diff options
| -rw-r--r-- | net/ipv6/route.c | 26 |
1 files changed, 6 insertions, 20 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 399d1bceec4a..606e80325b21 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1136,15 +1136,7 @@ static struct rt6_info *rt6_make_pcpu_route(struct rt6_info *rt) dst_hold(&pcpu_rt->dst); p = this_cpu_ptr(rt->rt6i_pcpu); prev = cmpxchg(p, NULL, pcpu_rt); - if (prev) { - /* If someone did it before us, return prev instead */ - /* release refcnt taken by ip6_rt_pcpu_alloc() */ - dst_release_immediate(&pcpu_rt->dst); - /* release refcnt taken by above dst_hold() */ - dst_release_immediate(&pcpu_rt->dst); - dst_hold(&prev->dst); - pcpu_rt = prev; - } + BUG_ON(prev); rt6_dst_from_metrics_check(pcpu_rt); return pcpu_rt; @@ -1739,31 +1731,25 @@ uncached_rt_out: struct rt6_info *pcpu_rt; dst_use_noref(&rt->dst, jiffies); + local_bh_disable(); pcpu_rt = rt6_get_pcpu_route(rt); - if (pcpu_rt) { - rcu_read_unlock(); - } else { + if (!pcpu_rt) { /* atomic_inc_not_zero() is needed when using rcu */ if (atomic_inc_not_zero(&rt->rt6i_ref)) { - /* We have to do the read_unlock first - * because rt6_make_pcpu_route() may trigger - * ip6_dst_gc() which will take the write_lock. - * - * No dst_hold() on rt is needed because grabbing + /* No dst_hold() on rt is needed because grabbing * rt->rt6i_ref makes sure rt can't be released. */ - rcu_read_unlock(); pcpu_rt = rt6_make_pcpu_route(rt); rt6_release(rt); } else { /* rt is already removed from tree */ - rcu_read_unlock(); pcpu_rt = net->ipv6.ip6_null_entry; dst_hold(&pcpu_rt->dst); } } - + local_bh_enable(); + rcu_read_unlock(); trace_fib6_table_lookup(net, pcpu_rt, table->tb6_id, fl6); return pcpu_rt; } |