From: Eric Dumazet <eduma...@google.com>
Date: Tue, 2 Oct 2018 12:35:05 -0700
> Timer handlers do not imply rcu_read_lock(), so my recent fix
> triggered a LOCKDEP warning when SYNACK is retransmit.
>
> Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt
> usages instead of guessing what is done by callers, since it is
> not worth the pain.
>
> Get rid of ireq_opt_deref() helper since it hides the logic
> without real benefit, since it is now a standard rcu_dereference().
>
> Fixes: 1ad98e9d1bdf ("tcp/dccp: fix lockdep issue when SYN is backlogged")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Reported-by: Willem de Bruijn <will...@google.com>
Applied, thanks Eric.
