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Message-Id: <20230517042757.161832-2-kuifeng@meta.com>
Date: Tue, 16 May 2023 21:27:56 -0700
From: Kui-Feng Lee <thinker.li@...il.com>
To: netdev@...r.kernel.org,
ast@...nel.org,
martin.lau@...ux.dev,
kernel-team@...a.com
Cc: Kui-Feng Lee <kuifeng@...a.com>
Subject: [RFC PATCH net-next 1/2] net: Remove expired routes with separated timers.
FIB6 GC walks tries of fib6_tables to remove expired routes. Walking a
tree can be expensive if the number of routes in a table is big.
Creating a separated timer for each route that can expire will avoid
this potential issue.
Signed-off-by: Kui-Feng Lee <kuifeng@...a.com>
---
include/net/ip6_fib.h | 19 ++++------
net/ipv6/addrconf.c | 8 ++--
net/ipv6/ip6_fib.c | 88 ++++++++++++++++++++++++++++++++++++-------
net/ipv6/ndisc.c | 2 +-
net/ipv6/route.c | 6 +--
5 files changed, 91 insertions(+), 32 deletions(-)
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 05e6f756feaf..850995306718 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -161,6 +161,8 @@ struct fib6_nh {
struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
};
+struct fib6_info_timer;
+
struct fib6_info {
struct fib6_table *fib6_table;
struct fib6_info __rcu *fib6_next;
@@ -179,6 +181,7 @@ struct fib6_info {
refcount_t fib6_ref;
unsigned long expires;
+ struct fib6_info_timer *timer;
struct dst_metrics *fib6_metrics;
#define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
@@ -247,18 +250,11 @@ static inline bool fib6_requires_src(const struct fib6_info *rt)
return rt->fib6_src.plen > 0;
}
-static inline void fib6_clean_expires(struct fib6_info *f6i)
-{
- f6i->fib6_flags &= ~RTF_EXPIRES;
- f6i->expires = 0;
-}
+void fib6_clean_expires(struct fib6_info *f6i);
-static inline void fib6_set_expires(struct fib6_info *f6i,
- unsigned long expires)
-{
- f6i->expires = expires;
- f6i->fib6_flags |= RTF_EXPIRES;
-}
+void fib6_set_expires(struct net *net,
+ struct fib6_info *f6i,
+ unsigned long expires);
static inline bool fib6_check_expired(const struct fib6_info *f6i)
{
@@ -388,6 +384,7 @@ struct fib6_table {
struct inet_peer_base tb6_peers;
unsigned int flags;
unsigned int fib_seq;
+ struct hlist_head tb6_timer_hlist;
#define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3797917237d0..13e2366613c4 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1254,7 +1254,8 @@ cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long expires,
ip6_del_rt(dev_net(ifp->idev->dev), f6i, false);
else {
if (!(f6i->fib6_flags & RTF_EXPIRES))
- fib6_set_expires(f6i, expires);
+ fib6_set_expires(dev_net(ifp->idev->dev),
+ f6i, expires);
fib6_info_release(f6i);
}
}
@@ -2762,7 +2763,8 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
rt = NULL;
} else if (addrconf_finite_timeout(rt_expires)) {
/* not infinity */
- fib6_set_expires(rt, jiffies + rt_expires);
+ fib6_set_expires(net, rt,
+ jiffies + rt_expires);
} else {
fib6_clean_expires(rt);
}
@@ -4723,7 +4725,7 @@ static int modify_prefix_route(struct inet6_ifaddr *ifp,
if (!expires)
fib6_clean_expires(f6i);
else
- fib6_set_expires(f6i, expires);
+ fib6_set_expires(dev_net(ifp->idev->dev), f6i, expires);
fib6_info_release(f6i);
}
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 2438da5ff6da..8a10a0355816 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -25,6 +25,7 @@
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
+#include <linux/timer.h>
#include <net/ip.h>
#include <net/ipv6.h>
@@ -54,6 +55,12 @@ struct fib6_cleaner {
#define FWS_INIT FWS_L
#endif
+struct fib6_info_timer {
+ struct timer_list timer;
+ struct fib6_info *f6i;
+ struct net *net;
+};
+
static struct fib6_info *fib6_find_prefix(struct net *net,
struct fib6_table *table,
struct fib6_node *fn);
@@ -144,6 +151,66 @@ static __be32 addr_bit_set(const void *token, int fn_bit)
addr[fn_bit >> 5];
}
+static void f6i_gc_timer_cb(struct timer_list *t)
+{
+ struct fib6_info_timer *timer;
+ struct nl_info info = {
+ .nlh = NULL,
+ };
+ struct fib6_info *f6i;
+ int res;
+
