Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:
 "A bit has accumulated, but it's been a week or so since my last batch
  of post-merge-window fixes, so...

   1) Missing module license in netfilter reject module, from Pablo.
      Lots of people ran into this.

   2) Off by one in mac80211 baserate calculation, from Karl Beldan.

   3) Fix incorrect return value from ax88179_178a driver's set_mac_addr
      op, which broke use of it with bonding.  From Ian Morgan.

   4) Checking of skb_gso_segment()'s return value was not all
      encompassing, it can return an SKB pointer, a pointer error, or
      NULL.  Fix from Florian Westphal.

      This is crummy, and longer term will be fixed to just return error
      pointers or a real SKB.

   6) Encapsulation offloads not being handled by
      skb_gso_transport_seglen().  From Florian Westphal.

   7) Fix deadlock in TIPC stack, from Ying Xue.

   8) Fix performance regression from using rhashtable for netlink
      sockets.  The problem was the synchronize_net() invoked for every
      socket destroy.  From Thomas Graf.

   9) Fix bug in eBPF verifier, and remove the strong dependency of BPF
      on NET.  From Alexei Starovoitov.

  10) In qdisc_create(), use the correct interface to allocate
      ->cpu_bstats, otherwise the u64_stats_sync member isn't
      initialized properly.  From Sabrina Dubroca.

  11) Off by one in ip_set_nfnl_get_byindex(), from Dan Carpenter.

  12) nf_tables_newchain() was erroneously expecting error pointers from
      netdev_alloc_pcpu_stats().  It only returna a valid pointer or
      NULL.  From Sabrina Dubroca.

  13) Fix use-after-free in _decode_session6(), from Li RongQing.

  14) When we set the TX flow hash on a socket, we mistakenly do so
      before we've nailed down the final source port.  Move the setting
      deeper to fix this.  From Sathya Perla.

  15) NAPI budget accounting in amd-xgbe driver was counting descriptors
      instead of full packets, fix from Thomas Lendacky.

  16) Fix total_data_buflen calculation in hyperv driver, from Haiyang
      Zhang.

  17) Fix bcma driver build with OF_ADDRESS disabled, from Hauke
      Mehrtens.

  18) Fix mis-use of per-cpu memory in TCP md5 code.  The problem is
      that something that ends up being vmalloc memory can't be passed
      to the crypto hash routines via scatter-gather lists.  From Eric
      Dumazet.

  19) Fix regression in promiscuous mode enabling in cdc-ether, from
      Olivier Blin.

  20) Bucket eviction and frag entry killing can race with eachother,
      causing an unlink of the object from the wrong list.  Fix from
      Nikolay Aleksandrov.

  21) Missing initialization of spinlock in cxgb4 driver, from Anish
      Bhatt.

  22) Do not cache ipv4 routing failures, otherwise if the sysctl for
      forwarding is subsequently enabled this won't be seen.  From
      Nicolas Cavallari"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (131 commits)
  drivers: net: cpsw: Support ALLMULTI and fix IFF_PROMISC in switch mode
  drivers: net: cpsw: Fix broken loop condition in switch mode
  net: ethtool: Return -EOPNOTSUPP if user space tries to read EEPROM with lengh 0
  stmmac: pci: set default of the filter bins
  net: smc91x: Fix gpios for device tree based booting
  mpls: Allow mpls_gso to be built as module
  mpls: Fix mpls_gso handler.
  r8152: stop submitting intr for -EPROTO
  netfilter: nft_reject_bridge: restrict reject to prerouting and input
  netfilter: nft_reject_bridge: don't use IP stack to reject traffic
  netfilter: nf_reject_ipv6: split nf_send_reset6() in smaller functions
  netfilter: nf_reject_ipv4: split nf_send_reset() in smaller functions
  netfilter: nf_tables_bridge: update hook_mask to allow {pre,post}routing
  drivers/net: macvtap and tun depend on INET
  drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO packets
  drivers/net: Disable UFO through virtio
  net: skb_fclone_busy() needs to detect orphaned skb
  gre: Use inner mac length when computing tunnel length
  mlx4: Avoid leaking steering rules on flow creation error flow
  net/mlx4_en: Don't attempt to TX offload the outer UDP checksum for VXLAN
  ...

