From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yan Zheng Subject: [PATCH]IPv6: Acquire addrconf_hash_lock for reading instead of writing in addrconf_verify(...) Date: Thu, 17 Nov 2005 10:14:11 +0800 Message-ID: <437BE773.6010007@21cn.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, yoshfuji@linux-ipv6.org Return-path: To: netdev@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi. 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 ============================================================ --- a/net/ipv6/addrconf.c 2005-11-17 09:27:54.000000000 +0800 +++ b/net/ipv6/addrconf.c 2005-11-17 09:25:42.000000000 +0800 @@ -2627,7 +2627,7 @@ static void addrconf_verify(unsigned lon 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 @@ restart: 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 @@ restart: 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 @@ restart: 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 @@ restart: 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;