+ timer = from_timer(timer, t, timer);
+ info.nl_net = timer->net;
+ f6i = timer->f6i;
+ spin_lock(&f6i->fib6_table->tb6_lock);
+
+ res = fib6_del(f6i, &info);
+ if (res != 0) {
+#if RT6_DEBUG >= 2
+ pr_debug("%s: del failed: rt=%p@%p err=%d\n",
+ __func__, f6i,
+ rcu_access_pointer(f6i->fib6_node),
+ res);
+#endif
+ }
+
+ spin_unlock(&f6i->fib6_table->tb6_lock);
+
+ fib6_info_release(f6i);
+}
+
+void fib6_clean_expires(struct fib6_info *f6i)
+{
+ f6i->fib6_flags &= ~RTF_EXPIRES;
+ f6i->expires = 0;
+ if (!f6i->timer)
+ return;
+ if (try_to_del_timer_sync(&f6i->timer->timer) == 1)
+ fib6_info_release(f6i);
+}
+
+void fib6_set_expires(struct net *net,struct fib6_info *f6i,
+ unsigned long expires)
+{
+ f6i->expires = expires;
+ f6i->fib6_flags |= RTF_EXPIRES;
+ if (!f6i->timer) {
+ f6i->timer = kzalloc(sizeof(*f6i->timer), GFP_ATOMIC);
+ if (!f6i->timer) {
+ /* XXX: error handling */
+ panic("fib6_set_expires: kzalloc failed");
+ return;
+ }
+ f6i->timer->f6i = f6i;
+ f6i->timer->net = net;
+ timer_setup(&f6i->timer->timer, f6i_gc_timer_cb, 0);
+ }
+ fib6_info_hold(f6i);
+ if (mod_timer(&f6i->timer->timer, expires) == 1)
+ fib6_info_release(f6i);
+}
+
struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh)
{
struct fib6_info *f6i;
@@ -175,6 +242,7 @@ void fib6_info_destroy_rcu(struct rcu_head *head)
fib6_nh_release(f6i->fib6_nh);
ip_fib_metrics_put(f6i->fib6_metrics);
+ kfree(f6i->timer);
kfree(f6i);
}
EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu);
@@ -246,6 +314,7 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
net->ipv6.fib6_null_entry);
table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
inet_peer_base_init(&table->tb6_peers);
+ INIT_HLIST_HEAD(&table->tb6_timer_hlist);
}
return table;
@@ -1120,7 +1189,8 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
if (!(rt->fib6_flags & RTF_EXPIRES))
fib6_clean_expires(iter);
else
- fib6_set_expires(iter, rt->expires);
+ fib6_set_expires(info->nl_net,
+ iter, rt->expires);
if (rt->fib6_pmtu)
fib6_metric_set(iter, RTAX_MTU,
@@ -2025,6 +2095,9 @@ int fib6_del(struct fib6_info *rt, struct nl_info *info)
if (rt == cur) {
if (fib6_requires_src(cur))
fib6_routes_require_src_dec(info->nl_net);
+ if (cur->timer &&
+ try_to_del_timer_sync(&cur->timer->timer) == 1)
+ fib6_info_release(cur);
fib6_del_route(table, fn, rtp, info);
return 0;
}
@@ -2290,19 +2363,6 @@ static int fib6_age(struct fib6_info *rt, void *arg)
struct fib6_gc_args *gc_args = arg;
unsigned long now = jiffies;
- /*
- * check addrconf expiration here.
- * Routes are expired even if they are in use.
- */
-
- if (rt->fib6_flags & RTF_EXPIRES && rt->expires) {
- if (time_after(now, rt->expires)) {
- RT6_TRACE("expiring %p\n", rt);
- return -1;
- }
- gc_args->more++;
- }
-
/* Also age clones in the exception table.
* Note, that clones are aged out
* only if they are not in use now.
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 18634ebd20a4..1d4cf7f73097 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1407,7 +1407,7 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
}
if (rt)
- fib6_set_expires(rt, jiffies + (HZ * lifetime));
+ fib6_set_expires(net, rt, jiffies + (HZ * lifetime));
if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
ra_msg->icmph.icmp6_hop_limit) {
if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index e3aec46bd466..87721a2a91b6 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -990,7 +990,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
if (!addrconf_finite_timeout(lifetime))
fib6_clean_expires(rt);
else
- fib6_set_expires(rt, jiffies + HZ * lifetime);
+ fib6_set_expires(net, rt, jiffies + HZ * lifetime);
fib6_info_release(rt);
}
@@ -3755,8 +3755,8 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
rt->dst_nocount = true;
if (cfg->fc_flags & RTF_EXPIRES)
- fib6_set_expires(rt, jiffies +
- clock_t_to_jiffies(cfg->fc_expires));
+ fib6_set_expires(net, rt, jiffies +
+ clock_t_to_jiffies(cfg->fc_expires));
else
fib6_clean_expires(rt);
--
2.34.1
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