The commit 2b760fcf5cfb ("ipv6: hook up exception table to store
dst cache") partially reverted 1e2ea8ad37be ("ipv6: set
dst.obsolete when a cached route has expired").
This change brings back the dst obsoleting and push it a step
farther: cached dst are always obsoleted when removed from the
fib tree, and removal by time expiration is now performed
regardless of dst->__refcnt, to be consistent with what we
already do for RTF_GATEWAY dst.
Fixes: 2b760fcf5cfb ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Paolo Abeni <pab...@redhat.com>
---
net/ipv6/route.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 8b25a31b6b03..fce740049e3e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1147,6 +1147,12 @@ static void rt6_remove_exception(struct
rt6_exception_bucket *bucket,
if (!bucket || !rt6_ex)
return;
+ /* sockets, flow cache, etc. can hold a refence to this dst, be sure
+ * they will drop it.
+ */
+ if (rt6_ex->rt6i)
+ rt6_ex->rt6i->dst.obsolete = DST_OBSOLETE_FORCE_CHK;
+
net = dev_net(rt6_ex->rt6i->dst.dev);
rt6_ex->rt6i->rt6i_node = NULL;
hlist_del_rcu(&rt6_ex->hlist);
@@ -1575,8 +1581,11 @@ static void rt6_age_examine_exception(struct
rt6_exception_bucket *bucket,
{
struct rt6_info *rt = rt6_ex->rt6i;
- if (atomic_read(&rt->dst.__refcnt) == 1 &&
- time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
+ /* we are pruning and obsoleting the exception route even if others
+ * have still reference to it, so that on next dst_check() such
+ * reference can be dropped
+ */
+ if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
RT6_TRACE("aging clone %p\n", rt);
rt6_remove_exception(bucket, rt6_ex);
return;
--
2.13.6
