netpoll: move setting of NETPOLL_RX_DROP into netpoll_poll_dev
Today netpoll depends on setting NETPOLL_RX_DROP before networking
drivers receive packets in interrupt context so that the packets can
be dropped. Move this setting into netpoll_poll_dev from
poll_one_napi so that if ndo_poll_controller happens to receive
packets we will drop the packets on the floor instead of letting the
packets bounce through the networking stack and potentially cause problems.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index a664f78..ef4f45d 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -144,8 +144,7 @@
* network adapter, forcing superfluous retries and possibly timeouts.
* Thus, we set our budget to greater than 1.
*/
-static int poll_one_napi(struct netpoll_info *npinfo,
- struct napi_struct *napi, int budget)
+static int poll_one_napi(struct napi_struct *napi, int budget)
{
int work;
@@ -156,16 +155,12 @@
if (!test_bit(NAPI_STATE_SCHED, &napi->state))
return budget;
- npinfo->rx_flags |= NETPOLL_RX_DROP;
- atomic_inc(&trapped);
set_bit(NAPI_STATE_NPSVC, &napi->state);
work = napi->poll(napi, budget);
trace_napi_poll(napi);
clear_bit(NAPI_STATE_NPSVC, &napi->state);
- atomic_dec(&trapped);
- npinfo->rx_flags &= ~NETPOLL_RX_DROP;
return budget - work;
}
@@ -178,8 +173,7 @@
list_for_each_entry(napi, &dev->napi_list, dev_list) {
if (napi->poll_owner != smp_processor_id() &&
spin_trylock(&napi->poll_lock)) {
- budget = poll_one_napi(rcu_dereference_bh(dev->npinfo),
- napi, budget);
+ budget = poll_one_napi(napi, budget);
spin_unlock(&napi->poll_lock);
if (!budget)
@@ -215,6 +209,9 @@
return;
}
+ ni->rx_flags |= NETPOLL_RX_DROP;
+ atomic_inc(&trapped);
+
ops = dev->netdev_ops;
if (!ops->ndo_poll_controller) {
up(&ni->dev_lock);
@@ -226,6 +223,9 @@
poll_napi(dev);
+ atomic_dec(&trapped);
+ ni->rx_flags &= ~NETPOLL_RX_DROP;
+
up(&ni->dev_lock);
if (dev->flags & IFF_SLAVE) {