Commit 66018506 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ip: Router Alert RCU conversion 



Straightforward conversion to RCU.

One rwlock becomes a spinlock, and is static.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8b37ef0a

include/net/ip.h

+1 −1
Original line number Diff line number Diff line
@@ -62,10 +62,10 @@ struct ip_ra_chain { 
	struct ip_ra_chain	*next;

	struct sock		*sk;

	void			(*destructor)(struct sock *);

	struct rcu_head		rcu;

};



extern struct ip_ra_chain *ip_ra_chain;

extern rwlock_t ip_ra_lock;



/* IP flags. */

#define IP_CE		0x8000		/* Flag: "Congestion"		*/

net/ipv4/ip_input.c

+3 −8
Original line number Diff line number Diff line
@@ -146,7 +146,7 @@ 
#include <linux/netlink.h>



/*

 *	Process Router Attention IP option

 *	Process Router Attention IP option (RFC 2113)

 */

int ip_call_ra_chain(struct sk_buff *skb)

{
@@ -155,8 +155,7 @@ int ip_call_ra_chain(struct sk_buff *skb) 
	struct sock *last = NULL;

	struct net_device *dev = skb->dev;



	read_lock(&ip_ra_lock);

	for (ra = ip_ra_chain; ra; ra = ra->next) {

	for (ra = rcu_dereference(ip_ra_chain); ra; ra = rcu_dereference(ra->next)) {

		struct sock *sk = ra->sk;



		/* If socket is bound to an interface, only report
@@ -167,11 +166,9 @@ int ip_call_ra_chain(struct sk_buff *skb) 
		     sk->sk_bound_dev_if == dev->ifindex) &&

		    net_eq(sock_net(sk), dev_net(dev))) {

			if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {

				if (ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN)) {

					read_unlock(&ip_ra_lock);

				if (ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN))

					return 1;

			}

			}

			if (last) {

				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);

				if (skb2)
@@ -183,10 +180,8 @@ int ip_call_ra_chain(struct sk_buff *skb) 


	if (last) {

		raw_rcv(last, skb);

		read_unlock(&ip_ra_lock);

		return 1;

	}

	read_unlock(&ip_ra_lock);

	return 0;

}

net/ipv4/ip_sockglue.c

+14 −9
Original line number Diff line number Diff line
@@ -239,7 +239,12 @@ int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc) 
   sent to multicast group to reach destination designated router.

 */

struct ip_ra_chain *ip_ra_chain;

DEFINE_RWLOCK(ip_ra_lock);

static DEFINE_SPINLOCK(ip_ra_lock);



static void ip_ra_free_rcu(struct rcu_head *head)

{

	kfree(container_of(head, struct ip_ra_chain, rcu));

}



int ip_ra_control(struct sock *sk, unsigned char on,

		  void (*destructor)(struct sock *))
@@ -251,35 +256,35 @@ int ip_ra_control(struct sock *sk, unsigned char on, 


	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;



	write_lock_bh(&ip_ra_lock);

	spin_lock_bh(&ip_ra_lock);

	for (rap = &ip_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {

		if (ra->sk == sk) {

			if (on) {

				write_unlock_bh(&ip_ra_lock);

				spin_unlock_bh(&ip_ra_lock);

				kfree(new_ra);

				return -EADDRINUSE;

			}

			*rap = ra->next;

			write_unlock_bh(&ip_ra_lock);

			rcu_assign_pointer(*rap, ra->next);

			spin_unlock_bh(&ip_ra_lock);



			if (ra->destructor)

				ra->destructor(sk);

			sock_put(sk);

			kfree(ra);

			call_rcu(&ra->rcu, ip_ra_free_rcu);

			return 0;

		}

	}

	if (new_ra == NULL) {

		write_unlock_bh(&ip_ra_lock);

		spin_unlock_bh(&ip_ra_lock);

		return -ENOBUFS;

	}

	new_ra->sk = sk;

	new_ra->destructor = destructor;



	new_ra->next = ra;

	*rap = new_ra;

	rcu_assign_pointer(*rap, new_ra);

	sock_hold(sk);

	write_unlock_bh(&ip_ra_lock);

	spin_unlock_bh(&ip_ra_lock);



	return 0;

}