(queue);

		xennet_alloc_rx_buffers(queue);



		spin_lock_irq(&queue->tx_lock);

		xennet_tx_buf_gc(queue);

		spin_unlock_irq(&queue->tx_lock);



		spin_lock_bh(&queue->rx_lock);

		xennet_alloc_rx_buffers(queue);

		spin_unlock_bh(&queue->rx_lock);

	}