diff options
| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-04-28 20:04:29 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-01 05:44:04 +0300 |
| commit | ba3f571d5dde27fc4ae83aabe2c06ff08087af49 (patch) | |
| tree | 27f69a0cce85e6e464684e0660809cf7fc4964be /net/ipv4 | |
| parent | 5010e948420ea1cff85f6c2f64ec7a011aea3d07 (diff) | |
| download | linux-ba3f571d5dde27fc4ae83aabe2c06ff08087af49.tar.xz | |
ipv4: get rid of ip_ra_lock
After commit 1215e51edad1 ("ipv4: fix a deadlock in ip_ra_control")
we always take RTNL lock for ip_ra_control() which is the only place
we update the list ip_ra_chain, so the ip_ra_lock is no longer needed.
As Eric points out, BH does not need to disable either, RCU readers
don't care.
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_sockglue.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 1d46d05efb0f..ec4fe3d4b5c9 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -330,7 +330,6 @@ int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc, sent to multicast group to reach destination designated router. */ struct ip_ra_chain __rcu *ip_ra_chain; -static DEFINE_SPINLOCK(ip_ra_lock); static void ip_ra_destroy_rcu(struct rcu_head *head) @@ -352,21 +351,17 @@ int ip_ra_control(struct sock *sk, unsigned char on, new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL; - spin_lock_bh(&ip_ra_lock); for (rap = &ip_ra_chain; - (ra = rcu_dereference_protected(*rap, - lockdep_is_held(&ip_ra_lock))) != NULL; + (ra = rtnl_dereference(*rap)) != NULL; rap = &ra->next) { if (ra->sk == sk) { if (on) { - spin_unlock_bh(&ip_ra_lock); kfree(new_ra); return -EADDRINUSE; } /* dont let ip_call_ra_chain() use sk again */ ra->sk = NULL; RCU_INIT_POINTER(*rap, ra->next); - spin_unlock_bh(&ip_ra_lock); if (ra->destructor) ra->destructor(sk); @@ -380,17 +375,14 @@ int ip_ra_control(struct sock *sk, unsigned char on, return 0; } } - if (!new_ra) { - spin_unlock_bh(&ip_ra_lock); + if (!new_ra) return -ENOBUFS; - } new_ra->sk = sk; new_ra->destructor = destructor; RCU_INIT_POINTER(new_ra->next, ra); rcu_assign_pointer(*rap, new_ra); sock_hold(sk); - spin_unlock_bh(&ip_ra_lock); return 0; } |