1 files changed, 201 insertions, 118 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 08f65996534c..6563f0713fc0 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -55,13 +55,20 @@
 bool separate_tx_rx_irq = 1;
 module_param(separate_tx_rx_irq, bool, 0644);
 
-/* When guest ring is filled up, qdisc queues the packets for us, but we have
- * to timeout them, otherwise other guests' packets can get stuck there
+/* The time that packets can stay on the guest Rx internal queue
+ * before they are dropped.
  */
 unsigned int rx_drain_timeout_msecs = 10000;
 module_param(rx_drain_timeout_msecs, uint, 0444);
 unsigned int rx_drain_timeout_jiffies;
 
+/* The length of time before the frontend is considered unresponsive
+ * because it isn't providing Rx slots.
+ */
+static unsigned int rx_stall_timeout_msecs = 60000;
+module_param(rx_stall_timeout_msecs, uint, 0444);
+static unsigned int rx_stall_timeout_jiffies;
+
 unsigned int xenvif_max_queues;
 module_param_named(max_queues, xenvif_max_queues, uint, 0644);
 MODULE_PARM_DESC(max_queues,
@@ -83,7 +90,6 @@ static void make_tx_response(struct xenvif_queue *queue,
 			     s8       st);
 
 static inline int tx_work_todo(struct xenvif_queue *queue);
-static inline int rx_work_todo(struct xenvif_queue *queue);
 
 static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue,
 					     u16      id,
@@ -163,6 +169,69 @@ bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed)
 	return false;
 }
 
+void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->rx_queue.lock, flags);
+
+	__skb_queue_tail(&queue->rx_queue, skb);
+
+	queue->rx_queue_len += skb->len;
+	if (queue->rx_queue_len > queue->rx_queue_max)
+		netif_tx_stop_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
+
+	spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
+}
+
+static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)
+{
+	struct sk_buff *skb;
+
+	spin_lock_irq(&queue->rx_queue.lock);
+
+	skb = __skb_dequeue(&queue->rx_queue);
+	if (skb)
+		queue->rx_queue_len -= skb->len;
+
+	spin_unlock_irq(&queue->rx_queue.lock);
+
+	return skb;
+}
+
+static void xenvif_rx_queue_maybe_wake(struct xenvif_queue *queue)
+{
+	spin_lock_irq(&queue->rx_queue.lock);
+
+	if (queue->rx_queue_len < queue->rx_queue_max)
+		netif_tx_wake_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
+
+	spin_unlock_irq(&queue->rx_queue.lock);
+}
+
+
+static void xenvif_rx_queue_purge(struct xenvif_queue *queue)
+{
+	struct sk_buff *skb;
+	while ((skb = xenvif_rx_dequeue(queue)) != NULL)
+		kfree_skb(skb);
+}
+
+static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue)
+{
+	struct sk_buff *skb;
+
+	for(;;) {
+		skb = skb_peek(&queue->rx_queue);
+		if (!skb)
+			break;
+		if (time_before(jiffies, XENVIF_RX_CB(skb)->expires))
+			break;
+		xenvif_rx_dequeue(queue);
+		kfree_skb(skb);
+	}
+}
+
 /*
  * Returns true if we should start a new receive buffer instead of
  * adding 'size' bytes to a buffer which currently contains 'offset'
@@ -237,13 +306,6 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
 	return meta;
 }
 
-struct xenvif_rx_cb {
-	int meta_slots_used;
-	bool full_coalesce;
-};
-
-#define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
-
 /*
  * Set up the grant operations for this fragment. If it's a flipping
  * interface, we also set up the unmap request from here.
@@ -587,12 +649,15 @@ static void xenvif_rx_action(struct xenvif_queue *queue)
 
 	skb_queue_head_init(&rxq);
 
