[VLAN]: Keep track of number of QoS mappings

Keep track of the number of configured ingress/egress QoS mappings to
avoid iteration while calculating the netlink attribute size.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 24 insertions, 6 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index aeddb49193f9..b46d4225f74e 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -112,7 +112,10 @@ struct vlan_dev_info {
         /** This will be the mapping that correlates skb->priority to
          * 3 bits of VLAN QOS tags...
          */
+        unsigned int nr_ingress_mappings;
         u32 ingress_priority_map[8];
+
+        unsigned int nr_egress_mappings;
         struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
 
         unsigned short vlan_id;        /*  The VLAN Identifier for this interface. */
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 05a23601f670..4f6ede752a37 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -537,35 +537,50 @@ int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
 void vlan_dev_set_ingress_priority(const struct net_device *dev,
                                    u32 skb_prio, short vlan_prio)
 {
-        VLAN_DEV_INFO(dev)->ingress_priority_map[vlan_prio & 0x7] = skb_prio;
+        struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
+
+        if (vlan->ingress_priority_map[vlan_prio & 0x7] && !skb_prio)
+                vlan->nr_ingress_mappings--;
+        else if (!vlan->ingress_priority_map[vlan_prio & 0x7] && skb_prio)
+                vlan->nr_ingress_mappings++;
+
+        vlan->ingress_priority_map[vlan_prio & 0x7] = skb_prio;
 }
 
 int vlan_dev_set_egress_priority(const struct net_device *dev,
                                  u32 skb_prio, short vlan_prio)
 {
+        struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
         struct vlan_priority_tci_mapping *mp = NULL;
         struct vlan_priority_tci_mapping *np;
+        u32 vlan_qos = (vlan_prio << 13) & 0xE000;
 
         /* See if a priority mapping exists.. */
-        mp = VLAN_DEV_INFO(dev)->egress_priority_map[skb_prio & 0xF];
+        mp = vlan->egress_priority_map[skb_prio & 0xF];
         while (mp) {
                 if (mp->priority == skb_prio) {
-                        mp->vlan_qos = ((vlan_prio << 13) & 0xE000);
+                        if (mp->vlan_qos && !vlan_qos)
+                                vlan->nr_egress_mappings--;
+                        else if (!mp->vlan_qos && vlan_qos)
+                                vlan->nr_egress_mappings++;
+                        mp->vlan_qos = vlan_qos;
                         return 0;
                 }
                 mp = mp->next;
         }
 
         /* Create a new mapping then. */
-        mp = VLAN_DEV_INFO(dev)->egress_priority_map[skb_prio & 0xF];
+        mp = vlan->egress_priority_map[skb_prio & 0xF];
         np = kmalloc(sizeof(struct vlan_priority_tci_mapping), GFP_KERNEL);
         if (!np)
                 return -ENOBUFS;
 
         np->next = mp;
         np->priority = skb_prio;
-        np->vlan_qos = ((vlan_prio << 13) & 0xE000);
-        VLAN_DEV_INFO(dev)->egress_priority_map[skb_prio & 0xF] = np;
+        np->vlan_qos = vlan_qos;
+        vlan->egress_priority_map[skb_prio & 0xF] = np;
+        if (vlan_qos)
+                vlan->nr_egress_mappings++;
         return 0;
 }