vxlan: Use linked list to traverse FDB entries

In preparation for removing the fixed size hash table, convert FDB entry
traversal to use the newly added FDB linked list.

No functional changes intended.

Reviewed-by: Petr Machata <[email protected]>
Signed-off-by: Ido Schimmel <[email protected]>
Link: https://patch.msgid.link/[email protected]
Reviewed-by: Nikolay Aleksandrov <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

Author: idosch

drivers/net/vxlan/vxlan_core.c

@@ -517,24 +517,20 @@ int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
 	struct vxlan_dev *vxlan;
 	struct vxlan_rdst *rdst;
 	struct vxlan_fdb *f;
-	unsigned int h;
 	int rc = 0;
 
 	if (!netif_is_vxlan(dev))
 		return -EINVAL;
 	vxlan = netdev_priv(dev);
 
 	spin_lock_bh(&vxlan->hash_lock);
-	for (h = 0; h < FDB_HASH_SIZE; ++h) {
-		hlist_for_each_entry(f, &vxlan->fdb_head[h], hlist) {
-			if (f->vni == vni) {
-				list_for_each_entry(rdst, &f->remotes, list) {
-					rc = vxlan_fdb_notify_one(nb, vxlan,
-								  f, rdst,
-								  extack);
-					if (rc)
-						goto unlock;
-				}
+	hlist_for_each_entry(f, &vxlan->fdb_list, fdb_node) {
+		if (f->vni == vni) {
+			list_for_each_entry(rdst, &f->remotes, list) {
+				rc = vxlan_fdb_notify_one(nb, vxlan, f, rdst,
+							  extack);
+				if (rc)
+					goto unlock;
 			}
 		}
 	}
@@ -552,18 +548,17 @@ void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni)
 	struct vxlan_dev *vxlan;
 	struct vxlan_rdst *rdst;
 	struct vxlan_fdb *f;
-	unsigned int h;
 
 	if (!netif_is_vxlan(dev))
 		return;
 	vxlan = netdev_priv(dev);
 
 	spin_lock_bh(&vxlan->hash_lock);
-	for (h = 0; h < FDB_HASH_SIZE; ++h) {
-		hlist_for_each_entry(f, &vxlan->fdb_head[h], hlist)
-			if (f->vni == vni)
-				list_for_each_entry(rdst, &f->remotes, list)
-					rdst->offloaded = false;
+	hlist_for_each_entry(f, &vxlan->fdb_list, fdb_node) {
+		if (f->vni == vni) {
+			list_for_each_entry(rdst, &f->remotes, list)
+				rdst->offloaded = false;
+		}
 	}
 	spin_unlock_bh(&vxlan->hash_lock);
 
@@ -1351,52 +1346,46 @@ static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
 {
 	struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	unsigned int h;
+	struct vxlan_fdb *f;
 	int err = 0;
 
-	for (h = 0; h < FDB_HASH_SIZE; ++h) {
-		struct vxlan_fdb *f;
-
-		rcu_read_lock();
-		hlist_for_each_entry_rcu(f, &vxlan->fdb_head[h], hlist) {
-			struct vxlan_rdst *rd;
-
-			if (rcu_access_pointer(f->nh)) {
-				if (*idx < ctx->fdb_idx)
-					goto skip_nh;
-				err = vxlan_fdb_info(skb, vxlan, f,
-						     NETLINK_CB(cb->skb).portid,
-						     cb->nlh->nlmsg_seq,
-						     RTM_NEWNEIGH,
-						     NLM_F_MULTI, NULL);
-				if (err < 0) {
-					rcu_read_unlock();
-					goto out;
-				}
-skip_nh:
-				*idx += 1;
-				continue;
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(f, &vxlan->fdb_list, fdb_node) {
+		struct vxlan_rdst *rd;
+
+		if (rcu_access_pointer(f->nh)) {
+			if (*idx < ctx->fdb_idx)
+				goto skip_nh;
+			err = vxlan_fdb_info(skb, vxlan, f,
+					     NETLINK_CB(cb->skb).portid,
+					     cb->nlh->nlmsg_seq,
+					     RTM_NEWNEIGH, NLM_F_MULTI, NULL);
+			if (err < 0) {
+				rcu_read_unlock();
+				goto out;
 			}
+skip_nh:
+			*idx += 1;
+			continue;
+		}
 
