Re: [PATCH v3 net 0/5] ipv6: Fix dst_entry refcnt bugs in ip6_tunnel

From: Martin KaFai Lau <redacted>
Date: Fri, 11 Sep 2015 11:06:16 -0700

v3:
- Merge a 'if else if' test in patch 4
- Use rcu_dereference_protected in patch 5 to fix a sparse check when
  CONFIG_SPARSE_RCU_POINTER is enabled

v2:
- Add patch 4 and 5 to remove the spinlock

v1:
This patch series is to fix the dst refcnt bugs in ip6_tunnel.

Patch 1 and 2 are the prep works.  Patch 3 is the fix.

I can reproduce the bug by adding and removing the ip6gre tunnel
while running a super_netperf TCP_CRR test.  I get the following
trace by adding WARN_ON_ONCE(newrefcnt < 0) to dst_release():

 ...

Series applied, thanks Martin.