[VLAN]: Tag vlan_group_device with net device, not ifindex.

Currently vlan group is searched using one key - the ifindex.
We'll have to lookup the vlan_group by two keys - ifindex and
net. Turning the vlan_group lookup key to struct net_device
pointer will make this process easier.

Besides, this will eliminate one more place in the networking,
that assumes that indexes are unique in the kernel.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/if_vlan.h

@@ -81,7 +81,9 @@ extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
 
 struct vlan_group {
-	int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
+	struct net_device	*real_dev; /* The ethernet(like) device
+					    * the vlan is attached to.
+					    */
 	unsigned int		nr_vlans;
 	struct hlist_node	hlist;	/* linked list */
 	struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];

net/8021q/vlan.c

@@ -65,14 +65,14 @@ static inline unsigned int vlan_grp_hashfn(unsigned int idx)
 }
 
 /* Must be invoked with RCU read lock (no preempt) */
-static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
+static struct vlan_group *__vlan_find_group(struct net_device *real_dev)
 {
 	struct vlan_group *grp;
 	struct hlist_node *n;
-	int hash = vlan_grp_hashfn(real_dev_ifindex);
+	int hash = vlan_grp_hashfn(real_dev->ifindex);
 
 	hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) {
-		if (grp->real_dev_ifindex == real_dev_ifindex)
+		if (grp->real_dev == real_dev)
 			return grp;
 	}
 
@@ -86,7 +86,7 @@ static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
 struct net_device *__find_vlan_dev(struct net_device *real_dev,
 				   unsigned short VID)
 {
-	struct vlan_group *grp = __vlan_find_group(real_dev->ifindex);
+	struct vlan_group *grp = __vlan_find_group(real_dev);
 
 	if (grp)
 		return vlan_group_get_device(grp, VID);
@@ -103,7 +103,7 @@ static void vlan_group_free(struct vlan_group *grp)
 	kfree(grp);
 }
 
-static struct vlan_group *vlan_group_alloc(int ifindex)
+static struct vlan_group *vlan_group_alloc(struct net_device *real_dev)
 {
 	struct vlan_group *grp;
 
@@ -111,9 +111,9 @@ static struct vlan_group *vlan_group_alloc(int ifindex)
 	if (!grp)
 		return NULL;
 
-	grp->real_dev_ifindex = ifindex;
+	grp->real_dev = real_dev;
 	hlist_add_head_rcu(&grp->hlist,
-			   &vlan_group_hash[vlan_grp_hashfn(ifindex)]);
+			&vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]);
 	return grp;
 }
 
@@ -151,7 +151,7 @@ void unregister_vlan_dev(struct net_device *dev)
 
 	ASSERT_RTNL();
 
-	grp = __vlan_find_group(real_dev->ifindex);
+	grp = __vlan_find_group(real_dev);
 	BUG_ON(!grp);
 
 	vlan_proc_rem_dev(dev);
@@ -246,9 +246,9 @@ int register_vlan_dev(struct net_device *dev)
 	struct vlan_group *grp, *ngrp = NULL;
 	int err;
 
-	grp = __vlan_find_group(real_dev->ifindex);
+	grp = __vlan_find_group(real_dev);
 	if (!grp) {
-		ngrp = grp = vlan_group_alloc(real_dev->ifindex);
+		ngrp = grp = vlan_group_alloc(real_dev);
 		if (!grp)
 			return -ENOBUFS;
 	}
@@ -412,7 +412,7 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 		goto out;
 	}
 
-	grp = __vlan_find_group(dev->ifindex);
+	grp = __vlan_find_group(dev);
 	if (!grp)
 		goto out;