[dpdk-dev] [dpdk-stable] [PATCH v3 1/5] net/tap: fix mbuf double free when writev fails

[wangyunjian]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen at networkplumber.org]
> Sent: Thursday, April 9, 2020 10:51 PM
> To: wangyunjian <wangyunjian at huawei.com>
> Cc: Ferruh Yigit <ferruh.yigit at intel.com>; dev at dpdk.org;
> keith.wiles at intel.com; Lilijun (Jerry) <jerry.lilijun at huawei.com>; xudingke
> <xudingke at huawei.com>; stable at dpdk.org
> Subject: Re: [dpdk-dev] [dpdk-stable] [PATCH v3 1/5] net/tap: fix mbuf double
> free when writev fails
> 
> On Thu, 9 Apr 2020 08:03:23 +0000
> wangyunjian <wangyunjian at huawei.com> wrote:
> 
> > error = tap_write_mbufs(txq, num_mbufs, mbuf,
> >                      &num_packets, &num_tx_bytes); if (error == -1) {
> >     txq->stats.errs++;
> >     /* free tso mbufs */
> >     for (j = 0; j < ret; j++)
> >         rte_pktmbuf_free(mbuf[j]);
> >     break;
> > }
> 
> There is a free bulk, and normally each buf counts against errors.
> 
>         if (error == -1) {
> 		txq->stats.errs += num_packets;

I think to consider only the original packet number, not sent packets.

> 		rte_pktmbuf_free_bulk(mbuf, num_packets);

Thanks for your suggestion, will include it in next version.

Yunjian
> 		break;
> 	}