Message ID | e01f765a8ee21c7a5a8d0a098a5a656bb517f574.1518606362.git.lucien.xin@gmail.com |
---|---|
State | Awaiting Upstream, archived |
Delegated to: | David Miller |
Headers | show |
Series | [net] xfrm: reuse uncached_list to track xdsts | expand |
From: Xin Long <lucien.xin@gmail.com> Date: Wed, 14 Feb 2018 19:06:02 +0800 > In early time, when freeing a xdst, it would be inserted into > dst_garbage.list first. Then if it's refcnt was still held > somewhere, later it would be put into dst_busy_list in > dst_gc_task(). > > When one dev was being unregistered, the dev of these dsts in > dst_busy_list would be set with loopback_dev and put this dev. > So that this dev's removal wouldn't get blocked, and avoid the > kmsg warning: > > kernel:unregister_netdevice: waiting for veth0 to become \ > free. Usage count = 2 > > However after Commit 52df157f17e5 ("xfrm: take refcnt of dst > when creating struct xfrm_dst bundle"), the xdst will not be > freed with dst gc, and this warning happens. > > To fix it, we need to find these xdsts that are still held by > others when removing the dev, and free xdst's dev and set it > with loopback_dev. > > But unfortunately after flow_cache for xfrm was deleted, no > list tracks them anymore. So we need to save these xdsts > somewhere to release the xdst's dev later. > > To make this easier, this patch is to reuse uncached_list to > track xdsts, so that the dev refcnt can be released in the > event NETDEV_UNREGISTER process of fib_netdev_notifier. > > Thanks to Florian, we could move forward this fix quickly. > > Fixes: 52df157f17e5 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle") > Reported-by: Jianlin Shi <jishi@redhat.com> > Reported-by: Hangbin Liu <liuhangbin@gmail.com> > Tested-by: Eyal Birger <eyal.birger@gmail.com> > Signed-off-by: Xin Long <lucien.xin@gmail.com> Steffen, I assume you will take this via your ipsec tree? Thank you.
On Thu, Feb 15, 2018 at 03:31:45PM -0500, David Miller wrote: > From: Xin Long <lucien.xin@gmail.com> > Date: Wed, 14 Feb 2018 19:06:02 +0800 > > > In early time, when freeing a xdst, it would be inserted into > > dst_garbage.list first. Then if it's refcnt was still held > > somewhere, later it would be put into dst_busy_list in > > dst_gc_task(). > > > > When one dev was being unregistered, the dev of these dsts in > > dst_busy_list would be set with loopback_dev and put this dev. > > So that this dev's removal wouldn't get blocked, and avoid the > > kmsg warning: > > > > kernel:unregister_netdevice: waiting for veth0 to become \ > > free. Usage count = 2 > > > > However after Commit 52df157f17e5 ("xfrm: take refcnt of dst > > when creating struct xfrm_dst bundle"), the xdst will not be > > freed with dst gc, and this warning happens. > > > > To fix it, we need to find these xdsts that are still held by > > others when removing the dev, and free xdst's dev and set it > > with loopback_dev. > > > > But unfortunately after flow_cache for xfrm was deleted, no > > list tracks them anymore. So we need to save these xdsts > > somewhere to release the xdst's dev later. > > > > To make this easier, this patch is to reuse uncached_list to > > track xdsts, so that the dev refcnt can be released in the > > event NETDEV_UNREGISTER process of fib_netdev_notifier. > > > > Thanks to Florian, we could move forward this fix quickly. > > > > Fixes: 52df157f17e5 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle") > > Reported-by: Jianlin Shi <jishi@redhat.com> > > Reported-by: Hangbin Liu <liuhangbin@gmail.com> > > Tested-by: Eyal Birger <eyal.birger@gmail.com> > > Signed-off-by: Xin Long <lucien.xin@gmail.com> > > Steffen, I assume you will take this via your ipsec tree? Yes, this is applied to the ipsec tree now. Thanks a lot everyone!
