提交 66018506 编写于 作者: E Eric Dumazet 提交者: David S. Miller

ip: Router Alert RCU conversion

Straightforward conversion to RCU.

One rwlock becomes a spinlock, and is static.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
上级 8b37ef0a
......@@ -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" */
......
......@@ -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;
}
......
......@@ -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;
}
......
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