-	while ((skb = skb_dequeue(&queue->rx_queue)) != NULL) {
+	while (xenvif_rx_ring_slots_available(queue, XEN_NETBK_RX_SLOTS_MAX)
+	       && (skb = xenvif_rx_dequeue(queue)) != NULL) {
 		RING_IDX max_slots_needed;
 		RING_IDX old_req_cons;
 		RING_IDX ring_slots_used;
 		int i;
 
+		queue->last_rx_time = jiffies;
+
 		/* We need a cheap worse case estimate for the number of
 		 * slots we'll use.
 		 */
@@ -634,15 +699,6 @@ static void xenvif_rx_action(struct xenvif_queue *queue)
 		    skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
 			max_slots_needed++;
 
-		/* If the skb may not fit then bail out now */
-		if (!xenvif_rx_ring_slots_available(queue, max_slots_needed)) {
-			skb_queue_head(&queue->rx_queue, skb);
-			need_to_notify = true;
-			queue->rx_last_skb_slots = max_slots_needed;
-			break;
-		} else
-			queue->rx_last_skb_slots = 0;
-
 		old_req_cons = queue->rx.req_cons;
 		XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo, queue);
 		ring_slots_used = queue->rx.req_cons - old_req_cons;
@@ -1869,12 +1925,6 @@ void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
 	}
 }
 
-static inline int rx_work_todo(struct xenvif_queue *queue)
-{
-	return (!skb_queue_empty(&queue->rx_queue) &&
-	       xenvif_rx_ring_slots_available(queue, queue->rx_last_skb_slots));
-}
-
 static inline int tx_work_todo(struct xenvif_queue *queue)
 {
 	if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
@@ -1931,92 +1981,121 @@ err:
 	return err;
 }
 
-static void xenvif_start_queue(struct xenvif_queue *queue)
+static void xenvif_queue_carrier_off(struct xenvif_queue *queue)
 {
-	if (xenvif_schedulable(queue->vif))
-		xenvif_wake_queue(queue);
+	struct xenvif *vif = queue->vif;
+
+	queue->stalled = true;
+
+	/* At least one queue has stalled? Disable the carrier. */
+	spin_lock(&vif->lock);
+	if (vif->stalled_queues++ == 0) {
+		netdev_info(vif->dev, "Guest Rx stalled");
+		netif_carrier_off(vif->dev);
+	}
+	spin_unlock(&vif->lock);
 }
 
-/* Only called from the queue's thread, it handles the situation when the guest
- * doesn't post enough requests on the receiving ring.
- * First xenvif_start_xmit disables QDisc and start a timer, and then either the
- * timer fires, or the guest send an interrupt after posting new request. If it
- * is the timer, the carrier is turned off here.
- * */
-static void xenvif_rx_purge_event(struct xenvif_queue *queue)
+static void xenvif_queue_carrier_on(struct xenvif_queue *queue)
 {
-	/* Either the last unsuccesful skb or at least 1 slot should fit */
-	int needed = queue->rx_last_skb_slots ?
-		     queue->rx_last_skb_slots : 1;
+	struct xenvif *vif = queue->vif;
 