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 27d23a6..ac0866b 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -179,6 +179,9 @@ void rt6_disable_ip(struct net_device *dev, unsigned long event); void rt6_sync_down_dev(struct net_device *dev, unsigned long event); void rt6_multipath_rebalance(struct rt6_info *rt); +void rt6_uncached_list_add(struct rt6_info *rt); +void rt6_uncached_list_del(struct rt6_info *rt); + static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) { const struct dst_entry *dst = skb_dst(skb); diff --git a/include/net/route.h b/include/net/route.h index 1eb9ce4..40b870d 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -227,6 +227,9 @@ struct in_ifaddr; void fib_add_ifaddr(struct in_ifaddr *); void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); +void rt_add_uncached_list(struct rtable *rt); +void rt_del_uncached_list(struct rtable *rt); + static inline void ip_rt_put(struct rtable *rt) { /* dst_release() accepts a NULL parameter. diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 49cc1c1..1d1e4ab 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1383,7 +1383,7 @@ struct uncached_list { static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); -static void rt_add_uncached_list(struct rtable *rt) +void rt_add_uncached_list(struct rtable *rt) { struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); @@ -1394,14 +1394,8 @@ static void rt_add_uncached_list(struct rtable *rt) spin_unlock_bh(&ul->lock); } -static void ipv4_dst_destroy(struct dst_entry *dst) +void rt_del_uncached_list(struct rtable *rt) { - struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); - struct rtable *rt = (struct rtable *) dst; - - if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) - kfree(p); - if (!list_empty(&rt->rt_uncached)) { struct uncached_list *ul = rt->rt_uncached_list; @@ -1411,6 +1405,17 @@ static void ipv4_dst_destroy(struct dst_entry *dst) } } +static void ipv4_dst_destroy(struct dst_entry *dst) +{ + struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); + struct rtable *rt = (struct rtable *)dst; + + if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) + kfree(p); + + rt_del_uncached_list(rt); +} + void rt_flush_dev(struct net_device *dev) { struct net *net = dev_net(dev); diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c index 05017e2..8d33f7b 100644 --- a/net/ipv4/xfrm4_policy.c +++ b/net/ipv4/xfrm4_policy.c @@ -102,6 +102,7 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, xdst->u.rt.rt_pmtu = rt->rt_pmtu; xdst->u.rt.rt_table_id = rt->rt_table_id; INIT_LIST_HEAD(&xdst->u.rt.rt_uncached); + rt_add_uncached_list(&xdst->u.rt); return 0; } @@ -241,7 +242,8 @@ static void xfrm4_dst_destroy(struct dst_entry *dst) struct xfrm_dst *xdst = (struct xfrm_dst *)dst; dst_destroy_metrics_generic(dst); - + if (xdst->u.rt.rt_uncached_list) + rt_del_uncached_list(&xdst->u.rt); xfrm_dst_destroy(xdst); } diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 9dcfadd..cef76eb 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -128,7 +128,7 @@ struct uncached_list { static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list); -static void rt6_uncached_list_add(struct rt6_info *rt) +void rt6_uncached_list_add(struct rt6_info *rt) { struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list); @@ -139,7 +139,7 @@ static void rt6_uncached_list_add(struct rt6_info *rt) spin_unlock_bh(&ul->lock); } -static void rt6_uncached_list_del(struct rt6_info *rt) +void rt6_uncached_list_del(struct rt6_info *rt) { if (!list_empty(&rt->rt6i_uncached)) { struct uncached_list *ul = rt->rt6i_uncached_list; diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c index 09fb44e..416fe67 100644 --- a/net/ipv6/xfrm6_policy.c +++ b/net/ipv6/xfrm6_policy.c @@ -113,6 +113,9 @@ static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; xdst->u.rt6.rt6i_dst = rt->rt6i_dst; xdst->u.rt6.rt6i_src = rt->rt6i_src; + INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached); + rt6_uncached_list_add(&xdst->u.rt6); + atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache); return 0; } @@ -244,6 +247,8 @@ static void xfrm6_dst_destroy(struct dst_entry *dst) if (likely(xdst->u.rt6.rt6i_idev)) in6_dev_put(xdst->u.rt6.rt6i_idev); dst_destroy_metrics_generic(dst); + if (xdst->u.rt6.rt6i_uncached_list) + rt6_uncached_list_del(&xdst->u.rt6); xfrm_dst_destroy(xdst); }