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authorNikolay Aleksandrov <nikolay@nvidia.com>2021-11-22 18:15:12 +0300
committerDavid S. Miller <davem@davemloft.net>2021-11-22 18:44:49 +0300
commit8837cbbf854246f5f4d565f21e6baa945d37aded (patch)
tree23c2e14d568ef38ace50fa87f761599df6601068
parent4177d5b017a71433d4760889b88f7a29e11fad10 (diff)
downloadlinux-8837cbbf854246f5f4d565f21e6baa945d37aded.tar.xz
net: ipv6: add fib6_nh_release_dsts stub
We need a way to release a fib6_nh's per-cpu dsts when replacing nexthops otherwise we can end up with stale per-cpu dsts which hold net device references, so add a new IPv6 stub called fib6_nh_release_dsts. It must be used after an RCU grace period, so no new dsts can be created through a group's nexthop entry. Similar to fib6_nh_release it shouldn't be used if fib6_nh_init has failed so it doesn't need a dummy stub when IPv6 is not enabled. Fixes: 7bf4796dd099 ("nexthops: add support for replace") Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/ip6_fib.h1
-rw-r--r--include/net/ipv6_stubs.h1
-rw-r--r--net/ipv6/af_inet6.c1
-rw-r--r--net/ipv6/route.c19
4 files changed, 22 insertions, 0 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index c412dde4d67d..83b8070d1cc9 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -485,6 +485,7 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
struct fib6_config *cfg, gfp_t gfp_flags,
struct netlink_ext_ack *extack);
void fib6_nh_release(struct fib6_nh *fib6_nh);
+void fib6_nh_release_dsts(struct fib6_nh *fib6_nh);
int call_fib6_entry_notifiers(struct net *net,
enum fib_event_type event_type,
diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index afbce90c4480..45e0339be6fa 100644
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -47,6 +47,7 @@ struct ipv6_stub {
struct fib6_config *cfg, gfp_t gfp_flags,
struct netlink_ext_ack *extack);
void (*fib6_nh_release)(struct fib6_nh *fib6_nh);
+ void (*fib6_nh_release_dsts)(struct fib6_nh *fib6_nh);
void (*fib6_update_sernum)(struct net *net, struct fib6_info *rt);
int (*ip6_del_rt)(struct net *net, struct fib6_info *rt, bool skip_notify);
void (*fib6_rt_update)(struct net *net, struct fib6_info *rt,
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 0c4da163535a..dab4a047590b 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -1026,6 +1026,7 @@ static const struct ipv6_stub ipv6_stub_impl = {
.ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
.fib6_nh_init = fib6_nh_init,
.fib6_nh_release = fib6_nh_release,
+ .fib6_nh_release_dsts = fib6_nh_release_dsts,
.fib6_update_sernum = fib6_update_sernum_stub,
.fib6_rt_update = fib6_rt_update,
.ip6_del_rt = ip6_del_rt,
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 3ae25b8ffbd6..42d60c76d30a 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3680,6 +3680,25 @@ void fib6_nh_release(struct fib6_nh *fib6_nh)
fib_nh_common_release(&fib6_nh->nh_common);
}
+void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
+{
+ int cpu;
+
+ if (!fib6_nh->rt6i_pcpu)
+ return;
+
+ for_each_possible_cpu(cpu) {
+ struct rt6_info *pcpu_rt, **ppcpu_rt;
+
+ ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
+ pcpu_rt = xchg(ppcpu_rt, NULL);
+ if (pcpu_rt) {
+ dst_dev_put(&pcpu_rt->dst);
+ dst_release(&pcpu_rt->dst);
+ }
+ }
+}
+
static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
gfp_t gfp_flags,
struct netlink_ext_ack *extack)