Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[firefly-linux-kernel-4.4.55.git] / drivers / net / tun.c

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index c81680dc10eb7c43baaf61a0bfea1456dbe33c5c..cc09b67c23bcd30402d73a93594f7aef9cb100da 100644 (file)
--- 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))
@@ -1583,6 +1587,8 @@ 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;
@@ -1606,8 +1612,8 @@ 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;