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authorKirill Tkhai <ktkhai@virtuozzo.com>2018-03-22 12:45:02 +0300
committerDavid S. Miller <davem@davemloft.net>2018-03-22 15:12:55 -0400
commit76d3e153d0d16032ab68e3b698c4df05acef48c5 (patch)
tree99dc22608c62b6beb7e22913c1aabe0b6f615d24 /net/ipv4/ip_sockglue.c
parentliquidio: Added support for trusted VF (diff)
downloadlinux-dev-76d3e153d0d16032ab68e3b698c4df05acef48c5.tar.xz
linux-dev-76d3e153d0d16032ab68e3b698c4df05acef48c5.zip
net: Revert "ipv4: get rid of ip_ra_lock"
This reverts commit ba3f571d5dde. The commit was made after 1215e51edad1 "ipv4: fix a deadlock in ip_ra_control", and killed ip_ra_lock, which became useless after rtnl_lock() made used to destroy every raw ipv4 socket. This scales very bad, and next patch in series reverts 1215e51edad1. ip_ra_lock will be used again. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_sockglue.c')
-rw-r--r--net/ipv4/ip_sockglue.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 74c962b9b09c..be7c3b71914d 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -334,6 +334,7 @@ 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)
@@ -355,17 +356,21 @@ 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 = rtnl_dereference(*rap)) != NULL;
+ (ra = rcu_dereference_protected(*rap,
+ lockdep_is_held(&ip_ra_lock))) != 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);
@@ -379,14 +384,17 @@ int ip_ra_control(struct sock *sk, unsigned char on,
return 0;
}
}
- if (!new_ra)
+ if (!new_ra) {
+ spin_unlock_bh(&ip_ra_lock);
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;
}