[IPV6]: Acquire addrconf_hash_lock for read in addrconf_verify(...)
addrconf_verify(...) only traverse address hash table when
addrconf_hash_lock is held for writing, and it may hold
addrconf_hash_lock for a long time. So I think it's better to acquire
addrconf_hash_lock for reading instead of writing
Signed-off-by: Yan Zheng <yanzheng@21cn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 56a09a4..a16064b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2627,7 +2627,7 @@
for (i=0; i < IN6_ADDR_HSIZE; i++) {
restart:
- write_lock(&addrconf_hash_lock);
+ read_lock(&addrconf_hash_lock);
for (ifp=inet6_addr_lst[i]; ifp; ifp=ifp->lst_next) {
unsigned long age;
#ifdef CONFIG_IPV6_PRIVACY
@@ -2649,7 +2649,7 @@
if (age >= ifp->valid_lft) {
spin_unlock(&ifp->lock);
in6_ifa_hold(ifp);
- write_unlock(&addrconf_hash_lock);
+ read_unlock(&addrconf_hash_lock);
ipv6_del_addr(ifp);
goto restart;
} else if (age >= ifp->prefered_lft) {
@@ -2668,7 +2668,7 @@
if (deprecate) {
in6_ifa_hold(ifp);
- write_unlock(&addrconf_hash_lock);
+ read_unlock(&addrconf_hash_lock);
ipv6_ifa_notify(0, ifp);
in6_ifa_put(ifp);
@@ -2686,7 +2686,7 @@
in6_ifa_hold(ifp);
in6_ifa_hold(ifpub);
spin_unlock(&ifp->lock);
- write_unlock(&addrconf_hash_lock);
+ read_unlock(&addrconf_hash_lock);
ipv6_create_tempaddr(ifpub, ifp);
in6_ifa_put(ifpub);
in6_ifa_put(ifp);
@@ -2703,7 +2703,7 @@
spin_unlock(&ifp->lock);
}
}
- write_unlock(&addrconf_hash_lock);
+ read_unlock(&addrconf_hash_lock);
}
addr_chk_timer.expires = time_before(next, jiffies + HZ) ? jiffies + HZ : next;