-	/* It is assumed that if the guest post new slots after this, the RX
-	 * interrupt will set the QUEUE_STATUS_RX_PURGE_EVENT bit and wake up
-	 * the thread again
-	 */
-	set_bit(QUEUE_STATUS_RX_STALLED, &queue->status);
-	if (!xenvif_rx_ring_slots_available(queue, needed)) {
-		rtnl_lock();
-		if (netif_carrier_ok(queue->vif->dev)) {
-			/* Timer fired and there are still no slots. Turn off
-			 * everything except the interrupts
-			 */
-			netif_carrier_off(queue->vif->dev);
-			skb_queue_purge(&queue->rx_queue);
-			queue->rx_last_skb_slots = 0;
-			if (net_ratelimit())
-				netdev_err(queue->vif->dev, "Carrier off due to lack of guest response on queue %d\n", queue->id);
-		} else {
-			/* Probably an another queue already turned the carrier
-			 * off, make sure nothing is stucked in the internal
-			 * queue of this queue
-			 */
-			skb_queue_purge(&queue->rx_queue);
-			queue->rx_last_skb_slots = 0;
-		}
-		rtnl_unlock();
-	} else if (!netif_carrier_ok(queue->vif->dev)) {
-		unsigned int num_queues = queue->vif->num_queues;
-		unsigned int i;
-		/* The carrier was down, but an interrupt kicked
-		 * the thread again after new requests were
-		 * posted
-		 */
-		clear_bit(QUEUE_STATUS_RX_STALLED,
-			  &queue->status);
-		rtnl_lock();
-		netif_carrier_on(queue->vif->dev);
-		netif_tx_wake_all_queues(queue->vif->dev);
-		rtnl_unlock();
+	queue->last_rx_time = jiffies; /* Reset Rx stall detection. */
+	queue->stalled = false;
 
-		for (i = 0; i < num_queues; i++) {
-			struct xenvif_queue *temp = &queue->vif->queues[i];
+	/* All queues are ready? Enable the carrier. */
+	spin_lock(&vif->lock);
+	if (--vif->stalled_queues == 0) {
+		netdev_info(vif->dev, "Guest Rx ready");
+		netif_carrier_on(vif->dev);
+	}
+	spin_unlock(&vif->lock);
+}
 
-			xenvif_napi_schedule_or_enable_events(temp);
-		}
-		if (net_ratelimit())
-			netdev_err(queue->vif->dev, "Carrier on again\n");
-	} else {
-		/* Queuing were stopped, but the guest posted
-		 * new requests and sent an interrupt
-		 */
-		clear_bit(QUEUE_STATUS_RX_STALLED,
-			  &queue->status);
-		del_timer_sync(&queue->rx_stalled);
-		xenvif_start_queue(queue);
+static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue)
+{
+	RING_IDX prod, cons;
+
+	prod = queue->rx.sring->req_prod;
+	cons = queue->rx.req_cons;
+
+	return !queue->stalled
+		&& prod - cons < XEN_NETBK_RX_SLOTS_MAX
+		&& time_after(jiffies,
+			      queue->last_rx_time + rx_stall_timeout_jiffies);
+}
+
+static bool xenvif_rx_queue_ready(struct xenvif_queue *queue)
+{
+	RING_IDX prod, cons;
+
+	prod = queue->rx.sring->req_prod;
+	cons = queue->rx.req_cons;
+
+	return queue->stalled
+		&& prod - cons >= XEN_NETBK_RX_SLOTS_MAX;
+}
+
+static bool xenvif_have_rx_work(struct xenvif_queue *queue)
+{
+	return (!skb_queue_empty(&queue->rx_queue)
+		&& xenvif_rx_ring_slots_available(queue, XEN_NETBK_RX_SLOTS_MAX))
+		|| xenvif_rx_queue_stalled(queue)
+		|| xenvif_rx_queue_ready(queue)
+		|| kthread_should_stop()
+		|| queue->vif->disabled;
+}
+
+static long xenvif_rx_queue_timeout(struct xenvif_queue *queue)
+{
+	struct sk_buff *skb;
+	long timeout;
+
+	skb = skb_peek(&queue->rx_queue);
+	if (!skb)
+		return MAX_SCHEDULE_TIMEOUT;
+
+	timeout = XENVIF_RX_CB(skb)->expires - jiffies;
+	return timeout < 0 ? 0 : timeout;
+}
+
+/* Wait until the guest Rx thread has work.
+ *
+ * The timeout needs to be adjusted based on the current head of the
+ * queue (and not just the head at the beginning).  In particular, if
+ * the queue is initially empty an infinite timeout is used and this
+ * needs to be reduced when a skb is queued.
+ *
+ * This cannot be done with wait_event_timeout() because it only
+ * calculates the timeout once.
+ */
+static void xenvif_wait_for_rx_work(struct xenvif_queue *queue)
+{
+	DEFINE_WAIT(wait);
+
+	if (xenvif_have_rx_work(queue))
+		return;
+
+	for (;;) {
+		long ret;
+
+		prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE);
+		if (xenvif_have_rx_work(queue))
+			break;
+		ret = schedule_timeout(xenvif_rx_queue_timeout(queue));
+		if (!ret)
+			break;
 	}
+	finish_wait(&queue->wq, &wait);
 }
 
