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From: Jason Wang <jasowang@redhat.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, mst@redhat.com, yuehaibing@huawei.com,
	xiyou.wangcong@gmail.com, weiyongjun1@huawei.com,
	eric.dumazet@gmail.com
Subject: Re: [PATCH net V2] tuntap: synchronize through tfiles array instead of tun->numqueues
Date: Thu, 9 May 2019 11:16:13 +0800	[thread overview]
Message-ID: <7f45aef5-c55b-875f-3458-c34a9b90b564@redhat.com> (raw)
In-Reply-To: <20190508.103613.1782548019381525988.davem@davemloft.net>


On 2019/5/9 上午1:36, David Miller wrote:
> From: Jason Wang <jasowang@redhat.com>
> Date: Tue,  7 May 2019 00:03:36 -0400
>
>> @@ -1313,6 +1315,10 @@ static int tun_xdp_xmit(struct net_device *dev, int n,
>>   
>>   	tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
>>   					    numqueues]);
>> +	if (!tfile) {
>> +		rcu_read_unlock();
>> +		return -ENXIO; /* Caller will free/return all frames */
>> +	}
>>   
>>   	spin_lock(&tfile->tx_ring.producer_lock);
>>   	for (i = 0; i < n; i++) {
> The only way we can see a NULL here is if a detach happened in parallel,
> and if that happens we should retry the tfile[] indexing after resampling
> numqueues rather than dropping the packet.


Ok, will fix this in V3.

Thanks


      reply	other threads:[~2019-05-09  3:16 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-07  4:03 [PATCH net V2] tuntap: synchronize through tfiles array instead of tun->numqueues Jason Wang
2019-05-07  4:54 ` Cong Wang
2019-05-07  6:19   ` Jason Wang
2019-05-07 14:41     ` Cong Wang
2019-05-08  2:54       ` Jason Wang
2019-05-09  5:34         ` Cong Wang
2019-05-09 12:55           ` Jason Wang
2019-05-08  4:16 ` Michael S. Tsirkin
2019-05-08  4:30   ` Jason Wang
2019-05-08 17:36 ` David Miller
2019-05-09  3:16   ` Jason Wang [this message]

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