redonkable/remarkable-linux
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ip: Router Alert RCU conversion

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Straightforward conversion to RCU.

One rwlock becomes a spinlock, and is static.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-06-07 03:12:08 +00:00 committed by David S. Miller
parent 8b37ef0a1f
commit 66018506e1
3 changed files with 18 additions and 18 deletions
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2
include/net/ip.h
View file

@ -62,10 +62,10 @@ struct ip_ra_chain {
struct ip_ra_chain *next; struct ip_ra_chain *next;
struct sock *sk; struct sock *sk;
void (*destructor)(struct sock *); void (*destructor)(struct sock *);
struct rcu_head rcu;
}; };
extern struct ip_ra_chain *ip_ra_chain; extern struct ip_ra_chain *ip_ra_chain;
extern rwlock_t ip_ra_lock;
/* IP flags. */ /* IP flags. */
#define IP_CE 0x8000 /* Flag: "Congestion" */ #define IP_CE 0x8000 /* Flag: "Congestion" */

11
net/ipv4/ip_input.c
View file

@ -146,7 +146,7 @@
#include <linux/netlink.h> #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) 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 sock *last = NULL;
struct net_device *dev = skb->dev; struct net_device *dev = skb->dev;
read_lock(&ip_ra_lock); for (ra = rcu_dereference(ip_ra_chain); ra; ra = rcu_dereference(ra->next)) {
for (ra = ip_ra_chain; ra; ra = ra->next) {
struct sock *sk = ra->sk; struct sock *sk = ra->sk;
/* If socket is bound to an interface, only report /* 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) && sk->sk_bound_dev_if == dev->ifindex) &&
net_eq(sock_net(sk), dev_net(dev))) { net_eq(sock_net(sk), dev_net(dev))) {
if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
if (ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN)) { if (ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN))
read_unlock(&ip_ra_lock);
return 1; return 1;
} }
}
if (last) { if (last) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2) if (skb2)
@ -183,10 +180,8 @@ int ip_call_ra_chain(struct sk_buff *skb)
if (last) { if (last) {
raw_rcv(last, skb); raw_rcv(last, skb);
read_unlock(&ip_ra_lock);
return 1; return 1;
} }
read_unlock(&ip_ra_lock);
return 0; return 0;
} }

23
net/ipv4/ip_sockglue.c
View file

@ -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. sent to multicast group to reach destination designated router.
*/ */
struct ip_ra_chain *ip_ra_chain; 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, int ip_ra_control(struct sock *sk, unsigned char on,
void (*destructor)(struct sock *)) 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; 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) { for (rap = &ip_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {
if (ra->sk == sk) { if (ra->sk == sk) {
if (on) { if (on) {
write_unlock_bh(&ip_ra_lock); spin_unlock_bh(&ip_ra_lock);
kfree(new_ra); kfree(new_ra);
return -EADDRINUSE; return -EADDRINUSE;
} }
*rap = ra->next; rcu_assign_pointer(*rap, ra->next);
write_unlock_bh(&ip_ra_lock); spin_unlock_bh(&ip_ra_lock);
if (ra->destructor) if (ra->destructor)
ra->destructor(sk); ra->destructor(sk);
sock_put(sk); sock_put(sk);
kfree(ra); call_rcu(&ra->rcu, ip_ra_free_rcu);
return 0; return 0;
} }
} }
if (new_ra == NULL) { if (new_ra == NULL) {
write_unlock_bh(&ip_ra_lock); spin_unlock_bh(&ip_ra_lock);
return -ENOBUFS; return -ENOBUFS;
} }
new_ra->sk = sk; new_ra->sk = sk;
new_ra->destructor = destructor; new_ra->destructor = destructor;
new_ra->next = ra; new_ra->next = ra;
*rap = new_ra; rcu_assign_pointer(*rap, new_ra);
sock_hold(sk); sock_hold(sk);
write_unlock_bh(&ip_ra_lock); spin_unlock_bh(&ip_ra_lock);
return 0; return 0;
} }