Commit 998b5d96 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'mpls-remove-rtnl-dependency' 

Kuniyuki Iwashima says:

====================
mpls: Remove RTNL dependency.

MPLS uses RTNL

  1) to guarantee the lifetime of struct mpls_nh.nh_dev
  2) to protect net->mpls.platform_label

, but neither actually requires RTNL.

If struct mpls_nh holds a refcnt for nh_dev, we do not need RTNL,
and it can be replaced with a dedicated mutex.

The series removes RTNL from net/mpls/.

Overview:

  Patch 1 is misc cleanup.

  Patch 2 - 9 are prep to drop RTNL for RTM_{NEW,DEL,GET}ROUTE
  handlers.

  Patch 10 & 11 converts mpls_dump_routes() and RTM_GETNETCONF to RCU.

  Patch 12 replaces RTNL with a new per-netns mutex.

  Patch 13 drops RTNL from RTM_{NEW,DEL,GET}ROUTE.
====================

Link: https://patch.msgid.link/20251029173344.2934622-1-kuniyu@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 209ff7af 7d99a7c6

include/net/addrconf.h

+5 −0
Original line number Diff line number Diff line
@@ -347,6 +347,11 @@ static inline struct inet6_dev *__in6_dev_get(const struct net_device *dev) 
	return rcu_dereference_rtnl(dev->ip6_ptr);

}



static inline struct inet6_dev *in6_dev_rcu(const struct net_device *dev)

{

	return rcu_dereference(dev->ip6_ptr);

}



static inline struct inet6_dev *__in6_dev_get_rtnl_net(const struct net_device *dev)

{

	return rtnl_net_dereference(dev_net(dev), dev->ip6_ptr);

include/net/netns/mpls.h

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ struct netns_mpls { 
	int default_ttl;

	size_t platform_labels;

	struct mpls_route __rcu * __rcu *platform_label;

	struct mutex platform_mutex;



	struct ctl_table_header *ctl;

};

net/mpls/af_mpls.c

+199 −122

File changed.

Preview size limit exceeded, changes collapsed.

net/mpls/internal.h

+16 −3
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ enum mpls_payload_type { 


struct mpls_nh { /* next hop label forwarding entry */

	struct net_device	*nh_dev;

	netdevice_tracker	nh_dev_tracker;



	/* nh_flags is accessed under RCU in the packet path; it is

	 * modified handling netdev events with rtnl lock held
@@ -184,9 +185,20 @@ static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr * 
	return result;

}



static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)

#define mpls_dereference(net, p)					\

	rcu_dereference_protected(					\

		(p),							\

		lockdep_is_held(&(net)->mpls.platform_mutex))



static inline struct mpls_dev *mpls_dev_rcu(const struct net_device *dev)

{

	return rcu_dereference(dev->mpls_ptr);

}



static inline struct mpls_dev *mpls_dev_get(const struct net *net,

					    const struct net_device *dev)

{

	return rcu_dereference_rtnl(dev->mpls_ptr);

	return mpls_dereference(net, dev->mpls_ptr);

}



int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
@@ -196,7 +208,8 @@ int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels, 
bool mpls_output_possible(const struct net_device *dev);

unsigned int mpls_dev_mtu(const struct net_device *dev);

bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);

void mpls_stats_inc_outucastpkts(struct net_device *dev,

void mpls_stats_inc_outucastpkts(struct net *net,

				 struct net_device *dev,

				 const struct sk_buff *skb);



#endif /* MPLS_INTERNAL_H */

net/mpls/mpls_iptunnel.c

+3 −3
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ static int mpls_xmit(struct sk_buff *skb) 


	/* Find the output device */

	out_dev = dst->dev;

	net = dev_net(out_dev);

	net = dev_net_rcu(out_dev);



	if (!mpls_output_possible(out_dev) ||

	    !dst->lwtstate || skb_warn_if_lro(skb))
@@ -128,7 +128,7 @@ static int mpls_xmit(struct sk_buff *skb) 
		bos = false;

	}



	mpls_stats_inc_outucastpkts(out_dev, skb);

	mpls_stats_inc_outucastpkts(net, out_dev, skb);



	if (rt) {

		if (rt->rt_gw_family == AF_INET6)
@@ -153,7 +153,7 @@ static int mpls_xmit(struct sk_buff *skb) 
	return LWTUNNEL_XMIT_DONE;



drop:

	out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;

	out_mdev = out_dev ? mpls_dev_rcu(out_dev) : NULL;

	if (out_mdev)

		MPLS_INC_STATS(out_mdev, tx_errors);

	kfree_skb(skb);