Re: Latest net-next from GIT panic

quoted

Thanks very much Pawel for the feedback.

I was looking into the code (specifically IPv4 part) and found that in
free_fib_info_rcu(), we call free_nh_exceptions() without holding the
fnhe_lock. I am wondering if that could cause some race condition on
fnhe->fnhe_rth_input/output so a double call on dst_dev_put() on the
same dst could be happening.

But as we call free_fib_info_rcu() only after the grace period, and
the lookup code which could potentially modify
fnhe->fnhe_rth_input/output all holds rcu_read_lock(), it seems
fine...

Hi Pawel,

Could you try the following debug patch on top of net-next branch and
reproduce the issue check if there are warning msg showing?

diff --git a/include/net/dst.h b/include/net/dst.h
index 93568bd0a352..82aff41c6f63 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h

@@ -271,7 +271,7 @@ static inline void dst_use_noref(struct dst_entry

*dst, unsigned long time)
 static inline struct dst_entry *dst_clone(struct dst_entry *dst)
 {
        if (dst)
-               atomic_inc(&dst->__refcnt);
+               dst_hold(dst);
        return dst;
 }

Thanks.
Wei