diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dst.c | 26 | ||||
| -rw-r--r-- | net/decnet/dn_route.c | 6 | ||||
| -rw-r--r-- | net/ipv4/fib_semantics.c | 21 | ||||
| -rw-r--r-- | net/ipv4/route.c | 26 |
4 files changed, 39 insertions, 40 deletions
diff --git a/net/core/dst.c b/net/core/dst.c index d9e33ebe170f..069d51d29414 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -258,15 +258,6 @@ again: } EXPORT_SYMBOL(dst_destroy); -static void dst_rcu_destroy(struct rcu_head *head) -{ - struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); - - dst = dst_destroy(dst); - if (dst) - __dst_free(dst); -} - void dst_release(struct dst_entry *dst) { if (dst) { @@ -274,14 +265,10 @@ void dst_release(struct dst_entry *dst) newrefcnt = atomic_dec_return(&dst->__refcnt); WARN_ON(newrefcnt < 0); - if (unlikely(dst->flags & (DST_NOCACHE | DST_RCU_FREE)) && !newrefcnt) { - if (dst->flags & DST_RCU_FREE) { - call_rcu_bh(&dst->rcu_head, dst_rcu_destroy); - } else { - dst = dst_destroy(dst); - if (dst) - __dst_free(dst); - } + if (unlikely(dst->flags & DST_NOCACHE) && !newrefcnt) { + dst = dst_destroy(dst); + if (dst) + __dst_free(dst); } } } @@ -333,14 +320,11 @@ EXPORT_SYMBOL(__dst_destroy_metrics_generic); */ void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) { - bool hold; - WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); /* If dst not in cache, we must take a reference, because * dst_release() will destroy dst as soon as its refcount becomes zero */ - hold = (dst->flags & (DST_NOCACHE | DST_RCU_FREE)) == DST_NOCACHE; - if (unlikely(hold)) { + if (unlikely(dst->flags & DST_NOCACHE)) { dst_hold(dst); skb_dst_set(skb, dst); } else { diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c index 26719779ad8e..85a3604c87c8 100644 --- a/net/decnet/dn_route.c +++ b/net/decnet/dn_route.c @@ -184,12 +184,6 @@ static __inline__ unsigned int dn_hash(__le16 src, __le16 dst) return dn_rt_hash_mask & (unsigned int)tmp; } -static inline void dst_rcu_free(struct rcu_head *head) -{ - struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); - dst_free(dst); -} - static inline void dnrt_free(struct dn_route *rt) { call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index e55171f184f9..625cf185c489 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -161,6 +161,21 @@ static void free_nh_exceptions(struct fib_nh *nh) kfree(hash); } +static void rt_nexthop_free(struct rtable __rcu **rtp) +{ + struct rtable *rt = rcu_dereference_protected(*rtp, 1); + + if (!rt) + return; + + /* Not even needed : RCU_INIT_POINTER(*rtp, NULL); + * because we waited an RCU grace period before calling + * free_fib_info_rcu() + */ + + dst_free(&rt->dst); +} + /* Release a nexthop info record */ static void free_fib_info_rcu(struct rcu_head *head) { @@ -171,10 +186,8 @@ static void free_fib_info_rcu(struct rcu_head *head) dev_put(nexthop_nh->nh_dev); if (nexthop_nh->nh_exceptions) free_nh_exceptions(nexthop_nh); - if (nexthop_nh->nh_rth_output) - dst_release(&nexthop_nh->nh_rth_output->dst); - if (nexthop_nh->nh_rth_input) - dst_release(&nexthop_nh->nh_rth_input->dst); + rt_nexthop_free(&nexthop_nh->nh_rth_output); + rt_nexthop_free(&nexthop_nh->nh_rth_input); } endfor_nexthops(fi); release_net(fi->fib_net); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d6eabcfe8a90..2bd107477469 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1199,23 +1199,31 @@ restart: fnhe->fnhe_stamp = jiffies; } +static inline void rt_free(struct rtable *rt) +{ + call_rcu(&rt->dst.rcu_head, dst_rcu_free); +} + static void rt_cache_route(struct fib_nh *nh, struct rtable *rt) { - struct rtable *orig, *prev, **p = &nh->nh_rth_output; + struct rtable *orig, *prev, **p = (struct rtable **)&nh->nh_rth_output; if (rt_is_input_route(rt)) - p = &nh->nh_rth_input; + p = (struct rtable **)&nh->nh_rth_input; orig = *p; - rt->dst.flags |= DST_RCU_FREE; - dst_hold(&rt->dst); prev = cmpxchg(p, orig, rt); if (prev == orig) { if (orig) - dst_release(&orig->dst); + rt_free(orig); } else { - dst_release(&rt->dst); + /* Routes we intend to cache in the FIB nexthop 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; } } @@ -1412,7 +1420,7 @@ static int __mkroute_input(struct sk_buff *skb, do_cache = false; if (res->fi) { if (!itag) { - rth = FIB_RES_NH(*res).nh_rth_input; + rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); if (rt_cache_valid(rth)) { skb_dst_set_noref(skb, &rth->dst); goto out; @@ -1574,7 +1582,7 @@ local_input: do_cache = false; if (res.fi) { if (!itag) { - rth = FIB_RES_NH(res).nh_rth_input; + rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); if (rt_cache_valid(rth)) { skb_dst_set_noref(skb, &rth->dst); err = 0; @@ -1742,7 +1750,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res, if (fi) { fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr); if (!fnhe) { - rth = FIB_RES_NH(*res).nh_rth_output; + rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_output); if (rt_cache_valid(rth)) { dst_hold(&rth->dst); return rth; |