-			list_for_each_entry_rcu(rd, &f->remotes, list) {
-				if (*idx < ctx->fdb_idx)
-					goto skip;
-
-				err = vxlan_fdb_info(skb, vxlan, f,
-						     NETLINK_CB(cb->skb).portid,
-						     cb->nlh->nlmsg_seq,
-						     RTM_NEWNEIGH,
-						     NLM_F_MULTI, rd);
-				if (err < 0) {
-					rcu_read_unlock();
-					goto out;
-				}
-skip:
-				*idx += 1;
+		list_for_each_entry_rcu(rd, &f->remotes, list) {
+			if (*idx < ctx->fdb_idx)
+				goto skip;
+
+			err = vxlan_fdb_info(skb, vxlan, f,
+					     NETLINK_CB(cb->skb).portid,
+					     cb->nlh->nlmsg_seq,
+					     RTM_NEWNEIGH, NLM_F_MULTI, rd);
+			if (err < 0) {
+				rcu_read_unlock();
+				goto out;
 			}
+skip:
+			*idx += 1;
 		}
-		rcu_read_unlock();
 	}
+	rcu_read_unlock();
 out:
 	return err;
 }
@@ -2830,35 +2819,30 @@ static void vxlan_cleanup(struct timer_list *t)
 {
 	struct vxlan_dev *vxlan = from_timer(vxlan, t, age_timer);
 	unsigned long next_timer = jiffies + FDB_AGE_INTERVAL;
-	unsigned int h;
+	struct hlist_node *n;
+	struct vxlan_fdb *f;
 
 	if (!netif_running(vxlan->dev))
 		return;
 
 	spin_lock(&vxlan->hash_lock);
-	for (h = 0; h < FDB_HASH_SIZE; ++h) {
-		struct hlist_node *p, *n;
-
-		hlist_for_each_safe(p, n, &vxlan->fdb_head[h]) {
-			struct vxlan_fdb *f
-				= container_of(p, struct vxlan_fdb, hlist);
-			unsigned long timeout;
+	hlist_for_each_entry_safe(f, n, &vxlan->fdb_list, fdb_node) {
+		unsigned long timeout;
 
-			if (f->state & (NUD_PERMANENT | NUD_NOARP))
-				continue;
+		if (f->state & (NUD_PERMANENT | NUD_NOARP))
+			continue;
 
-			if (f->flags & NTF_EXT_LEARNED)
-				continue;
+		if (f->flags & NTF_EXT_LEARNED)
+			continue;
 
-			timeout = READ_ONCE(f->updated) + vxlan->cfg.age_interval * HZ;
-			if (time_before_eq(timeout, jiffies)) {
-				netdev_dbg(vxlan->dev,
-					   "garbage collect %pM\n",
-					   f->eth_addr);
-				f->state = NUD_STALE;
-				vxlan_fdb_destroy(vxlan, f, true, true);
-			} else if (time_before(timeout, next_timer))
-				next_timer = timeout;
+		timeout = READ_ONCE(f->updated) + vxlan->cfg.age_interval * HZ;
+		if (time_before_eq(timeout, jiffies)) {
+			netdev_dbg(vxlan->dev, "garbage collect %pM\n",
+				   f->eth_addr);
+			f->state = NUD_STALE;
+			vxlan_fdb_destroy(vxlan, f, true, true);
+		} else if (time_before(timeout, next_timer)) {
+			next_timer = timeout;
 		}
 	}
 	spin_unlock(&vxlan->hash_lock);
@@ -3050,31 +3034,25 @@ static void vxlan_flush(struct vxlan_dev *vxlan,
 			const struct vxlan_fdb_flush_desc *desc)
 {
 	bool match_remotes = vxlan_fdb_flush_should_match_remotes(desc);
-	unsigned int h;
+	struct hlist_node *n;
+	struct vxlan_fdb *f;
 
 	spin_lock_bh(&vxlan->hash_lock);
-	for (h = 0; h < FDB_HASH_SIZE; ++h) {
-		struct hlist_node *p, *n;
-
-		hlist_for_each_safe(p, n, &vxlan->fdb_head[h]) {
-			struct vxlan_fdb *f
-				= container_of(p, struct vxlan_fdb, hlist);
-
-			if (!vxlan_fdb_flush_matches(f, vxlan, desc))
-				continue;
-
-			if (match_remotes) {
-				bool destroy_fdb = false;
+	hlist_for_each_entry_safe(f, n, &vxlan->fdb_list, fdb_node) {
+		if (!vxlan_fdb_flush_matches(f, vxlan, desc))
+			continue;
 
-				vxlan_fdb_flush_match_remotes(f, vxlan, desc,
-							      &destroy_fdb);
+		if (match_remotes) {
+			bool destroy_fdb = false;
 
-				if (!destroy_fdb)
-					continue;
-			}
+			vxlan_fdb_flush_match_remotes(f, vxlan, desc,
+						      &destroy_fdb);
 
-			vxlan_fdb_destroy(vxlan, f, true, true);
+			if (!destroy_fdb)
+				continue;
 		}
+
+		vxlan_fdb_destroy(vxlan, f, true, true);
 	}
 	spin_unlock_bh(&vxlan->hash_lock);
 }
@@ -4860,7 +4838,7 @@ static void vxlan_fdb_nh_flush(struct nexthop *nh)
 		vxlan = rcu_dereference(fdb->vdev);
 		WARN_ON(!vxlan);
 		spin_lock_bh(&vxlan->hash_lock);
-		if (!hlist_unhashed(&fdb->hlist))
+		if (!hlist_unhashed(&fdb->fdb_node))
 			vxlan_fdb_destroy(vxlan, fdb, false, false);
 		spin_unlock_bh(&vxlan->hash_lock);
 	}