Commit d21385fa authored by David S. Miller's avatar David S. Miller

Merge branch 'sunvnet-next'

Sowmini Varadhan says:

====================
sunvnet: edge-case/race-conditions bug fixes

This patch series contains fixes for race-conditions in sunvnet,
that can encountered when there is a difference in latency between
producer and consumer.

Patch 1 addresses a case when the STOPPED LDC ack from a peer is
processed before vnet_start_xmit can finish updating the dr->prod
state.

Patch 2 fixes the edge-case when outgoing data and incoming
stopped-ack cross each other in flight.

Patch 3 adds a missing rcu_read_unlock(), found by code-inspection.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 6f6e741f df20286a
...@@ -559,18 +559,20 @@ static int vnet_ack(struct vnet_port *port, void *msgbuf) ...@@ -559,18 +559,20 @@ static int vnet_ack(struct vnet_port *port, void *msgbuf)
return 0; return 0;
end = pkt->end_idx; end = pkt->end_idx;
if (unlikely(!idx_is_pending(dr, end)))
return 0;
vp = port->vp; vp = port->vp;
dev = vp->dev; dev = vp->dev;
netif_tx_lock(dev);
if (unlikely(!idx_is_pending(dr, end))) {
netif_tx_unlock(dev);
return 0;
}
/* sync for race conditions with vnet_start_xmit() and tell xmit it /* sync for race conditions with vnet_start_xmit() and tell xmit it
* is time to send a trigger. * is time to send a trigger.
*/ */
netif_tx_lock(dev);
dr->cons = next_idx(end, dr); dr->cons = next_idx(end, dr);
desc = vio_dring_entry(dr, dr->cons); desc = vio_dring_entry(dr, dr->cons);
if (desc->hdr.state == VIO_DESC_READY && port->start_cons) { if (desc->hdr.state == VIO_DESC_READY && !port->start_cons) {
/* vnet_start_xmit() just populated this dring but missed /* vnet_start_xmit() just populated this dring but missed
* sending the "start" LDC message to the consumer. * sending the "start" LDC message to the consumer.
* Send a "start" trigger on its behalf. * Send a "start" trigger on its behalf.
...@@ -979,8 +981,10 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev) ...@@ -979,8 +981,10 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
rcu_read_lock(); rcu_read_lock();
port = __tx_port_find(vp, skb); port = __tx_port_find(vp, skb);
if (unlikely(!port)) if (unlikely(!port)) {
rcu_read_unlock();
goto out_dropped; goto out_dropped;
}
if (skb->len > port->rmtu) { if (skb->len > port->rmtu) {
unsigned long localmtu = port->rmtu - ETH_HLEN; unsigned long localmtu = port->rmtu - ETH_HLEN;
......
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