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From: Johannes Berg <johannes@sipsolutions.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dave Jones <davej@redhat.com>, David Miller <davem@davemloft.net>,
	netdev@vger.kernel.org, Yuchung Cheng <ycheng@google.com>
Subject: Re: [PATCH] net-tcp: fix panic in tcp_fastopen_cache_set()
Date: Thu, 14 Nov 2013 21:53:23 +0100	[thread overview]
Message-ID: <1384462403.13941.41.camel@jlt4.sipsolutions.net> (raw)
In-Reply-To: <1384457922.28716.32.camel@edumazet-glaptop2.roam.corp.google.com> (sfid-20131114_203846_741927_1B40F181)

On Thu, 2013-11-14 at 11:38 -0800, Eric Dumazet wrote:

> > > Doesn't that __sk_dst_get() have to go inside the rcu_read_lock()?
> > > 
> > > Then again, I guess we hold the socket. Still looks a bit weird to be
> > > moving it out.
> > 
> > Yep, in fact this rcu_read_lock() is not needed. I'll send a v2.
> 
> I take it back.
> 
> the rcu_read_lock() protects the tcp_get_metrics(), not the
> __sk_dst_get(sk)
> 
> So the patch is correct, unless you disagree of course ;)

Heh. I have no idea, it just seemed a little odd on first look given
that __sk_dst_get() *can* actually use RCU protection. :)

johannes

  reply	other threads:[~2013-11-14 20:53 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-13 20:45 oops in tcp_get_metrics, followed by lockup Dave Jones
2013-11-13 22:40 ` Eric Dumazet
2013-11-13 23:00   ` [PATCH] net-tcp: fix panic in tcp_fastopen_cache_set() Eric Dumazet
2013-11-13 23:08     ` Yuchung Cheng
2013-11-14 17:55     ` Dave Jones
2013-11-14 19:13     ` Johannes Berg
2013-11-14 19:36       ` Eric Dumazet
2013-11-14 19:38         ` Eric Dumazet
2013-11-14 20:53           ` Johannes Berg [this message]
2013-11-14 21:22             ` Eric Dumazet
2013-11-14 21:33     ` David Miller

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