 int xenvif_kthread_guest_rx(void *data)
 {
 	struct xenvif_queue *queue = data;
-	struct sk_buff *skb;
+	struct xenvif *vif = queue->vif;
 
-	while (!kthread_should_stop()) {
-		wait_event_interruptible(queue->wq,
-					 rx_work_todo(queue) ||
-					 queue->vif->disabled ||
-					 test_bit(QUEUE_STATUS_RX_PURGE_EVENT, &queue->status) ||
-					 kthread_should_stop());
+	for (;;) {
+		xenvif_wait_for_rx_work(queue);
 
 		if (kthread_should_stop())
 			break;
@@ -2028,35 +2107,38 @@ int xenvif_kthread_guest_rx(void *data)
 		 * context so we defer it here, if this thread is
 		 * associated with queue 0.
 		 */
-		if (unlikely(queue->vif->disabled && queue->id == 0)) {
-			xenvif_carrier_off(queue->vif);
-		} else if (unlikely(queue->vif->disabled)) {
-			/* kthread_stop() would be called upon this thread soon,
-			 * be a bit proactive
-			 */
-			skb_queue_purge(&queue->rx_queue);
-			queue->rx_last_skb_slots = 0;
-		} else if (unlikely(test_and_clear_bit(QUEUE_STATUS_RX_PURGE_EVENT,
-						     &queue->status))) {
-			xenvif_rx_purge_event(queue);
-		} else if (!netif_carrier_ok(queue->vif->dev)) {
-			/* Another queue stalled and turned the carrier off, so
-			 * purge the internal queue of queues which were not
-			 * blocked
-			 */
-			skb_queue_purge(&queue->rx_queue);
-			queue->rx_last_skb_slots = 0;
+		if (unlikely(vif->disabled && queue->id == 0)) {
+			xenvif_carrier_off(vif);
+			xenvif_rx_queue_purge(queue);
+			continue;
 		}
 
 		if (!skb_queue_empty(&queue->rx_queue))
 			xenvif_rx_action(queue);
 
+		/* If the guest hasn't provided any Rx slots for a
+		 * while it's probably not responsive, drop the
+		 * carrier so packets are dropped earlier.
+		 */
+		if (xenvif_rx_queue_stalled(queue))
+			xenvif_queue_carrier_off(queue);
+		else if (xenvif_rx_queue_ready(queue))
+			xenvif_queue_carrier_on(queue);
+
+		/* Queued packets may have foreign pages from other
+		 * domains.  These cannot be queued indefinitely as
+		 * this would starve guests of grant refs and transmit
+		 * slots.
+		 */
+		xenvif_rx_queue_drop_expired(queue);
+
+		xenvif_rx_queue_maybe_wake(queue);
+
 		cond_resched();
 	}
 
 	/* Bin any remaining skbs */
-	while ((skb = skb_dequeue(&queue->rx_queue)) != NULL)
-		dev_kfree_skb(skb);
+	xenvif_rx_queue_purge(queue);
 
 	return 0;
 }
@@ -2113,6 +2195,7 @@ static int __init netback_init(void)
 		goto failed_init;
 
 	rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs);
+	rx_stall_timeout_jiffies = msecs_to_jiffies(rx_stall_timeout_msecs);
 
 #ifdef CONFIG_DEBUG_FS
 	xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);