From: David Ahern <dsa@cumulusnetworks•com>
To: Florian Westphal <fw@strlen•de>
Cc: netdev@vger•kernel.org, eric.dumazet@gmail•com
Subject: Re: [PATCH] net: Updates to netif_index_is_vrf
Date: Sun, 16 Aug 2015 07:34:12 -0600 [thread overview]
Message-ID: <55D09154.9030206@cumulusnetworks.com> (raw)
In-Reply-To: <20150816003926.GA31357@breakpoint.cc>
On 8/15/15 6:39 PM, Florian Westphal wrote:
> David Ahern <dsa@cumulusnetworks•com> wrote:
>> As Eric noted netif_index_is_vrf is not called with rcu_read_lock held,
>> so use dev_get_by_index instead of dev_get_by_index_rcu.
>>
>> If VRF is not enabled or oif is 0 skip the device lookup.
>>
>> Signed-off-by: David Ahern <dsa@cumulusnetworks•com>
>
> Why not
>
>> static inline bool netif_index_is_vrf(struct net *net, int ifindex)
>> {
>> - struct net_device *dev = dev_get_by_index_rcu(net, ifindex);
>> bool rc = false;
>>
>> - if (dev)
>> - rc = netif_is_vrf(dev);
>> +#if IS_ENABLED(CONFIG_NET_VRF)
>> + struct net_device *dev;
>> +
>> + if (ifindex == 0)
>> + return false;
>
> rcu_read_lock();
>
> dev = dev_get_by_index_rcu(net, ifindex);
> if (dev)
> rc = netif_is_vrf(dev);
>
> rcu_read_unlock();
>
>> +#endif
>> return rc;
>
> instead?
sure. That saves the inc and dec on the refcnt. will respin.
David
prev parent reply other threads:[~2015-08-16 13:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-16 0:09 [PATCH] net: Updates to netif_index_is_vrf David Ahern
2015-08-16 0:39 ` Florian Westphal
2015-08-16 13:34 ` David Ahern [this message]
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