From 3ee943728fff536edaf8f59faa58aaa1aa7366e3 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Sat, 8 May 2010 01:57:52 -0700 Subject: [PATCH] ipv4: remove ip_rt_secret timer (v4) A while back there was a discussion regarding the rt_secret_interval timer. Given that we've had the ability to do emergency route cache rebuilds for awhile now, based on a statistical analysis of the various hash chain lengths in the cache, the use of the flush timer is somewhat redundant. This patch removes the rt_secret_interval sysctl, allowing us to rely solely on the statistical analysis mechanism to determine the need for route cache flushes. Signed-off-by: Neil Horman Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/netns/ipv4.h | 1 - kernel/sysctl_binary.c | 1 - net/ipv4/route.c | 108 +++------------------------------------ 3 files changed, 8 insertions(+), 102 deletions(-) diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index ae07feec644..d68c3f12177 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -55,7 +55,6 @@ struct netns_ipv4 { int sysctl_rt_cache_rebuild_count; int current_rt_cache_rebuild_count; - struct timer_list rt_secret_timer; atomic_t rt_genid; #ifdef CONFIG_IP_MROUTE diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c index 59030570f5c..937d31dc856 100644 --- a/kernel/sysctl_binary.c +++ b/kernel/sysctl_binary.c @@ -224,7 +224,6 @@ static const struct bin_table bin_net_ipv4_route_table[] = { { CTL_INT, NET_IPV4_ROUTE_MTU_EXPIRES, "mtu_expires" }, { CTL_INT, NET_IPV4_ROUTE_MIN_PMTU, "min_pmtu" }, { CTL_INT, NET_IPV4_ROUTE_MIN_ADVMSS, "min_adv_mss" }, - { CTL_INT, NET_IPV4_ROUTE_SECRET_INTERVAL, "secret_interval" }, {} }; diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a947428ef0a..dea3f926425 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -129,7 +129,6 @@ static int ip_rt_gc_elasticity __read_mostly = 8; static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; static int ip_rt_min_advmss __read_mostly = 256; -static int ip_rt_secret_interval __read_mostly = 10 * 60 * HZ; static int rt_chain_length_max __read_mostly = 20; static struct delayed_work expires_work; @@ -918,32 +917,11 @@ void rt_cache_flush_batch(void) rt_do_flush(!in_softirq()); } -/* - * We change rt_genid and let gc do the cleanup - */ -static void rt_secret_rebuild(unsigned long __net) -{ - struct net *net = (struct net *)__net; - rt_cache_invalidate(net); - mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval); -} - -static void rt_secret_rebuild_oneshot(struct net *net) -{ - del_timer_sync(&net->ipv4.rt_secret_timer); - rt_cache_invalidate(net); - if (ip_rt_secret_interval) - mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval); -} - static void rt_emergency_hash_rebuild(struct net *net) { - if (net_ratelimit()) { + if (net_ratelimit()) printk(KERN_WARNING "Route hash chain too long!\n"); - printk(KERN_WARNING "Adjust your secret_interval!\n"); - } - - rt_secret_rebuild_oneshot(net); + rt_cache_invalidate(net); } /* @@ -3101,48 +3079,6 @@ static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, return -EINVAL; } -static void rt_secret_reschedule(int old) -{ - struct net *net; - int new = ip_rt_secret_interval; - int diff = new - old; - - if (!diff) - return; - - rtnl_lock(); - for_each_net(net) { - int deleted = del_timer_sync(&net->ipv4.rt_secret_timer); - long time; - - if (!new) - continue; - - if (deleted) { - time = net->ipv4.rt_secret_timer.expires - jiffies; - - if (time <= 0 || (time += diff) <= 0) - time = 0; - } else - time = new; - - mod_timer(&net->ipv4.rt_secret_timer, jiffies + time); - } - rtnl_unlock(); -} - -static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos) -{ - int old = ip_rt_secret_interval; - int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos); - - rt_secret_reschedule(old); - - return ret; -} - static ctl_table ipv4_route_table[] = { { .procname = "gc_thresh", @@ -3251,13 +3187,6 @@ static ctl_table ipv4_route_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, - { - .procname = "secret_interval", - .data = &ip_rt_secret_interval, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = ipv4_sysctl_rt_secret_interval, - }, { } }; @@ -3336,34 +3265,15 @@ static __net_initdata struct pernet_operations sysctl_route_ops = { }; #endif - -static __net_init int rt_secret_timer_init(struct net *net) +static __net_init int rt_genid_init(struct net *net) { - atomic_set(&net->ipv4.rt_genid, - (int) ((num_physpages ^ (num_physpages>>8)) ^ - (jiffies ^ (jiffies >> 7)))); - - net->ipv4.rt_secret_timer.function = rt_secret_rebuild; - net->ipv4.rt_secret_timer.data = (unsigned long)net; - init_timer_deferrable(&net->ipv4.rt_secret_timer); - - if (ip_rt_secret_interval) { - net->ipv4.rt_secret_timer.expires = - jiffies + net_random() % ip_rt_secret_interval + - ip_rt_secret_interval; - add_timer(&net->ipv4.rt_secret_timer); - } + get_random_bytes(&net->ipv4.rt_genid, + sizeof(net->ipv4.rt_genid)); return 0; } -static __net_exit void rt_secret_timer_exit(struct net *net) -{ - del_timer_sync(&net->ipv4.rt_secret_timer); -} - -static __net_initdata struct pernet_operations rt_secret_timer_ops = { - .init = rt_secret_timer_init, - .exit = rt_secret_timer_exit, +static __net_initdata struct pernet_operations rt_genid_ops = { + .init = rt_genid_init, }; @@ -3424,9 +3334,6 @@ int __init ip_rt_init(void) schedule_delayed_work(&expires_work, net_random() % ip_rt_gc_interval + ip_rt_gc_interval); - if (register_pernet_subsys(&rt_secret_timer_ops)) - printk(KERN_ERR "Unable to setup rt_secret_timer\n"); - if (ip_rt_proc_init()) printk(KERN_ERR "Unable to create route proc files\n"); #ifdef CONFIG_XFRM @@ -3438,6 +3345,7 @@ int __init ip_rt_init(void) #ifdef CONFIG_SYSCTL register_pernet_subsys(&sysctl_route_ops); #endif + register_pernet_subsys(&rt_genid_ops); return rc; } -- 2.39.3