ipmr: Refactor mr_rtm_dumproute

Move per-table loops from mr_rtm_dumproute to mr_table_dump and export
mr_table_dump for dumps by specific table id.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/mroute_base.h

@@ -283,6 +283,12 @@ void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg);
 
 int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 		   struct mr_mfc *c, struct rtmsg *rtm);
+int mr_table_dump(struct mr_table *mrt, struct sk_buff *skb,
+		  struct netlink_callback *cb,
+		  int (*fill)(struct mr_table *mrt, struct sk_buff *skb,
+			      u32 portid, u32 seq, struct mr_mfc *c,
+			      int cmd, int flags),
+		  spinlock_t *lock);
 int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 		     struct mr_table *(*iter)(struct net *net,
 					      struct mr_table *mrt),

net/ipv4/ipmr_base.c

@@ -268,31 +268,26 @@ int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 }
 EXPORT_SYMBOL(mr_fill_mroute);
 
-int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
-		     struct mr_table *(*iter)(struct net *net,
-					      struct mr_table *mrt),
-		     int (*fill)(struct mr_table *mrt,
-				 struct sk_buff *skb,
+int mr_table_dump(struct mr_table *mrt, struct sk_buff *skb,
+		  struct netlink_callback *cb,
+		  int (*fill)(struct mr_table *mrt, struct sk_buff *skb,
 			      u32 portid, u32 seq, struct mr_mfc *c,
 			      int cmd, int flags),
 		  spinlock_t *lock)
 {
-	unsigned int t = 0, e = 0, s_t = cb->args[0], s_e = cb->args[1];
-	struct net *net = sock_net(skb->sk);
-	struct mr_table *mrt;
+	unsigned int e = 0, s_e = cb->args[1];
+	unsigned int flags = NLM_F_MULTI;
 	struct mr_mfc *mfc;
+	int err;
 
-	rcu_read_lock();
-	for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
-		if (t < s_t)
-			goto next_table;
 	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
 		if (e < s_e)
 			goto next_entry;
-			if (fill(mrt, skb, NETLINK_CB(cb->skb).portid,
-				 cb->nlh->nlmsg_seq, mfc,
-				 RTM_NEWROUTE, NLM_F_MULTI) < 0)
-				goto done;
+
+		err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
+			   cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
+		if (err < 0)
+			goto out;
 next_entry:
 		e++;
 	}
@@ -303,25 +298,52 @@ int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 	list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
 		if (e < s_e)
 			goto next_entry2;
-			if (fill(mrt, skb, NETLINK_CB(cb->skb).portid,
-				 cb->nlh->nlmsg_seq, mfc,
-				 RTM_NEWROUTE, NLM_F_MULTI) < 0) {
+
+		err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
+			   cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
+		if (err < 0) {
 			spin_unlock_bh(lock);
-				goto done;
+			goto out;
 		}
 next_entry2:
 		e++;
 	}
 	spin_unlock_bh(lock);
+	err = 0;
 	e = 0;
-		s_e = 0;
+
+out:
+	cb->args[1] = e;
+	return err;
+}
+
+int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
+		     struct mr_table *(*iter)(struct net *net,
+					      struct mr_table *mrt),
+		     int (*fill)(struct mr_table *mrt,
+				 struct sk_buff *skb,
+				 u32 portid, u32 seq, struct mr_mfc *c,
+				 int cmd, int flags),
+		     spinlock_t *lock)
+{
+	unsigned int t = 0, s_t = cb->args[0];
+	struct net *net = sock_net(skb->sk);
+	struct mr_table *mrt;
+	int err;
+
+	rcu_read_lock();
+	for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
+		if (t < s_t)
+			goto next_table;
+
+		err = mr_table_dump(mrt, skb, cb, fill, lock);
+		if (err < 0)
+			break;
 next_table:
 		t++;
 	}
-done:
 	rcu_read_unlock();
 
-	cb->args[1] = e;
 	cb->args[0] = t;
 
 	return skb->len;