diff options
author | David S. Miller <davem@davemloft.net> | 2012-07-31 15:02:02 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-07-31 15:02:02 -0700 |
commit | c5038a8327b980a5b279fa193163c468011de009 (patch) | |
tree | 6d24fd005340e73360f9c1aa20dd3a1d21fd1625 /net/ipv4/route.c | |
parent | d26b3a7c4b3b26319f18bb645de93eba8f4bdcd5 (diff) | |
download | linux-c5038a8327b980a5b279fa193163c468011de009.tar.gz linux-c5038a8327b980a5b279fa193163c468011de009.tar.bz2 linux-c5038a8327b980a5b279fa193163c468011de009.zip |
ipv4: Cache routes in nexthop exception entries.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r-- | net/ipv4/route.c | 103 |
1 files changed, 57 insertions, 46 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 4f6276ce0af3..b102eeb16e34 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -587,11 +587,17 @@ static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, build_sk_flow_key(fl4, sk); } -static DEFINE_SEQLOCK(fnhe_seqlock); +static inline void rt_free(struct rtable *rt) +{ + call_rcu(&rt->dst.rcu_head, dst_rcu_free); +} + +static DEFINE_SPINLOCK(fnhe_lock); static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) { struct fib_nh_exception *fnhe, *oldest; + struct rtable *orig; oldest = rcu_dereference(hash->chain); for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; @@ -599,6 +605,11 @@ static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) oldest = fnhe; } + orig = rcu_dereference(oldest->fnhe_rth); + if (orig) { + RCU_INIT_POINTER(oldest->fnhe_rth, NULL); + rt_free(orig); + } return oldest; } @@ -620,7 +631,7 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, int depth; u32 hval = fnhe_hashfun(daddr); - write_seqlock_bh(&fnhe_seqlock); + spin_lock_bh(&fnhe_lock); hash = nh->nh_exceptions; if (!hash) { @@ -667,7 +678,7 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, fnhe->fnhe_stamp = jiffies; out_unlock: - write_sequnlock_bh(&fnhe_seqlock); + spin_unlock_bh(&fnhe_lock); return; } @@ -1167,41 +1178,40 @@ static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) static void rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, __be32 daddr) { - __be32 fnhe_daddr, gw; - unsigned long expires; - unsigned int seq; - u32 pmtu; - -restart: - seq = read_seqbegin(&fnhe_seqlock); - fnhe_daddr = fnhe->fnhe_daddr; - gw = fnhe->fnhe_gw; - pmtu = fnhe->fnhe_pmtu; - expires = fnhe->fnhe_expires; - if (read_seqretry(&fnhe_seqlock, seq)) - goto restart; - - if (daddr != fnhe_daddr) - return; + spin_lock_bh(&fnhe_lock); - if (pmtu) { - unsigned long diff = expires - jiffies; + if (daddr == fnhe->fnhe_daddr) { + struct rtable *orig; - if (time_before(jiffies, expires)) { - rt->rt_pmtu = pmtu; - dst_set_expires(&rt->dst, diff); + if (fnhe->fnhe_pmtu) { + unsigned long expires = fnhe->fnhe_expires; + unsigned long diff = expires - jiffies; + + if (time_before(jiffies, expires)) { + rt->rt_pmtu = fnhe->fnhe_pmtu; + dst_set_expires(&rt->dst, diff); + } + } + if (fnhe->fnhe_gw) { + rt->rt_flags |= RTCF_REDIRECTED; + rt->rt_gateway = fnhe->fnhe_gw; } - } - if (gw) { - rt->rt_flags |= RTCF_REDIRECTED; - rt->rt_gateway = gw; - } - fnhe->fnhe_stamp = jiffies; -} -static inline void rt_free(struct rtable *rt) -{ - call_rcu(&rt->dst.rcu_head, dst_rcu_free); + orig = rcu_dereference(fnhe->fnhe_rth); + rcu_assign_pointer(fnhe->fnhe_rth, rt); + if (orig) + rt_free(orig); + + fnhe->fnhe_stamp = jiffies; + } else { + /* Routes we intend to cache in nexthop exception have + * the DST_NOCACHE bit clear. However, if we are + * unsuccessful at storing this route into the cache + * we really need to set it. + */ + rt->dst.flags |= DST_NOCACHE; + } + spin_unlock_bh(&fnhe_lock); } static void rt_cache_route(struct fib_nh *nh, struct rtable *rt) @@ -1249,13 +1259,13 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr, if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) rt->rt_gateway = nh->nh_gw; - if (unlikely(fnhe)) - rt_bind_exception(rt, fnhe, daddr); dst_init_metrics(&rt->dst, fi->fib_metrics, true); #ifdef CONFIG_IP_ROUTE_CLASSID rt->dst.tclassid = nh->nh_tclassid; #endif - if (!(rt->dst.flags & DST_NOCACHE)) + if (unlikely(fnhe)) + rt_bind_exception(rt, fnhe, daddr); + else if (!(rt->dst.flags & DST_NOCACHE)) rt_cache_route(nh, rt); } @@ -1753,22 +1763,23 @@ static struct rtable *__mkroute_output(const struct fib_result *res, fnhe = NULL; if (fi) { - fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr); - if (!fnhe && FIB_RES_NH(*res).nh_pcpu_rth_output) { - struct rtable __rcu **prth; + struct rtable __rcu **prth; + fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr); + if (fnhe) + prth = &fnhe->fnhe_rth; + else prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output); - rth = rcu_dereference(*prth); - if (rt_cache_valid(rth)) { - dst_hold(&rth->dst); - return rth; - } + rth = rcu_dereference(*prth); + if (rt_cache_valid(rth)) { + dst_hold(&rth->dst); + return rth; } } rth = rt_dst_alloc(dev_out, IN_DEV_CONF_GET(in_dev, NOPOLICY), IN_DEV_CONF_GET(in_dev, NOXFRM), - fi && !fnhe); + fi); if (!rth) return ERR_PTR(-ENOBUFS); |