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

Bring in the 'net' tree so that we can get some ipv4/ipv6 bug
fixes that some net-next work will build upon.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 8 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 293ce8dfc9e6..8d208dd92963 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -109,11 +109,11 @@ struct tap_filter {
 	unsigned char	addr[FLT_EXACT_COUNT][ETH_ALEN];
 };
 
-/* 1024 is probably a high enough limit: modern hypervisors seem to support on
- * the order of 100-200 CPUs so this leaves us some breathing space if we want
- * to match a queue per guest CPU.
- */
-#define MAX_TAP_QUEUES 1024
+/* DEFAULT_MAX_NUM_RSS_QUEUES were choosed to let the rx/tx queues allocated for
+ * the netdevice to be fit in one page. So we can make sure the success of
+ * memory allocation. TODO: increase the limit. */
+#define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
+#define MAX_TAP_FLOWS  4096
 
 #define TUN_FLOW_EXPIRE (3 * HZ)
 
@@ -186,6 +186,7 @@ struct tun_struct {
 	unsigned int numdisabled;
 	struct list_head disabled;
 	void *security;
+	u32 flow_count;
 };
 
 static inline u32 tun_hashfn(u32 rxhash)
@@ -219,6 +220,7 @@ static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
 		e->queue_index = queue_index;
 		e->tun = tun;
 		hlist_add_head_rcu(&e->hash_link, head);
+		++tun->flow_count;
 	}
 	return e;
 }
@@ -229,6 +231,7 @@ static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
 		  e->rxhash, e->queue_index);
 	hlist_del_rcu(&e->hash_link);
 	kfree_rcu(e, rcu);
+	--tun->flow_count;
 }
 
 static void tun_flow_flush(struct tun_struct *tun)
@@ -318,7 +321,8 @@ static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
 		e->updated = jiffies;
 	} else {
 		spin_lock_bh(&tun->lock);
-		if (!tun_flow_find(head, rxhash))
+		if (!tun_flow_find(head, rxhash) &&
+		    tun->flow_count < MAX_TAP_FLOWS)
 			tun_flow_create(tun, head, rxhash, queue_index);
 
 		if (!timer_pending(&tun->flow_gc_timer))
@@ -1587,6 +1591,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 	else {
 		char *name;
 		unsigned long flags = 0;
+		int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
+			     MAX_TAP_QUEUES : 1;
 
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			return -EPERM;
@@ -1610,8 +1616,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 			name = ifr->ifr_name;
 
 		dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
-				       tun_setup,
-				       MAX_TAP_QUEUES, MAX_TAP_QUEUES);
+				       tun_setup, queues, queues);
+
 		if (!dev)
 			return -ENOMEM;