ipvlan: do not use cond_resched_rcu() in ipvlan_process_multicast()

BugLink: https://bugs.launchpad.net/bugs/1868629

[ Upstream commit afe207d8 ]

Commit e18b353f ("ipvlan: add cond_resched_rcu() while
processing muticast backlog") added a cond_resched_rcu() in a loop
using rcu protection to iterate over slaves.

This is breaking rcu rules, so lets instead use cond_resched()
at a point we can reschedule

Fixes: e18b353f ("ipvlan: add cond_resched_rcu() while processing muticast backlog")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

drivers/net/ipvlan/ipvlan_core.c

@@ -240,7 +240,6 @@ void ipvlan_process_multicast(struct work_struct *work)
 				ret = netif_rx(nskb);
 acct:
 			ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
-			cond_resched_rcu();
 		}
 		rcu_read_unlock();
 
@@ -252,6 +251,7 @@ void ipvlan_process_multicast(struct work_struct *work)
 		} else {
 			kfree_skb(skb);
 		}
+		cond_resched();
 	}
 }